Light emitting device, display device, imaging device, electronic apparatus, and wearable device

Abstract

To provide a technique advantageous in improving the light emission efficiency of each of a light emitting element configured to emit visible light and a light emitting element configured to emit infrared light while suppressing an increase in the number of steps.SOLUTION: A light emitting device includes a plurality of light emitting elements including a first light emitting element and a second light emitting element that emit visible light, and a third light emitting element that emits infrared light. Each of the plurality of light emitting elements includes: a reflective layer; a lower electrode disposed on the reflective layer; a light emitting layer disposed on the lower electrode; and an upper electrode disposed on the light emitting layer. A distance from an upper surface of the reflective layer of the first light emitting element to an upper surface of the lower electrode of the first light emitting element is different from a distance from an upper surface of the reflective layer of the second light emitting element to an upper surface of the lower electrode of the second light emitting element, and a distance from the upper surface of the reflective layer of the first light emitting element to the upper surface of the lower electrode of the first light emitting element is substantially the same as a distance from the upper surface of the reflective layer of the third light emitting element to the upper surface of the lower electrode of the third light emitting element.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a light-emitting device, a display device, an imaging device, an electronic device, and a wearable device. [Background technology]

[0002] An organic light-emitting device is a device that emits light by applying a voltage to a light-emitting layer that has an organic compound layer. Because organic light-emitting devices are self-emitting devices, they do not require a separate light source and display control such as a shutter, as is the case with liquid crystal display devices. This has the advantage of enabling them to be thinner and consume less power than liquid crystal display devices. For this reason, they have attracted attention as display devices for camera viewfinders, head-mounted displays, wearable devices known as smart glasses, and other applications.

[0003] In such display devices, it is desirable to detect the user's gaze point by detecting the user's line of sight toward the display unit. Information on the detected gaze point can be reflected in the driving of the display device. One method for detecting the user's gaze point is to detect a reflected image of the user's eyeball by irradiating infrared light onto the user's eyeball as he or she looks at the display device. In addition, a method is known in which the light-emitting efficiency is improved by differentiating the optical distance for each emitted color in order to reduce the power consumption of the display unit of the display device.

[0004] Patent Document 1 discloses a technique for providing a light-emitting element constituting a display unit and an infrared light-emitting element that emits infrared light on the same substrate. Patent Document 1 also discloses making the optical distance (the distance between the reflecting surfaces) different between the display element and the infrared light-emitting element. Patent Document 2 discloses making the optical distance of a resonator structure having a mirror and a half mirror different for each emitted color. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-15731 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-116516 Summary of the Invention [Problem to be solved by the invention]

[0006] Even in the infrared light-emitting element of Patent Document 1, using the configuration of Patent Document 2 to make the optical distance of the light-emitting element that emits infrared light different from all of the multiple optical distances of the light-emitting element that emits visible light leads to an increase in the number of processes.

[0007] An object of the present invention is to provide an advantageous technique for improving the luminous efficiency of a light-emitting element that emits visible light and a light-emitting element that emits infrared light while suppressing an increase in the number of steps. [Means for solving the problem]

[0008] One aspect of the present invention relates to a light-emitting device having a plurality of light-emitting elements, including first and second light-emitting elements that emit visible light, and a third light-emitting element that emits infrared light, wherein each of the plurality of light-emitting elements includes a reflective layer, a lower electrode arranged on the reflective layer, a light-emitting layer arranged on the lower electrode, and an upper electrode arranged on the light-emitting layer, wherein the distance from the upper surface of the reflective layer of the first light-emitting element to the upper surface of the lower electrode of the first light-emitting element is different from the distance from the upper surface of the reflective layer of the second light-emitting element to the upper surface of the lower electrode of the second light-emitting element, and the distance from the upper surface of the reflective layer of the first light-emitting element to the upper surface of the lower electrode of the first light-emitting element is approximately the same as the distance from the upper surface of the reflective layer of the third light-emitting element to the upper surface of the lower electrode of the third light-emitting element. [Effects of the Invention]

[0009] According to the present invention, an advantageous technique is provided for improving the luminous efficiency of a light-emitting element that emits visible light and a light-emitting element that emits infrared light while suppressing an increase in the number of steps. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view schematically showing the configuration of a light emitting device according to a first embodiment. [Figure 2] FIG. 10 is a cross-sectional view schematically showing the configuration of a light emitting device according to a second embodiment. [Figure 3] FIG. 10 is a cross-sectional view schematically showing the configuration of a light emitting device according to a third embodiment. [Figure 4] FIG. 10 is a cross-sectional view schematically showing the configuration of a light emitting device according to a fourth embodiment. [Figure 5] FIG. 10 is a cross-sectional view schematically showing the configuration of a light emitting device according to a fifth embodiment. [Figure 6] FIG. 10 is a cross-sectional view schematically showing the configuration of a light emitting device according to a sixth embodiment. [Figure 7] 10A to 10C show application examples of a light-emitting device. [Figure 8] 10A to 10C show application examples of a light-emitting device. [Figure 9] 10A to 10C show application examples of a light-emitting device. [Figure 10] 10A to 10C show application examples of a light-emitting device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted. (First embodiment) FIG. 1 is a cross-sectional view schematically illustrating the configuration of a light-emitting device ED according to a first embodiment. The light-emitting device ED can have a function of displaying an image and a function of emitting infrared light. In describing the structure of the light-emitting device ED, directions such as up and down refer to directions such as up and down on the plane of FIG. 1. From another perspective, the direction from the organic compound layer 3 toward the substrate 1 is down, and the direction from the substrate 1 toward the organic compound layer 3 is up.

[0012] The display device ED may have a substrate 1. The substrate 1 is formed of a material capable of supporting a plurality of light-emitting elements formed thereon, and for example, a glass substrate, a plastic substrate, or a semiconductor substrate (e.g., a silicon substrate) may be used as the substrate 1. The substrate 1 may include switching elements (not shown) such as transistors, wiring patterns, vias, interlayer insulating films, etc. The transistor may be a MOS transistor including a portion formed inside the semiconductor substrate, or may be a TFT.

[0013] The light-emitting device ED includes a plurality of light-emitting elements. The plurality of light-emitting elements may include at least a first light-emitting element 101 and a second light-emitting element 102 that emit visible light, and a third light-emitting element 103 that emits infrared light. Note that the ordinal numbers such as first and second are merely used to distinguish the components to which they are attached, and do not indicate characteristics, properties, etc.

[0014] The plurality of light-emitting elements each include a reflective layer, a lower electrode disposed on the reflective layer, a light-emitting layer disposed on the lower electrode, and an upper electrode disposed on the light-emitting layer. In other words, the first light-emitting element 101 includes a first reflective layer 81, a first lower electrode 21 disposed on the first reflective layer 81, a first light-emitting layer 31 disposed on the first lower electrode 21, and a first upper electrode 41 disposed on the first light-emitting layer 31. The second light-emitting element 102 includes a second reflective layer 82, a second lower electrode 22 disposed on the second reflective layer 82, a second light-emitting layer 32 disposed on the second lower electrode 22, and a second upper electrode 42 disposed on the second light-emitting layer 32. The third light-emitting element 103 includes a third reflective layer 83, a third lower electrode 23 disposed on the third reflective layer 83, a third light-emitting layer 33 disposed on the third lower electrode 23, and a third upper electrode 43 disposed on the third light-emitting layer 33.

[0015] From the viewpoint of light-emitting efficiency, the lower electrodes such as the first lower electrode 21, the second lower electrode 22, and the third lower electrode 23 are preferably made of a light-transmitting material. Specifically, the lower electrodes may be made of a thin film of a transparent conductive oxide such as ITO or IZO, a metal such as Al, Ag, Pt, Au, or Ti, an alloy thereof, or a compound thereof.

[0016] Light-emitting layers such as the first light-emitting layer 31, the second light-emitting layer 32, and the third light-emitting layer 33 may constitute part of the organic compound layer 3. The organic compound layer 3 may be disposed on a lower electrode such as the first lower electrode 21, the second lower electrode 22, or the third lower electrode 23. The organic compound layer 3 may be formed by, for example, vapor deposition, spin coating, or inkjet printing. The organic compound layer 3 may be composed of multiple layers, and may include, in addition to the light-emitting layer, a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a charge generation layer. The light-emitting layer may be disposed between the electron blocking layer and the hole blocking layer. The configuration of the organic compound layer 3 is not particularly limited, and it may further include other layers. Furthermore, each layer constituting the organic compound layer 3 may be composed of multiple films, and the light-emitting layer may include multiple light-emitting films. When the light-emitting layer has multiple light-emitting films, the light-emitting films may be stacked so as to be in contact with each other, or may be stacked via other films.

[0017] The light-emitting layer contains a light-emitting material. The light-emitting material is, for example, any one of a blue light-emitting material, a green light-emitting material, a red light-emitting material, and an infrared light-emitting material. When the light-emitting layer has multiple light-emitting films, each light-emitting film may contain one type of light-emitting material. Alternatively, each light-emitting film may contain two or more types of light-emitting materials. Furthermore, the light-emitting layer may be provided commonly on the lower electrodes, such as the first lower electrode 21, the second lower electrode 22, and the third lower electrode 23, or may be provided individually for each of them. Alternatively, a common light-emitting layer may be provided on the first lower electrode 21, the second lower electrode 22, and the third lower electrode 24, and another light-emitting layer may be provided on the third lower electrode 23.

[0018] The first light-emitting layer 31 of the first light-emitting element 101 and the second light-emitting layer 32 of the second light-emitting element 102 may contain any one of a blue light-emitting material, a green light-emitting material, and a red light-emitting material, or light-emitting materials that emit visible light in multiple different bands. The third light-emitting layer 33 of the third light-emitting element (infrared light-emitting element) 103 contains at least an infrared light-emitting material. Therefore, the first light-emitting element 101 and the second light-emitting element 102 emit visible light, and the third light-emitting element (infrared light-emitting element) 103 emits infrared light.

[0019] Upper electrodes, such as the first upper electrode 41, the second upper electrode 42, and the third upper electrode 43, are disposed on the organic compound layer 3 and are translucent. Each upper electrode may be made of a semi-transparent material that transmits part of the light reaching its surface and reflects the other part (i.e., semi-transparent / reflective). Each upper electrode may be made of a transparent material such as a transparent conductive oxide, an elemental metal such as aluminum, silver, or gold, an alkali metal such as lithium or cesium, or an alkaline earth metal such as magnesium, calcium, or barium. Alternatively, each upper electrode may be made of a semi-transparent material made of an alloy material containing any of these metal materials. An alloy primarily composed of magnesium or silver is particularly preferred as the semi-transparent material. Each upper electrode may have a laminate structure of the above materials as long as it has a desired transmittance. The first upper electrode 41, the second upper electrode 42, and the third upper electrode 43 may be provided in common to the first light-emitting element 101, the second light-emitting element 102, and the third light-emitting element 103, or may be provided individually.

[0020] The reflective layers, such as the first reflective layer 81, the second reflective layer 82, and the third reflective layer 83, are made of a material with high reflectivity, and may be made of a metal material such as Al, Ag, Ti, W, Mo, Au, Ni, or Pt, or an alloy of the above materials, or may have a laminate structure thereof. The reflective layers, such as the first reflective layer 81, the second reflective layer 82, and the third reflective layer 83, are preferably made of the same material. Furthermore, it is preferable that the distance between the bottom surface of the reflective layer, such as the first reflective layer 81, the second reflective layer 82, and the third reflective layer 83, and the top surface of the substrate 1 is approximately the same.

[0021] A first light-transmitting layer 91 may be provided between the first reflective layer 81 and the first lower electrode 21, a second light-transmitting layer 92 may be provided between the second reflective layer 82 and the second lower electrode 22, and a third light-transmitting layer 93 may be provided between the third reflective layer 83 and the third lower electrode 23. The light-transmitting layers, such as the first light-transmitting layer 91, the second light-transmitting layer 92, and the third light-transmitting layer 93, are made of a material that transmits light, and are particularly preferably made of SiO, SiN, or SiON. The light-transmitting layers may be formed by, for example, a sputtering method, a CVD method, or an ALD method.

[0022] In the first embodiment, the distance from the upper surface of the first reflective layer 81 to the upper surface of the first lower electrode 21 in the first light-emitting element 101 is different from the distance from the upper surface of the second reflective layer 82 to the upper surface of the second lower electrode 22 in the second light-emitting element 102. Also, in the first embodiment, the distance from the upper surface of the first reflective layer 81 to the upper surface of the first lower electrode 21 in the first light-emitting element 101 is approximately the same as the distance from the upper surface of the third reflective layer 83 to the upper surface of the third lower electrode 23 in the third light-emitting element (infrared light-emitting element) 103. Here, "approximately the same" means that the ratio of the larger value to the smaller value of the two is within 1.05. This is because variations in manufacturing are taken into consideration.

[0023] Here, the distance from the upper surface of the first reflective layer 81 of the first light-emitting element 101 to the upper surface of the first lower electrode 21 may be defined as the first distance. Furthermore, the distance from the upper surface of the second reflective layer 82 of the second light-emitting element 102 to the upper surface of the second lower electrode 22 may be defined as the second distance. Furthermore, the distance from the upper surface of the third reflective layer 83 of the third light-emitting element 103 to the upper surface of the third lower electrode 23 may be defined as the third distance. Explained according to this definition, the light-emitting device ED of the first embodiment has an aspect in which the difference between the first distance and the third distance is smaller than the difference between the first distance and the second distance.

[0024] In the present invention, as long as the above conditions are met, there are no particular limitations on the film thickness of each of the first translucent layer 91, the second translucent layer 92, the third translucent layer 93, the first lower electrode 21, the second lower electrode 22, and the third lower electrode 23.

[0025] In the first embodiment, the first lower electrode 21, the second lower electrode 22, and the third lower electrode 23 have substantially the same film thickness. Also, in the first embodiment, the first translucent layer 91 and the second translucent layer 92 have different film thicknesses, and the first translucent layer 91 and the third translucent layer 93 have substantially the same film thickness. By optimizing the film thicknesses of the first translucent layer 91, the second translucent layer 92, and the third translucent layer 93 for each light-emitting element, it is possible to improve the luminous efficiency of each of the first light-emitting element 101, the second light-emitting element 102, and the third light-emitting element (infrared light-emitting element) 103.

[0026] On the other hand, the first lower electrode 21 and the third lower electrode 23 have substantially the same film thickness, and the first translucent layer 91 and the third translucent layer 93 have substantially the same film thickness. Therefore, when manufacturing the light emitting device ED, the translucent layers and lower electrodes of the first light emitting element 101 and the third light emitting element 103 can be formed in the same process. Furthermore, by making the film thicknesses of the first translucent layer 91 and the second translucent layer 92 different from each other, it is possible to make the chromaticities of the first light emitting element 101 and the second light emitting element 102 different from each other. Therefore, multicolor display is possible in the display area.

[0027] Therefore, according to the first embodiment, it is possible to improve the luminous efficiency of the first light-emitting element 101 and the third light-emitting element (infrared light-emitting element) 103 while minimizing an increase in the number of manufacturing processes, and it is also possible to display in multiple colors.

[0028] According to the first embodiment, if the optical distance from the upper surface of the third reflective layer 83 of the third light-emitting element (infrared light-emitting element) 103 to the lower surface of the third upper electrode 43 is ND3, it is preferable that ND3 satisfies the condition shown in equation (1).

[0029] ND31≦ND3≦ND32 ND31=-φ3 / 4π×λ3×0.9 ND32=-φ3 / 4π×λ3×1.1 ···(1) Here, φ3 is the sum of the phase shifts in the third reflective layer 83 and the third upper electrode 43, and λ3 is the peak wavelength of the PL emission spectrum of the infrared light-emitting material contained in the third light-emitting layer 33.

[0030] In order to satisfy the condition shown in formula (1), if the distance from the upper surface of the third reflective layer 83 of the third light-emitting element (infrared light-emitting element) 103 to the lower surface of the third upper electrode 43 is L3, it is particularly preferable that L3 and λ3 satisfy the condition shown in formula (2).

[0031] 0.20≦λ3 / L3≦0.30 (2) Furthermore, L3 is preferably 160 nm or more and 300 nm or less.

[0032] By satisfying the conditions shown in formulas (1) and (2), the luminous efficiency of the third light-emitting element (infrared light-emitting element) 103 can be improved.

[0033] λ3 is preferably 800 nm or more and 1000 nm or less.

[0034] Furthermore, when the optical distance from the upper surface of the first reflective layer 81 of the first light emitting element 101 to the lower surface of the first upper electrode 41 is ND1, it is particularly preferable that ND1 satisfies the condition shown in formula (3).

[0035] ND11≦ND1≦ND12, ND11=(1-φ1 / 2π)×λ1×0.9 ND12=(1-φ1 / 2π)×λ1×1.1 ···(3) Here, φ1 is the sum of the phase shifts in the first reflective layer 81 and the first upper electrode 41, and λ1 is the peak wavelength of the PL emission spectrum of the light-emitting material contained in the first light-emitting layer 31.

[0036] In order to satisfy the condition shown in formula (3), if the distance from the upper surface of the first reflective layer 81 of the first light-emitting element 101 to the lower surface of the first upper electrode 41 is L1, it is particularly preferable that L1 and λ1 satisfy the condition shown in formula (4).

[0037] 0.45≦λ1 / L1≦0.65 (4) By satisfying the conditions shown in formulas (3) and (4), the luminous efficiency of first light emitting element 101 can be improved.

[0038] As described above, in the first embodiment, the distance from the upper surface of the first reflective layer 81 to the upper surface of the first lower electrode 21 in the first light-emitting element 101 is approximately the same as the distance from the upper surface of the third reflective layer 83 to the upper surface of the third lower electrode 23 in the third light-emitting element 103. In this case, it is preferable that the first light-emitting layer 31 of the first light-emitting element 101 contains a blue light-emitting material. This is because when the first light-emitting layer 31 contains a blue light-emitting material, the luminous efficiency of both the first light-emitting element and the third light-emitting element is easily improved.

[0039] The light-emitting device ED may have an insulating layer 5 between the lower electrodes of adjacent light-emitting elements. The insulating layer 5 may have an opening that covers the peripheral portion of each lower electrode while exposing the inside of the peripheral portion. For example, the first light-emitting element 101 and the third light-emitting element 103 may be arranged adjacent to each other, and the first lower electrode 21 of the first light-emitting element 101 and the third lower electrode 23 of the third light-emitting element 103 may be separated from each other by the insulating layer 5. The insulating layer 5 between the first lower electrode 21 and the third lower electrode 23 may have a T-shape in the cross section shown in FIG. 1 (a cross section cutting the reflective layer, lower electrode, light-emitting layer, and upper electrode). The insulating layer 5 between the first lower electrode 21 and the third lower electrode 23 may have a flat upper surface.

[0040] The first light-emitting element 101 and the second light-emitting element 102 may be disposed adjacent to each other, and the first lower electrode 21 of the first light-emitting element 101 and the second lower electrode 22 of the second light-emitting element 102 may be separated from each other by an insulating layer 5. The insulating layer 5 between the first lower electrode 21 and the second lower electrode 22 may have a step corresponding to the difference in height between the upper surface of the first lower electrode 21 and the upper surface of the second lower electrode 22.

[0041] The upper surface of the lower electrode (the inside of its periphery) and the lower surface of the organic compound layer 3 can come into contact through the opening in the insulating layer 5. The opening in the insulating layer 5 has the function of defining the light-emitting region of the light-emitting element and is useful for accurately forming the light-emitting region into a desired shape. The insulating layer 5 can also have the function of electrically insulating the lower electrodes of two adjacent light-emitting elements from each other. The insulating layer 5 can also be called a pixel separation layer (PDL), a partition wall, a bank, etc. If the insulating layer 5 is not provided, the light-emitting region can be defined by the shape of the lower electrode.

[0042] The insulating layer 5 is preferably formed of an inorganic material such as silicon nitride (SiN), silicon oxynitride (SiON), or silicon oxide (SiO). The insulating layer 5 can be formed by a method such as sputtering or chemical vapor deposition (CVD). The insulating layer 5 may also be formed of an organic material such as acrylic resin or polyimide resin.

[0043] The light-emitting device ED may have a sealing layer 6 formed to cover the organic compound layer 3 and the upper electrode. The sealing layer 6 preferably contains an inorganic material that is translucent and has extremely low permeability to oxygen and moisture from the outside. The inorganic material contained in the sealing layer 6 is preferably silicon nitride (SiN), silicon oxynitride (SiON), silicon oxide (SiO), aluminum oxide (Al2O3), or titanium oxide (TiO2). Among these, the sealing layer 6 preferably contains SiN, SiON, or Al2O3 to enhance sealing performance. The sealing layer 6 can be formed by chemical vapor deposition (CVD), atomic layer deposition (ALD), sputtering, or ion plating. As long as the sealing layer 6 has sufficient moisture-blocking properties, it may have a single-layer structure or a multilayer structure composed of multiple films formed using any combination of the above materials and formation methods. The sealing layer 6 may also have a multilayer structure composed of an inorganic material and an organic material such as a resin. Alternatively, a continuous sealing layer 6 may be formed so as to cover all of the upper electrodes of the plurality of light emitting elements.

[0044] Up to this point, an example has been described in which the light emitting device ED includes the first light emitting element 101, the second light emitting element 102, and the third light emitting element 103. However, the light emitting device ED may also include a fourth light emitting element 104 that emits visible light. The fourth light emitting element 104 includes a fourth reflective layer 84, a fourth lower electrode 24 disposed on the fourth reflective layer 84, a fourth light emitting layer 34 disposed on the fourth lower electrode 24, and a fourth upper electrode 44 disposed on the fourth light emitting layer 34. The distance from the upper surface of the fourth reflective layer 84 to the upper surface of the fourth lower electrode 24 is preferably different from the distance from the upper surface of the first reflective layer 81 to the upper surface of the first lower electrode 21 and the distance from the upper surface of the second reflective layer 82 to the upper surface of the second lower electrode 22. By making these distances different, the chromaticities of the first light emitting element 101, the second light emitting element 102, and the fourth light emitting element 104 can be made different, thereby improving the luminous efficiency. By using blue, green and red light emitting elements as the first light emitting element 101, the second light emitting element 102 and the fourth light emitting element 104, respectively, a full color display is possible.

[0045] The first light-emitting element 101, the second light-emitting element 102, the fourth light-emitting element 104, and the infrared light-emitting element 103 can each be considered as a sub-pixel, and the four light-emitting elements can be considered to constitute one main pixel. The arrangement of the multiple sub-pixels in the main pixel may be any arrangement, such as a stripe arrangement or a Bayer arrangement. Furthermore, a display device can be constructed by arranging multiple main pixels within a display plane.

[0046] In the first embodiment, the fourth light-emitting element 104 may be a red light-emitting element that emits red light. Furthermore, the distance from the upper surface of the fourth reflective layer 84 to the upper surface of the fourth lower electrode 24 in the fourth light-emitting element 104 as a red light-emitting element is shorter than the distance from the upper surface of the third reflective layer 83 to the upper surface of the third lower electrode 43 in the third light-emitting element 103 as an infrared light-emitting element. In the first embodiment, the first light-emitting element 101 may be a blue light-emitting element that emits blue light, and the second light-emitting element 102 may be a green light-emitting element that emits green light.

[0047] The second light-emitting element 102 and the fourth light-emitting element 104 may be disposed adjacent to each other, and the second lower electrode 22 of the second light-emitting element 102 and the fourth lower electrode 24 of the fourth light-emitting element 104 may be separated from each other by an insulating layer 5. The insulating layer 5 between the second lower electrode 22 and the fourth lower electrode 24 may have a step corresponding to the difference in height between the upper surface of the second lower electrode 22 and the upper surface of the fourth lower electrode 24. Second Embodiment The second embodiment will be described below. Fig. 2 is a cross-sectional view showing a schematic configuration of a light emitting device ED according to the second embodiment. Matters not mentioned in the second embodiment may follow those of the first embodiment.

[0048] In the second embodiment as well, the distance from the upper surface of the first reflective layer 81 in the first light-emitting element 101 to the upper surface of the first lower electrode 21 is different from the distance from the upper surface of the second reflective layer 82 to the upper surface of the second lower electrode 22 in the second light-emitting element 102. Moreover, the distance from the upper surface of the first reflective layer 81 in the first light-emitting element 101 to the upper surface of the first lower electrode 21 is approximately the same as the distance from the upper surface of the third reflective layer 83 to the upper surface of the third lower electrode 23 in the third light-emitting element (infrared light-emitting element) 103.

[0049] In the second embodiment, the film thickness of the first lower electrode 21 and the film thickness of the second lower electrode 22 are different from each other, and the film thickness of the first lower electrode 21 and the film thickness of the third lower electrode 23 are approximately the same from each other. This makes it possible to realize shapes in which the distance from the upper surface of the first reflective layer 81 to the upper surface of the first lower electrode 21 and the distance from the upper surface of the second reflective layer 82 to the upper surface of the second lower electrode 22 are different from each other. On the other hand, the distance from the upper surface of the first reflective layer 81 to the upper surface of the first lower electrode 21 and the distance from the upper surface of the third reflective layer 83 to the upper surface of the third lower electrode 23 are approximately the same from each other.

[0050] In each light-emitting element, the reflective layer and the lower electrode may be in contact with each other, or a light-transmitting layer may be disposed between the reflective layer and the lower electrode. When a light-transmitting layer is disposed between the reflective layer and the lower electrode, it is preferable that the thickness of the light-transmitting layer of each of the light-emitting elements is approximately the same. (Third embodiment) The third embodiment will be described below. Fig. 3 is a cross-sectional view schematically showing the configuration of a light emitting device ED according to the third embodiment. Matters not mentioned in the third embodiment may follow the first or second embodiment.

[0051] In the third embodiment, the first light-emitting layer 31 of the first light-emitting element 101 and the third light-emitting layer 33 of the third light-emitting element (infrared light-emitting element) 103 are separated. Also, in the third embodiment, the second light-emitting layer 32 of the second light-emitting element 102 and the third light-emitting layer 33 of the third light-emitting element (infrared light-emitting element) 103 are separated. Also, when the fourth light-emitting element 104 is provided, the fourth light-emitting layer 34 of the fourth light-emitting element 104 and the third light-emitting layer 33 of the third light-emitting element (infrared light-emitting element) 103 are separated. From another perspective, in the third embodiment, the light-emitting layer of the light-emitting element for displaying an image and the light-emitting layer of the light-emitting element that emits infrared light are separated. Such a configuration is advantageous for increasing the light-emitting efficiency of each light-emitting element. (Fourth embodiment) The fourth embodiment will be described below. Fig. 4 is a cross-sectional view showing a schematic configuration of a light emitting device ED according to the fourth embodiment. Matters not mentioned in the fourth embodiment may follow the first or second embodiment.

[0052] In the fourth embodiment, adjacent light-emitting layers may be separated from each other. For example, the first light-emitting layer 31 of the first light-emitting element 101 and the second light-emitting layer 32 of the second light-emitting element 102 may be separated from each other. Furthermore, when the fourth light-emitting element 104 is provided, the second light-emitting layer 32 of the second light-emitting element 102 and the second light-emitting layer 34 of the fourth light-emitting element 104 may be separated from each other. Furthermore, the third light-emitting layer 33 of the third light-emitting element 103 may also be separated from the light-emitting layers of the other light-emitting elements. Such a configuration is advantageous for increasing the luminous efficiency of each light-emitting element. Fifth Embodiment The fifth embodiment will be described below. Fig. 5 is a cross-sectional view showing a schematic configuration of a light emitting device ED according to the fifth embodiment. Matters not mentioned in the fifth embodiment may follow those of the first to fourth embodiments.

[0053] The light-emitting device ED of the fifth embodiment includes a display region DR and an infrared light emission region IRR. The infrared light emission region IRR is disposed outside the display region DR. The display region DR may include a plurality of first light-emitting elements 101, a plurality of second light-emitting elements 102, and a plurality of fourth light-emitting elements 103. The infrared light emission region IRR may include one or a plurality of third light-emitting elements (infrared light-emitting elements) 103. This configuration is advantageous for increasing the area (pixel area) of the first light-emitting element 101, the second light-emitting element 102, and the fourth light-emitting element 104 within the display region DR, which makes it possible to suppress, for example, deterioration in brightness of the light-emitting elements due to driving the light-emitting elements.

[0054] The first light-emitting element 101, the second light-emitting element 102, and the fourth light-emitting element 104 can each be considered a sub-pixel, and the three light-emitting elements can be considered one main pixel. The pixel arrangement of the multiple sub-pixels within the main pixel may be any pixel arrangement, such as a delta arrangement, a stripe arrangement, or a Bayer arrangement. In particular, the delta arrangement is preferable because it makes it easy to arrange circular lenses within the display region DR. (Sixth embodiment) The sixth embodiment will be described below. Fig. 6 is a cross-sectional view showing a schematic configuration of a light emitting device ED according to the sixth embodiment. Matters not mentioned in the sixth embodiment may follow those of the first to fifth embodiments.

[0055] In the sixth embodiment, a planarization layer 7 may be disposed on the sealing layer 6. The planarization layer 7 is preferably formed by a wet process such as spin coating, dip coating, slit coating, or blade coating. A wet process is advantageous for flattening the light-emitting surface of the planarization layer 7. When forming the planarization layer 7 by a wet process, it is preferable to first dispose or apply a material for forming the planarization layer 7 on the sealing layer 6, and then harden the material by a hardening method such as heating or UV irradiation. The planarization layer 7 may be a continuous planarization film that covers all of the sealing layers 6 of each of the multiple light-emitting elements.

[0056] Furthermore, a first color filter 111, a second color filter 112, a fourth color filter 114, and an infrared color filter 113 may be provided above the first light-emitting element 101, the second light-emitting element 102, the fourth light-emitting element 104, and the infrared light-emitting element 103, respectively. The wavelength range of light transmitted by the first color filter 111, the second color filter 112, the fourth color filter 114, and the infrared color filter 113 can be adjusted. Each color filter can be formed by applying a color resist onto the planarization film 7 and then patterning it by lithography. The color resist is made of, for example, a photocurable resin, and a pattern can be formed by curing a portion irradiated with ultraviolet light or the like.

[0057] A first lens 121, a second lens 122, a fourth lens 124, and a third lens 123 may be provided on the light-emitting side of the first light-emitting element 101, the second light-emitting element 102, the fourth light-emitting element 104, and the infrared light-emitting element 103, respectively. Providing lenses for each light-emitting element can improve the light-emitting efficiency of the light-emitting element. The lenses are optically transparent and may be made of organic materials such as acrylic resin, epoxy resin, and silicone resin, or inorganic materials such as silicon nitride (SiN), silicon oxynitride (SiON), and silicon oxide (SiO). The lenses may be convex or concave. In the case of a convex shape, a material with a lower refractive index than the material constituting the lens may be disposed on the light-emitting side of the lens. Gases such as air and nitrogen, materials with a low refractive index such as silica aerogel, and vacuum are particularly preferred. When a convex lens is made of a highly refractive material such as SiN, the light-emitting side of the lens may also be made of a material with a relatively low refractive index, such as an organic material such as acrylic resin, epoxy resin, and silicone resin, or an inorganic material such as silicon oxide (SiO). In the case of a concave lens, a material having a higher refractive index than the material constituting the lens may be disposed on the light exit side of the lens. The shape of the lens is not particularly limited, and spherical, aspherical, or other shapes may be adopted. (Application example) Hereinafter, several embodiments of application examples of the light-emitting device ED will be described by way of example. The light-emitting device ED can be used, for example, as a component of a display device or a lighting device. In addition, the light-emitting device ED can be used as an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, etc.

[0058] The display device includes an image input unit that receives image information from an area CCD, a linear CCD, a memory card, etc., an information processing unit that processes the received image information, and a display unit that displays the received image information or the processed image information, and the display unit can be constituted by a light-emitting device ED.

[0059] The light-emitting device ED may also be configured as a display unit of an imaging device or a printer. Such a display unit may be provided with a touch panel function. The driving method for the touch panel function may be an infrared type, a capacitance type, a resistive film type, or an electromagnetic induction type, and is not particularly limited. The light-emitting device ED may also be configured as a display unit of a multifunction printer.

[0060] FIG. 7 shows an example in which the light-emitting device ED is applied to a display device. The display device 1000 may have a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. The light-emitting device ED may be configured as the display panel 1005. The touch panel 1003 and the display panel 1005 are connected by flexible printed circuits FPCs 1002 and 1004. Transistors are printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different position even if the display device is a portable device.

[0061] The light emitting device ED configured as the display panel 1005 may have color filters having red, green, and blue colors, and the red, green, and blue colors may be arranged in a delta configuration in the color filters.

[0062] The light-emitting device ED may be configured as a display unit of a mobile terminal. In this case, the light-emitting device ED may be configured to have both a display function and an operation function. Examples of the mobile terminal include a mobile phone such as a smartphone, a tablet, and a head-mounted display.

[0063] The light-emitting device ED may be configured as a display unit of an imaging device having an optical unit with multiple lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information acquired by the imaging element. The display unit may be a display unit exposed to the outside of the imaging device or a display unit disposed within the viewfinder. The imaging device may be a digital camera or a digital video camera.

[0064] 8(a) is a diagram showing an example in which the light emitting device ED is applied to an imaging device. The imaging device 1100 may have a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may be configured with the light emitting device ED. In this case, the viewfinder 1101 may display not only an image to be captured, but also environmental information, imaging instructions, etc. The environmental information may include the intensity of external light, the direction of external light, the speed at which the subject is moving, the possibility that the subject will be blocked by an obstruction, etc.

[0065] Since the optimum timing for capturing an image is very short, it is better to display information as soon as possible. Therefore, it is preferable to use a display device using the organic light-emitting element of the present invention. This is because the organic light-emitting element has a fast response speed. A display device using an organic light-emitting element can be used more preferably than a liquid crystal display device, which requires a high display speed.

[0066] The imaging device 1100 has an optical section (not shown). The optical section has multiple lenses, which form an image on an imaging element housed in a housing 1104. The focus of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically. The imaging device may also be called a photoelectric conversion device. Instead of sequentially capturing images, the photoelectric conversion device can include an imaging method that detects the difference from the previous image, or a method of cutting out an image from a constantly recorded image, etc.

[0067] FIG. 8(b) is a diagram showing an example in which the light-emitting device ED is applied to an electronic device. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The light-emitting device ED can be configured as the display unit 1201. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit may be a biometric recognition unit that recognizes a fingerprint to perform operations such as unlocking. An electronic device having a communication unit can also be called a communication device. The electronic device may further have a camera function by including a lens and an image sensor. An image captured by the camera function is displayed on the display unit 1201. Examples of the electronic device include a smartphone and a laptop computer.

[0068] 9(a) and 9(b) show examples in which the light-emitting device ED is applied to a display device. FIG. 9(a) shows a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The display unit 1302 can be formed by the light-emitting device ED.

[0069] The display device has a frame 1301 and a base 1303 that supports a display unit 1302. The base 1303 is not limited to the form shown in FIG. 9(a). The bottom side of the frame 1301 may also serve as the base. The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0070] FIG. 9(b) shows another example in which the light-emitting device ED is applied to a display device. The display device 1310 in FIG. 9(b) is configured to be bendable, and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The first display unit 1311 and the second display unit 1312 can be configured with the light-emitting device ED. The first display unit 1311 and the second display unit 1312 may be a single, seamless display unit. The first display unit 1311 and the second display unit 1312 can be separated by the bending point. The first display unit 1311 and the second display unit 1312 may each display different images, or the first and second display units may display a single image.

[0071] 10(a) and 10(b) show examples in which the light-emitting device ED is applied to a wearable device. The light-emitting device ED can be applied to the display unit of a wearable device such as smart glasses, an HMD, or a smart contact lens. Such an application example can include an imaging device capable of photoelectrically converting visible light and a display device capable of emitting visible light.

[0072] 10(a) is a diagram illustrating glasses 1600 (smart glasses) according to one application example. An imaging device 1602 such as a CMOS sensor or SPAD is provided on the front side of a lens 1601 of the glasses 1600. In addition, a display device constituted by a light-emitting device ED is provided on the back side of the lens 1601.

[0073] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the image capture device 1602 and the display device according to each embodiment. The control device 1603 also controls the operations of the image capture device 1602 and the display device. The lens 1601 is formed with an optical system for focusing light onto the image capture device 1602.

[0074] FIG. 10(b) illustrates glasses 1610 (smart glasses) according to another application example. The glasses 1610 include a control device 1612. The control device 1612 is equipped with an imaging device equivalent to the imaging device 1602 and a display device. A lens 1611 is formed with an optical system for projecting light emitted by the display device within the control device 1612, and an image is projected onto the lens 1611. The control device 1612 functions as a power source for supplying power to the imaging device and the display device and controls the operation of the imaging device and the display device. The control device may also include a gaze detection unit for detecting the wearer's gaze. The gaze detection may be performed using infrared light emitted by an infrared light-emitting element of a display device incorporating the light-emitting device ED. The infrared light-emitting unit emits infrared light toward the eyeball of a user gazing at a displayed image. An imaging unit with a light-receiving element detects the reflected light of the emitted infrared light from the eyeball, thereby obtaining an image of the eyeball. A reduction unit for reducing light from the infrared light-emitting unit to the display unit in a planar view reduces degradation of image quality.

[0075] The gaze of the user relative to the displayed image is detected from an image of the eyeball obtained by capturing infrared light. Any known method can be used for gaze detection using an image of the eyeball. One example is a gaze detection method based on the Purkinje image formed by reflection of irradiated light on the cornea.

[0076] More specifically, gaze detection processing is performed based on the pupil-corneal reflex method, which calculates a gaze vector representing the direction (rotation angle) of the eyeball based on the pupil image and Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0077] A display device according to an embodiment may have an imaging device having a light receiving element, and may control the image displayed on the display device based on information about the user's line of sight from the imaging device.

[0078] Specifically, the display device determines a first display area on which the user gazes and a second display area other than the first display area based on the line-of-sight information. The first display area and the second display area may be determined by a control device of the display device, or may be determined by an external control device and received. In the display area of ​​the display device, the display resolution of the first display area may be controlled to be higher than the display resolution of the second display area. In other words, the resolution of the second display area may be lower than that of the first field of view area.

[0079] The display area includes a first display area and a second display area different from the first display area, and a high-priority area is determined from the first display area and the second display area based on line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received. The resolution of the high-priority area may be controlled to be higher than the resolution of areas other than the high-priority area. In other words, the resolution of an area with a relatively low priority may be lowered.

[0080] Note that AI may be used to determine the first display area and the area with high priority. The AI ​​may be a model configured to estimate the angle of gaze and the distance to an object in the line of sight from the image of the eyeball, using as training data an image of the eyeball and the actual direction in which the eyeball in the image was looking. The AI ​​program may be included in the display device, the imaging device, or an external device. If included in the external device, it is transmitted to the display device via communication.

[0081] When display control is performed based on visual recognition detection, the smart glasses can be preferably applied to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured external information in real time.

[0082] As described above, a device incorporating the light emitting device ED is advantageous in terms of improving light emitting efficiency, and makes it possible to display images for a long period of time, for example.

[0083] The present specification and drawings include the following disclosure. (Item 1) A light emitting device having a plurality of light emitting elements including a first light emitting element and a second light emitting element that emit visible light, and a third light emitting element that emits infrared light, each of the plurality of light-emitting elements includes a reflective layer, a lower electrode disposed on the reflective layer, a light-emitting layer disposed on the lower electrode, and an upper electrode disposed on the light-emitting layer; a distance from an upper surface of the reflective layer of the first light-emitting element to an upper surface of the lower electrode of the first light-emitting element is different from a distance from an upper surface of the reflective layer of the second light-emitting element to an upper surface of the lower electrode of the second light-emitting element, a distance from the upper surface of the reflective layer of the first light-emitting element to the upper surface of the lower electrode of the first light-emitting element is approximately the same as a distance from the upper surface of the reflective layer of the third light-emitting element to the upper surface of the lower electrode of the third light-emitting element; A light-emitting device characterized by: (Item 2) The light-emitting layer of the third light-emitting element contains an infrared light-emitting material, and when a PL emission spectrum peak wavelength of the infrared light-emitting material is λ3 and a distance from the upper surface of the reflective layer of the third light-emitting element to a lower surface of the upper electrode of the third light-emitting element is L3, 0.20≦λ3 / L3≦0.30 2. The light emitting device according to item 1, wherein the above-mentioned condition is satisfied. (Item 3) 160nm≦L3≦300nm 3. The light emitting device according to item 2, wherein the above-mentioned condition is satisfied. (Item 4) Let ND3 be the optical distance from the upper surface of the reflective layer of the third light-emitting element to the lower surface of the upper electrode of the third light-emitting element, φ3 be the sum of the phase shifts in the reflective layer of the third light-emitting element and the upper electrode of the third light-emitting element, and λ3 be the PL emission spectrum peak of the infrared light-emitting material of the light-emitting layer of the third light-emitting element. ND31≦ND3≦ND32, ND31=-φ3 / 4π×λ3×0.9, ND32=-φ3 / 4π×λ3×1.1 4. The light emitting device according to any one of items 1 to 3, wherein the above condition is satisfied. (Item 5) The light-emitting layer of the first light-emitting element contains a visible light-emitting material, and when a PL emission spectrum peak wavelength of the light-emitting material is λ1 and a distance from the upper surface of the reflective layer of the first light-emitting element to a lower surface of the upper electrode of the first light-emitting element is L1, 0.45≦λ1 / L1≦0.65 5. The light emitting device according to any one of items 1 to 4, wherein the above condition is satisfied. (Item 6) When the optical distance from the upper surface of the reflective layer of the first light-emitting element to the lower surface of the upper electrode of the first light-emitting element is ND1, the sum of the phase shifts of the reflective layer of the first light-emitting element and the upper electrode of the first light-emitting element is φ1, and the PL emission spectrum peak of the light-emitting material of the light-emitting layer of the first light-emitting element is λ1, ND11≦ND1≦ND12, ND11=(1-φ1 / 2π)×λ1×0.9, ND12=(1-φ1 / 2π)×λ1×1.1 6. The light emitting device according to any one of items 1 to 5, wherein the above condition is satisfied. (Item 7) The first light-emitting element is a blue light-emitting element. 7. The light emitting device according to any one of items 1 to 6, (Item 8) the first light-emitting element includes a transparent layer disposed between the reflective layer and the lower electrode; the third light-emitting element includes a transparent layer disposed between the reflective layer and the lower electrode; 2. The light emitting device according to item 1. (Item 9) the light-transmitting layer of the first light-emitting element and the light-transmitting layer of the third light-emitting element have substantially the same thickness; the lower electrode of the first light-emitting element and the lower electrode of the third light-emitting element have approximately the same thickness; 9. The light emitting device according to item 8, (Item 10) a light-emitting material contained in the light-emitting layer of the first light-emitting element and a light-emitting material contained in the light-emitting layer of the third light-emitting element are different from each other; 2. The light emitting device according to item 1. (Item 11) the reflective layer of the first light-emitting element and the lower electrode of the first light-emitting element are in contact with each other, and the reflective layer of the third light-emitting element and the lower electrode of the third light-emitting element are in contact with each other; 2. The light emitting device according to item 1. (Item 12) the first light-emitting element and the third light-emitting element are arranged adjacent to each other, the lower electrode of the first light-emitting element and the lower electrode of the third light-emitting element are separated from each other by an insulating layer; the insulating layer has a T-shape in a cross section taken through the reflective layer, the lower electrode, the light-emitting layer, and the upper electrode; 12. The light emitting device according to any one of items 1 to 11, (Item 13) the insulating layer has a flat upper surface; Item 13. The light emitting device according to item 12. (Item 14) A light emitting device having a plurality of light emitting elements including a first light emitting element that emits visible light, a second light emitting element that emits visible light having a wavelength different from that of the first light emitting element, and a third light emitting element that emits infrared light, each of the plurality of light-emitting elements includes a reflective layer, a lower electrode disposed on the reflective layer, a light-emitting layer disposed on the lower electrode, and an upper electrode disposed on the light-emitting layer; a first distance from an upper surface of the reflective layer of the first light-emitting element to an upper surface of the lower electrode of the first light-emitting element; a second distance from an upper surface of the reflective layer of the second light-emitting element to an upper surface of the lower electrode of the second light-emitting element; a third distance from an upper surface of the reflective layer of the third light-emitting element to an upper surface of the lower electrode of the third light-emitting element; a difference between the first distance and the third distance is smaller than a difference between the first distance and the second distance; A light-emitting device characterized by: (Item 15) Item 15. The light emitting device according to item 14, wherein the first distance and the third distance are substantially the same. (Item 16) the first light-emitting element and the third light-emitting element are arranged adjacent to each other, the lower electrode of the first light-emitting element and the lower electrode of the third light-emitting element are separated from each other by an insulating layer; the insulating layer has a T-shape in a cross section taken through the reflective layer, the lower electrode, the light-emitting layer, and the upper electrode; Item 16. The light emitting device according to item 15. (Item 17) the insulating layer has a flat upper surface; Item 17. The light emitting device according to item 16. (Item 18) A light emitting device having a plurality of light emitting elements including a red light emitting element that emits red light and an infrared light emitting element that emits infrared light, each of the plurality of light-emitting elements includes a reflective layer, a lower electrode disposed on the reflective layer, a light-emitting layer disposed on the lower electrode, and an upper electrode disposed on the light-emitting layer; a distance from an upper surface of the reflective layer of the infrared light-emitting element to an upper surface of the lower electrode of the infrared light-emitting element is smaller than a distance from an upper surface of the reflective layer of the red light-emitting element to an upper surface of the lower electrode of the red light-emitting element; A light-emitting device characterized by: (Item 19) 19. The light emitting device according to any one of items 1 to 18, configured as a display device. (Item 20) an optical unit having a plurality of lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays an image; 19. An imaging device, wherein the display unit displays an image captured by the imaging element, and the imaging device comprises the light-emitting device according to any one of items 1 to 18. (Item 21) A display unit is provided in the housing, and a communication unit is provided in the housing and communicates with an external device. 19. An electronic device, wherein the display unit comprises the light-emitting device according to any one of items 1 to 18. (Item 22) 1. A wearable device having a display device for displaying an image, A wearable device characterized in that the display device has the light-emitting device described in any one of items 1 to 18.

[0084] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0085] 1: substrate, 21, 22, 23, 24: lower electrode, 3: organic compound layer, 31, 32, 33, 34: light-emitting layer, 41, 42, 43, 44: upper electrode, 5: insulating layer, 6: sealing layer, 7: planarizing layer, 81, 82, 83, 84: reflective layer, 91, 92, 93, 94: light-transmitting layer, 101: first light-emitting element, 102: second light-emitting element, 103: infrared light-emitting element, 104: fourth light-emitting element, 111, 112, 113, 114: color filter, 121, 122, 123, 124, lens, DR: display area, IRR: infrared light-emitting area

Claims

1. A light emitting device having a plurality of light emitting elements including a first light emitting element and a second light emitting element that emit visible light, and a third light emitting element that emits infrared light, each of the plurality of light-emitting elements includes a reflective layer, a lower electrode disposed on the reflective layer, a light-emitting layer disposed on the lower electrode, and an upper electrode disposed on the light-emitting layer; a distance from an upper surface of the reflective layer of the first light-emitting element to an upper surface of the lower electrode of the first light-emitting element is different from a distance from an upper surface of the reflective layer of the second light-emitting element to an upper surface of the lower electrode of the second light-emitting element, a distance from the upper surface of the reflective layer of the first light-emitting element to the upper surface of the lower electrode of the first light-emitting element is approximately the same as a distance from the upper surface of the reflective layer of the third light-emitting element to the upper surface of the lower electrode of the third light-emitting element; A light-emitting device characterized by:

2. The light-emitting layer of the third light-emitting element contains an infrared light-emitting material, and when a PL emission spectrum peak wavelength of the infrared light-emitting material is λ3 and a distance from the upper surface of the reflective layer of the third light-emitting element to a lower surface of the upper electrode of the third light-emitting element is L3, 0.20≦λ3 / L3≦0.30 2. The light emitting device according to claim 1, wherein the following is satisfied:

3. 160 nm≦L3≦300 nm 3. The light emitting device according to claim 2, wherein the following is satisfied:

4. Let ND3 be the optical distance from the upper surface of the reflective layer of the third light-emitting element to the lower surface of the upper electrode of the third light-emitting element, φ3 be the sum of the phase shifts in the reflective layer of the third light-emitting element and the upper electrode of the third light-emitting element, and λ3 be the PL emission spectrum peak of the infrared light-emitting material of the light-emitting layer of the third light-emitting element. ND31≦ND3≦ND32, ND31=-φ3 / 4π×λ3×0.9, ND32=-φ3 / 4π×λ3×1.1 2. The light emitting device according to claim 1, wherein the following is satisfied:

5. The light-emitting layer of the first light-emitting element contains a visible light-emitting material, and the PL emission spectrum peak wavelength of the light-emitting material is λ1. The distance from the upper surface of the reflective layer of the first light-emitting element to the lower surface of the upper electrode of the first light-emitting element is L1. 0.45≦λ1 / L1≦0.65 2. The light emitting device according to claim 1, wherein the following is satisfied:

6. When the optical distance from the upper surface of the reflective layer of the first light-emitting element to the lower surface of the upper electrode of the first light-emitting element is ND1, the sum of the phase shifts of the reflective layer of the first light-emitting element and the upper electrode of the first light-emitting element is φ1, and the PL emission spectrum peak of the light-emitting material of the light-emitting layer of the first light-emitting element is λ1, ND11≦ND1≦ND12, ND11=(1-φ1 / 2π)×λ1×0.9, ND12=(1-φ1 / 2π)×λ1×1.1 2. The light emitting device according to claim 1, wherein the following is satisfied:

7. The first light-emitting element is a blue light-emitting element.

2. The light emitting device according to claim 1.

8. the first light-emitting element includes a transparent layer disposed between the reflective layer and the lower electrode; the third light-emitting element includes a transparent layer disposed between the reflective layer and the lower electrode; 2. The light emitting device according to claim 1.

9. the light-transmitting layer of the first light-emitting element and the light-transmitting layer of the third light-emitting element have substantially the same thickness; the lower electrode of the first light-emitting element and the lower electrode of the third light-emitting element have approximately the same thickness; 9. The light emitting device according to claim 8.

10. a light-emitting material contained in the light-emitting layer of the first light-emitting element and a light-emitting material contained in the light-emitting layer of the third light-emitting element are different from each other; 2. The light emitting device according to claim 1.

11. the reflective layer of the first light-emitting element and the lower electrode of the first light-emitting element are in contact with each other, and the reflective layer of the third light-emitting element and the lower electrode of the third light-emitting element are in contact with each other; 2. The light emitting device according to claim 1.

12. the first light-emitting element and the third light-emitting element are arranged adjacent to each other, the lower electrode of the first light-emitting element and the lower electrode of the third light-emitting element are separated from each other by an insulating layer; the insulating layer has a T-shape in a cross section taken through the reflective layer, the lower electrode, the light-emitting layer, and the upper electrode; 2. The light emitting device according to claim 1.

13. the insulating layer has a flat upper surface; 13. The light emitting device according to claim 12.

14. A light emitting device having a plurality of light emitting elements including a first light emitting element that emits visible light, a second light emitting element that emits visible light having a wavelength different from that of the first light emitting element, and a third light emitting element that emits infrared light, each of the plurality of light-emitting elements includes a reflective layer, a lower electrode disposed on the reflective layer, a light-emitting layer disposed on the lower electrode, and an upper electrode disposed on the light-emitting layer; a first distance from an upper surface of the reflective layer of the first light-emitting element to an upper surface of the lower electrode of the first light-emitting element; a second distance from an upper surface of the reflective layer of the second light-emitting element to an upper surface of the lower electrode of the second light-emitting element; a third distance from an upper surface of the reflective layer of the third light-emitting element to an upper surface of the lower electrode of the third light-emitting element; a difference between the first distance and the third distance is smaller than a difference between the first distance and the second distance; A light-emitting device characterized by:

15. The light emitting device of claim 14 , wherein the first distance and the third distance are substantially the same.

16. the first light-emitting element and the third light-emitting element are arranged adjacent to each other, the lower electrode of the first light-emitting element and the lower electrode of the third light-emitting element are separated from each other by an insulating layer; the insulating layer has a T-shape in a cross section taken through the reflective layer, the lower electrode, the light-emitting layer, and the upper electrode; 16. The light emitting device according to claim 15.

17. the insulating layer has a flat upper surface; 17. The light emitting device according to claim 16.

18. A light emitting device having a plurality of light emitting elements including a red light emitting element that emits red light and an infrared light emitting element that emits infrared light, each of the plurality of light-emitting elements includes a reflective layer, a lower electrode disposed on the reflective layer, a light-emitting layer disposed on the lower electrode, and an upper electrode disposed on the light-emitting layer; a distance from an upper surface of the reflective layer of the infrared light-emitting element to an upper surface of the lower electrode of the infrared light-emitting element is smaller than a distance from an upper surface of the reflective layer of the red light-emitting element to an upper surface of the lower electrode of the red light-emitting element; A light-emitting device characterized by:

19. 19. The light emitting device according to claim 1, configured as a display device.

20. an optical unit having a plurality of lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays an image; 19. An imaging apparatus, wherein the display section displays an image captured by the imaging element, and the imaging apparatus comprises the light emitting device according to claim 1.

21. A display unit is provided in the housing, and a communication unit is provided in the housing and communicates with an external device.

19. An electronic device, wherein the display unit comprises the light-emitting device according to claim 1.

22. 1. A wearable device having a display device for displaying an image, A wearable device, wherein the display device comprises the light-emitting device according to claim 1 .

Images