Display device

Abstract

Provided is a display device having a plurality of light-emitting elements arranged on a substrate, wherein each of the light-emitting elements is provided with: a light-emitting layer that emits light; a microstructure that creates a point light source by extracting the light from a minute region; and a lens structure that is stacked above the light-emitting layer and guides the light emitted from the point light source in a prescribed direction.

Description

Display device

[0001] This disclosure relates to a display device.

[0002] In recent years, the development of display devices using self-emitting elements such as electroluminescence (EL) elements as light-emitting elements has been progressing. In such a display device, for example, a plurality of light-emitting elements having a stacked structure composed of a lower electrode, a light-emitting layer stacked on the lower electrode, and an upper electrode stacked on the light-emitting layer are arranged on a substrate. Then, when a predetermined voltage is applied to the lower electrode and the upper electrode, the light-emitting layer sandwiched between the lower electrode and the upper electrode emits light.

[0003] Japanese Patent Application Laid-Open No. 2022-69533

[0004] Since the above-described display device can display high-quality and high-definition images, it is used not only for direct-view display devices such as monitors but also for small display devices such as electronic viewfinders (EVFs) and head-mounted displays (HMDs). Furthermore, in order to use these display devices particularly in applications such as virtual reality (VR) and augmented reality (AR), there is a strong demand to increase the front emission intensity of light for the display device.

[0005] Therefore, in a display device, by providing an on-chip lens or the like having a function of collimating (parallelizing) light, the light from the light-emitting element is guided to the upper front of the display surface of the display device, thereby increasing the front emission intensity of light. However, in the display device of the prior art, most of the emitted light does not reach the on-chip lens. Also, in the display device of the prior art, the distance between the on-chip lens and the light-emitting layer serving as a light source is short, and there is also a limit to the collimation of light by the on-chip lens. Therefore, in the prior art, it has been difficult to further increase the front emission intensity of light of the display device.

[0006] This disclosure proposes a display device capable of further increasing the front emission intensity of light.

[0007] According to the present disclosure, there is provided a display device having a plurality of light-emitting elements arranged on a substrate, wherein each of the light-emitting elements includes a light-emitting layer that emits light, a microstructure that creates a point light source by extracting the light from a minute region, and a lens structure that is laminated above the light-emitting layer and guides the light emitted from the point light source in a predetermined direction.

[0008] This is a schematic diagram showing an example of the overall configuration of a display device according to an embodiment of this disclosure. This is a circuit diagram showing an example of a subpixel of a display device according to an embodiment of this disclosure. This is a schematic diagram showing an example of the cross-sectional configuration of a light-emitting element according to a comparative example. This is a schematic diagram showing an example of the cross-sectional configuration of a light-emitting element according to the first embodiment of this disclosure. This is a schematic diagram showing an example of the planar configuration of a light-emitting element according to the first embodiment of this disclosure. This is a schematic diagram showing an example of the planar configuration of a light-emitting element according to modification 1 of the first embodiment of this disclosure. This is a schematic diagram showing an example of the planar configuration of a light-emitting element according to modification 2 of the first embodiment of this disclosure. This is a schematic diagram (1) showing an example of the cross-sectional configuration of a light-emitting element according to modification 3 of the first embodiment of this disclosure. This is a schematic diagram (2) showing an example of the cross-sectional configuration of a light-emitting element according to modification 3 of the first embodiment of this disclosure. This is a schematic diagram (3) showing an example of the cross-sectional configuration of a light-emitting element according to modification 3 of the first embodiment of this disclosure. This is a schematic diagram (1) showing an example of the cross-sectional configuration of a light-emitting element according to modification 4 of the first embodiment of this disclosure. This is a schematic diagram (2) showing an example of the cross-sectional configuration of a light-emitting element according to modification 4 of the first embodiment of this disclosure. This is a schematic diagram showing an example of the cross-sectional configuration of a light-emitting element according to the second embodiment of this disclosure. This is a schematic diagram showing an example of the planar configuration of a light-emitting element according to the second embodiment of this disclosure. This is a schematic diagram showing an example of the planar configuration of a light-emitting element according to modification 1 of the second embodiment of this disclosure. This is a schematic diagram (1) showing an example of the cross-sectional configuration of a light-emitting element according to modification 2 of the second embodiment of this disclosure. This is a schematic diagram (2) showing an example of the cross-sectional configuration of a light-emitting element according to modification 2 of the second embodiment of this disclosure. This is a schematic diagram (1) showing an example of the cross-sectional configuration of a light-emitting element according to modification 3 of the second embodiment of this disclosure. This is a schematic diagram (2) showing an example of the cross-sectional configuration of a light-emitting element according to modification 3 of the second embodiment of this disclosure. This is a schematic diagram (1) showing an example of the cross-sectional configuration of a light-emitting element according to the third embodiment of this disclosure. This is a schematic diagram (2) showing an example of the cross-sectional configuration of a light-emitting element according to the third embodiment of this disclosure. This is a schematic diagram (3) showing an example of the cross-sectional configuration of a light-emitting element according to the third embodiment of this disclosure. This is a schematic diagram (1) showing an example of the cross-sectional configuration of a light-emitting element according to the fourth embodiment of this disclosure.This is a schematic diagram (2) showing an example of the cross-sectional configuration of a light-emitting element according to the fourth embodiment of this disclosure. This is a schematic diagram (3) showing an example of the cross-sectional configuration of a light-emitting element according to the fourth embodiment of this disclosure. This is a conceptual diagram (1) for explaining the relationship between the normal vector LN passing through the center of the light-emitting part, the normal vector LN' passing through the center of the lens member, and the normal vector LN" passing through the center of the wavelength-selecting part. This is a conceptual diagram (2) for explaining the relationship between the normal vector LN passing through the center of the light-emitting part, the normal vector LN' passing through the center of the lens member, and the normal vector LN" passing through the center of the wavelength-selecting part. This is a conceptual diagram (3) for explaining the relationship between the normal vector LN passing through the center of the light-emitting part, the normal vector LN' passing through the center of the lens member, and the normal vector LN" passing through the center of the wavelength-selecting part. This is a conceptual diagram (4) for explaining the relationship between the normal vector LN passing through the center of the light-emitting part, the normal vector LN' passing through the center of the lens member, and the normal vector LN" passing through the center of the wavelength-selecting part. This is a conceptual diagram (No. 5) illustrating the relationship between the normal vector LN passing through the center of the light-emitting part, the normal vector LN' passing through the center of the lens member, and the normal vector LN'' passing through the center of the wavelength selection part. This is a conceptual diagram (No. 6) illustrating the relationship between the normal vector LN passing through the center of the light-emitting part, the normal vector LN' passing through the center of the lens member, and the normal vector LN'' passing through the center of the wavelength selection part. This is a conceptual diagram (No. 7) illustrating the relationship between the normal vector LN passing through the center of the light-emitting part, the normal vector LN' passing through the center of the lens member, and the normal vector LN'' passing through the center of the wavelength selection part. This is a schematic cross-sectional view illustrating the first example of a resonator structure. This is a schematic cross-sectional view illustrating the second example of a resonator structure. This is a schematic cross-sectional view illustrating the third example of a resonator structure. This is a schematic cross-sectional view illustrating the fourth example of a resonator structure. This is a schematic cross-sectional view illustrating the fifth example of a resonator structure. This is a schematic cross-sectional view illustrating the sixth example of a resonator structure. This is a schematic cross-sectional view illustrating the seventh example of a resonator structure. This is a front view showing an example of the appearance of a digital still camera. This is a rear view showing an example of the appearance of a digital still camera. This is an external view of a head-mounted display. This is an external view of a see-through head-mounted display. This is an external view of a television system. This is an external view of a smartphone. This is a diagram (No. 1) showing the internal configuration of an automobile. This is a diagram (No. 2) showing the internal configuration of an automobile.

[0009] Preferred embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configuration will be denoted by the same reference numeral to avoid redundant explanation. In addition, in this specification and drawings, multiple components having substantially the same or similar functional configurations may be distinguished by adding a different alphabet after the same reference numeral. However, if there is no particular need to distinguish each of multiple components having substantially the same or similar functional configurations, only the same reference numeral will be used.

[0010] Furthermore, the drawings referenced in the following description are intended to illustrate and facilitate understanding of one embodiment of this disclosure, and for the sake of clarity, the shapes, dimensions, ratios, etc. shown in the drawings may differ from those of the actual product. In addition, the apparatus shown in the drawings may be modified in design as appropriate, taking into consideration the following description and known technology.

[0011] Furthermore, in the following descriptions of circuits (electrical connections), unless otherwise specified, "electrically connected" means connecting multiple elements in such a way that electricity (signals) can conduct through them. In addition, "electrically connected" in the following descriptions includes not only cases where multiple elements are directly and electrically connected, but also cases where they are indirectly and electrically connected through other elements.

[0012] The explanation will proceed in the following order: 1. Display device according to the embodiment of this disclosure 1.1 Display device 1.2 Pixel 2. Background leading to the creation of the embodiments of this disclosure 3. First embodiment 3.1 Detailed configuration 3.2 Modification 4. Second embodiment 4.1 Detailed configuration 4.2 Modification 5. Third embodiment 6. Fourth embodiment 7. Summary 8. Modification 8.1 Modification 1 8.2 Modification 2 9. Application examples 10. Supplement

[0013] <<1. Display Device According to the Embodiment of the Present Disclosure>> <1.1 Display Device> First, with reference to Figure 1, an example of the overall configuration of a display device 10 according to the embodiment of the present disclosure, which is used as a display device or lighting device, will be described. Figure 1 is a schematic diagram showing an example of the overall configuration of a display device 10 according to the embodiment of the present disclosure.

[0014] The display device 10 is a device in which light-emitting elements such as OLEDs (Organic Light Emitting Diodes) or Micro-OLEDs are formed in an array. Such a display device 10 can be applied to, for example, VR, MR, or AR display devices, electronic viewfinders (EVFs), or small projectors. The display device 10 can also be applied to various lighting devices. In addition, the display device 10 may be a device that uses light-emitting elements made of inorganic materials instead of organic materials such as OLEDs.

[0015] Furthermore, in the embodiments of this disclosure, the light-emitting element may be a self-emissive element as well as a current-driven electro-optic element. For example, in addition to OLEDs, current-driven electro-optic elements include inorganic EL elements, LED elements, semiconductor laser elements, etc. Furthermore, an organic EL display device using an OLED as the light-emitting element has the following features. Specifically, because the OLED is a self-emissive element, the organic EL display device has higher image visibility compared to liquid crystal display devices, which are also planar display devices, and is easy to make lighter and thinner because it does not require lighting members such as backlights. Moreover, because the response speed of OLED is very fast, on the order of a few microseconds, the organic EL display device does not produce afterimages when displaying moving images.

[0016] Here, as an example, we will explain using an active-matrix organic EL display device that uses a current-driven light-emitting element, such as an OLED, which changes its luminescence depending on the current flowing through the device, as the light-emitting element. In the following, "active-matrix organic EL display device" will simply be referred to as "display device".

[0017] As shown in Figure 1, the display device 10 has a configuration comprising a pixel array section 20 in which a plurality of subpixels 400, including light-emitting elements, are arranged in a matrix-like (two-dimensional) arrangement on a semiconductor substrate (not shown), and a drive circuit section arranged around the pixel array section 20. The drive circuit section includes, for example, a horizontal drive circuit 11 and a vertical drive circuit 12 mounted on the same display panel 40 as the pixel array section 20, and drives each subpixel 400 of the pixel array section 20.

[0018] Here, if the display device 10 is color-compatible, one pixel (unit pixel) that forms a color image is composed of multiple subpixels 400. More specifically, in a color-compatible display device 10, one pixel may be composed of three subpixels 400, for example, a subpixel 400R that emits red light, a subpixel 400G that emits green light, and a subpixel 400B that emits blue light. Furthermore, a pixel may be composed of, for example, one, two, or more subpixels 400, and is not particularly limited. Also, in this embodiment, one pixel is not limited to, for example, a combination of three primary color subpixels 400: red, green, and blue. In this embodiment, for example, one pixel may be composed of three primary color subpixels 400 plus one or more additional subpixels 400. More specifically, the display device 10 may, for example, add a subpixel 400 that emits white light to improve brightness and constitute a single pixel, or add at least one subpixel 400 that emits complementary color light to expand the color reproduction range and constitute a single pixel.

[0019] Furthermore, in this embodiment, a single pixel is not limited to being composed of multiple subpixels 400 that emit different light, as described above, but may be composed of multiple subpixels 400 that emit light of the same color. Here, a pixel means the smallest unit (pixel) that is controlled when controlling the light emission of the display device 10, and is composed of multiple subpixels 400 that are treated as a single unit during control. In other words, in this embodiment, the display device 10 has multiple pixels arranged in a matrix on the display panel 40.

[0020] In detail, the horizontal drive circuit 11 scans each sub-pixel 400 row by row (in Figure 1, the direction extending along the X direction is called the row direction) when writing a signal to each sub-pixel 400, and each scan line SCL ｍ Scanning signals can be supplied sequentially. The horizontal drive circuit 11 can be configured, for example, by a shift register that sequentially shifts (transfers) start pulses in synchronization with the input clock pulse.

[0021] Furthermore, the vertical drive circuit 12 outputs the signal voltage of the signal corresponding to the brightness information supplied from the signal source (not shown) to the signal line DTL. ｎ It can be supplied to selected subpixels 400 in column units (in Figure 1, the direction extending along the Y direction is called the column direction) via this.

[0022] In the embodiments of this disclosure, the configuration of the display device 10 is not limited to the configuration shown in Figure 1. That is, the configuration shown in Figure 1 is merely an example, and the display device 10 according to the embodiments of this disclosure can take various configurations.

[0023] <1.2 Pixels> Next, the circuit configuration of the sub-pixel 400 of the display device 10 according to the embodiment of the present disclosure shown in Figure 1 will be described. Figure 2 is a circuit diagram showing an example of the sub-pixel 400 of the display device 10 according to the embodiment of the present disclosure, and more specifically, it is a schematic circuit diagram for explaining the wiring relationship in the sub-pixel 400 of the mth row and nth column.

[0024] In the display device 10, as previously described, the subpixels 400 including the light-emitting element 100 have scan lines SCLs that extend in the row direction (X direction in Figure 1). ｍ and the signal line DTL extending in the column direction (Y direction in Figure 1) ｎ They are arranged in a two-dimensional matrix while connected to each other.

[0025] Furthermore, as shown in Figure 2, the display device 10 has a power supply line PS1 that supplies a drive voltage to the subpixels 400. ｍ It also has a common power supply line PS2 that is connected to all sub-pixels 400 in common. And power supply line PS1 ｍis supplied with a predetermined driving voltage V from a power supply unit (not shown), and a common voltage V ＣＣ etc. is supplied to the common power supply line PS2, and a common voltage V Ｃａｔ (for example, the ground potential) is supplied.

[0026] Here, let the number of scanning lines SCL and power supply lines PS1 be M each. The sub-pixel 400 in the m-th row (where m = 1, 2,..., P) is connected to the m-th scanning line SCL ｍ , the m-th power supply line PS1 ｍ and constitutes one display element row. In FIG. 2, only the scanning line SCL ｍ and the power supply line PS1 ｍ are shown. Also, let the number of signal lines DTL be N. The sub-pixel 400 in the n-th column (where n = 1, 2,..., N) is connected to the n-th signal line DTL ｎ . In FIG. 2, only the signal line DTL ｎ is shown. Hereinafter, the sub-pixel 400 located at the m-th row and n-th column may be referred to as the (n, m)-th sub-pixel 400.

[0027] And, as described above, the display device 10 is sequentially scanned in row units by the scanning signal from the horizontal drive circuit 11. Specifically, in the display device 10, the M sub-pixels 400 arranged in the m-th row are driven simultaneously. In other words, in the M sub-pixels 400 arranged along the row direction, the light emission / non-light emission timing is controlled in the row units to which they belong. For example, when the display frame rate of the display device 10 is FR (times / second), the scanning period per row (so-called horizontal scanning period) when the display device 10 is sequentially scanned in row units is less than (1 / FR)×(1 / P) seconds.

[0028] Also, as shown in FIG. 2, the sub-pixel 400 is composed of a light emitting element 100 and a drive circuit for driving the same. The light emitting element 100 is composed of an organic electroluminescence light emitting element or an inorganic electroluminescence light emitting element. The drive circuit is composed of a writing transistor TR Ｗ , and a drive transistor TR Ｄ , and a capacitance part C １ . The drive transistor TRＤ When current flows through the light-emitting element 100, the light-emitting element 100 can emit light. Each transistor is composed of, for example, a p-channel type field-effect transistor.

[0029] As shown in Figure 2, in the sub-pixel 400, the drive transistor TR Ｄ One of the source / drain regions is the capacitance section C １ One end and power supply line PS1 ｍ The source / drain region is electrically connected to one end of the light-emitting element 100 (specifically, the anode electrode). Ｄ The gate electrode is the writing transistor TR Ｗ It is connected to the other source / drain region, and the capacitance section C １ It is electrically connected to the other end.

[0030] Also, as shown in Figure 2, the writing transistor TR Ｗ One of the source / drain regions is the signal line DTL ｎ It is electrically connected to the writing transistor TR Ｗ The gate electrode is the scan line SCL ｍ It is electrically connected to it.

[0031] Furthermore, as shown in Figure 2, the other end of the light-emitting element 100 (specifically, the cathode electrode) is electrically connected to the common power supply line PS2. In addition, a predetermined cathode voltage V is supplied to the common power supply line PS2. Ｃａｔ This is supplied. In Figure 2, the capacitance of the light-emitting element 100 is indicated by the code C. ＥＬ It is represented as follows.

[0032] The overview of the driving of the sub-pixel 400 will be described. In the sub-pixel 400, the signal line DTL is transmitted from the vertical drive circuit 12. ｎ With a voltage corresponding to the brightness of the image to be displayed supplied, the writing transistor TR is activated by a scanning signal from the horizontal drive circuit 11. Ｗ When it is in a conductive state, capacitance part C １ A voltage corresponding to the brightness is written to it. (Writing transistor TR) Ｗ After the capacitor is de-conducted, the capacitance part C１ The drive transistor TR operates according to the voltage held in Ｄ When an electric current flows through it, the light-emitting element 100 emits light.

[0033] In the embodiments of this disclosure, the configuration of the drive circuit that controls the light emission of the light-emitting element 100 is not limited to the configuration shown in Figure 2. Therefore, the configuration shown in Figure 2 is merely an example, and various configurations can be taken in the display device 10 according to the embodiments of this disclosure.

[0034] <<2. Background to the Creation of the Embodiments of the Disclosure>> Next, before describing the details of the embodiments of the disclosure, the background to the creation of the embodiments of the disclosure will be explained with reference to Figure 3. Figure 3 is a schematic diagram showing an example of the cross-sectional configuration of a comparative example light-emitting element 100a. Here, the comparative example refers to a light-emitting element 100a that the inventors had been studying before creating the embodiments of the disclosure.

[0035] Incidentally, as explained earlier, the display device 10 described above can display high-quality and high-resolution images, and is therefore used not only in direct-view display devices such as monitors, but also in small display devices such as EVFs and HMDs. In recent years, there has been a strong demand to increase the frontal radiation intensity of light for the display device 10, especially for use in applications such as VR and AR.

[0036] Therefore, in the comparative example, in order to guide light to the front of the display panel 40 of the display device 10 and increase brightness, an on-chip lens 132 having a light collimation (parallelization) function is provided on the light-emitting element 100a, as shown in Figure 3. Specifically, in the light-emitting element 100a of the comparative example, as shown in Figure 3, a reflector 104, a spacer layer 106, a lower electrode 110, a light-emitting layer 112, an upper electrode 114, a spacer layer 120, a color filter 130, and an on-chip lens 132 are sequentially stacked on the substrate 102 in this order. In the comparative example, the on-chip lens 132 causes the light from the light-emitting layer 112 (see Figure 3) to be emitted as collimated light (parallel light) towards the upper front of the light-emitting element 100.

[0037] However, in the comparative example, most of the light emitted by the light-emitting layer 112 does not reach the on-chip lens 132. Furthermore, in the comparative example, although the planar size of the light-emitting layer 112 is minute, it functions as a surface light source with the entire surface emitting light, and because of its close distance to the on-chip lens 132, there were limitations to the collimation (parallelization) of light by the on-chip lens 132. Consequently, in the comparative example, it is difficult to further increase the frontal radiation intensity of the light from the display device 10.

[0038] Furthermore, in such cases, in order to ideally collimate the light, it is conceivable to reduce the area of ​​the light-emitting layer 112 so that the light-emitting layer 112 functions as a point light source. However, in such cases, because the light-emitting layer 112 is made smaller, there is a limit to the voltage or current that can be applied to the light-emitting element 100 from the standpoint of reliability, so the voltage or current will have to be reduced. Consequently, in such cases, the current (electrons, holes) that can be injected into the light-emitting layer 112 will be reduced, and the brightness of the light-emitting element 100 will not necessarily improve. In addition, making the light-emitting layer 112 smaller makes it more difficult to process, and the probability of damage to the light-emitting layer 112 during manufacturing increases. Moreover, making the light-emitting layer 112 smaller makes it more susceptible to damage during operation.

[0039] Therefore, in view of this situation, the inventors have devised a way to generate a point light source without reducing the size of the light-emitting layer 112 by providing a microstructure on the light-emitting element 100 to form a micro-region for extracting light from the light-emitting layer 112. Specifically, the microstructure has a nano-optical structure that is smaller than the wavelength of the light from the light-emitting layer 112, and acts on the light-emitting layer 112 to generate an extremely small light extraction region relative to the area of ​​the light-emitting element 100 (area in a plan view). Specifically, the microstructure may include, for example, a resonator structure that can confine light in a predetermined region and cause the light to resonate (the microstructure can extract light in the resonant mode). Alternatively, the microstructure may include, for example, a waveguide structure that can collect light in a predetermined micro-region (the microstructure can extract light in the scattering mode). In the embodiment of this disclosure devised by the inventors, the micro-region from which light can be extracted, generated by such a microstructure, functions as a point light source. In this embodiment, by positioning such a point light source at the focal point of the on-chip lens 132, the on-chip lens 132 can suitably collimate the light from the point light source.

[0040] Therefore, according to this embodiment, since the function of the on-chip lens 132 can be made to the fullest extent by using a point light source, a large portion of the light emitted from the light-emitting element 100 is emitted towards the upper front of the display panel 40. As a result, the display device 10 according to this embodiment has good radiation directivity and can achieve a higher frontal radiation intensity of light. Furthermore, in this embodiment, if the microstructure has a resonator structure, it is possible to resonate with light of a specific wavelength, thereby increasing the brightness and color purity of the light. In other words, in this embodiment, the luminous efficiency of the light-emitting element 100 can be increased. In addition, in this embodiment, since the light-emitting layer 112 is not made smaller, the probability of damage to the light-emitting layer 112 during manufacturing and operation is low.

[0041] In other words, according to the embodiments of the present disclosure devised by the present inventors, it is possible to provide a display device 10 that can further increase the frontal radiation intensity of light. The details of the embodiments of the present disclosure created by the present inventors will be described in order below.

[0042] <<3. First Embodiment>> <3.1 Detailed Configuration> First, an example of the configuration of the light-emitting element 100 according to the first embodiment of the present disclosure will be described with reference to Figures 4A and 4B. Figure 4A is a schematic diagram showing an example of the cross-sectional configuration of the light-emitting element 100 according to the present embodiment. Figure 4B is a schematic diagram showing an example of the planar configuration of the light-emitting element 100 according to the present embodiment, and in detail shows a cross-section when the light-emitting element 100 is cut along the line B-B' shown in Figure 4A.

[0043] The display device 10 according to this embodiment has a plurality of light-emitting elements 100. More specifically, the plurality of light-emitting elements 100 are arranged in a matrix in a predetermined area on a substrate 102 (see Figure 4A). Each of the light-emitting elements 100 can be, for example, a light-emitting element 100r that emits red (R) light, a light-emitting element 100g that emits green (G) light, and a light-emitting element 100b that emits blue (B) light (see, for example, Figure 14A).

[0044] In the light-emitting element 100 according to this embodiment, as in the comparative example, as shown in Figure 4A, a reflector 104, a spacer layer 106, a lower electrode 110, a light-emitting layer 112, an upper electrode 114, a spacer layer 120, a color filter 130, and an on-chip lens (an example of a lens structure) 132 are sequentially stacked on the substrate 102. Furthermore, in this embodiment, unlike the comparative example, a high refractive index dielectric 200 with a minute size is provided as a microstructure within the spacer layer 106. The details of each element constituting the light-emitting element 100 will be described sequentially below.

[0045] (Substrate 102) The substrate 102 can be formed from a transparent material such as glass or a semiconductor material such as silicon. For example, the drive circuit for driving the light-emitting element 100 may be constructed by appropriately forming transistors, wiring, etc., within the various substrates 102 described above.

[0046] (Reflector 104) The reflector 104 can reflect the light emitted from the light-emitting layer 112, which will be described later, upward toward the light-emitting element 100. The reflector 104 can be made from, for example, aluminum (Al), silver (Ag), copper (Cu), or an alloy thereof.

[0047] (Spacer layer 106) The spacer layer 106 is, for example, silicon nitride (SiN ｘ ), silicon oxide (SiO ｘ ), silicon oxynitride (SiO ｘ N ｙ It can be formed from inorganic insulating materials such as ), or organic resin materials such as acrylic resins or polyimide resins. The spacer layer 106 may also be a single layer or a laminate of the above-mentioned material.

[0048] In the light-emitting element 100, the light from the light-emitting layer 112 is reflected by the reflector 104 located below the light-emitting layer 112, causing the reflected light to radiate upwards from the light-emitting element 100. Furthermore, by optimizing the distance between the reflector 104 and the upper electrode (reflective surface) 114 (satisfying the resonance condition), the light from the light-emitting layer 112 can be made to resonate between the reflector 104 and the upper electrode 114, thereby increasing the intensity of the light. This resonance condition can be satisfied by adjusting the film thickness of the spacer layer 106. In this specification, such a configuration is referred to as a microcavity structure.

[0049] (Lower electrode 110) The lower electrode 110 can be formed from a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0050] (Light-emitting layer 112) The light-emitting layer 112 has a structure in which, for example, a hole injection layer, a hole transport layer, light-emitting layers of each color that emit light of each color, and an electron transport layer are sequentially stacked from bottom to top. The light-emitting layer may be a multilayer structure in which different light-emitting materials that emit light of the same color are stacked, or it may be a multilayer structure in which different light-emitting materials that emit light of different colors are stacked. Note that the stacking order of the light-emitting layer 112 is not limited to the order described above, and may be stacked in an inverted order.

[0051] The hole-injection layer can be composed of, for example, hexaazatriphenylene (HAT).

[0052] The hall transport layer can be composed of, for example, α-NPD[N,N'-di(1-naphthyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine].

[0053] The red light-emitting layer generates red light when an electric field is applied, as some of the holes injected from the lower electrode 110 via the hole injection layer and hole transport layer recombine with some of the electrons injected from the upper electrode 114 via the electron transport layer. The red light-emitting layer includes, for example, at least one of a red light-emitting material, a hole transport material, an electron transport material, and a dual charge transport material. The red light-emitting material may be fluorescent or phosphorescent. Specifically, the red light-emitting layer can be composed of, for example, 4,4-bis(2,2-diphenylbinin)biphenyl (DPVBi) mixed with 30% by weight of 2,6-bis[(4'-methoxydiphenylamino)styryl]-1,5-dicyanonaphthalene (BSN).

[0054] The blue light-emitting layer generates blue light when an electric field is applied, as a portion of the holes injected from the lower electrode 110 via the hole injection layer, hole transport layer, and light emission separation layer recombine with a portion of the electrons injected from the upper electrode 114 via the electron transport layer. The blue light-emitting layer includes, for example, at least one of the following: a blue light-emitting material, a hole transport material, an electron transport material, and a dual charge transport material. The blue light-emitting material may be fluorescent or phosphorescent. Specifically, the blue light-emitting layer can be composed of, for example, a mixture of DPVBi and 2.5% by weight of 4,4'-bis[2-{4-(N,N-diphenylamino)phenyl}vinyl]biphenyl (DPAVBi).

[0055] The green light-emitting layer generates green light when an electric field is applied, as a portion of the holes injected from the lower electrode 110 via the hole injection layer, hole transport layer, and light emission separation layer recombine with a portion of the electrons injected from the upper electrode 114 via the electron transport layer. The green light-emitting layer includes, for example, at least one of the following: a green light-emitting material, a hole transport material, an electron transport material, and a dual charge transport material. The green light-emitting material may be fluorescent or phosphorescent. Specifically, the green light-emitting layer can be composed of, for example, a mixture of DPVBi with 5% by weight of coumarin 6.

[0056] In the above description, the light-emitting layer 112 was described as being made of an organic light-emitting material, but in this embodiment, it is not limited to this. In this embodiment, the light-emitting layer 112 can be formed from an inorganic light-emitting material, a perovskite material, a colloidal quantum dot (QD) material, a quantum well material, or a mixture thereof. In this embodiment, the perovskite material is, for example, ABX ３ The composition can be a metal halide perovskite. For example, here A is cesium (Cs) and a methylamino group (CH ３ NH ３ , HC (NH ２ ) ２) etc., B can be lead (Pb), tin (Sn), etc., and X can be chlorine (Cl), bromine (Br), iodine (I), etc. Furthermore, the perovskite material may be a quantum dot structure, as described later, in addition to the usual bulk structure.

[0057] Furthermore, colloidal quantum dot materials are nanoscale structures with unique optical properties that follow quantum mechanics, and typically have a diameter of several nanometers. Generally, colloidal quantum dot materials allow for adjustment of the band gap by size, thus enabling particle size-dependent optical confinement. Colloidal quantum dot materials have the characteristic of being able to adjust the wavelength of light to be confined by the particle size, and not only do they have a narrow spectral full width at half maximum, but also high quantum efficiency. In detail, a colloidal quantum dot material has, for example, a core and a shell that covers the surface of the core. The core and shell can be formed from, for example, an inorganic compound material. Examples of inorganic compound materials include CdSe, CdS, CdZnSe, CdTe, ZnSe, ZnS, ZnTe, and InP.

[0058] Furthermore, in this embodiment, the light-emitting layer 112 may be a color conversion layer that is excited by incident light from an adjacent layer and emits light of a predetermined color. In this embodiment, for example, a color conversion layer made of colloidal quantum dot material may be placed on the blue light-emitting layer. Also, in this embodiment, the color conversion layer does not have to be sandwiched between the lower electrode 110 and the upper electrode 114.

[0059] Examples of electron transport layers include BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Alq3 (aluminum quinolinol), and Bphen (basophenanthroline). The electron transport layer consists of at least one layer and may include an electron transport layer doped with an alkali metal or alkaline earth metal. An electron transport layer doped with an alkali metal or alkaline earth metal can be constructed by co-depositing, for example, 0.5 to 15% by weight, of an alkali metal such as lithium (Li), sodium (Na), potassium (K), rubidium (Rb), or cesium (Cs), or an alkaline earth metal such as magnesium (Mg), calcium (Ca), strontium (Sr), or barium (Ba), as a host material.

[0060] Furthermore, an electron injection layer may be provided between the electron transport layer and the upper electrode 114. The electron injection layer is for increasing electron injection from the cathode and can be composed of an alkali metal or alkaline earth metal in its elemental form, a compound containing them, or a mixture containing them. For example, the electron injection layer can be composed of lithium (Li) or lithium fluoride (LiF), etc.

[0061] Furthermore, a buffer layer may be provided between the electron transport layer and the upper electrode 114. The buffer layer is intended to mitigate process damage to the light-emitting layer 112 during the deposition of the upper electrode 114. The buffer layer may be made of, for example, magnesium (Mg), magnesium-silver alloy (MgAg), calcium (Ca), lithium (Li), lithium fluoride (LiF), or lithium carbonate (Li ２ CO ３ ), cesium (Cs), cesium carbonate (Cs ２ CO ３ It can be composed of elements of alkali metals or alkaline earth metals, compounds containing them, or mixtures containing them, such as )

[0062] (Upper electrode 114) In this embodiment, if the light-emitting element 100 has the above-mentioned microcavity structure, it is preferable that the upper electrode 114 functions as a semi-transparent reflective film and an electrode. In this case, the upper electrode 114 can be formed using magnesium (Mg), silver (Ag), or a magnesium-silver alloy (MgAg) mainly composed of these, or an alloy containing alkali metals or alkaline earth metals. Alternatively, in this embodiment, the upper electrode 114 may be formed from a transparent conductive material that has good light transmittance to visible light (for example, visible light with wavelengths of about 360 nm to 780 nm) and a small work function. For example, the upper electrode 118 can be formed from a metal film containing at least one of the elements and alloys of metals such as aluminum (Al), magnesium (Mg), calcium (Ca), sodium (Na), and silver (Ag). Specific examples of alloys include aluminum (Al) alloys such as MgAg alloy or AlLi alloy, and silver (Ag) alloys. Furthermore, the upper electrode 114 may be formed from a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), or zinc oxide (ZnO).

[0063] (Spacer layer 120) The spacer layer 120 can be formed from, for example, an inorganic insulating material such as silicon nitride, silicon oxide, or silicon oxynitride, or from an organic resin material such as an acrylic resin or a polyimide resin. The spacer layer 120 may also be a single layer or a laminate of the above-mentioned material. In this embodiment, the spacer layer 120 has the function of positioning the on-chip lens 132 appropriately and protecting the light-emitting layer 112 below it.

[0064] (Color filter 130) The color filter 130 can be formed from, for example, a color filter that transmits red wavelength components, a color filter that transmits green wavelength components, or a color filter that transmits blue wavelength components. The color filter 130 can be formed from, for example, a material in which a pigment or dye is dispersed in a transparent binder such as silicone. In this embodiment, the color filter 130 may not be provided.

[0065] (On-chip lens 132) The on-chip lens 132 can be formed from, for example, a styrene resin, an acrylic resin, a styrene-acrylic copolymer resin, or a siloxane resin. The on-chip lens 132 can emit light from a point light source produced by the high refractive index dielectric 200 (described later) as collimated light, either directly above or diagonally above the light-emitting element 100, that is, in a desired direction. Furthermore, in this embodiment, the on-chip lens 132 is not limited to being provided on the color filter 130 (or spacer layer 120), but may be provided on, for example, another substrate (not shown) located several μm above the color filter 130.

[0066] In this embodiment, the lens structure is not limited to the on-chip lens 132, but any lens structure capable of guiding light from a point light source in a predetermined direction is acceptable. Examples of such lens structures include metasurfaces and waveguides. Here, a metasurface refers to a structure in which structures smaller than the wavelength of light are periodically arranged in two dimensions, and can be formed from, for example, metal or dielectric material. Furthermore, when using a metasurface, it is not limited to being provided for each light-emitting element 100 (sub-pixel 400), but may be provided so as to span multiple light-emitting elements 100.

[0067] (High-Refractive Index Dielectric 200) In this embodiment, the high-refractive index dielectric 200 functions as a microstructure that creates a point light source by extracting light emitted from the light-emitting layer 112 from a predetermined minute region. Specifically, a portion of the light energy generated in the light-emitting layer 112 propagates as propagating light, moving upward or downward (vertically) from the light-emitting element 100. The propagating light that travels downward is reflected by the reflector 104 and reaches the on-chip lens 132. However, a portion of the remaining light energy generated in the light-emitting layer 112 has a different mode from the propagating light, propagates laterally, and may be lost as thermal energy. Therefore, in this embodiment, the high-refractive index dielectric 200, which has a minute size smaller than the wavelength of the light from the light-emitting layer 112, can act on the light energy of the different mode and extract that light energy as propagating light. Furthermore, such a high-refractive index dielectric 200 can generate a minute light extraction point (minute region) with very high brightness and color purity. In other words, the high-refractive index dielectric 200 can function as a microstructure that creates a point light source. In this embodiment, the microstructure that creates the point light source is not limited to a rectangular high-refractive-index dielectric 200 made of a high-refractive-index dielectric material, but may also be, for example, a polygonal high-refractive-index dielectric, a rectangular or polygonal metal body made of a metal material, nanometal particles, a metal nanostructure, etc.

[0068] Furthermore, in this embodiment, various configurations can be used as the microstructure, even if they are mechanisms different from those described above, as long as they are configured to extract light from a micro-region. For example, the microstructure may be a waveguide structure that guides light from the light-emitting layer 112 to a micro-region and extracts it from that micro-region (e.g., a nanogap). More specifically, the microstructure may be a layer having a high refractive index relative to the upper and lower layers, and the layer may function as a slab to guide light to a micro-region and extract light from that micro-region. Alternatively, in this embodiment, the microstructure may be, for example, a photonic crystal structure having a periodic structure. In this case, the photonic crystal structure has defects (resonator structures) with disordered periodicity, and by confining and resonating light of a predetermined wavelength in the defects, it is possible to generate a tiny light extraction point (micro-region) with very high brightness and color purity. Details of an embodiment using a photonic crystal structure will be described later as a second embodiment of this disclosure.

[0069] Furthermore, in this embodiment, as shown in Figure 4A, the high refractive index dielectric 200 is provided within the spacer 106 layer. In this embodiment, the microstructure may be stacked above or below the light-emitting layer 112, or provided within the light-emitting layer 112. In addition, in this embodiment, it is preferable that the distance of the microstructure from the light-emitting layer 112 be within approximately one wavelength of light from the light-emitting layer 112. Details of the layer on which the microstructure is provided will be described later as a modification of this embodiment.

[0070] Furthermore, in this embodiment, as shown in Figure 4B, the high refractive index dielectric 200 is very small in size relative to the light-emitting element 100. Specifically, the high refractive index dielectric 200 is, for example, rectangular in shape, with sides shorter than the wavelength of light emitted from the light-emitting layer 112. The high refractive index dielectric 200 generates a minute region 300 from which light can be extracted. In this embodiment, the minute region 300 refers to a region from which 80% or more of the light with the highest intensity peak wavelength in the spectrum of the components of light emitted by the light-emitting layer 112 that are effectively utilized can be extracted. Effectively, the size of the high-brightness spot observed when the light emission of the light-emitting element 100 is observed under a microscope serves as an indicator of the minute region 300. In this embodiment, it is preferable that the size of the minute region 300 is less than 50% of the planar area of ​​the light-emitting element 100.

[0071] In addition, in this embodiment, it is preferable to position the on-chip lens 132 such that the focal point of the on-chip lens 132 coincides with the position of the center O of the minute region 300 in order to radiate light as collimated light in front of the light-emitting element 100. More specifically, in this embodiment, for example as shown in Figure 4B, the on-chip lens 132 is provided such that the center O of the minute region 300 coincides with the center of the on-chip lens 132 when the light-emitting element 100 is viewed from above. Furthermore, in the example of Figure 4B, the position of the center O of the minute region 300 coincides with the position of the center of the high refractive index dielectric 200, which is a microstructure.

[0072] In this embodiment, the high refractive index dielectric 200, which is a microstructure, extracts most of the light from the light-emitting layer 112 from a micro-region 300, thereby creating a minute point light source. Furthermore, in this embodiment, the on-chip lens 132, which is a lens structure, can efficiently guide the light from such a point light source as collimated light to the upper front of the light-emitting element 100.

[0073] As described above, in this embodiment, the function of the on-chip lens 132 can be maximized by the point light source created by the high refractive index dielectric 200, so that much of the light emitted from the light-emitting element 100 is emitted upward in front of the display panel 40. Therefore, the display device 10 according to this embodiment has good radiation directivity and can achieve a higher frontal radiation intensity of light. In other words, in this embodiment, the luminous efficiency of the light-emitting element 100 can be increased. Furthermore, in this embodiment, the size of the light-emitting layer 112 is not reduced, so the likelihood of damage to the light-emitting layer 112 during manufacturing and operation is low.

[0074] In this embodiment, the light-emitting element 100 is not limited to the form shown in Figures 4A and 4B, but can take on various forms.

[0075] In this embodiment, for example, a reflective layer (not shown) or a side wall (not shown) may be provided between adjacent light-emitting elements 100. By doing so, it is possible to suppress light leakage to the adjacent light-emitting element 100, thereby avoiding light loss and color mixing.

[0076] <3.2 Modifications> (Modification 1) Next, Modification 1 of this embodiment will be described with reference to Figure 5. Figure 5 is a schematic diagram showing an example of the planar configuration of the light-emitting element 100 according to Modification 1 of this embodiment.

[0077] In this modified example, the microstructure may be, for example, a triangular metal body 200a as shown on the left side of Figure 5. In this case, a micro-region 300 from which light is extracted is generated surrounding the vertices of the metal body 200a, and the center of the microstructure (metal body 200a) and the center O of the micro-region 300 do not coincide, that is, their positions are different. In such a case, it is preferable to provide the on-chip lens 132 such that the position of the center O of the micro-region 300 coincides with the position of the on-chip lens 132. By providing the on-chip lens 132 in this way, the on-chip lens 132 can guide the light from the micro-region 300, which is a point light source, as collimated light to the upper front of the light-emitting element 100.

[0078] Furthermore, in this modified example, the microstructure may be, for example, two trapezoidal metal bodies 200b as shown on the right side of Figure 5. In this case, a micro-region 300 from which light is extracted is generated so as to surround the center between the two metal bodies 200b. Even in this case, it is preferable to provide the on-chip lens 132 such that the position of the center O of the micro-region 300 coincides with the position of the center of the on-chip lens 132. By providing the on-chip lens 132 in this way, the on-chip lens 132 can guide the light from the micro-region 300, which is a point light source, as collimated light to the upper front of the light-emitting element 100.

[0079] In this modified example, as shown on the right side of Figure 5, there may be multiple microstructures (metal body 200b in the example shown), and there may also be multiple microregions 300 from which light is extracted. Furthermore, in this modified example, if there are multiple microregions 300, multiple on-chip lenses 132 may be provided according to their respective positions, or a metasurface may be designed.

[0080] (Modification 2) Next, modification 2 of this embodiment will be described with reference to Figure 6. Figure 6 is a schematic diagram showing an example of the planar configuration of the light-emitting element 100 according to modification 1 of this embodiment.

[0081] In this modified example, as shown in Figure 6, the high refractive index dielectric 200 does not have to be located at the center of the light-emitting element 100; that is, the center Oa of the minute region 300 does not have to be located at the center of the light-emitting element 100. Also, in this modified example, the position of the center Ob of the on-chip lens 132 does not have to coincide with the position of the center Oa of the minute region 300. In this modified example, for example, the position of the center Oa of the minute region 300 and the position of the center Ob of the on-chip lens 132 may be shifted from the center of the light-emitting element 100 depending on the position of the light-emitting element 100 on the display panel 40 of the display device 10. In this modified example, by doing so, the light from the light-emitting layer 112 may be guided diagonally rather than directly above the light-emitting element 100, thereby focusing the light onto the center of the display panel 40.

[0082] (Modification 3) Next, modification 3 of this embodiment will be described with reference to Figures 7A to 7C. Figures 7A to 7C are schematic diagrams showing an example of the cross-sectional configuration of the light-emitting element 100 according to modification 3 of this embodiment.

[0083] In this modified example, the microstructure is not limited to being provided on the spacer layer 106, but may be provided on any of the lower electrode 110, light-emitting layer 112, upper electrode 114, spacer layer 120, and color filter 130 of the light-emitting element 100. More specifically, in this modified example, as shown in Figures 7A to 7C, the high refractive index dielectric 200, which is an example of a microstructure, may be provided on any of the lower electrode 110, light-emitting layer 112, upper electrode 114, spacer layer 120, and color filter 130. By doing so, in this modified example, the microstructure can be provided inside the light-emitting layer 112 or near the light-emitting layer 112, allowing the microstructure to act suitably on the light from the light-emitting layer 112 and facilitating the manufacture of the light-emitting element 100.

[0084] (Modification 4) Next, Modification 4 of this embodiment will be described with reference to Figures 8A and 8B. Figures 8A and 8B are schematic diagrams showing an example of the cross-sectional configuration of the light-emitting element 100 according to Modification 4 of this embodiment.

[0085] In this modified example, as shown in Figure 8A, the high refractive index dielectric 200, which is an example of a microstructure, may be provided in contact with the interface between the layer on which the high refractive index dielectric 200 is provided and other layers. Also, in this modified example, as shown in Figure 8B, the high refractive index dielectric 200, which is an example of a microstructure, may be provided so as to penetrate one layer, or it may be provided so as to span multiple layers. By doing so, according to this modified example, the microstructure can act suitably on the light of the light-emitting layer 112, and the manufacturing of the light-emitting element 100 can be facilitated.

[0086] <<4. Second Embodiment>> <4.1 Detailed Configuration> Next, an example of the configuration of the light-emitting element 100 according to the second embodiment of the present disclosure will be described with reference to Figures 9A and 9B. Figure 9A is a schematic diagram showing an example of the cross-sectional configuration of the light-emitting element 100 according to the present embodiment. Figure 9B is a schematic diagram showing an example of the planar configuration of the light-emitting element 100 according to the present embodiment, and in detail shows a cross-section when the light-emitting element 100 is cut along the line B-B' shown in Figure 9A.

[0087] In this embodiment, as shown in Figures 9A and 9B, a photonic crystal structure 250 with defects is used as a microstructure. A photonic crystal structure is an artificial crystal with a nanoperiodic structure in which materials with different refractive indices are arranged at intervals approximately equal to the wavelength of light, and can confine light of a desired wavelength. Specifically, as shown in Figure 9B, the photonic crystal structure 250 has a plurality of pores 264 with nanoscale diameters arranged periodically. The pores 264 may be voids, or they may be filled with materials that have a different refractive index than the surrounding material. Furthermore, in this embodiment, as shown in Figure 9B, the photonic crystal structure 250 has defects 260 introduced where the periodic arrangement of the pores 264 is disrupted, that is, where there are no pores 264. For example, the defects 260 are spaces approximately the length of the wavelength of light from the light-emitting layer 112. In this embodiment, light with a predetermined wavelength corresponding to the periodic structure of the photonic crystal structure is confined and resonates at the locations of the minute defects 260. In the example shown in the figure, the minute region 300 from which light can be extracted coincides with the location of the defect 260. That is, in this embodiment, the photonic crystal structure 250 includes a resonator structure that can strongly confine light and functions as the minute region 300 from which light can be extracted.

[0088] Therefore, in this embodiment, the photonic crystal structure 250 can confine and extract light with a specific wavelength in a minute region 300, thereby generating a point light source. Furthermore, in this embodiment, the photonic crystal structure 250, which includes a resonator structure, can resonate light with a specific wavelength in the minute region 300, thereby increasing the brightness and color purity of the light. In other words, in this embodiment, the luminescence efficiency of the light-emitting element 100 can be further increased.

[0089] In this embodiment, the microstructure is not limited to a photonic crystal structure 250 with defects, as shown in Figures 9A and 9B. In this embodiment, for example, the photonic crystal structure 250 may include periodic structural disorder by changing the size, spacing, and shape of some of the unit structures within the photonic crystal structure 250. Alternatively, in this embodiment, the microstructure may be a photonic crystal structure 250 that includes multiple periodic structural disorder. Furthermore, in this embodiment, the microstructure may include a waveguide that guides and confines light to a predetermined micro-region 300. Also, in this embodiment, the microstructure may guide light in multiple different directions and may have different emission modes for each wavelength. Even in such cases, by suitably designing and arranging the on-chip lens 132, the on-chip lens 132 can guide light in the desired direction.

[0090] In this embodiment, depending on the structure of the photonic crystal structure 250, the location of the minute region 300 from which light can be extracted may overlap with the location of the defect 260. Even in this case, in this embodiment, by suitably designing and arranging the on-chip lens 132, the on-chip lens 132 can guide the light in the desired direction.

[0091] Furthermore, in this embodiment, the photonic crystal structure 250 may be designed such that the spectral half-width of the resonance peak of the light obtained from the resonant structure is significantly narrower than the emission spectrum from the light-emitting layer 112, thereby reducing aberrations to the on-chip lens 132.

[0092] Furthermore, in this embodiment, it is preferable to increase the Q value of the resonator structure. In the photonic crystal structure 250 in this embodiment, by introducing defects into the photonic crystal, light can resonate within a very small mode volume (V). Specifically, since the lattice density in the optical resonator is proportional to Q / V, by making the volume V of the resonator structure small and increasing the Q value, light can be confined in a small region at an extremely high density for a long time, and therefore the speed and intensity of emission can be increased by the Purcell effect. Accordingly, in this embodiment, by including such a resonator structure in the photonic crystal structure 250, the direction of light propagation can be controlled and the brightness and color purity of the light can be increased. Also, if the spectral linewidth of the resonant mode determined by the Q value is lower than the spectral linewidth of the material (typically 20 to 50 nm), the Purcell effect may saturate, but even in such cases, the effect of increasing color purity is increased. On the other hand, in such cases, self-absorption and speckle noise of the material tend to become more apparent. Therefore, in regions where the spectral linewidth of the resonant mode is lower than the spectral linewidth of the material, it is preferable to design with attention to the balance of each parameter.

[0093] As described above, in this embodiment, the point light source created by the photonic crystal structure 250 makes the most of the function of the on-chip lens 132, so that much of the light emitted from the light-emitting element 100 is emitted towards the upper front of the display panel 40. Therefore, the display device 10 according to this embodiment has good radiation directivity and can achieve a higher frontal radiation intensity of light. Furthermore, in this embodiment, since the photonic crystal structure 250 has a resonator structure, it can resonate with light of a specific wavelength, and therefore the brightness and color purity of the light can be increased. In other words, in this embodiment, the luminous efficiency of the light-emitting element 100 can be increased. In addition, in this embodiment, the size of the light-emitting layer 112 is not reduced, so the probability of damage to the light-emitting layer 112 during manufacturing and operation is low.

[0094] In this embodiment, the light-emitting element 100 is not limited to the form shown in Figures 9A and 9B, but can take on various forms.

[0095] <4.2 Modifications> (Modification 1) Next, Modification 1 of this embodiment will be described with reference to Figure 10. Figure 10 is a schematic diagram showing an example of the planar configuration of the light-emitting element 100 according to Modification 1 of this embodiment.

[0096] In this modified example, as shown in Figure 10, the photonic crystal structure 250 may have other defects 262 in addition to the defect 260 that becomes the minute region 300 from which light is extracted. Such other defects 262 can function as waveguides, for example, as shown on the left side of Figure 10, and guide light to the defect 260 that becomes the minute region 300. Alternatively, such other defects 262 can become resonators that couple with the defect 260 that becomes the minute region 300, for example, as shown on the right side of Figure 10. In the example shown on the right side of Figure 10, although the other defects 262 become resonators that couple with the defect 260 that becomes the minute region 300, the energy amplified there propagates to the defect 260 that becomes the minute region 300, and therefore does not become a minute region 300 from which light can be extracted.

[0097] (Modification 2) Next, Modification 2 of this embodiment will be described with reference to Figures 11A and 11B. Figures 11A and 11B are schematic diagrams showing an example of the cross-sectional configuration of the light-emitting element 100 according to Modification 2 of this embodiment.

[0098] In this modified example, the photonic crystal structure 250, which is an example of a microstructure, is not limited to being provided on the spacer layer 106. More specifically, in this modified example, as shown in Figures 11A and 11B, the photonic crystal structure 250 may be provided on any of the lower electrode 110, the light-emitting layer 112, the upper electrode 114, and the spacer layer 120. According to this modified example, by providing the photonic crystal structure 250 in or near the light-emitting layer 112, the photonic crystal structure 250 can act suitably on the light from the light-emitting layer 112. Furthermore, according to this modified example, the manufacturing of the light-emitting element 100 can be facilitated.

[0099] (Modification 3) Next, Modification 3 of this embodiment will be described with reference to Figures 12A and 12B. Figures 12A and 12B are schematic diagrams showing an example of the cross-sectional configuration of the light-emitting element 100 according to Modification 3 of this embodiment.

[0100] In this modified example, as shown in Figure 12A, the photonic crystal structure 250, which is an example of a microstructure, may be provided in contact with the interface between the layer on which the photonic crystal structure 250 is provided and other layers. Also in this modified example, as shown in Figure 12B, the photonic crystal structure 250 may be provided so as to penetrate one layer, or it may be provided so as to span multiple layers. By doing so, this modified example allows the photonic crystal structure 250 to act suitably on the light of the light-emitting layer 112, and facilitates the manufacture of the light-emitting element 100.

[0101] <<5. Third Embodiment>> Next, an example of the configuration of the light-emitting element 100 according to the third embodiment of the present disclosure will be described with reference to Figures 13A to 13C. Figures 13A to 13C are schematic diagrams showing an example of the cross-sectional configuration of the light-emitting element 100 according to the present embodiment.

[0102] In this embodiment, as shown in Figure 13A, if the position of the center of the minute region 300 from which light can be extracted (in this example, also the center of the high refractive index dielectric 200, which is a microstructure) coincides with the position of the center of the on-chip lens 132, the central axis A passing through the center O of the minute region 300 may be offset from the center of the light-emitting layer 112. In this embodiment, since light is extracted from the minute region 300 offset from the center of the light-emitting layer 112, the on-chip lens 132 can guide the light from the minute region 300, which is a point light source, as collimated light to the upper front of the light-emitting element 100.

[0103] Furthermore, in this embodiment, as shown in Figure 13B, the central axis Aa passing through the center Oa of the minute region 300 and the central axis Ab passing through the center Ob of the on-chip lens 132 may be misaligned. In this embodiment, by doing so, the on-chip lens 132 can guide the light from the minute region 300 to the light-emitting element 100 in an oblique direction.

[0104] Furthermore, in this embodiment, as shown in Figure 13C, the central axis A passing through the center of the microstructure (in this example, the high refractive index dielectric 200) may be offset from the center of the lower electrode 110 and the light-emitting layer 112 into which the current or holes are injected. Even in this case, the microstructure can generate a micro-region 300 from which light can be extracted. In this embodiment, by doing so, the density of electrons or holes injected into the light-emitting layer 112 can be increased, thereby enabling the light-emitting element 100 to emit light efficiently.

[0105] In other words, in this embodiment, since the microstructure can concentrate light from the microregion 300, the light-emitting layer 112 may emit light over a wider area than the microregion 300. Also, in this embodiment, since the microstructure can concentrate light to the microregion 300, the light-emitting layer 112 may emit light at a position different from the microregion 300.

[0106] In detail, the light-emitting region of the light-emitting layer 112 can be defined by the lower electrode 110 and the upper electrode 114, for example, because it is determined by the region in which electrons and holes are injected. Alternatively, it can be defined by the concentration of impurities in the adjacent layers of the light-emitting layer 112.

[0107] In this embodiment, the light-emitting element 100 is not limited to the form shown in Figures 13A to 13C, but can take on various forms.

[0108] <<6. Fourth Embodiment>> Next, an example of the configuration of the light-emitting element 100 according to the fourth embodiment of the present disclosure will be described with reference to Figures 14A to 14C. Figures 14A to 14C are schematic diagrams showing an example of the cross-sectional configuration of the light-emitting element 100 according to the present embodiment.

[0109] In this embodiment, as shown in Figure 14A, we consider an example in which three types of light-emitting elements 100 are included: a light-emitting element 100r that emits red (R) light, a light-emitting element 100g that emits green (G) light, and a light-emitting element 100b that emits blue (B) light. However, in this embodiment, it is not limited to including such three types of light-emitting elements 100; it is sufficient to include two or more different types of light-emitting elements 100. Furthermore, in this embodiment, the color of the light emitted by the light-emitting elements 100 is not limited to red, blue, or green.

[0110] In this embodiment, as shown in Figure 14A, the light-emitting elements 100b, 100g, and 100r may also be provided with similar microstructures (high refractive index dielectrics 200 in this example).

[0111] Furthermore, in this embodiment, as shown in Figure 14B, the thickness of the layer (spacer layer 120 in this example) may be changed for each color (wavelength) of light emitted by each light-emitting element 100. Since the focal position of the lens structure (on-chip lens 132 in this example) differs for each wavelength of light, by adjusting the thickness of the layer, the position of the point light source (micro-region 300) made of the high refractive index dielectric 200 can be adjusted to match the focal position of the on-chip lens 132.

[0112] Furthermore, in this embodiment, as shown in Figure 14C, the position of the microstructure (high refractive index dielectric 200 in this example) may be changed for each color (wavelength) of light emitted by each light-emitting element 100. Since the focal position of the lens structure (on-chip lens 132 in this example) differs for each wavelength of light, by adjusting the position of the high refractive index dielectric 200, the position of the point light source (micro-region 300) created by the high refractive index dielectric 200 can be adjusted to match the focal position of the on-chip lens 132.

[0113] In this embodiment, the light-emitting element 100 is not limited to the form shown in Figures 14A to 14C, but can take on various forms.

[0114] <<7. Summary>> As described above, in each embodiment of this disclosure, the function of the on-chip lens 132 can be made to the fullest extent by the point light source created by the microstructure, so that a large portion of the light emitted from the light-emitting element 100 is emitted towards the upper front of the display panel 40. Therefore, the display device 10 according to this embodiment has good radiation directivity and can achieve a higher frontal radiation intensity of light. In other words, in this embodiment, the luminous efficiency of the light-emitting element 100 can be increased. Furthermore, in this embodiment, the light-emitting layer 112 is not made smaller, so the probability of damage to the light-emitting layer 112 during manufacturing and operation is low.

[0115] Furthermore, the embodiments of this disclosure are not limited to those shown in the figures, and can be modified in various ways and combined with each other.

[0116] Furthermore, the display device 10 according to the embodiment of this disclosure can be applied to, for example, display devices for VR (Virtual Reality), MR (Mixed Reality), or AR (Augmented Reality), display devices for smartphones, television equipment, electronic viewfinders (EVF), or small projectors, as will be described later. The display device 10 can also be applied to various lighting devices.

[0117] Furthermore, the light-emitting element 100 according to the embodiment of this disclosure can be manufactured using methods, apparatus, and conditions commonly used in the manufacture of semiconductor devices. In other words, the light-emitting element 100 according to this embodiment can be manufactured using existing semiconductor device manufacturing methods.

[0118] Examples of the methods mentioned above include the PVD (Physical Vapor Deposition) method, the CVD (Chemical Vapor Deposition) method, and the ALD (Atomic Layer Deposition) method. Examples of PVD methods include vacuum deposition, electron beam (EB) deposition, various sputtering methods (magnetron sputtering, RF (Radio Frequency)-DC (Direct Current) coupled bias sputtering, ECR (Electron Cyclotron Resonance) sputtering, counter-target sputtering, high-frequency sputtering, etc.), ion plating, laser ablation, molecular beam epitaxy (MBE (Molecular Beam Epitaxy)), and laser transfer. Examples of CVD methods include plasma CVD, thermal CVD, metal-organic (MO) CVD, and optical CVD. Furthermore, other methods include electrolytic plating, electroless plating, spin coating, immersion, casting, microcontact printing, drop casting, various printing methods such as screen printing, inkjet printing, offset printing, gravure printing, and flexographic printing, as well as stamping, spraying, air doctor coater, blade coater, rod coater, knife coater, squeeze coater, reverse roll coater, transfer roll coater, gravure coater, kiss coater, cast coater, spray coater, slit orifice coater, and calender coater. In addition, patterning methods include chemical etching such as shadow masks, laser transfer, and photolithography, as well as physical etching using ultraviolet light or lasers. Furthermore, planarization techniques include CMP (Chemical Mechanical Polishing), laser planarization, and reflow.

[0119] <<8. Modifications>> <8.1 Modification 1> Next, as a modification of the embodiment of the present disclosure, a modification concerning the relationship between the normal LN passing through the center of the light-emitting element 100, the normal LN' passing through the center of the lens structure (for example, the on-chip lens 132 provided on the light-emitting element 100), and the normal LN" passing through the center of the wavelength selection unit (for example, the color filter 130 provided on the light-emitting element 100) will be described with reference to Figures 15A to 15G. Figures 15A to 15G are conceptual diagrams for explaining the relationship between the normal LN passing through the center of the light-emitting part, the normal LN' passing through the center of the lens member, and the normal LN" passing through the center of the wavelength selection unit. In the following description, "center of the light-emitting part" corresponds to the center of the minute region 300 from which light can be extracted in the embodiment of the present disclosure described above.

[0120] In embodiments of this disclosure, the size of the wavelength selection area may be appropriately changed in accordance with the light emitted by the light-emitting element 100. Furthermore, if a light-absorbing layer (black matrix layer) is provided between the wavelength selection area of ​​an adjacent light-emitting element 100, the size of the light-absorbing layer (black matrix layer) may be appropriately changed in accordance with the light emitted by the light-emitting element 100. In addition, the size of the wavelength selection area may be determined by the distance (offset amount) d between the normal passing through the center of the light-emitting element 100 and the normal passing through the center of the wavelength selection area. ０ Depending on the circumstances, it may be changed as appropriate. The planar shape of the wavelength selection section may be the same as, similar to, or different from the planar shape of the lens element.

[0121] For example, as shown in Figure 15A, the normal vector LN passing through the center of the light-emitting part, the normal vector LN'' passing through the center of the wavelength selection part, and the normal vector LN' passing through the center of the lens member may be made to coincide. In other words, the distance (offset amount) D between the normal vector passing through the center of the light-emitting part and the normal vector passing through the center of the lens member. ０ The distance (offset amount) d between the normal vector passing through the center of the light-emitting part and the normal vector passing through the center of the wavelength-selecting part. ０ This is equivalent to 0 (zero).

[0122] Furthermore, for example, as shown in Figure 15B, the normal vector LN passing through the center of the light-emitting part and the normal vector LN'' passing through the center of the wavelength-selecting part coincide, but the normal vector LN passing through the center of the light-emitting part and the normal vector LN'' passing through the center of the wavelength-selecting part do not have to coincide with the normal vector LN' passing through the center of the lens member. In other words, D ０ ≠d ０ It may also be equal to 0.

[0123] Furthermore, for example, as shown in Figure 15C, the normal vector LN passing through the center of the light-emitting part, the normal vector LN'' passing through the center of the wavelength-selecting part, and the normal vector LN' passing through the center of the lens member do not coincide, but the normal vector LN'' passing through the center of the wavelength-selecting part and the normal vector LN' passing through the center of the lens member may coincide. In other words, D ０ = d ０ It can also be 0.

[0124] Furthermore, as shown in Figure 15D, for example, the normal vector LN passing through the center of the light-emitting part, the normal vector LN'' passing through the center of the wavelength-selecting part, and the normal vector LN' passing through the center of the lens member do not coincide, and the normal vector LN' passing through the center of the lens member does not coincide with the normal vector LN passing through the center of the surface of the light-emitting part and the normal vector LN'' passing through the center of the wavelength-selecting part. Here, it is preferable that the center of the wavelength-selecting part (shown as a black circle in Figure 15D) is located on a straight line LL connecting the center of the surface of the light-emitting part and the center of the lens member (shown as a black circle in Figure 15D). Specifically, the distance from the center of the surface of the light-emitting part in the thickness direction to the center of the wavelength-selecting part is LL. １ The distance from the center of the wavelength selection area in the thickness direction to the center of the lens material is LL ２ In that case, D ０ >d ０ > 0, and considering manufacturing variations, d ０ : D ０ =LL １ : (LL １ +LL ２ It is preferable that the following conditions be met.

[0125] Furthermore, the stacking relationship between the wavelength selection unit and the lens member may be reversed. In such a case, for example, as shown in Figure 15E, the normal vector LN passing through the center of the light-emitting unit, the normal vector LN'' passing through the center of the wavelength selection unit, and the normal vector LN' passing through the center of the lens member may be made to coincide. In other words, D ０ = d ０ It may also be equal to 0.

[0126] Furthermore, for example, as shown in Figure 15F, the normal vector LN passing through the center of the light-emitting part, the normal vector LN'' passing through the center of the wavelength-selecting part, and the normal vector LN' passing through the center of the lens member do not coincide, but the normal vector LN'' passing through the center of the wavelength-selecting part and the normal vector LN' passing through the center of the lens member may coincide. In other words, D ０ = d ０ It can also be 0.

[0127] Furthermore, as shown in the conceptual diagram Figure 15G, the normal vector LN passing through the center of the surface of the light-emitting part, the normal vector LN'' passing through the center of the wavelength-selecting part, and the normal vector LN' passing through the center of the lens member do not coincide, and the normal vector LN' passing through the center of the lens member does not coincide with the normal vector LN passing through the center of the surface of the light-emitting part and the normal vector LN'' passing through the center of the wavelength-selecting part. Here, it is preferable that the center of the wavelength-selecting part is located on the straight line LL connecting the center of the surface of the light-emitting part and the center of the lens member. Specifically, the distance from the center of the surface of the light-emitting part in the thickness direction to the center of the wavelength-selecting part (shown as a black circle in Figure 15G) is LL. １ The distance from the center of the wavelength selection area in the thickness direction to the center of the lens member (shown as a black circle in Figure 15G) is LL ２ When that happens, d ０ >D ０ > 0, and considering manufacturing variations, D ０ :d ０ =LL ２ : (LL １ +LL ２ It is preferable that the following conditions be met.

[0128] <8.2 Modification 2> The subpixel 1100 (more specifically, the light-emitting element 100) used in the display device 10 according to the embodiment of the present disclosure described above may be configured to have a resonator structure that resonates the light generated in the light-emitting layer 112. However, the resonator structure in this Modification 2 refers to a structure that performs one-dimensional confinement in the stacking direction (vertical direction) of the light-emitting element 100, rather than a light extraction structure (microstructure) that utilizes the resonance mode in the embodiment of the present disclosure. The resonator structure will be described below with reference to Figures 16 to 22. Figure 16 is a schematic cross-sectional view illustrating a first example of the resonator structure, Figure 17 is a schematic cross-sectional view illustrating a second example of the resonator structure, and Figure 18 is a schematic cross-sectional view illustrating a third example of the resonator structure. Furthermore, Figure 19 is a schematic cross-sectional view illustrating a fourth example of the resonator structure, and Figure 20 is a schematic cross-sectional view illustrating a fifth example of the resonator structure. Furthermore, Figure 21 is a schematic cross-sectional view illustrating a sixth example of the resonator structure, and Figure 22 is a schematic cross-sectional view illustrating a seventh example of the resonator structure. In these figures, the letters attached to each reference numeral indicate the corresponding color; specifically, "B" indicates blue, "G" indicates green, and "R" indicates red.

[0129] (Resonator Structure: First Example) Figure 16 is a schematic cross-sectional view illustrating the first example of a resonator structure. In the first example, the first electrode (specifically, the lower electrode 110) 1202 is formed with a common film thickness in each subpixel 1100. The same applies to the second electrode (specifically, the upper electrode 114) 1206.

[0130] As shown in Figure 16, a reflector (specifically, a reflector 104) 1401 is placed below the first electrode 1202 of the subpixel 1100, with an optical adjustment layer (specifically, a spacer layer 106) 1402 in between. A resonator structure is formed between the reflector 1401 and the second electrode 1206, which resonates the light generated by the organic layer (specifically, a light-emitting layer 112) 1204.

[0131] The reflector 1401 is formed with a common film thickness for each subpixel 1100. The film thickness of the optical adjustment layer 1402 differs depending on the color that the subpixel 1100 is to display. By having optical adjustment layers 1402R, 1402G, and 1402B with different film thicknesses, it is possible to set the optical distance that produces the optimal resonance for the wavelength of light corresponding to the color to be displayed.

[0132] In the example shown in Figure 16, the upper surfaces of the reflectors 1401 for subpixels 1100R, 1100G, and 1100B are aligned. As described above, the thickness of the optical adjustment layer 1402 differs depending on the color that the subpixel 1100 should display, so the position of the upper surface of the second electrode 1206 differs depending on the type of subpixel 1100R, 1100G, and 1100B.

[0133] The reflector 1401 can be formed using, for example, a metal such as aluminum (Al), silver (Ag), or copper (Cu), or an alloy mainly composed of these metals.

[0134] The optical adjustment layer 1402 is made of silicon nitride (SiN ｘ ), silicon oxide (SiO ｘ ), silicon oxynitride (SiO ｘ N ｙ It can be constructed using inorganic insulating materials such as ) or organic resin materials such as acrylic resins or polyimide resins. The optical adjustment layer 1402 may be a single layer or a laminated film of multiple materials. Also, the number of layers may differ depending on the type of subpixel 1100.

[0135] The first electrode 1202 can be formed using a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), or zinc oxide (ZnO).

[0136] The second electrode 1206 preferably functions as a semi-transparent reflective film. The second electrode 1206 can be formed using magnesium (Mg), silver (Ag), or a magnesium-silver alloy (MgAg) mainly composed of these, or an alloy containing alkali metals or alkaline earth metals.

[0137] (Resonator structure: Second example) Figure 17 is a schematic cross-sectional view illustrating a second example of the resonator structure. In this second example as well, the first electrode 1202 and the second electrode 1206 are formed with a common film thickness in each subpixel 1100.

[0138] In the second example as well, a reflector 1401 is placed beneath the first electrode 1202 of the subpixel 1100, with an optical adjustment layer 1402 in between. A resonator structure is formed between the reflector 1401 and the second electrode 1206 to resonate the light generated by the organic layer 1204. Similar to the first example, the reflector 1401 is formed with a common film thickness for each subpixel 1100, while the film thickness of the optical adjustment layer 1402 differs according to the color that the subpixel 1100 should display.

[0139] In the first example shown in Figure 16, the upper surfaces of the reflectors 1401 for subpixels 1100R, 1100G, and 1100B were aligned, while the position of the upper surface of the second electrode 1206 differed depending on the type of subpixel 1100R, 1100G, and 1100B.

[0140] In contrast, in the second example shown in Figure 17, the upper surface of the second electrode 1206 is arranged to align with the subpixels 1100R, 1100G, and 1100B. In order to align the upper surfaces of the second electrode 1206, the upper surface of the reflector 1401 is arranged differently for the subpixels 1100R, 1100G, and 1100B, depending on the type of subpixel. As a result, the lower surface of the reflector 1401 has a stepped shape depending on the type of subpixel 1100R, 1100G, and 1100B.

[0141] The materials and other components constituting the reflector 1401, the optical adjustment layer 1402, the first electrode 1202, and the second electrode 1206 are the same as those described in the first example, so their explanation will be omitted.

[0142] (Resonator structure: Third example) Figure 18 is a schematic cross-sectional view illustrating the third example of the resonator structure. In the third example as well, the first electrode 1202 and the second electrode 1206 are formed with a common film thickness in each subpixel 1100.

[0143] In the third example, the reflector 1401 is positioned below the first electrode 1202 of the subpixel 1100, with the optical adjustment layer 1402 in between. A resonator structure is formed between the reflector 1401 and the second electrode 1206 to resonate the light generated by the organic layer 1204. Similar to the first and second examples, the thickness of the optical adjustment layer 1402 varies depending on the color that the subpixel 1100 should display. And, similar to the second example, the upper surface of the second electrode 1206 is positioned so that it aligns with the subpixels 1100R, 1100G, and 1100B.

[0144] In the second example shown in Figure 17, the lower surface of the reflector 1401 had a stepped shape corresponding to the type of sub-pixel 1100R, 1100G, and 1100B in order to align the upper surface of the second electrode 1206.

[0145] In contrast, in the third example shown in Figure 18, the film thickness of the reflector 1401 is set to differ depending on the type of sub-pixel 1100R, 1100G, and 1100B. More specifically, the film thickness is set so that the lower surfaces of the reflectors 1401R, 1401G, and 1401B are aligned.

[0146] The materials constituting the reflector 1401, the optical adjustment layer 1402, the first electrode 1202, and the second electrode 1206 are the same as those described in the first example, so their explanation will be omitted.

[0147] (Resonator structure: 4th example) Figure 19 is a schematic cross-sectional view illustrating the 4th example of a resonator structure.

[0148] In the first example shown in Figure 16, the first electrode 1202 and the second electrode 1206 of the subpixel 1100 are formed with a common film thickness. A reflector 1401 is placed below the first electrode 1202 of the subpixel 1100, with an optical adjustment layer 1402 in between.

[0149] In contrast, in the fourth example shown in Figure 19, the optical adjustment layer 1402 is omitted, and the film thickness of the first electrode 1202 is set to differ depending on the type of subpixel 1100R, 1100G, and 1100B.

[0150] The reflector 1401 is formed with a common film thickness for each subpixel 1100. The film thickness of the first electrode 1202 differs depending on the color that the subpixel 1100 is to display. By having the first electrodes 1202R, 1202G, and 1202B have different film thicknesses, it is possible to set the optical distance that produces the optimal resonance for the wavelength of light corresponding to the color to be displayed.

[0151] The materials constituting the reflector 1401, the first electrode 1202, and the second electrode 1206 are the same as those described in the first example, so their explanation will be omitted.

[0152] (Resonator structure: Fifth example) Figure 20 is a schematic cross-sectional view illustrating the fifth example of a resonator structure.

[0153] In the first example shown in Figure 16, the first electrode 1202 and the second electrode 1206 are formed with a common film thickness in each subpixel 1100. A reflector 1401 is placed below the first electrode 1202 of the subpixel 1100, with an optical adjustment layer 1402 in between.

[0154] In contrast, in the fifth example shown in Figure 20, the optical adjustment layer 1402 was omitted, and instead, an oxide film 1404 was formed on the surface of the reflector 1401. The thickness of the oxide film 1404 was set to differ depending on the type of subpixel 1100R, 1100G, and 1100B.

[0155] The thickness of the oxide film 1404 varies depending on the color that the subpixel 1100 is to display. By having oxide films 1404R, 1404G, and 1404B with different thicknesses, it is possible to set the optical distance that produces the optimal resonance for the wavelength of light corresponding to the color to be displayed.

[0156] The oxide film 1404 is a film obtained by oxidizing the surface of the reflector 1401, and is composed of, for example, aluminum oxide, tantalum oxide, titanium oxide, magnesium oxide, zirconium oxide, etc. The oxide film 1404 functions as an insulating film for adjusting the optical path length (optical distance) between the reflector 1401 and the second electrode 1206.

[0157] The oxide film 1404, which has a different thickness depending on the type of subpixel 1100R, 1100G, and 1100B, can be formed, for example, as follows.

[0158] First, the container is filled with electrolyte, and the substrate on which the reflector 1401 is formed is immersed in the electrolyte. Then, electrodes are positioned opposite the reflector 1401.

[0159] Then, a positive voltage is applied to the reflector 1401 with the electrode as the reference, and the reflector 1401 is anodized. The thickness of the oxide film formed by anodization is proportional to the voltage value applied to the electrode. Therefore, anodization is performed on each of the reflectors 1401R, 1401G, and 1401B with a voltage corresponding to the type of sub-pixel 1100R, 1100G, and 1100B applied. This makes it possible to form oxide films 1404 of different thicknesses all at once.

[0160] The materials constituting the reflector 1401, the first electrode 1202, and the second electrode 1206 are the same as those described in the first example, so their explanation will be omitted.

[0161] (Resonator Structure: Sixth Example) Figure 21 is a schematic cross-sectional view illustrating the sixth example of a resonator structure. In the sixth example, the subpixel 1100 is constructed by stacking a first electrode 1202, an organic layer 1204, and a second electrode 1206. However, in the sixth example, the first electrode 1202 is formed to serve both as an electrode and a reflector. The first electrode (and reflector) 1202 is made of a material having optical constants selected according to the type of subpixel 1100R, 1100G, and 1100B. By different phase shifts caused by the first electrode (and reflector) 1202, it is possible to set an optical distance that produces optimal resonance for the wavelength of light corresponding to the color to be displayed.

[0162] The first electrode (and reflector) 1202 can be made from a single metal such as aluminum (Al), silver (Ag), gold (Au), or copper (Cu), or from an alloy mainly composed of these metals. For example, the first electrode (and reflector) 1202R of the subpixel 1100R can be made of copper (Cu), and the first electrode (and reflector) 1202G of the subpixel 1100G and the first electrode (and reflector) 1202B of the subpixel 1100B can be made of aluminum.

[0163] The materials and other components constituting the second electrode 1206 are the same as those described in the first example, so we will omit further explanation.

[0164] (Resonator Structure: Seventh Example) Figure 22 is a schematic cross-sectional view illustrating the seventh example of the resonator structure. The seventh example basically applies the sixth example to sub-pixels 1100R and 1100G, and the first example to sub-pixel 1100B. In this configuration as well, it is possible to set the optical distance that produces optimal resonance for the wavelength of light corresponding to the color to be displayed.

[0165] The first electrodes (which also serve as reflectors) 1202R and 1202G used in the sub-pixels 1100R and 1100G can be made from elemental metals such as aluminum (Al), silver (Ag), gold (Au), and copper (Cu), or alloys in which these metals are the main components.

[0166] The materials constituting the reflector 1401B, optical adjustment layer 1402B, and first electrode 1202B used in the subpixel 1100B are the same as those described in the first example, so their explanation will be omitted.

[0167] <<9. Examples of Application>> For example, the technology relating to this disclosure may be applied to the display units of various electronic devices. Therefore, examples of electronic devices to which this technology can be applied will be described below.

[0168] (Specific Example 1) Figure 23A is a front view showing an example of the external appearance of the digital still camera 500, and Figure 23B is a rear view showing an example of the external appearance of the digital still camera 500. This digital still camera 500 is a single-lens reflex type with interchangeable lenses, and has an interchangeable shooting lens unit (interchangeable lens) 512 located approximately in the center of the front of the camera body 511, and a grip portion 513 for the photographer to hold on the left side of the front.

[0169] A monitor 514 is provided on the back of the camera body 511, slightly to the left of the center. An electronic viewfinder (eyepiece) 515 is provided above the monitor 514. The photographer can determine the composition by looking through the electronic viewfinder 515 and visually confirming the light image of the subject guided by the shooting lens unit 512. The display device 10 according to the embodiment of this disclosure can be used as the monitor 514 and the electronic viewfinder 515.

[0170] (Specific Example 2) Figure 24 is an external view of a head-mounted display 600. The head-mounted display 600 has, for example, an eyeglass-shaped display unit 611 and ear hooks 612 on both sides for attachment to the user's head. In this head-mounted display 600, the display device 10 according to the embodiment of this disclosure can be used as the display unit 611.

[0171] (Specific Example 3) Figure 25 is an external view of the see-through head-mounted display 634. The see-through head-mounted display 634 consists of a main body 632, an arm 633, and a lens barrel 631.

[0172] The main body 632 is connected to the arm 633 and the eyeglasses 630. Specifically, the long end of the main body 632 is connected to the arm 633, and one side of the main body 632 is connected to the eyeglasses 630 via a connecting member. The main body 632 may also be directly attached to the head of a person.

[0173] The main body 632 houses a control board for controlling the operation of the see-through head-mounted display 634 and a display unit. The arm 633 connects the main body 632 to the lens barrel 631 and supports the lens barrel 631. Specifically, the arm 633 is connected to the end of the main body 632 and the end of the lens barrel 631, respectively, and fixes the lens barrel 631 in place. The arm 633 also houses signal lines for communicating image-related data provided from the main body 632 to the lens barrel 631.

[0174] The lens barrel 631 projects image light, provided from the main body 632 via the arm 633, through the eyepiece lens towards the eyes of the user wearing the see-through head-mounted display 634. In this see-through head-mounted display 634, the display device 10 according to the embodiment of this disclosure can be used in the display section of the main body 632.

[0175] (Specific Example 4) Figure 26 shows an example of the appearance of a television device 710. This television device 710 has, for example, a video display screen section 711 including a front panel 712 and a filter glass 713, and this video display screen section 711 is configured with a display device 10 according to the embodiment of this disclosure.

[0176] (Specific Example 5) Figure 27 shows an example of the appearance of a smartphone 800. The smartphone 800 has a display unit 802 that displays various information, and an operation unit consisting of buttons, etc. that accept user input. The display unit 802 may be the display device 10 according to this embodiment.

[0177] (Specific Example 6) Figures 28A and 28B show the internal configuration of an automobile having a display device 10 according to the present disclosure as a display device. More specifically, Figure 28A shows the interior of the automobile from the rear to the front, and Figure 28B shows the interior of the automobile from the diagonally rear to the diagonally front.

[0178] The automobile shown in Figures 28A and 28B includes a center display 911, a console display 912, a head-up display 913, a digital rear mirror 914, a steering wheel display 915, and a rear entertainment display 916. Some or all of these displays can be fitted with the display device 10 according to the embodiment of this disclosure.

[0179] The center display 911 is positioned on the center console 907, facing the driver's seat 901 and the passenger seat 902. Figures 28A and 28B show an example of a horizontally elongated center display 911 extending from the driver's seat 901 to the passenger seat 902, but the screen size and placement of the center display 911 are arbitrary. The center display 911 can display information detected by various sensors (not shown). As a specific example, the center display 911 can display images captured by an image sensor, distance images to obstacles in front of or to the side of the vehicle measured by a ToF (Time of Flight) sensor, and the body temperature of passengers detected by an infrared sensor. The center display 911 can be used to display at least one of the following: safety-related information, operation-related information, life logs, health-related information, authentication / identification-related information, and entertainment-related information.

[0180] Safety-related information includes information such as drowsiness detection, distraction detection, detection of mischief by a passenger, seatbelt fastening status, and detection of an unattended occupant. This information is detected, for example, by a sensor (not shown) placed on top of the back of the center display 1911. Operation-related information is detected by sensing occupant gestures using sensors. The detected gestures may include the operation of various equipment in the vehicle. For example, the sensor detects the operation of air conditioning equipment, navigation systems, AV (Audio / Visual) systems, lighting systems, etc. Life logs include the life logs of all occupants. For example, life logs include records of each occupant's actions while riding in the vehicle. By acquiring and saving life logs, it is possible to confirm the state of the occupants at the time of an accident. Health-related information is detected by sensing the occupant's body temperature using a temperature sensor and inferring the occupant's health status based on the detected body temperature. Alternatively, the occupant's face may be captured using an image sensor, and the occupant's health status may be inferred from the facial expression captured. Furthermore, the system may engage in automated voice conversations with the occupants and infer their health status based on their responses. Authentication / identification-related information includes keyless entry functions that use sensors for facial recognition and functions that automatically adjust seat height and position based on facial recognition. Entertainment-related information includes functions that use sensors to detect information on how the occupants operate the AV equipment and functions that use sensors to recognize the occupants' faces and provide content suitable for the occupants through the AV equipment.

[0181] The console display 912 can be used, for example, to display life log information. The console display 912 is located near the shift lever 908 on the center console 907 between the driver's seat 901 and the passenger seat 902. The console display 912 can also display information detected by various sensors (not shown). In addition, the console display 912 may display an image of the area around the vehicle captured by an image sensor, or it may display an image showing the distance to obstacles around the vehicle.

[0182] The head-up display 913 is virtually displayed behind the windshield 904 in front of the driver's seat 901. The head-up display 913 can be used to display at least one of the following: safety-related information, operation-related information, life logs, health-related information, authentication / identification-related information, and entertainment-related information. Because the head-up display 913 is often virtually positioned in front of the driver's seat 901, it is suitable for displaying information directly related to the operation of the vehicle, such as the vehicle's speed and fuel (battery) level.

[0183] The digital rearview mirror 914 can not only display what is behind the vehicle, but also what is happening to the passengers in the rear seat. By placing a sensor (not shown) on top of the back of the digital rearview mirror 914, it can be used, for example, to display life log information.

[0184] The steering wheel display 915 is positioned near the center of the steering wheel 906 of the automobile. The steering wheel display 915 can be used to display at least one of the following: safety-related information, operation-related information, life log, health-related information, authentication / identification-related information, and entertainment-related information. In particular, because the steering wheel display 915 is located near the driver's hands, it is suitable for displaying life log information such as the driver's body temperature, or information related to the operation of AV equipment, air conditioning equipment, etc.

[0185] The rear entertainment display 916 is mounted on the back of the driver's seat 901 and the passenger seat 902, and is intended for viewing by rear-seat passengers. The rear entertainment display 916 can be used to display at least one of the following: safety-related information, operation-related information, life logs, health-related information, authentication / identification-related information, and entertainment-related information. In particular, because the rear entertainment display 916 is in front of the rear-seat passengers, it displays information relevant to the rear-seat passengers. For example, it may display information related to the operation of AV equipment or air conditioning equipment, or it may display the results of measurements of the rear-seat passengers' body temperature, etc., taken by a temperature sensor (not shown).

[0186] <<10. Supplementary Information>> Although preferred embodiments of the present disclosure have been described in detail above with reference to the attached drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person with ordinary skill in the art of the present disclosure may conceive of various modifications or alterations within the scope of the technical ideas described in the claims, and these will naturally also fall within the technical scope of the present disclosure.

[0187] Furthermore, the effects described herein are merely descriptive or illustrative and not limiting. In other words, the technology relating to this disclosure may produce other effects that will be apparent to those skilled in the art from the description herein, in addition to or in lieu of the effects described herein.

[0188] Furthermore, this technology can also take the following configurations: (1) A display device having a plurality of light-emitting elements arranged on a substrate, wherein each light-emitting element comprises: a light-emitting layer that emits light; a microstructure that creates a point light source by extracting the light from a minute region; and a lens structure laminated above the light-emitting layer to guide the light emitted from the point light source in a predetermined direction. (2) The display device according to (1) above, wherein the microstructure is made of nanometal particles, a high refractive index dielectric, a nanogap, or a photonic crystal containing defects with respect to period. (3) The display device according to (1) or (2) above, wherein the microstructure includes a resonant structure that resonates with light. (4) The display device according to any one of (1) to (3) above, wherein the microstructure includes a waveguide structure that guides light to a predetermined region. (5) The display device according to any one of (1) to (4) above, wherein when each light-emitting element is viewed from above the substrate, the position of the center of the microstructure and the position of the center of the minute region coincide. (6) A display device according to any one of (1) to (4) above, wherein when each of the light-emitting elements is viewed from above the substrate, the position of the center of the microstructure and the position of the center of the microregion are different. (7) A display device according to any one of (1) to (6) above, wherein when each of the light-emitting elements is viewed from above the substrate, the position of the center of the light-emitting layer and the position of the center of the microregion are different. (8) A display device according to any one of (1) to (7) above, wherein when each of the light-emitting elements is viewed from above the substrate, the area of ​​the microregion is less than half the area of ​​the light-emitting region of the light-emitting layer. (9) A display device according to any one of (1) to (8) above, wherein the lens structure consists of an on-chip lens, a metasurface, or a waveguide. (10) A display device according to any one of (1) to (9) above, wherein the center of the microregion is located at the focal point of the lens structure. (11) The display device according to any one of (1) to (9) above, wherein when each of the light-emitting elements is viewed from above the substrate, the position of the center of the lens structure and the position of the center of the minute region coincide.(12) The display device according to any one of (1) to (9) above, wherein when each light-emitting element is viewed from above the substrate, the position of the center of the lens structure and the position of the center of the minute region are different. (13) The display device according to any one of (1) to (12) above, wherein the minute structure is laminated above or below the light-emitting layer, or is provided within the light-emitting layer. (14) The display device according to any one of (1) to (13) above, wherein the position of the minute region in the light-emitting element differs for each wavelength of light emitted by the light-emitting element. (15) The display device according to (13) or (14) above, wherein each light-emitting element is further provided on the lower electrode and the upper electrode sandwiching the light-emitting layer. (16) The display device according to (15) above, wherein each light-emitting element is further provided with a spacer layer laminated below the lower electrode, or laminated above the upper electrode. (17) The display device according to (16) above, wherein each light-emitting element is further provided with a color filter laminated above the upper electrode. (18) The display device according to (17), wherein the microstructure is provided on the spacer layer, the lower electrode, the light-emitting layer, the upper electrode, or the color filter. (19) The display device according to (18), wherein the microstructure is provided across a plurality of layers. (20) The display device according to (18), wherein the microstructure is provided in contact with the interface of a plurality of layers.

[0189] 10 Display device 11 Horizontal drive circuit 12 Vertical drive circuit 20 Pixel array section 40 Display panel 100, 100a, 100b, 100g, 100r Light-emitting element 102 Substrate 104 Reflector 106, 120 Spacer layer 110, 114 Electrode 112 Light-emitting layer 130, 130b, 130g, 130r Color filter 132 On-chip lens 200 High refractive index dielectric 200a, 200b Metal body 250 Photonic crystal structure 260, 262 Defect 264 Hole 300 Micro-region 400, 400B, 400G, 400R Sub-pixel

Claims

1. A display device having a plurality of light-emitting elements arranged on a substrate, wherein each light-emitting element comprises: a light-emitting layer that emits light; a microstructure that creates a point light source by extracting the light from a minute region; and a lens structure stacked above the light-emitting layer to guide the light emitted from the point light source in a predetermined direction.

2. The display device according to claim 1, wherein the microstructure comprises nanometal particles, a high refractive index dielectric, a nanogap, or a photonic crystal containing defects for periodicity.

3. The display device according to claim 1, wherein the microstructure includes a resonant structure that resonates with light.

4. The display device according to claim 1, wherein the microstructure includes a waveguide structure for guiding light to a predetermined region.

5. The display device according to claim 1, wherein when each light-emitting element is viewed from above the substrate, the position of the center of the microstructure and the position of the center of the microregion coincide.

6. The display device according to claim 1, wherein, when each light-emitting element is viewed from above the substrate, the position of the center of the microstructure and the position of the center of the microregion are different.

7. The display device according to claim 1, wherein, when each light-emitting element is viewed from above the substrate, the position of the center of the light-emitting layer and the position of the center of the minute region are different.

8. The display device according to claim 1, wherein, when each of the light-emitting elements is viewed from above the substrate, the area of ​​the minute region is less than half the area of ​​the light-emitting region of the light-emitting layer.

9. The display device according to claim 1, wherein the lens structure comprises an on-chip lens, a metasurface, or a waveguide.

10. The display device according to claim 1, wherein the center of the minute region is located at the focal point of the lens structure.

11. The display device according to claim 1, wherein, when each of the light-emitting elements is viewed from above the substrate, the position of the center of the lens structure and the position of the center of the minute region coincide.

12. The display device according to claim 1, wherein, when each of the light-emitting elements is viewed from above the substrate, the position of the center of the lens structure and the position of the center of the minute region are different.

13. The display device according to claim 1, wherein the microstructure is laminated above or below the light-emitting layer, or is provided within the light-emitting layer.

14. The display device according to claim 1, wherein the position of the minute region in each light-emitting element differs for each wavelength of light emitted by the light-emitting element.

15. The display device according to claim 13, wherein each of the light-emitting elements is further provided on a lower electrode and an upper electrode sandwiching the light-emitting layer.

16. The display device according to claim 15, wherein each light-emitting element further comprises a spacer layer stacked below the lower electrode or above the upper electrode.

17. The display device according to claim 16, wherein each light-emitting element further comprises a color filter stacked above the upper electrode.

18. The display device according to claim 17, wherein the microstructure is provided on the spacer layer, the lower electrode, the light-emitting layer, the upper electrode, or the color filter.

19. The display device according to claim 18, wherein the microstructure is provided across multiple layers.

20. The display device according to claim 18, wherein the microstructure is provided in contact with the interfaces of a plurality of layers.

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