Image display components

Abstract

An image display element (200) comprises: micro-light emitting elements (100) arranged in an array; a driving circuit substrate (50) comprising a driving circuit for supplying current to the micro-light emitting elements (100) so that the micro-light emitting elements (100) emit light; and a light distribution control unit (70) arranged on a light emitting surface of the micro-light emitting elements (100), with a partition wall (80) arranged around the light distribution control unit (70), the partition wall (80) not transmitting light emitted by the micro-light emitting elements (100).

Description

Technical Field

[0001] The present invention relates to an image display element comprising a micro-light emitting element. Background Art

[0002] A display element is proposed in which a plurality of micro-light-emitting elements constituting pixels are arranged on a substrate (backplane). For example, in the technology disclosed in Japanese Patent Publication No. 2002-141492, a drive circuit is formed on a silicon substrate, and a micro-light-emitting diode (LED) array that emits ultraviolet light is arranged on the drive circuit. In addition, in the above technology, a small display element is disclosed, which displays a color image by providing a wavelength conversion layer (wavelength conversion layer) on the LED array that converts ultraviolet light into red, green and blue visible light.

[0003] This type of display element is not only small, but also has high brightness and durability. Therefore, it is expected to be used as a display element for glasses-like devices and head-up displays (HUD).

[0004] In such a display element, it is necessary to improve the luminous efficiency and efficiently take the generated light into the optical system on the basis of improving the power efficiency. Therefore, as disclosed in the specification of U.S. Patent No. 2011 / 0297975, a technology is proposed to improve the light extraction efficiency and collimate the emitted light by providing a photonic crystal structure on a micro-light-emitting element. Summary of the invention

[0005] However, the structure of the micro-light emitting element and the display element disclosed in Japanese Patent Application Laid-Open No. 2002-141492 also has the following problem: light is confined inside the micro-light emitting element, the ratio of light emitted to the outside is low, and the light emission efficiency is low.

[0006] This reduction in light extraction efficiency is caused by the fact that the refractive index of the light emitting material constituting the micro light emitting element is larger than that of air or resin. The reduction in light emitting efficiency leads to an increase in power consumption and a temperature rise due to heat generation.

[0007] Furthermore, the micro-luminescent element has a light emission distribution close to the Lambertian spectrum distribution and a wide light emission angle distribution, so that a large amount of useless light is emitted from a display element for a small eyeglass-type terminal or a mobile display. As a result, the power consumption is increased in vain.

[0008] Therefore, it is considered to increase the light emission to the front and improve the light utilization efficiency by setting optical elements such as micro beads and micro lenses on the light emitting surface of the micro light emitting element. As a result, power consumption can be reduced. However, it is known that such attempts will increase the emission of light to the surrounding pixels and produce so-called optical crosstalk. Optical crosstalk will reduce the contrast of the displayed image. In addition, in full-color display elements, problems such as color mixing and reduced color reproducibility are caused.

[0009] One aspect of the present invention is completed in view of the above-mentioned problems, and its purpose is to suppress optical crosstalk while improving the light emission efficiency toward the front of the micro-light-emitting element to achieve an image display element with high contrast, color reproducibility and low power consumption.

[0010] In order to solve the above-mentioned problem, an image display element according to one aspect of the present invention includes: a driving circuit substrate, which includes a driving circuit for supplying current to micro-light-emitting elements to make the micro-light-emitting elements emit light; and the micro-light-emitting elements are arranged in an array on the driving circuit substrate, and a light distribution control unit for increasing the front emission of the micro-light-emitting elements is arranged on the light emitting surface of the micro-light-emitting elements, and a partition wall is arranged around the light distribution control unit, and the partition wall does not transmit the light emitted by the micro-light-emitting elements.

[0011] According to one aspect of the present invention, an image display element includes: a driving circuit substrate, which includes a driving circuit for supplying current to a micro-light-emitting element to make the micro-light-emitting element emit light; and the micro-light-emitting elements are arranged in an array on the driving circuit substrate, a plurality of optical elements are arranged on the light emitting surface of the micro-light-emitting element, and partition walls are arranged around the plurality of optical elements, and the partition walls do not transmit the light emitted by the micro-light-emitting element.

[0012] According to an aspect of the present invention, optical crosstalk of micro light emitting elements can be suppressed, and light emission distribution can be controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic cross-sectional view of a pixel region of an image display element according to a first embodiment of the present invention.

[0014] Figure 2 1 is a schematic plan view of a pixel region of the image display element according to the first embodiment of the present invention.

[0015] Figure 3 Simulation results showing the light emission angle distribution according to the first embodiment of the present invention.

[0016] Figure 41 is a schematic cross-sectional view of a pixel region of an image display element according to a modification of the first embodiment of the present invention.

[0017] Figure 5 1 is a schematic cross-sectional view of a pixel region of an image display element according to a modification of the first embodiment of the present invention.

[0018] Figure 6 1 is a schematic plan view of a pixel region of an image display element according to a modification of the first embodiment of the present invention.

[0019] Figure 7 1 is a schematic plan view of a pixel region of an image display element according to a modification of the first embodiment of the present invention.

[0020] Figure 8 1 is a schematic plan view of a pixel region of an image display element according to a modification of the first embodiment of the present invention.

[0021] Fig. 9 1 is a schematic cross-sectional view of a pixel region of an image display element according to a modification of the first embodiment of the present invention.

[0022] Fig.10 1 is a schematic cross-sectional view of a pixel region of an image display element according to a modification of the first embodiment of the present invention.

[0023] Fig.11 is a schematic cross-sectional view of a pixel region of an image display element according to a second embodiment of the present invention.

[0024] Fig.12 is a schematic cross-sectional view of a pixel region of an image display element according to a third embodiment of the present invention.

[0025] Fig.13 is a schematic cross-sectional view of a pixel region of an image display element according to a fourth embodiment of the present invention.

[0026] Fig.14 is a schematic cross-sectional view of a pixel region of an image display element according to a fifth embodiment of the present invention.

[0027] Fig.15 is a schematic cross-sectional view of a pixel region of an image display element according to a sixth embodiment of the present invention.

[0028] Fig.16 is a schematic cross-sectional view of a pixel region of an image display element according to a seventh embodiment of the present invention.

[0029] Fig.17 FIG. 1 is a schematic cross-sectional view of a red micro-luminescent element according to a seventh embodiment of the present invention.

[0030] Fig.18 is a schematic cross-sectional view of a pixel region of an image display element according to an eighth embodiment of the present invention.

[0031] Fig.19 is a schematic cross-sectional view of a pixel region of an image display element according to a ninth embodiment of the present invention.

[0032] Fig. 20 is a schematic cross-sectional view of a pixel region of an image display element according to a tenth embodiment of the present invention. DETAILED DESCRIPTION

[0033] Next, an example of an image display element 200 having a plurality of micro-light-emitting elements 100 is given, and reference is made to the accompanying drawings. Figures 1 to 20 The embodiment of the present invention is described. In addition, the image display element 200 includes a plurality of micro-light emitting elements 100 and a driving circuit substrate 50, and the driving circuit substrate 50 supplies current to the micro-light emitting elements 100 located in a pixel region 1 to control light emission. In the pixel region 1, the micro-light emitting elements 100 are arranged in an array. The micro-light emitting elements 100 emit light to the opposite side of the driving circuit substrate 50.

[0034] Unless otherwise specified, the surface of the micro-light emitting element 100 that emits light into the air is referred to as the light emitting surface 130 (light emitting surface). In addition, in the description of the structure of the image display element 200, unless otherwise specified, the light emitting surface 130 is referred to as the upper surface (first surface) of the micro-light emitting element 100, the surface on the side opposite to the light emitting surface is referred to as the lower surface (second surface), and the side surfaces other than the upper surface and the lower surface are referred to as side surfaces. In the direction of the perpendicular line relative to the light emitting surface 130, the direction toward the air is referred to as the front. In addition, with respect to other components, the surface on the light emitting direction side is also referred to as the upper surface of the component, and the surface on the opposite side is referred to as the lower surface.

[0035] The driving circuit substrate 50 is configured in the pixel area 1 with a micro light emitting element driving circuit (micro light emitting element driving circuit) that controls the current supplied to each micro light emitting element 100, and a row selection circuit that selects each row of the micro light emitting elements 100 configured in a two-dimensional matrix, a column signal output circuit that outputs a light emitting signal to each column, an image processing circuit that calculates the light emitting signal based on the input signal, an input-output circuit, etc. are configured outside the pixel area 1.

[0036] The surface of the bonding surface side of the driving circuit substrate 50 is provided with a P-drive electrode 52 (P-drive electrode) (second drive electrode) and an N-drive electrode 51 (N-drive electrode) (first drive electrode) connected to the micro-light-emitting element 100. Generally, the driving circuit substrate 50 is a silicon substrate (semiconductor substrate) on which an LSI is formed, or a glass substrate on which a TFT is formed, and can be manufactured by a known technology, so its function and structure are not described in detail.

[0037] In addition, the micro-light emitting element 100 is depicted in a nearly square shape in the figure, but the shape of the micro-light emitting element 100 is not particularly limited. In addition, the micro-light emitting element 100 can adopt various planar shapes such as rectangle, polygon, circle, ellipse, etc., but the maximum length is assumed to be less than 60 μm. The image display element 200 is assumed to have more than 3,000 micro-light emitting elements integrated in the pixel area 1.

[0038] [First embodiment]

[0039] (Configuration of Image Display Element 200)

[0040] Figure 1 1 is a schematic cross-sectional view of a pixel region 1 of an image display element 200 according to the first embodiment of the present invention. Figure 2 FIG. 1 is a schematic top view of a pixel region 1 of an image display element 200 according to a first embodiment of the present invention. Figure 2 As shown, the upper surface of the image display element 200 is a pixel region 1 where a plurality of pixels 5 are arranged in an array.

[0041] In the present embodiment, the image display element 200 is a monochrome display element, and each pixel 5 includes a monochrome micro-light-emitting element 100. In the present configuration, the upper surface of the micro-light-emitting element 100 is a light-emitting surface 130, and a light distribution control unit 70 is formed on the light-emitting surface 130. The light distribution control unit 70 increases the forward emission of the micro-light-emitting element 100. The light distribution control unit 70 is composed of a single or multiple optical elements 71 arranged closely. That is, the light distribution control device 70 arranges one or more optical elements 71. In the present embodiment, the optical element 71 is a spherical microbead made of a transparent resin with a refractive index of 1.7. The light distribution control unit 70 preferably covers the light-emitting surface 130 of the micro-light-emitting element 100. A partition wall 80 is arranged on the outside of the light distribution control unit 70. In addition, unless otherwise specified, the following are used. Figure 1 The coordinate system is described with the horizontal direction of the paper as the X axis, the depth direction of the paper as the Y axis, and the above direction as the Z axis. That is, the positive direction of the Z axis is the front.

[0042] A partition wall 80 is arranged between adjacent pixels 5. The partition wall 80 separates the light distribution control units 70 belonging to each pixel from each other. The partition wall 80 does not transmit the light emitted by the micro-light-emitting element 100. That is, the transmittance of the partition wall 80 to the light emitted by the micro-light-emitting element 100 is preferably at least 50% or less, and more preferably 10% or less. In order to prevent light crosstalk, the side of the partition wall 80 may also have either reflectivity or absorptivity. Moreover, in order to further improve the light extraction efficiency, the side of the partition wall 80 is preferably reflective. The side of the partition wall 80 is reflective, which means that the reflectivity of the side of the partition wall 80 relative to the emitted light is preferably at least 50% or more, and further 80% or more. In this configuration, the partition wall 80 is made of a metal material. Its side is made of a metal material with a high reflectivity relative to visible light. For example, silver or aluminum. In addition, the side is inclined in a manner that opens toward the light irradiation direction. That is, the side of the partition wall 80 is inclined in a forward cone shape. The inclination angle θw is preferably less than 90 degrees, more preferably about 45 to 80 degrees. The height of the partition wall 80 is preferably equal to or higher than the height of the light distribution control unit 70. The partition wall 80 is disposed on the embedding material 60 and preferably does not cover the light emitting surface 130.

[0043] The micro light-emitting element 100 includes a main body 16 made of a compound semiconductor layer 14, a common P electrode 30P (second electrode) and an N electrode 23N (first electrode). The compound semiconductor layer 14 is composed of a light-emitting layer 12 (light emission layer) that emits light, an N-side layer 11 (N-side layer, first conductive layer) that injects electrons into the light-emitting layer 12, and a P-side layer 13 (P-side layer, second conductive layer) that injects holes into the light-emitting layer 12. For example, in a micro light-emitting element that emits light in a wavelength range from ultraviolet light to red, the compound semiconductor layer 14 is a nitride semiconductor (AlInGaN system), and in the case of emitting light in a wavelength range from yellow-green to red, the compound semiconductor layer 14 is an AlInGaP system. In the wavelength range from red to infrared, it is an AlGaAs type or a GaAs type.

[0044] In the following, regarding the compound semiconductor 14 constituting the main body 16 of the micro-light-emitting element 100, a configuration in which the P-side layer 13 is arranged on the light-emitting side is specifically described, but it can also be a configuration in which the N-side layer 11 is arranged on the light-emitting side. The N-side layer 11, the light-emitting layer 12, and the P-side layer 13 are usually preferably not a single layer but include multiple layers, but since they are not directly related to the constitution of this patent, the detailed structure of each layer is not recorded. Generally speaking, the light-emitting layer is sandwiched by an N-type layer (N-type layer) and a P-type layer (P-type layer), and the N-type layer and the P-type layer are undoped layers, or depending on the situation, they may also be layers containing dopants with opposite conductivity, so they are recorded as N-side layer and P-side layer below.

[0045] Figure 1 It is shown in Figure 2 The cross-sectional view of the AA line. Figure 1 and Figure 2 As shown in FIG. 1 , the micro-light-emitting elements 100 are arranged in a two-dimensional array on the driving circuit substrate 50. The N electrodes 23N of the micro-light-emitting elements 100 are formed on the second surface, and the common P electrodes 30P are formed on the first surface. The N electrodes 23N are connected to the N driving electrodes 51 on the driving circuit substrate 50. The common P electrodes 30P are connected to the P driving electrodes 52 on the driving circuit substrate 50. Usually, the P driving electrodes 52 and the common P electrodes 30P are connected outside the pixel region 1, so that Figure 1 The common P electrode 30P is a transparent electrode and transmits the light emitted by the micro-light-emitting element 100. In the present configuration, the surface of the common P electrode 30P opposite to the surface in contact with the P-side layer 13 becomes the light-emitting surface 130. The electrode materials, protective films, reflective films and their configurations constituting the micro-light-emitting element 100 are not directly related to the present invention and can be applied to known technologies. Therefore, they are sometimes not described in detail and are omitted in the figure. In addition, in the present configuration, since the partition wall 80 is formed on the common P electrode 30P, the partition wall 80 can also be a part of the common P electrode 30P.

[0046] The current supplied from the driving circuit substrate 50 to the micro light-emitting element 100 is transmitted from the P driving electrode 52 to the P-side layer 13 via the common P electrode 30P. The current from the P-side layer 13 through the light-emitting layer 12 flows from the N-side layer 11 to the N driving electrode 51 via the N electrode 23N. In this way, the micro light-emitting element 100 emits light at a predetermined intensity according to the amount of current supplied by the driving circuit substrate 50.

[0047] The micro-light emitting element 100 is divided into individual parts, and the micro-light emitting element 100 is covered by the embedding material 60. It is preferred that the height of the light emitting surface 130 is substantially equal to the height of the embedding material 60. In order to prevent light from leaking to adjacent pixels, it is preferred that the embedding material 60 has a light shielding function based on reflection or absorption. In the case where the embedding material 60 is transparent, the embedding material 60 does not have a light shielding function, so it is preferred to cover the side wall of the micro-light emitting element with a metal film.

[0048] In this configuration, micro beads as optical elements 71 are densely arranged on the light emitting surface 130. In this embodiment, the average diameter of the micro beads is 500 nm, the distance between adjacent micro beads is approximately equal to the average diameter, and the micro beads are in contact with each other. Figure 2 In the top view, the micro beads are arranged regularly at the vertices of the regular triangle, but if they are densely arranged, they do not need to be arranged regularly. Figure 1 Although depicted as spherical in the figure, it may also be elliptical. Such microbeads can be formed by applying a slurry dispersed in water or an organic solvent, by rapid convective deposition, etc. Since the size of the microbeads has a deviation of about ±20%, the size is specified by the average value.

[0049] like Figure 1 As shown, the blue-light-emitting micro-light-emitting elements 100 are arranged in an array at a pitch of 8 μm, and micro-beads are formed thereon at an adjacent distance of 0.5 μm. The height is 0.5 μm. The refractive index of the micro-beads is 1.7. The amount of blue light emitted from the micro-light-emitting elements 100 was compared before and after the formation of the micro-beads. 10,000 micro-light-emitting elements 100 were lit at the same time, and the total beam intensity was measured. The luminous intensity has increased to 1.5 times by the formation of micro-beads. This is considered to be the improvement of the light extraction efficiency by the micro-beads. Moreover, in order to compare the emission intensity to the front, the emission angle distribution was measured, and the amount of light emitted at θ≤30 degrees has increased to about 2 times by the formation of micro-beads. Therefore, it can be confirmed that there is an effect of increasing the forward emission through the micro-beads. Here, unless otherwise specified, forward emission refers to emission mainly in the forward direction, and in the broadest sense, emission at θ≤45 degrees.

[0050] Furthermore, in order to evaluate the image quality, a single pixel is lit, the display surface is photographed with a camera, and the light intensity of the lit pixel is compared with that of the adjacent pixels to evaluate the contrast. Although the brightness of a single pixel is improved, the light intensity of the adjacent pixels that are not lit is also observed to be about 1 / 100 of that of the lit pixel. This is believed to be due to the leakage of light to the surrounding pixels due to the microbeads, which reduces the contrast.

[0051] In order to prevent the above-mentioned optical crosstalk, a structure in which a partition wall 80 is set between pixels is made. The microbeads between the pixels are etched away by dry etching, and an aluminum film with a thickness of 0.6μm is deposited by lift-off. The side walls of the aluminum film are tilted 80 degrees on average. Compared with the case without the partition wall 80, in the structure with the partition wall 80, the total beam intensity is roughly equal, the front intensity at θ≤30 degrees is increased to about 1.2 times, and the luminous intensity from the adjacent pixels is reduced to an unobservable level. It can be seen that the partition wall 80 can increase the front emission and reduce optical crosstalk.

[0052] In this configuration, in order to verify the effect of the partition wall 80, the emission angle distribution of light emitted from each pixel is simulated. For comparison, simulations are also performed without the partition wall 80 and without the light distribution control unit 70 and the partition wall 80. Figure 1 As shown, the light emission angle θ is the angle between the light emission direction and the Z axis. The integrated intensity distribution is shown for the azimuth direction of light emission. As the compound semiconductor layer 14, it is AlGaInN system (nitride semiconductor system), and the peak wavelength of light emission is 450nm. The size of the main body 16 is set to be a square with a side of 2μm and a thickness of 2μm in the plane shape, and the thickness of the P side layer 13 is set to 200nm. It is simulated that the surrounding of the main body 16 is covered with aluminum.

[0053] The optical element 71 is a sphere with a diameter of 500nm. When viewed from above, the optical element 71 is arranged at the vertex of an equilateral triangle with a side of 500nm. The height of the partition wall 80 is set to 500nm, and the inclination angle θw of the side is set to 70 degrees. The FDTD method (Finite-difference time-domain method) is used for simulation. The grid size is 25nm, the simulation area is X: 6μm, Y: 6μm, Z: 7μm, and a perfectly matched layer (Perfect Matched Layer) with a thickness of 1μm is arranged at the end of the simulation area. The light emitting surface 130 is arranged at Z=0, and the near field is calculated in the area of ​​Z>0, and based on the calculation result of the near field (Nearfield), the emission angle distribution at a distance is calculated.

[0054] exist Figure 3 , the light emission angle distribution when the refractive index of the optical element 71 is 2.0 is shown. In addition, the following Table 1 shows the simulation results of the light extraction efficiency at θ≦20 degrees, 30 degrees, 40 degrees, 90 degrees, and 90 degrees <θ≦180 degrees when the refractive index of the optical element 71 is changed. Table 1 is the simulation result of the case where only the light distribution control unit 70 is configured and the partition wall 80 is not provided.

[0055] [Table 1]

[0056] Refractive Index 2.4 2 1.7 1.43 1 θ≤20deg 3.1％ 3.3％ 2.1％ 0.8％ 0.6％ θ≤30deg 6.9％ 6.5％ 4.5％ 2.6％ 2.0％ θ≤40deg 10.3％ 12.9％ 9.5％ 5.2％ 5.0％ θ≤90deg 24.3％ 30.9％ 26.8％ 18.6％ 14.7％ 90<θ≤180deg 2.4％ 1.4％ 1.5％ 1.9％ 1.4％

[0057] Table 2 below shows a case where the light distribution control unit 70 and the partition wall 80 are provided.

[0058] [Table 2]

[0059] Refractive Index 2.4 2 1.7 1.43 θ≤20deg 4.4％ 4.1％ 3.3％ 1.1％ θ≤30deg 7.6％ 8.4％ 7.0％ 2.5％ θ≤40deg 12.1％ 13.3％ 13.1％ 4.9％ θ≤90deg 21.8％ 27.2％ 27.7％ 14.7％ 90<θ≤180deg 0.4％ 0.7％ 0.7％ 0.5％

[0060] By providing the light distribution control unit 70, the emission at θ≤90 degrees is increased, and the light extraction efficiency is greatly improved. In particular, the emission at θ≤30 degrees is significantly increased. As shown in Table 1, it can be seen that by increasing the refractive index of the optical element 71, the light extraction efficiency is improved. In the case where the main body 16 is a nitride semiconductor, the refractive index of the optical element 71 is preferably greater than 1.7, and more preferably greater than 2. Here, the refractive index of 1.7 is close to the geometric mean (multiply mean) of the refractive index of 2.47 of the nitride semiconductor and the refractive index of air (external medium). Therefore, as the preferred lower limit of the refractive index of the optical element 71, the geometric mean of the refractive index of the material constituting the portion where light is emitted and the external medium is preferably used.

[0061] By setting the light distribution control unit 70, the light extraction efficiency is improved, and the front emission is also increased, but the emission at 90 degrees <θ≤180 degrees is increased. This means that by setting the light distribution control unit 70, the light emitted from a position higher than the light emission surface 130 (in the positive direction of the Z axis) is increased, and the light traveling in the negative direction of the Z axis is increased. Such light is incident on the adjacent pixel, and through the reflection here, it appears as if it is emitted from the adjacent pixel, thus generating optical crosstalk. The light emitted at 90 degrees <θ≤180 degrees has more than half the intensity of the light emitted at θ≤20 degrees, which is a size that cannot be ignored.

[0062] The side surface of the microbead is a circular curved surface, and when arranged on the light emitting surface 130, the upper part of the curved surface becomes an inclined side surface whose inclination angle changes continuously with respect to the light emitting surface 130. The reason for the increase in emission at 90 degrees <θ ≦ 180 degrees is that, through the inclined surface of the optical element 71, not only the light refracted forward increases, but also the light refracted to the opposite side (the light emitting surface 130 side) increases. Therefore, if a transparent and refractive optical element 71 having a surface inclined with respect to the light emitting surface 130 is provided, the light emission to the front is strengthened, but on the other hand, the light causing such optical crosstalk is inevitably increased.

[0063] On the other hand, Figure 3As shown, by providing a partition wall 80 on the basis of the light distribution control unit 70, the amount of light emitted at 90 degrees <θ ≦ 180 degrees can be greatly reduced. As shown in Table 2, regardless of the refractive index of the optical element 71, it can be reduced to a level below the same level as when there is no light distribution control unit 70. In addition, as can be seen from the comparison between Table 1 and Table 2, the amount of light at θ≤90 degrees is reduced by the partition wall 80, but the amount of light at θ≤20 degrees, 30 degrees, and 40 degrees can be increased. That is, even if the light extraction efficiency is reduced, there is an advantage such as being able to strengthen the more important forward emission. In addition, in the present embodiment, the optical element 71 constituting the light distribution control unit 70 refracts light to increase the light emission to the front, but the same function can also be achieved by diffracting light. In the case where the optical element 71 has a certain height and diffracts light, as in the present embodiment, a portion of the light is emitted toward the light emitting surface 130, and optical crosstalk is generated. Therefore, when the optical element 71 controls the traveling direction of light by the diffraction effect, the optical crosstalk prevention effect by the partition wall 80 is also effective.

[0064] In addition, comparison Figure 3 θ≤5 degrees, it can be seen that the light output of this part is reduced by the light distribution control unit 70. This means that in the absence of the light distribution control unit 70, there is a certain amount of light traveling forward from the light emitting layer 12. This is considered to be because this light is refracted and changed in direction by the light distribution control unit 70, and thus is reduced in the case of the light distribution control unit 70. That is, by providing the light distribution control unit 70, although there is a loss of forward emission light, much more light is refracted forward by the light distribution control unit 70, and the forward emission can be greatly enhanced.

[0065] Table 3 below shows simulation results when the height h of the partition wall 80 was changed from 0.25 μm to 1 μm.

[0066] [Table 3]

[0067] h＝0 h＝0.25 h＝0.5 h＝0.75 h＝1 θ≤20deg 3.3％ 3.9％ 4.1％ 5.0％ 5.4％ θ≤30deg 6.5％ 7.2％ 8.4％ 9.5％ 10.6％ θ≤40deg 12.9％ 12.3％ 13.3％ 14.5％ 15.8％ θ≤90deg 30.9％ 27.6％ 27.2％ 27.1％ 27.1％ 90<θ≤180deg 2.3％ 1.6％ 0.7％ 0.5％ 0.4％

[0068] The side wall angle of the partition wall 80 is 70 degrees. h = 0 means there is no partition wall 80. Even if h = 0.25 μm, there is an effect of reducing the emission of 90 degrees < θ ≤ 180 degrees and increasing the emission from the front. By increasing the height of the partition wall 80, it is possible to further reduce the emission of 90 degrees < θ ≤ 180 degrees and increase the emission from the front. In particular, the effect is significant at the height of the partition wall 80 above the height of the optical element 71 (0.5 μm).

[0069] Table 4 below shows simulation results when the inclination angle θw of the side wall of the partition wall 80 is changed from 90 degrees to 50 degrees.

[0070] [Table 4]

[0071] θw=90 θw=80 θw=70 θw=60 θw=50 θ≤20deg 3.6％ 3.9％ 4.1％ 3.8％ 3.8％ θ≤30deg 7.1％ 8.4％ 8.4％ 8.1％ 7.7％ θ≤40deg 11.7％ 13.2％ 13.3％ 14.5％ 14.2％ θ≤90deg 25.6％ 26.9％ 27.2％ 29.6％ 29.6％ 90<θ≤180deg 1.0％ 0.8％ 0.7％ 0.6％ 0.7％

[0072] Even if θw=90 degrees, there is an effect of reducing the radiation at 90 degrees <θ ≤ 180 degrees. In order to obtain a significant effect of reducing the radiation at 90 degrees <θ ≤ 180 degrees and increasing the forward radiation, θw is preferably 70 to 60 degrees.

[0073] As described above, by disposing the light distribution control unit 70 on the light emitting surface 130 of the micro-light emitting element 100, the light output can be greatly improved to increase the light emission toward the front. In addition, by providing the partition wall 80, light crosstalk between pixels can be prevented, further improving the light output toward the front.

[0074] [Variation]

[0075] In the first embodiment of the present invention, the light distribution control unit 70 may be configured in various ways. Figures 4 to 10 Although the configurations of the light distribution control unit 70 and the partition wall 80 in these modified examples are different, the other parts are the same as those in the first embodiment.

[0076] In the first embodiment, the optical element 71 constituting the light distribution control unit 70 is a transparent sphere. Figure 4 In the image display element 200a shown in FIG. 1 , the optical element 71a constituting the light distribution control unit 70a is a micro-cone composed of a transparent triangular pyramid. Figure 4 In the figure, although the optical element 71a is depicted as a complete triangular pyramid, it may be a triangular pyramid with a flat surface on the upper surface. The side surfaces of the micro-cone and triangular pyramid are inclined relative to the light emitting surface 130, and when arranged on the light emitting surface 130, the side surfaces become the side surfaces inclined relative to the light emitting surface 130. In addition, the shape when viewed from above is not limited to a circle, and may also be an elliptical shape. Such a pattern can be easily formed by molding a resin on the light emitting surface 130 using a nanoimprint method.

[0077] exist Figure 5 In the image display element 200b shown, the optical element 71b constituting the light distribution control unit 70b is a hemispherical transparent body, i.e., a micro-dome. The shape of the micro-dome is not limited to a hemispherical shape, and can be any plane shape or cross-sectional shape as long as it is a dome-shaped shape. In the micro-dome, the side surface is a curved surface, and when it is arranged on the light emitting surface 130, the curved surface becomes an inclined side surface with an inclination angle continuously changing relative to the light emitting surface 130.

[0078] exist Figure 6In the image display element 200c shown, the optical elements constituting the light distribution control unit 70c are the same as the micro beads in the first embodiment, but the arrangement pattern is different. In the light distribution control unit 70c, the optical elements 71 are arranged at the four corners of the quadrilateral. In this way, the arrangement pattern can also be variously modified.

[0079] exist Figure 7 In the image display element 200d shown, the optical element 71d constituting the light distribution control unit 70d is a transparent body in the shape of a quadrangular pyramid. The upper surface of the pyramid can also converge to a point and be in the shape of a quadrangular pyramid. In addition, it is not limited to a quadrangular pyramid, and it can also be a triangular pyramid or a triangular pyramid, and it can also be a multi-sided pyramid or a multi-sided pyramid with a large number of edges. The side surface of the multi-sided pyramid or the multi-sided pyramid is inclined, and when it is arranged on the light emitting surface 130, the above-mentioned side surface becomes a side surface inclined relative to the light emitting surface 130.

[0080] exist Figure 8 In the image display element 200e shown, the optical element 71e constituting the light distribution control unit 70e is a microrod in the form of a transparent body in the shape of an elongated rod with a trapezoidal cross section. The cross-sectional shape may also be a triangle. The surface at the end of the rod is also preferably inclined as shown in the figure. The side surface of the microrod is inclined, and when it is arranged on the light emitting surface 130, the above-mentioned side surface becomes a side surface inclined relative to the light emitting surface 130.

[0081] remove Figure 6 Except for the case where these shapes are formed by processing a transparent resin by a photolithography method such as nanoimprinting. These light distribution control parts can be formed by precisely aligning the light emitting surface 130 and then forming the partition wall 80, or the optical elements can be formed on the embedding material 60 without alignment and then the optical elements in the area where the partition wall 80 is formed are removed to form the partition wall 80.

[0082] exist Fig. 9 In the image display element 200f shown, a fixing layer 72 for improving the close contact between the optical element 71 constituting the light distribution control unit 70f and the light emitting surface 130 is arranged between the optical element 71 and the light emitting surface 130. The fixing layer 72 is made of a material that is transparent to the emitted light. For example, it is a transparent resin material that is applied to the light emitting surface 130 and acts as an adhesive material to the optical element 71 that is subsequently arranged. Alternatively, it is a residual film that remains on the light emitting surface 130 when the optical element 71 is formed on the light emitting surface 130 by nanoimprinting. The residual film is made of the same material as the optical element 71 and is transparent to the emitted light. Alternatively, it may be an inorganic film or resin film such as a SiO2 film or a SiN film that is deposited as a protective film after the optical element 71 is arranged on the light emitting surface 130.

[0083] exist Fig.10 In the image display element 200g shown in FIG. 1 , the structure of the partition wall 80g is different. That is, in the first embodiment, the partition wall 80 is composed of a metal film alone. Fig.10 In the figure, a surface layer 82 is provided on the side wall of the partition wall base material 81. The partition wall base material 81 can be an inorganic material such as SiO2, SiN, or a resin. The partition wall 80g only needs to be covered with a material that does not transmit light, and can also contain any substance inside. The side of the partition wall 80g is preferably a metal film with high reflectivity, and the surface layer 82 is preferably a metal film with high reflectivity such as silver or aluminum. Regarding the raw materials of the partition wall, the focus is on the side wall, which is preferably a metal that reflects the light emitted by the micro-light-emitting element 100. If the structure is allowed to become complicated, a light absorber can be arranged on the upper surface of the partition wall.

[0084] The shape and arrangement pattern of the optical element constituting the light distribution control unit can be variously configured. The key point is that the cross-sectional shape of the optical element has a surface inclined relative to the light emitting surface 130, and the refractive index of the transparent body constituting the optical element. The refractive index of the optical element needs to be appropriately selected according to the material that emits light.

[0085] [Second embodiment]

[0086] use Fig.11 Other embodiments of the present invention are described. The image display element 200h of the second embodiment is a monochrome display element, and each pixel 5 includes a monochrome micro-light-emitting element 100h. Here, the case of a red display element is described, but the same is true for other display colors. In addition, the case of using blue light as excitation light is described, but blue-violet light (wavelength 400nm to 430nm) and ultraviolet light (wavelength less than 400nm) can also be used.

[0087] The micro light emitting element 100h is composed of an excitation light emitting element 105 that emits blue light and a red wavelength converting portion 32. A light emitting surface 130h of the micro light emitting element 100h is an upper surface of the red wavelength converting portion 32.

[0088] As in the first embodiment, the micro-light emitting element 100h is covered by the light-shielding embedding material 60h. That is, the excitation light emitting element 105 and the red wavelength conversion unit 32 are also covered by the embedding material 60h. Therefore, optical crosstalk between the micro-light emitting elements 100h can be prevented.

[0089] The excitation light emitting element 105 has a main body 16h composed of a nitride semiconductor layer 14h, a protective film 17, a P electrode 23P (second electrode) and an N electrode 23N (first electrode). The nitride semiconductor layer 14h is composed of a light emitting layer 12 (light emission 1ayer: light emitting diode) that emits light, an N-side layer 11 (N-side 1ayer, first conductive layer) that injects electrons into the light emitting layer 12, and a P-side layer 13 (P-side 1ayer, second conductive layer) that injects holes into the light emitting layer 12. The P electrode 23P and the N electrode 23N of the excitation light emitting element 105 are both formed on the second surface. The protective film 17 is an insulating film and protects the main body 16h. The P electrode 23P and the N electrode 23N are connected to the P driving electrode 52 and the N driving electrode 51 on the corresponding driving circuit substrate 50h. The current supplied from the driving circuit substrate 50h to the excitation light emitting element 105 is transmitted from the P driving electrode 52 to the P side layer 13 via the P electrode 23P. The current from the P-side layer 13 through the light-emitting layer 12 flows from the N-side layer 11 through the N-electrode 23N to the N-driving electrode 51. In this way, according to the amount of current supplied by the driving circuit substrate 50h, the excitation light emitting element 105 emits excitation light with a predetermined intensity, and the red wavelength conversion unit 32 absorbs the excitation light and emits red light by down-converting the excitation light according to the amount of the excitation light.

[0090] In addition, Fig.11 In the structure, the side wall of the main body 16h of the excitation light emitting element 105 is depicted as being perpendicular to the horizontal plane, but the periphery of the light emitting layer 12 or the side wall of the N-side layer 11 can also be inclined. For example, the periphery of the light emitting layer 12 is inclined from 35 degrees to 60 degrees, and the side of the N-side layer 11 is inclined from 85 degrees to about 70 degrees. By inclining the side surface, the amount of excitation light incident on the red wavelength conversion unit 32 can be increased, and the luminous efficiency can be improved. By also inclining the side wall of the red wavelength conversion unit 32, the red light emission efficiency to the outside can be improved. In addition, these inclined surfaces are covered with a transparent insulating film, and then the outer side is covered with a highly reflective metal film such as aluminum and silver, thereby further improving the light extraction efficiency.

[0091] The red wavelength conversion unit 32 is generally a resin containing a phosphor or quantum dot that absorbs the excitation light and performs down-conversion. In the case where the red wavelength conversion unit 32 is composed of quantum dots and a matrix resin, it may also contain a scatterer that scatters the excitation light. The scatterer is a particle with a size of tens to hundreds of nm composed of a transparent body with a refractive index different from that of the matrix resin. By extending the optical path length of the excitation light in the red wavelength conversion unit 32, the amount of excitation light absorbed is increased. In this way, the conversion efficiency from excitation light to red light can be improved.

[0092] The light distribution control unit 70h and the partition wall 80 are Figure 1 The same as the first embodiment shown. Figure 1 The difference is that, due to the conversion of the emission wavelength to red light and the change in the refractive index n of the light emitting surface 130, the configuration period of the optical element 71h constituting the light distribution control unit 70h, the size of the optical element 71h, and the refractive index change. Microbeads with an average diameter of 500nm are densely arranged on the surface of the red wavelength conversion unit 32 containing quantum dots. The microbeads are glass beads with a refractive index of 1.43. The light emission intensity measured in full beam increased by 15%. On the other hand, the front emission intensity at θ≤30 degrees increased by 9%.

[0093] In addition, Fig.11 In the embodiment, the surface of the red wavelength conversion unit 32 is depicted as a plane, but since the red wavelength conversion unit 32 is formed by coating a resin layer, a slight depression is generated. In this way, even if the light emitting surface 130 is slightly deviated from the plane, the effect of the light distribution control unit 70h is effective. In this embodiment, the same effect as the first embodiment can be achieved.

[0094] [Third embodiment]

[0095] use Fig.12 The following describes other embodiments of the present invention. As in the second embodiment, the image display element 200i of the third embodiment is a monochrome display element having a wavelength conversion unit, but the difference is that the surface of the wavelength conversion unit has a dielectric multilayer film 74. In this configuration, the surface of the dielectric multilayer film 74 is a light emitting surface 130.

[0096] The red wavelength conversion unit 32 is described, but the same is true for other wavelengths. The dielectric multilayer film 74 has the property of reflecting the excitation light and transmitting the red light. Therefore, even if the red wavelength conversion unit 32 is thin, the leakage of the excitation light can be reduced and the intensity of the red light can be increased.

[0097] In addition, Fig.12 In the embodiment, the dielectric multilayer film 74 is divided for each pixel. If the dielectric multilayer film 74 is continuous between pixels, optical crosstalk may sometimes occur via the dielectric multilayer film 74. In order to prevent such optical crosstalk, the dielectric multilayer film 74 is preferably disposed inside the partition wall 80. However, in the case where optical crosstalk via the dielectric multilayer film 74 is not a problem, a continuous dielectric multilayer film 74 may be disposed between pixels. The continuous dielectric multilayer film 74 can simplify the formation process. In this embodiment, the same effect as in the first embodiment can be achieved.

[0098] [Fourth embodiment]

[0099] use Fig.13The image display element 200j of this structure is a full-color display element of the three primary colors of RGB, and the pixel 5 includes a blue sub-pixel 6, a red sub-pixel 7, and a green sub-pixel 8. The blue sub-pixel 6 includes a blue light micro-luminescent element 100B, the red sub-pixel 7 includes a red light micro-luminescent element 100R, and the green sub-pixel 8 includes two green light micro-luminescent elements 100G.

[0100] The red light micro-luminescent element 100R is composed of an excitation light emitting element 105j that emits blue light and a red wavelength conversion section 32. Similarly, the green light micro-luminescent element 100G is composed of an excitation light emitting element 105j and a green wavelength conversion section 33. The blue light micro-luminescent element 100B is composed of an excitation light emitting element 105j and a transparent section 31. The excitation light emitting element 105j has the same structure as the micro-luminescent element 100 of the first embodiment. In addition, in this structure, for red and green, blue light is used as excitation light, and a wavelength conversion section that performs wavelength down-conversion is provided, and the blue light directly uses the excitation light. However, blue light can also be generated by using near-ultraviolet light or ultraviolet light as excitation light and performing down-conversion. In addition, in the following description, when there is no need to specifically distinguish the transparent section 31, the red wavelength conversion section 32, and the green wavelength conversion section 33, they are sometimes simply described as wavelength conversion sections.

[0101] The transparent portion 31, the red wavelength conversion portion 32, and the green wavelength conversion portion 33 may also include a scatterer. In the red wavelength conversion portion 32 and the green wavelength conversion portion 33, the scatterer improves the conversion efficiency by improving the absorption efficiency of the excitation light. In the transparent portion 31, the emission efficiency of the blue light can be improved by reducing the light confinement effect.

[0102] In this configuration, the surfaces of the red wavelength conversion portion 32, the green wavelength conversion portion 33, and the transparent portion 31 serve as the light emitting surface 130. Fig.13 In the embodiment, the light distribution control unit 70h of the second embodiment is arranged on the surface of the red wavelength conversion unit 32, the green wavelength conversion unit 33 and the transparent unit 31, and a partition wall 80 is formed between each sub-pixel. The size and shape of the optical element 71h constituting the light distribution control unit 70h can also be changed for each sub-pixel. Alternatively, a different light distribution control unit can be set in each sub-pixel. In this embodiment, the same effect as the first embodiment can be achieved.

[0103] [Fifth embodiment]

[0104] use Fig.14Another embodiment of the present invention will be described. The image display element 200k of this configuration is a full-color display element similar to the fourth embodiment. The difference from the fourth embodiment is that a color filter 75 is disposed on the wavelength conversion unit.

[0105] When a wavelength conversion unit is used to convert blue light into red or green, it is difficult to completely prevent the leakage of blue light as excitation light. In particular, when the thickness of the wavelength conversion unit must be reduced due to miniaturization of pixels, leakage of excitation light may occur. By configuring a color filter that absorbs excitation light and transmits red or green light, leakage of excitation light can be suppressed. Fig.14 As shown, a color filter 75 is arranged on the red wavelength conversion unit 32, and a light distribution control unit 70h is arranged on the surface of the color filter. The same is true for green. In this case, the light emitting surface of the red light micro-luminescent element 100Rk and the green light micro-luminescent element 100Gk becomes the color filter surface. The color filter 75 may also include a scatterer for scattering the excitation light. It has the effect of reducing the emission efficiency of the excitation light. In this embodiment, the same effect as the first embodiment can be achieved. In addition, the following secondary effect can also be achieved: the leakage of the excitation light can be reduced.

[0106] [Sixth embodiment]

[0107] use Fig.15 Another embodiment of the present invention will be described. The image display element 2001 of this configuration is a full-color display element similar to the fourth embodiment. The difference from the fourth embodiment is that a transparent layer 76 is disposed on the wavelength conversion unit.

[0108] In this configuration, even when the thickness of the red wavelength conversion section 32 and the green wavelength conversion section 33 increases, the surface of each sub-pixel can be easily made flat. For example, if the red wavelength conversion section 32 and the green wavelength conversion section 33 are formed respectively after the embedding material 60h is formed, and then, when the transparent section 31 is formed, a transparent resin with high fluidity is used to apply a transparent resin on the red sub-pixel 7 and the green sub-pixel 8, a flat surface can be obtained by utilizing the flow of the resin. If the surface can be made flat, it becomes easy to form the light distribution control section 70h and the partition wall 80. The transparent resin may also contain a scatterer for scattering the excitation light. In this embodiment, the same effect as the first embodiment can be achieved. In addition, the following secondary effect can also be achieved: the manufacture of the light distribution control section and the partition wall is simplified.

[0109] [Seventh embodiment]

[0110] Below, use Fig.16 as well as Fig.17The image display element 200m of this structure is the same full-color display element as the fourth embodiment, but the difference is that QLED is used as a micro-light-emitting element. In this structure, the red light micro-light-emitting element 100Rm is composed of a P driving electrode 52m, a red light-emitting layer 110R formed thereon, and a common N electrode 30N formed thereon. Fig.17 As shown, the red light-emitting layer 110R is provided with an electron transport layer 121 and a hole transport layer 122 on both sides of the red light-emitting quantum dot layer 120. Electrons and holes are respectively injected into the red light-emitting quantum dot layer 120 through the electron transport layer 121 and the hole transport layer 122, and light is emitted by recombination within the quantum dots. By changing the core size of the quantum dots, the emission wavelength can be controlled. Therefore, the blue light micro-luminescent element 100Bm and the green light micro-luminescent element 100Gm can also be similarly composed of QLEDs. In addition, in the following, when there is no need to distinguish between colors, it is sometimes recorded only as the light-emitting layer 110. Since the details of the structure of QLED are not directly related to the present invention, they are not mentioned.

[0111] The common N electrode 30N is a transparent conductive film. The surface of the P driving electrode 52m preferably has a high reflectivity relative to visible light. The light emitting surface in this structure is the surface of the common N electrode 30N. The red light micro-luminescent element 100Rm, the blue light micro-luminescent element 100Bm, and the green light micro-luminescent element 100Gm are insulated from each other by the first insulating film 19. The first insulating film preferably has a light-shielding property. The first insulating film is, for example, a resin material containing a light-absorbing pigment or dye. Or, it is a resin material containing scattering particles such as titanium oxide. The former is absorptive, and the latter is reflective. The first insulating film is more preferably reflective.

[0112] In this configuration, the surface of the common N-electrode 30N constituting the micro-light emitting element is the light emitting surface 130, and the surface of the micro-light emitting element is the light emitting surface 130. A light distribution control unit 70R is arranged on the common N-electrode 30N of the red light micro-light emitting element 100Rm. Similarly, a light distribution control unit 70G is arranged on the common N-electrode 30N of the green light micro-light emitting element 100Gm, and a light distribution control unit 70B is arranged on the common N-electrode 30N of the blue light micro-light emitting element 100Bm. The light distribution control units 70B, 70G, and 70R are all regular triangle patterns, and the distance between the optical elements 71 is 350nm for the blue light light distribution control unit 70B, 400nm for the green light light distribution control unit 70G, and 500nm for the red light light distribution control unit 70R. By changing the light distribution control unit for each light emitting color, the respective forward emission intensities can be improved.

[0113] The size of the optical element 71 may also be changed in accordance with the wavelength of the luminescent color. The shorter the wavelength, the smaller the optical element 71 may be. In order to simplify the manufacturing process, the size and arrangement pattern of the optical element 71 may be the same in all sub-pixels.

[0114] In this configuration, a partition wall 80 is provided between sub-pixels. The partition wall 80 may be electrically connected to the common N-electrode 30N. This can reduce the wiring resistance of the common N-electrode 30N.

[0115] In this configuration, the upper surface of the partition wall 80 between the sub-pixels is covered with a black matrix 78. The partition wall 80 is necessary to prevent optical crosstalk, but if the light emitting surface 130 has a large metal pattern, the displayed image deteriorates due to the reflection of external light. In order to prevent this, it is preferable to configure a black matrix 78 that absorbs external light. In this configuration, by configuring the light distribution control unit in a manner that covers the light emitting surface 130, the same effect as the first embodiment can be achieved.

[0116] [Variation]

[0117] As a modification of the seventh embodiment, each light emitting layer 110B, 110R, 110G may be replaced with an organic LED (OLED) instead of a QLED. OLED, like QLED, has an organic light emitting layer disposed between an electron transport layer 121 and a hole transport layer 122 .

[0118] [Eighth Embodiment]

[0119] use Fig.18 Other embodiments of the present invention are described. As in the seventh embodiment, the image display element 200n of this structure uses QLED as a micro-light-emitting element, but the difference is that the surface of the transparent layer 76 arranged on the QLED is used as the light emitting surface 130, and the partition wall 80n separates the QLEDs. That is, the partition wall 80n separates the micro-light-emitting element and the light distribution control unit 70 between the sub-pixels. Luminescent materials such as QLED usually have a high refractive index, and the light extraction efficiency tends to be low. Therefore, by configuring a transparent resin with a relatively high refractive index on the QLED to extract light into the transparent resin, and by emitting light from the transparent resin into the air, the light extraction efficiency can be improved. The light extraction efficiency from the transparent layer 76 to the air is improved by the side wall of the partition wall formed of a reflective material and in contact with the transparent layer 76, which is inclined in a manner that opens toward the light emission direction. In addition, when sufficient light extraction efficiency can be achieved using the light distribution control unit 70, the transparent layer 76 can be omitted.

[0120] Each sub-pixel is partitioned by a partition wall 80n, and the side wall of the partition wall 80n is inclined in a manner open with respect to the light emission direction. The side wall of the partition wall 80n is composed of a highly reflective material.

[0121] like Fig.18 As shown, the side wall is inclined at an angle θw relative to the light emitting surface 130. θw is preferably 30 to 60 degrees. Since the QLED emits light isotropically, Fig.18 In the embodiment of the present invention, light is also emitted in the horizontal direction. By reflecting the light traveling in the horizontal direction upward, it is possible to prevent light from leaking to adjacent pixels and improve light extraction efficiency. In addition, when the light output of the micro-light-emitting elements 100Rn, 100Bn, and 100Gn is surplus, the side wall of the partition wall 80n may also have light absorption.

[0122] In this configuration, the transparent layer 76 is also disposed in the partition wall 80n, and the side wall can improve the efficiency of light extraction from the transparent layer 76 to the air. By disposing the light distribution control unit 70 on the surface of the transparent layer 76, the light emission to the front can be increased. As in other embodiments, the light distribution control unit 70 disposed on the transparent layer 76 can also be changed for each luminous color. In addition, a black matrix 78 can also be disposed between sub-pixels.

[0123] The common N-electrode 30N may also be electrically connected to the partition wall 80n. By electrically connecting the common N-electrode 30N to the partition wall 80n, it is possible to prevent the resistance of the N-electrode from increasing even if the common N-electrode 30N is thinned. The height of the upper surface of the partition wall 80n is preferably higher than the surface of the light distribution control unit 70, and is preferably greater than the sum of the thickness of the light emitting layer 110, the thickness of the transparent layer 76, and the thickness of the light distribution control unit 70.

[0124] exist Fig.18 In the embodiment, the light emitting layer 110 contacts the partition wall 80n, but the P driving electrode 52m and the partition wall 80n are not short-circuited. Therefore, for example, the hole transport layer 122 can also be configured only on the P driving electrode 52m. In this configuration, by configuring the light distribution control unit, the same effect as the first embodiment can be achieved.

[0125] [Ninth embodiment]

[0126] use Fig.19 Another embodiment of the present invention is described. This embodiment is characterized in that a partition wall 80o is used to isolate the micro-light emitting elements. In the first embodiment, the micro-light emitting elements 100 are isolated from each other by the embedding material 60, and the partition wall 80 is provided on the embedding material 60. In this embodiment, the micro-light emitting element 100o and the light distribution control unit 70o are separated from each other by the partition wall 80o.

[0127] The image display element 200o of the ninth embodiment is intended to realize an image display element having pixels larger than those of the first embodiment. In the first embodiment, the micro-luminescent element 100 is covered with an embedding material 60 and a partition wall 80 is provided thereon, but in the present embodiment, the embedding material 60 is not used and a partition wall 80o is directly provided on the driving circuit substrate 50. That is, the partition wall 80o separates the light distribution control unit 70o from the micro-luminescent element 100. In the case where the pixel pitch is large and the space between the micro-luminescent elements 100o can be increased, such a method can be adopted. Such a partition wall 80o is not limited to metal, but can also be a reflective resin material composed of a resin containing a white pigment, or an absorptive resin material containing a black dye or pigment. That is, the partition wall 80o preferably does not transmit the light emitted by the micro-luminescent element 100.

[0128] In this embodiment, after the micro-light emitting elements 100o are arranged, the partition wall 80o is formed, and the micro-beads as the optical elements 71o are flowed into the partition wall 80o to arrange the micro-beads on the light emitting surface 130. When there is a space between the side wall of the micro-light emitting element 100o and the partition wall 80o, the micro-beads remain between the side wall of the micro-light emitting element 100o and the partition wall 80o. By filling the space between the side wall of the micro-light emitting element 100o and the partition wall 80o with a transparent resin or the like, it is also possible to prevent the micro-beads from remaining between the side wall of the micro-light emitting element 100o and the partition wall 80o.

[0129] Since the partition wall 80o is also high, the partition wall 80o formed in advance by die molding can also be bonded to the drive circuit substrate 50h. In this embodiment, the same effects as those of the first embodiment can be achieved.

[0130] [Tenth embodiment]

[0131] use Fig. 20 Other embodiments of the present invention are described. The image display element 200p of this configuration is a full-color display element similar to the fourth embodiment. The difference is that a wavelength conversion unit is arranged in the partition wall 80p, and a light distribution control unit 70 is arranged thereon. That is, the partition wall 80p separates the light distribution control unit 70 and the wavelength conversion unit between the sub-pixels.

[0132] In order to prevent optical crosstalk between sub-pixels, it is necessary to cover the periphery of the wavelength conversion unit with a light-shielding wall. In the fourth embodiment, the wavelength conversion unit is covered by the embedding material 60h, but in this embodiment, the wavelength conversion unit is covered by the partition wall 80p. Therefore, by configuring the wavelength conversion layer and the light distribution control unit inside the partition wall 80p, optical crosstalk caused by both the light distribution control unit 70 and the wavelength conversion unit is prevented.

[0133] The structure of the blue micro LED 105p as the excitation light source arranged on the driving circuit substrate 50p is similar to that of the first embodiment except that the polarity is reversed. A partition wall 80p is arranged on the common N electrode 30N, and inside the partition wall 80p, a transparent portion 31, a red wavelength conversion portion 32, and a green wavelength conversion portion 33 are formed in the blue sub-pixel 6, the red sub-pixel 7, and the green sub-pixel 8, respectively. The light distribution control portion 70 is arranged on the surface of the transparent portion 31, the red wavelength conversion portion 32, and the green wavelength conversion portion 33. The uppermost portion of the partition wall 80p is preferably higher than the upper surface of the light distribution control portion 70.

[0134] As the partition wall 80p, the Fig.10 The modified example shown here is a structure composed of a partition wall base material 81 and a surface layer 82, but the structure of the partition wall 80p may be a single layer or a more complex structure. In this embodiment, the same effects as those of the first embodiment can be achieved.

[0135] [Additional Notes]

[0136] The present invention is not limited to the above-mentioned embodiments, and various changes can be made within the scope of the claims. The embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Moreover, new technical features can be formed by combining the technical methods disclosed in each embodiment.

Claims

1. An image display element, characterized in that: include: a driving circuit substrate including a driving circuit for supplying current to the micro-light emitting element to cause the micro-light emitting element to emit light; as well as The micro light-emitting elements are arranged in an array on the driving circuit substrate. The light distribution control unit for increasing the forward emission of the micro-light emitting element is arranged on the light emitting surface which is the surface through which the micro-light emitting element emits light into the air. A partition wall is arranged around the light distribution control unit, and the partition wall does not transmit light emitted by the micro light emitting element. The side surfaces of the partition walls are in contact with air.

2. The image display element according to claim 1, characterized in that The height of the upper surface of the partition wall is greater than or equal to the height of the upper surface of the light distribution control unit.

3. The image display element according to claim 1, characterized in that The side surfaces of the partition walls reflect the light.

4. The image display element according to any one of claims 1 to 3, characterized in that: A side surface of the partition wall facing the light distribution control portion is inclined in a manner open with respect to a light emission direction.

5. The image display element according to claim 1, characterized in that A metal that reflects light emitted by the micro light emitting element is disposed on a side surface of the partition wall that faces the light distribution control unit.

6. The image display element according to claim 1, characterized in that The partition wall separates adjacent micro light-emitting elements from each other.

7. The image display element according to claim 1, characterized in that The micro-light emitting element includes an excitation light emitting element and a wavelength conversion unit. The excitation light emitting element generates excitation light, and the wavelength conversion unit absorbs the excitation light and emits down-converted light.

8. The image display element according to claim 7, characterized in that The partition wall separates the adjacent wavelength conversion sections from each other.

9. The image display element according to claim 7, characterized in that: The wavelength conversion section has a color filter on the light emitting surface side, the color filter absorbing the excitation light and transmitting the down-converted light.

10. The image display element according to claim 7, characterized in that The wavelength converting portion has a transparent layer on the light emitting surface side, the transparent layer transmitting the down-converted light.

11. The image display element according to claim 7, characterized in that: The wavelength conversion section has a dielectric multilayer film on the light emitting surface side, the dielectric multilayer film reflecting the excitation light and transmitting the down-converted light.

12. The image display element according to claim 1, characterized in that The micro-light emitting element includes a scatterer.

13. The image display element according to claim 1, characterized in that The partition wall forms a part of a wiring for supplying current to the micro light emitting element.

14. The image display element according to claim 1, characterized in that A black matrix is ​​disposed on the upper surface of the partition wall.

15. The image display element according to claim 1, characterized in that An optical element is arranged in the light distribution control portion. The optical element is transparent to the emitted light and has a side surface inclined relative to the light emitting surface.

16. The image display element according to claim 15, characterized in that The refractive index of the optical element is greater than or equal to the geometric average of the refractive index of the light-emitting portion of the micro-light-emitting element and the refractive index of the external medium.

17. The image display element according to claim 15, characterized in that The optical elements are arranged in contact with each other.

18. The image display element according to claim 1, characterized in that The image display element comprises: a first micro-light emitting element which emits light at a first light emitting wavelength; and a second micro-light emitting element which emits light at a second light emitting wavelength which is longer than the first light emitting wavelength. The light distribution control portion formed on the light emitting surface of the first micro-light emitting element has the same configuration as the light distribution control portion formed on the light emitting surface of the second micro-light emitting element.

19. An image display element, characterized in that: include: a driving circuit substrate including a driving circuit for supplying current to the micro-light emitting element to cause the micro-light emitting element to emit light; as well as The micro light-emitting elements are arranged in an array on the driving circuit substrate. A plurality of optical elements are arranged on a light emitting surface which is a surface on which the micro light emitting element emits light into the air, A partition wall is arranged around the plurality of optical elements, the partition wall not transmitting light emitted by the micro-light emitting elements, The side surfaces of the partition walls are in contact with air.

20. The image display element according to claim 19, characterized in that The optical element has a side surface inclined with respect to the light emitting surface.

Images