Light-emitting device, display device, imaging device, and electronic device

Abstract

The present disclosure provides a light-emitting device having an insulating layer, a light-emitting element that is arranged on a main surface of the insulating layer, that includes a light-emitting material, and that has a resonator structure, and a lens provided on the light-emitting element. The light-emitting device has, between the main surface of the insulating layer and the light-emitting material, an electrode for supplying electric charges to the light-emitting material, and an end and the other end of the electrode are covered with a pixel separation layer. The PL spectrum of the light-emitting material has a first peak with a wavelength of λpl in a visible light region. The light-emitting device is characterized in that in the resonator structure, a resonance peak wavelength λon of an interference spectrum that intensifies light emitted in a direction perpendicular to the main surface, a peak wavelength λEL of an EL light emission radiated via a light-extraction structure, and the λPL satisfy the following formula (1). Formula (1): |λEL - λPL| < |λon - λPL|

Description

[Technical Field]

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

[0002] An organic light-emitting device (also known as an organic electroluminescent device or OLED) is an electronic device that has a pair of electrodes and an organic compound layer disposed between the electrodes. Injecting electrons and holes from the pair of electrodes into the organic compound layer generates excitons from the light-emitting organic compound in the organic compound layer. When the excitons return to their ground state, the organic light-emitting device emits light. Recent advances in organic light-emitting devices have been remarkable, including low driving voltages, diverse emission wavelengths, fast response, and thinner, light-emitting devices. However, organic light-emitting devices have low light extraction efficiency because much of the light is trapped within the device and not extracted to the outside. To improve light extraction efficiency, organic light-emitting devices are sometimes equipped with light extraction structures such as microlenses. Patent Document 1 describes an organic light-emitting device equipped with a microlens as an outcoupling component to increase the amount of light extracted from the OLED. The organic light-emitting device in Patent Document 1 specifies the diameter of the microlens and the distance between the lens and the light-emitting region to address issues such as optical crosstalk and low contrast due to backscattering. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-17013 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the organic light-emitting device of Patent Document 1 does not specify interference conditions, and is not sufficiently configured to emit desired light in the normal direction of the substrate (that is, in the front direction). [Means for solving the problem]

[0005] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide an organic light-emitting element that has high radiance in the front direction by providing a light extraction structure such as a microlens and using optical interference that takes the light extraction structure into consideration.

[0006] an insulating layer; a light-emitting element including a light-emitting material and having a resonator structure, the light-emitting element being disposed on a main surface of the insulating layer; lens and The PL spectrum of the luminescent material has a wavelength λ PL a light emitting device having a first peak which is the light-emitting device has an electrode between a main surface of the insulating layer and the light-emitting material, the electrode supplying electric charges to the light-emitting material, and one end and the other end of the electrode are covered with a pixel separation layer; In the resonator structure, a resonance peak wavelength λ of an interference spectrum that intensifies light emitted in a direction perpendicular to the main surface on and the above lens The peak wavelength λ of the EL emission emitted through EL and the λ PL and a light-emitting device characterized in that the following formula (1) is satisfied: |λ EL -λ PL | < |λ on -λ PL | (1) [Effects of the Invention]

[0007] According to the present invention, by providing a light extraction structure and using optical interference in consideration of the light extraction structure, it is possible to provide an organic light emitting device having high radiance in the front direction. [Brief explanation of the drawings]

[0008] [Figure 1A] 1 is a plan view of a light emitting device according to an embodiment of the present invention. [Figure 1B] FIG. 1B is an enlarged view of the dashed line portion in FIG. 1A. [Figure 2A] FIG. 10 is a cross-sectional view schematically illustrating an example in which the light extraction structure of the light emitting device has a convex microlens on the side opposite to the substrate. [Figure 2B] FIG. 10 is a cross-sectional view schematically illustrating an example in which the light extraction structure of the light emitting device has a convex microlens on the substrate side. [Figure 3A] 1 is a schematic diagram showing light emitted from a light-emitting point toward the front of the light-emitting device. FIG. [Figure 3B] FIG. 2 is a schematic diagram showing light emitted from a light-emitting point in a direction inclined with respect to the main surface of the substrate. [Figure 4A] FIG. 10 is a schematic diagram showing a method for estimating Θeml, using a spherical microlens as an example of a light extraction structure. [Figure 4B] FIG. 10 is a schematic diagram showing a method for estimating Θeml, using a spherical microlens as an example of a light extraction structure. [Figure 4C] FIG. 10 is a schematic diagram showing a method for estimating Θeml, using a spherical microlens as an example of a light extraction structure. [Figure 4D] FIG. 10 is a schematic diagram showing a method for estimating Θeml, using a spherical microlens as an example of a light extraction structure. [Figure 5] (a) Graph showing the PL spectrum and interference spectra λoff and λon of a light-emitting substance according to a comparative example. (b) Graph showing the PL spectrum and interference spectra λoff and λon of a light-emitting substance in a light-emitting device that reinforces light emitted in a direction tilted relative to the substrate main surface. (c) and (d) are EL spectra of (a) and (b). [Figure 6A] 10 is a schematic diagram showing light refracted by a microlens in a conventional configuration in which the microlens is shifted to match the interference peak resonance wavelengths λon and λPL in the front direction of the main surface of the substrate. FIG. [Figure 6B] 10 is a schematic diagram showing light refracted by a microlens in a configuration in which the interference peak resonance wavelengths λoff and λPL in a direction inclined with respect to the main surface of the substrate are made to coincide with each other. FIG. [Figure 7A] FIG. 10 is a plan view of a display area showing that the relative positions of the microlenses and the pixels vary depending on the position in the display area. [Figure 7B] FIG. 7B is a schematic cross-sectional view taken along line EE' in FIG. 7A. [Figure 8A]10A and 10B are diagrams illustrating another example of the configuration of a light emitting device according to an embodiment of the present invention. [Figure 8B] 10A and 10B are diagrams illustrating another example of the configuration of a light emitting device according to an embodiment of the present invention. [Figure 8C] 10A and 10B are diagrams illustrating another example of the configuration of a light emitting device according to an embodiment of the present invention. [Figure 8D] 10A and 10B are diagrams illustrating another example of the configuration of a light emitting device according to an embodiment of the present invention. [Figure 9] FIG. 10 is a diagram showing the relationship between the radiation angle and the relative light amount in the light-emitting layer obtained by ray tracing. [Figure 10] 1 shows the PL spectrum PL1 of the luminescent material used in Example 1. [Figure 11] 1 is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention. [Figure 12A] 1 is a schematic diagram illustrating an example of an imaging device according to an embodiment of the present invention. [Figure 12B] 1 is a schematic diagram illustrating an example of an electronic device according to an embodiment of the present invention. [Figure 13A] 1 is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention. [Figure 13B] FIG. 1 is a schematic diagram illustrating an example of a foldable display device. [Figure 14A] FIG. 1 is a schematic diagram illustrating an example of a wearable device according to an embodiment of the present invention. [Figure 14B] 1 is a schematic diagram showing an example of a wearable device according to an embodiment of the present invention, the device having an imaging device. DETAILED DESCRIPTION OF THE INVENTION

[0009] A light-emitting device according to one embodiment of the present invention has an interference structure of an organic film aligned with the inclined portion of the light-extraction structure, thereby increasing the radiation intensity in the front direction of an organic EL element having the light-extraction structure. This is because light of the PL peak wavelength of the light-emitting material is effectively intensified and refracted in the front direction by the inclined portion of the light-extraction structure. The light-emitting device has an electrode between the main surface of the insulating layer and the light-emitting material that supplies charge to the light-emitting material, and one end and the other end of the electrode are covered with a pixel separation layer.

[0010] That is, a light emitting device according to one embodiment of the present invention includes an insulating layer, a light emitting element including a luminescent material and having a resonator structure, the light emitting element being disposed on a main surface of the insulating layer, and a light extraction structure being provided on the light emitting element, and the PL spectrum of the luminescent material has a wavelength λ within the visible light region. PL a resonant peak wavelength λ of an interference spectrum that intensifies light emitted in a direction perpendicular to the main surface in the resonator structure, on and the peak wavelength λ of EL light emitted through the light extraction structure. EL and the λ PL and satisfy the following formula (1): |λ EL -λ PL | < |λ on -λ PL | (1)

[0011] Furthermore, a light emitting device according to one embodiment of the present invention includes an insulating layer, a light emitting element including a luminescent material and having a resonator structure, the light emitting element being disposed on a main surface of the insulating layer, and a light extraction structure being provided on the light emitting element, wherein the PL spectrum of the luminescent material has a wavelength λ within a visible light region. PL a resonant peak wavelength λ of an interference spectrum that intensifies light emitted in a direction perpendicular to the main surface in the resonator structure, on and a resonant peak wavelength λ of an interference spectrum that intensifies light emitted in a direction perpendicular to the main surface due to refraction in the light extraction structure. off and the λ PLand may be a light emitting device characterized in that they satisfy the following formula (2): |λ off -λ PL | < |λ on -λ PL | (2)

[0012] In another embodiment, λ off is the distance from the light emitting region to the bottom end of the upper electrode of the light emitting element in the direction of the curved surface of the light extraction structure, λ on Alternatively, the distance from the light emitting region to the lower end of the upper electrode of the light emitting element in the direction perpendicular to the insulating layer can be used. Since the actual distance is used, the design is easy.

[0013] Hereinafter, a light emitting device according to one embodiment of the present invention will be described with reference to the drawings. It should be noted that, for parts not specifically shown or described in this specification, known techniques in the relevant technical field can be applied. Furthermore, the present invention is not limited to the embodiment described below.

[0014] FIG. 1A is a plan view of a light-emitting device according to one embodiment of the present invention. In this embodiment, the light-emitting device is a display device in which a plurality of light-emitting elements, including a first light-emitting element and a second light-emitting element, are arranged, each emitting a different color to display an image or the like. The display device has a display area 1 in which light-emitting elements 3 are arranged two-dimensionally on the main surface of an insulating layer such as a substrate, and in which images or the like are displayed. The arrangement of the light-emitting elements in FIGS. 1A and 1B is a delta arrangement, but may also be a stripe arrangement, square arrangement, Pentile arrangement, or Bayer arrangement. The edges of the display area are indicated by dashed lines and are designated as edges 2.

[0015] FIG. 1B is an enlarged view of the dashed line portion indicated by the edge 2 in FIG. 1A. The device has a light-emitting element 3 disposed on the main surface of the insulating layer and a light extraction structure 4 into which light from the light-emitting region of the light-emitting element 3 is incident. In FIG. 1B, the center of the light-emitting region and the center of the light extraction structure coincide in a plan view perpendicular to the main surface of the substrate. In this embodiment, the light-emitting region is hexagonal, but the shape is not limited thereto. If the light-emitting region is polygonal, the center can be estimated as the center of the inscribed circle of the polygon. If the light-emitting region is circular, the center of the circle can be estimated as the center of the light-emitting region.

[0016] 2A and 2B are cross-sectional schematic diagrams of a light-emitting device according to one embodiment of the present invention. The cross-sectional schematic diagrams shown here are the arrangement of the light-emitting device when viewed from a direction perpendicular to the main surface of the insulating layer (the normal direction to the main surface). FIG. 2A shows an example in which the light-extraction structure of the light-emitting device is a microlens that is convex on the side opposite to the substrate. The light-emitting device according to this embodiment has a reflective layer 6, an organic layer 7 containing a light-emitting substance, a semi-transparent electrode 8, a protective layer 9, and a microlens 10 on a substrate 5. The reflective layer 6 and the semi-transparent electrode 8 are also referred to as a lower electrode and an upper electrode, respectively, based on their positions. The PL spectrum of the light-emitting substance has a wavelength λ in the visible light region. PL The light-emitting element may have a resonator structure that intensifies the emitted light by the optical distance between the reflective layer 6 and the semi-transparent electrode 8. Here, the organic layer 7 is used for the description, but the light-emitting element may be organic or inorganic. In particular, when the light-emitting material is organic, the light-emitting device of this embodiment can be called an organic light-emitting device, and the light-emitting element can be called an organic light-emitting element. In this embodiment, the reflective layer also serves as an electrode, so it can also be called a reflective electrode.

[0017] In the resonator structure, the resonant peak wavelength λ of the interference spectrum that intensifies the light emitted in the direction perpendicular to the main surface of the substrate onThe light emitted in the direction perpendicular to the main surface of the substrate can also be referred to as light extracted in the direction perpendicular to the main surface of the substrate without a light extraction structure. In other words, the light is emitted in the front direction of the substrate without being refraction by the light extraction structure. The resonator structure also has a peak wavelength λ of the EL light emitted through the light extraction structure. EL λ EL is the wavelength of light emitted from the front of the substrate, taking into account optical interference due to the resonator structure and refraction due to the light extraction structure. Here, PL emission and PL spectra are properties of the light-emitting material, regardless of the structure of the light-emitting device. PL spectra can be obtained, for example, by forming an emitting layer containing the luminescent material of an organic light-emitting device on a substrate and causing it to emit light through photoexcitation. While it is preferable to reproduce the luminescent layer, PL emission can be measured using any solid film of the luminescent material. In contrast, EL emission and EL spectra are luminescence characteristics that take into account the optical distance between electrodes and the effects of the light extraction structure.

[0018] The light emitting device according to this embodiment has a first peak λ of the luminescent material. PL and λ EL , λ on is a light emitting device that satisfies the following formula (1), and by satisfying this formula, a light emitting device with good luminance emitted from the front surface of the substrate can be obtained. |λ EL -λ PL | < |λ on -λ PL | (1)

[0019] Satisfying formula (1) means that the difference between the wavelength of the EL emission and the first peak wavelength of the luminescent material is equal to or less than the interference peak λ on and the first peak wavelength of the luminescent material.

[0020] |λ on -λ PL | is λ PL The full width at half maximum of the peak may be smaller than that of the peak.

[0021] The light emitting device according to this embodiment has a resonator structure, and the resonant peak wavelength λ of the interference spectrum that intensifies the light emitted in the direction perpendicular to the main surface of the substrate due to refraction in the light extraction structure. off The light emitted in the front direction of the substrate due to refraction in the light extraction structure is light that is emitted from the light-emitting material and reflected by the reflective layer in a direction inclined with respect to the main surface of the substrate. In FIG. 2A, emitted light 12 is emitted from point 11 where the light-emitting material is emitting light. The emitted light is refracted by inclined portion 13 of microlens 10 and emitted in the front direction of the substrate.

[0022] The light emitting device according to this embodiment has a λ PL and λ off and λ on is a light emitting device that satisfies the following formula (2), and by satisfying this formula, a light emitting device with good luminance emitted from the front surface of the substrate can be obtained. |λ off -λ PL | < |λ on -λ PL | (2)

[0023] Equation (2) indicates that the difference between the interference peak λoff and the first peak wavelength of the luminescent material is smaller than the difference between the interference peak λon and the first peak wavelength of the luminescent material. In other words, it indicates that the first peak wavelength of the luminescent material is closer to the interference peak that intensifies light emitted in the front direction of the substrate via the light extraction structure than to the interference peak that intensifies light emitted in the front direction of the substrate. In other words, the interference peak that intensifies light emitted at an angle oblique to the substrate is closer to the first peak of the luminescent material. Here, the first peak may be the peak with the highest intensity in the PL spectrum of the luminescent material in the visible range. If the PL spectrum has a second peak, the second peak may be the peak with the second highest intensity after the first peak. The luminescent material is also called an emitting dopant. |λ on -λ PL | may be equal to or less than the full width at half maximum of λPL.

[0024] If there is a second peak, the wavelength of the second peak is λ PL2 It is preferable that the following formula (3) is satisfied. |λ off -λ PL |≦|λ on -λ PL2 | (3)

[0025] Equation (3) is the interference peak λ off and the first peak λ PL The difference between the interference peak λ on and the second peak λ PL2 In other words, the first peak may be given priority over the second peak and designed to match the interference peak. off The second peak coincides with λ on If the formula (3) is satisfied, the brightness on the front side of the substrate can be further improved, which is preferable. on -λ PL2 | may be equal to or less than the full width at half maximum of the second peak.

[0026] In contrast, the light emitting device may have a second light emitting element different from the light emitting element, and the second light emitting element may be an element that does not satisfy formula (1). The second light emitting element may be an element that emits light of a color different from the light emitting element. Since the second light emitting element has a different emission color, the light emitting device may have a light emitting element that does not satisfy either formula (1) or formula (2), taking into consideration the balance of front luminance. The emission color of the second light emitting element that does not satisfy formula (1) or formula (2) may be determined by the balance of RGB of the light emitting device, and may be blue, green, red, or a combination thereof.

[0027] In a light-emitting device according to an embodiment of the present invention, an element that prioritizes front luminance may satisfy (1) or (2) and (3), and an element that prioritizes color purity may be an element that does not satisfy (3). Also, an element that prioritizes color purity may not necessarily satisfy (1) and (2).

[0028] The element that prioritizes front luminance may be an element that emits green, and the element that prioritizes color purity may be an element that emits blue. In another embodiment, the element that prioritizes front luminance may be an element that emits blue, and the element that prioritizes color purity may be an element that emits green. In yet another embodiment, the element that prioritizes front luminance may be an element that emits red, and the element that prioritizes color purity may be a green element or an element that emits blue.

[0029] The second light-emitting element may have a second light-emitting material that is different from the light-emitting material of the first light-emitting element.

[0030] The full width at half maximum of the PL spectrum of the second light-emitting substance may be equal to or greater than the full width at half maximum of the PL spectrum of the light-emitting substance contained in the first light-emitting element.

[0031] Here, the full width at half maximum of the PL spectrum refers to the width of the first peak at an intensity of 0.5, when the PL intensity of the first peak is set to 1. In light-emitting substances with large first and second spectral widths, the minimum PL intensity in the boundary region between the first and second peaks may be 0.5 or greater. In such cases, the spectral width at an intensity of 0.5 for the spectrum obtained by adding together the spectral components of the first and second peaks is the full width at half maximum. Furthermore, if the spectral width of the first peak is very large, it may appear as if the second peak does not exist. In this case, the full width at half maximum refers to the width of the entire PL spectrum at an intensity of 0.5.

[0032] The luminescent material having an emission spectrum with a first peak and a second peak may be a fluorescent luminescent material, whereas the second luminescent material having a small second peak or no second peak may be a phosphorescent luminescent material.

[0033] That is, the light-emitting element having a fluorescent material may satisfy formula (1) or (2) of the present specification, and the second light-emitting element having a phosphorescent material may be in a form that does not satisfy either formula (1) or (2) of the present specification.

[0034] The emission color of the second light-emitting element may be green. The width of the PL spectrum of the second light-emitting material may be narrower than that of the other light-emitting elements. This is because the green wavelength is in the region between blue and red, and does not overlap with other colors.

[0035] The λ of the light emitting device according to this embodiment off Since the light with a radiation angle of 15° to the substrate main surface tends to be intensified, λ off may be the interference peak resonance wavelength at which light with a radiation angle of 15° is constructively coupled.

[0036] Specifically, to configure the light-emitting device according to this embodiment, the interference peak resonance wavelength in the front direction, determined by the material and film thickness of the organic layer of the light-emitting element, is set to be longer than the PL peak wavelength of the light-emitting substance. By setting it to the longer wavelength side, light near the PL peak wavelength with the highest intensity in the PL spectrum of the light-emitting substance can be emitted toward the inclined portion of the light-extraction structure. This inclined portion refracts light toward the front direction of the substrate, improving brightness in the front direction. The configuration of the light-emitting device according to this embodiment can be said to provide unique optical interference conditions for a light-emitting device with a light-extraction structure. The inclined portion of the light-extraction structure is preferably at an angle of 0° or more but less than 90° relative to the main surface of the substrate, and more preferably at an angle of 9° or more but less than 60°. By setting it in this range, brightness in the front direction of the substrate can be improved.

[0037] Strengthening the optical interference condition means adjusting the distance d0 from the light-emitting position of the light-emitting layer to the reflective surface of the light-reflecting material to d0 = mλ / 4n0 (i = 1, 3, 5,...), resulting in constructive interference. As a result, the radiation distribution of light with wavelength λ has more components in specific directions, improving the radiance at specific angles.

[0038] When the optical distance Lr from the light emitting position to the reflecting surface of the light reflecting layer constructively combines the wavelength λ, Lr is expressed by the following formula (4). Lr=(2m-(φr / π))×(λ / 4)×1 / cos(θ eml ) (4)

[0039] In the above formula (4), m is the interference order between the light emitting point and the reflecting layer and is an integer equal to or greater than 0, and n0 is the effective refractive index at wavelength λ of the layer from the light emitting point to the reflecting surface. In the ideal case where Φr=π, the cases of m=0 and m=1 are called the λ / 4 interference condition and the 3λ / 4 interference condition, respectively. φr [rad] is the sum of the phase shift amounts when light of wavelength λ is reflected on the reflecting surface, and θ eml is the radiation angle relative to the normal direction of the substrate in the light-emitting layer. The optical path length Lr is the sum of the products of the refractive index nj of each layer of the organic compound layer and the thickness dj of each layer. In other words, Lr is Σn j ×d j and can also be expressed as n0 × d0, where φ is a negative value.

[0040] Furthermore, if the optical distance from the light-emitting position to the reflective surface of the light-extraction electrode is Ls and the sum of the phase shifts when light of wavelength λ is reflected on the reflective surface of the light-extraction electrode is φs [rad], when the full-layer interference L intensifies the wavelength λ, L is expressed by the following formula (5): In the following formula (5), M is m+m', where m' is the order of interference between the light-emitting point and the light-extraction electrode and is an integer equal to or greater than 0. L=(Lr+Ls)=(2M-Φ / π )×(λ / 4)×1 / cos(θ eml ) (5)

[0041] Here, M is the sum (M=m+m') of the interference order m between the light-emitting point and the reflective layer and the interference order m' between the light-emitting point and the light-extraction electrode, and is an integer greater than or equal to 0. Φ is the sum (Φ=φr+φs) of the phase shifts when light of wavelength λ is reflected by the light-reflecting layer and the light-extraction electrode. Equation (5) represents the interference called full-layer interference of the organic compound layer.

[0042] In the case of an organic light-emitting element that does not have an inclined surface of the light extraction structure, the front direction, that is, θ eml The thickness and other dimensions of the organic layer are designed so as to satisfy the formulas (4) and (5) under the condition that the optical axis is in the direction of θ=0°.

[0043] The interference peak resonance wavelength in the front direction at that time is λ on (on-axis), we obtain equation (6). λon = 4πL / (2πM - Φ) (6)

[0044] In an organic light-emitting device having no inclined surface in the light extraction structure, the peak resonance wavelength λ in the front direction represented by the above formula (6) on is approximately the same as the peak wavelength λ of the PL spectrum of the light-emitting dopant PL and the film thickness and materials are designed accordingly.

[0045] On the other hand, when having a light extraction structure, that is, in the case of an embodiment of the present invention, within the pixel light-emitting region, the emission angle in the organic light-emitting device radiated in the front direction varies depending on the pixel emission position.

[0046] FIGS. 2A and 2B are diagrams showing a state in which the emitted light 12 radiated from a certain light-emitting point 11 on the reflection layer 6 is refracted at the inclined portion 13 having the microlens 10 and emitted in the substrate normal direction. Here, the microlens 10 is exemplified as an example of the light extraction structure 4, but regardless of the shape of the light extraction structure, it is determined by the relationship between the inclination angle and the emission position. n0, n1, n2, and n in FIG. 2A eml are the refractive index outside the element, the refractive index of the microlens, the refractive index of the protective layer, and the refractive index of the organic film light-emitting layer, respectively, and there is a relationship of n0 < n1. For simplicity here, n2 = n eml is assumed. Also, n3 in FIG. 2B is the refractive index of the filling layer filling between the microlens 10 and the protective layer 9, and a relationship of n3 < n1 is assumed. Although not described in detail in FIGS. 2A and 2B, the organic layer 7 and the protective layer 9 may each have a laminated structure, and in that case, the refractive index is the weighted average value Σn j × d j / Σd j and may be used as well.

[0047] Let R be the distance between the inclined portion 13 of the microlens 10, which has an inclination angle of ψ with respect to the principal surface of the substrate, and the center of the pixel in a direction parallel to the principal surface of the substrate, and let r be the distance between the inclined portion 13 and the light-emitting point 11 in a direction parallel to the principal surface of the substrate. In this case, the distance X between the light-emitting point 11, from which the emitted light 12 refracted in the front direction by the inclined portion 13 is emitted, and the center of the pixel is given by the following equation (7). Also, the radiation angle θ of the emitted light 41 in the light-emitting layer eml is expressed by the following formula (8). The pixel center may be the midpoint of the lower electrode in a cross section perpendicular to the main surface of the substrate. Alternatively, if an insulating layer is provided at the end of the lower electrode, it may be the midpoint of an opening in the insulating layer on the lower electrode in a cross section perpendicular to the main surface of the substrate.

[0048]

number

[0049] d i and n i are the film thickness and refractive index of the i-th layer. Here, R(ψ) is a structural parameter that indicates the relationship between the position of the light extraction structure and the tilt angle, and in the case of the spherical microlens shown in Figure 2A, R = A * sinψ. A is the radius of curvature of the microlens. X and θ eml Both are functions of the inclination angle ψ of the inclined portion of the light extraction structure. In other words, the pixel light-emitting area that contributes to the radiance in the front direction is determined for each inclination angle of the inclined portion of the light extraction structure, and the radiation angle in the light-emitting layer of light that is emitted from the light-emitting area and refracted to the front at the inclined surface is also determined. In other words, in an organic light-emitting element having a light extraction structure, it is sufficient to optimize the interference conditions according to the inclination angle at which the contribution rate is highest among the inclined portions that make up the light extraction structure. Specifically, the radiation angle θ corresponding to the inclination angle at which the contribution rate is highest is eml The aim is to reduce the difference between the PL peak wavelength and the interference peak resonance wavelength in the direction.

[0050] Next, define the slope where the contribution rate is highest, and calculate the radiation angle θ corresponding to the slope angle where the contribution rate is highest. emlThe inclined portion with the highest contribution rate refers to the inclined portion of the light extraction structure that has the largest light-emitting area within the pixel light-emitting range that can emit light refracted in the front direction.

[0051] 3A and 3B are diagrams illustrating the light extraction structure according to this embodiment extracting light toward the front of the light-emitting device. FIG. 3A is a schematic diagram illustrating light emitted from a light-emitting point toward the front of the light-emitting device. FIG. 3B is a schematic diagram illustrating light emitted from a light-emitting point in a direction tilted relative to the main surface of the substrate. FIG. 3A is a three-dimensional diagram illustrating the relationship between the light-emitting area 15a and the light-extraction surface 16a. The bottom diagram shows a cross-sectional view perpendicular to the main surface of the substrate, including the center of the pixel. FIG. 3A illustrates the light-extraction surface 16a (tilt angle 0°) that emits light toward the front of the main surface of the substrate due to optical interference in the front direction of the organic light-emitting element, the corresponding light-emitting area 15a, and the light-emitting region 20a in the cross section that emits light toward the front. FIG. 3B illustrates the light-emitting area 15b that can emit light refracted toward the front at the inclined portion 16b of the trapezoid (tilt angle 17b), and the light-emitting region 20b in the cross section that can emit light refracted toward the front. In the trapezoidal light-extraction structure shown in FIGS. 3A and 3B, the pixel area 15b is the largest. In this embodiment, the light extraction structure has an inclined portion, but the shape is not important as long as it can refract light emitted in a direction inclined with respect to the main surface of the substrate toward the front surface of the substrate.

[0052] Here, the radiation angle θ corresponding to the inclined portion where the contribution rate is the highest is eml The direction of is the radiation angle at the light emission point of light that is emitted from the maximum light emission area and refracted in the front direction at the inclined portion where the contribution is the highest.

[0053] In FIG. 3B, Θ eml is the radiation angle of light emitted from the maximum pixel area 16a and refracted in the front direction through the inclined portion 16b. eml Direction interference peak resonance wavelength λ off (off-axis) is expressed by the following equation (9): off Hereinafter, this will also be referred to as the interference peak resonance wavelength in the oblique direction. λ off =4πL / (2πM-Φ)×1 / cos(Θ eml ) (9)

[0054] The interference peak resonance wavelength λ in Eq. (9) off and the PL peak wavelength λ of the luminescent material PL The difference between these is the interference peak wavelength λ in the front direction defined by equation (9). on and λ PL It is desirable to determine the optical interference conditions of the organic light-emitting element so that the difference between λ and λ is smaller than the difference between λ and λ. off is the peak wavelength λ of the EL spectrum of the light-emitting device of this embodiment. EL In other words, λ EL and λ PL The difference between these is the interference peak wavelength λ on and λ PL The optical interference condition of the organic light-emitting element may be determined so that the difference between

[0055] 4A to 4D show the preferable radiation angle Θ using a spherical microlens as an example of the light extraction structure. eml 4A to 4D are schematic diagrams showing a method for estimating the radiative efficiency. Figures 4A to 4D show different angles of light emission relative to the substrate main surface. The upper diagrams are three-dimensional diagrams showing the relationship between light-emitting areas 18a to 18d, light extraction surface 19a, and inclined portions 19b to 19d, while the lower diagrams are cross-sectional views perpendicular to the substrate main surface including the pixel centers. 19a is not inclined, so it is referred to as a light extraction surface. 19b to 19d are inclined, so they are referred to as inclined portions, but they can also be called light extraction surfaces. Even in microlenses such as those shown in Figures 4A to 4D, the inclined portion with the highest contribution is the inclined portion with the largest light-emitting area within the pixel light-emitting range that can emit light refracted in the forward direction by the inclined portion of the light extraction structure. In other words, in the case of a spherical microlens, the position with the largest light-emitting area corresponds to the outermost region. Figure 4C shows how light emitted from the largest light-emitting area 18c, among the light-emitting regions that can be refracted in the forward direction by the inclined surface of the spherical microlens, is refracted in the forward direction by inclined portion 19c. In the case of a microlens, Θ emlThe direction may be the radiation angle in the light-emitting layer from the outermost peripheral region 18c toward the inclined portion 19c as shown in Fig. 4C. According to a ray tracing simulation, the radiation angle Θ eml is preferably greater than 0° and less than 30°, and more preferably between 5° and 20°.

[0056] Next, the interference peak resonance wavelength λ in the diagonal direction in Eq. (9) off and the PL peak wavelength λ of the luminescent material PL The difference between these is the interference peak wavelength λ in the front direction defined by equation (6). on and λ PL The effect of making the difference smaller than the difference between

[0057] 5A and 5B are graphs showing the PL spectrum of a light-emitting substance, the interference spectrum that intensifies the front direction, and the interference spectrum that intensifies the tilt direction. Fig. 5A shows a conventional example of a light-emitting device having a configuration in which light emitted in the front direction of the substrate main surface is intensified. off , λ on , λ PL FIG. 5(b) shows a configuration according to the present invention, which is a light emitting device that intensifies light emitted in a direction inclined with respect to the main surface of the substrate. The configuration of FIG. 5(b) has an interference peak resonance wavelength λ in a direction inclined with respect to the main surface of the substrate. off and the PL peak wavelength λ of the luminescent material PL The difference between these is the interference peak λ in the front direction of the main surface of the substrate. on and λ PL This is the case where the difference is smaller than the difference between the two. Figure 5(c) shows the spectrum of the light-emitting element with the configuration (a) in the front direction through a microlens. Figure 5(d) shows the spectrum of the light-emitting element with the configuration (b) in the front direction through a microlens. Figures 5(a) and (b) show the spectra of (c) and (d), respectively, broken down into radiation angle components within the light-emitting layer.

[0058] FIG. 5 assumes the microlenses shown in FIGS. 4A to 4D, and Θ eml It is assumed that the angle is approximately 15°. However, this effect is eml It does not depend on the value of

[0059] θ in Fig. 5(a) and (b) eml = 0° corresponds to the light emission intensity of the light-emitting element when there is no light extraction structure in each light-emitting element configuration. As mentioned above, in the case of an organic light-emitting element without a light extraction structure, the interference peak wavelength λ on and λ PL This is the θ in Figure 5(a). eml The radiance at θ = 0° is shown in Fig. 5(b). eml On the other hand, when a microlens is used, the radiance in the front direction is eml In other words, the amount of light refracted in the front direction varies depending on the angle.

[0060] In the conventional configuration shown in Figure 5(a), the interference peak resonant wavelength λ is the wavelength at which the efficiency of light extraction to the front by the light extraction structure (hereinafter referred to as the front extraction efficiency) is highest. off is the PL spectrum λ PL The PL spectrum drops sharply on the short-wave side of the PL peak. In other words, the intensity drops significantly. As a result, the spectral area (radiance) on the short-wave side of the PL peak wavelength becomes smaller. Therefore, the λ off In the wavelength region of off Although the effect of the constructive coupling of the two is large, the amount of light emitted from the light-emitting material is small, so the increase in the front light extraction efficiency due to the light extraction structure is small. eml This is also indicated by the low emission intensity at 15° and 25°.

[0061] In contrast, the interference peak resonance wavelength λ in the direction inclined to the substrate main surface off and PL peak wavelength λ PL The difference between these is the interference peak wavelength λ in the front direction of the main surface of the substrate. on and λ PL When the difference between the θ emlThe radiance at angles of 15° and 25° can be increased. Since the spectral area in FIG. 5(d) is larger than that in FIG. 5(c), the radiance of the light-emitting device in FIG. 5(d) is higher than that of the organic light-emitting device having a light extraction structure. In other words, the interference peak resonance wavelength λ in the direction inclined to the substrate main surface is off and PL peak wavelength λ PL The difference between these is the interference peak wavelength λ in the front direction of the main surface of the substrate. on and λ PL The smaller the difference between the two, the greater the radiance in the front direction.

[0062] The present invention provides an organic light-emitting element having a light extraction structure, which has an interference peak wavelength λ in front of the main surface of the substrate. on is the PL peak wavelength λ of the luminescent material PL In other words, the interference peak resonance wavelength λ in the direction inclined with respect to the substrate main surface is off and PL peak wavelength λ PL The difference between these is the interference peak wavelength λ on and λ PL As shown in Figures 5(b) and 5(d), the interference peak resonant wavelength λ in the direction inclined to the substrate main surface is off and the peak wavelength λ of the EL spectrum EL are roughly consistent.

[0063] In order to increase the radiance in the front direction of the main surface of the substrate, λ off and λ PL In addition, the spectrum of the luminescent material may be λ PL The second peak λ is weaker than PL2 If λ PL2 is λ on In other words, the interference spectrum in the direction inclined with respect to the main surface of the substrate is λ PL The interference spectrum in the front direction of the main surface of the substrate is λ PL2 When comparing the two, λ PL and λ off But λ PL2 and λ on It's better to be closer than that.

[0064] 6A and 6B are schematic diagrams showing light refracted by a microlens when the microlens is shifted. The interference peak resonance wavelength λ in the direction inclined with respect to the main surface of the substrate off is the PL peak wavelength λ PL Since the PL peak wavelength is closer to the center of the microlens, microlens shift can also refract light with a wider angle. Microlens shift (hereinafter, ΔML) refers to the distance between the center of the microlens and the center of the pixel aperture in a direction parallel to the principal surface of the substrate. The center of the microlens can be estimated at the midpoint of the microlens in a cross section perpendicular to the principal surface of the substrate. The center of the pixel aperture can be estimated at the midpoint of the lower electrode in a cross section perpendicular to the principal surface of the substrate. Furthermore, if the edge of the lower electrode is covered with a pixel isolation layer, the center of the pixel aperture can be estimated at the midpoint of the line segment from one pixel isolation layer to the other in the cross section. These cross sections may be selected so as to pass through the vertex of the microlens.

[0065] The light-emitting device of this embodiment has a second light-emitting element different from the light-emitting element, and a second light-extraction structure different from the light-extraction structure and into which light from the second light-emitting element is incident, and the distance in a direction parallel to the main surface of the substrate between the midpoint of the light-emitting region of the light-emitting element and the midpoint of the light-extraction structure in a cross section perpendicular to the main surface of the substrate may be smaller than the distance in a direction parallel to the main surface of the substrate between the midpoint of the light-emitting region of the second light-emitting element and the midpoint of the second light-extraction structure in a cross section perpendicular to the main surface of the substrate.

[0066] The device may further include a third light-emitting element different from the second light-emitting element, and a third light-extraction structure different from the second light-emitting element and into which light from the third light-emitting element is incident, and the distance in a direction parallel to the main surface of the substrate between the midpoint of the light-emitting region of the second light-emitting element in a cross section perpendicular to the main surface of the substrate and the midpoint of the second light-extraction structure may be smaller than the distance in a direction parallel to the main surface of the substrate between the midpoint of the light-emitting region of the third light-emitting element in a cross section perpendicular to the main surface of the substrate and the midpoint of the third light-extraction structure.

[0067] Figure 6A shows the interference peak resonance wavelengths λ on and λ PL matched in a conventional configuration. Figure 6B shows a configuration in which the interference peak resonance wavelengths λ off and λ PL are matched in a direction inclined with respect to the main surface of the substrate. As compared with the configuration of Figure 6A, the configuration of Figure 6B shows how light of the PL peak wavelength λ PL is radiated toward the wide-angle side by the micro lens shift. This is because an interference that strengthens light in a direction inclined with respect to the main surface of the substrate is configured in Figure 6B. Here, for simplicity, n1 = n2 = n eml is shown, and n0 < n1. Even when refraction occurs at each interface, the result that light of λ PL is emitted at a wider angle in Figure 6B than in Figure 6A is the same.

[0068] In Figures 6A and 6B, light is emitted from the light-emitting region, and the light is bent at an angle of θ0 (θ'0 in Figure 6B) by the inclined portion of the micro lens. When the inclination angle of the micro lens at this time is ψ (ψ' in Figure 6B), the condition of Figure 6A satisfies the following equation (10). n0 × sin(θ0 + ψ) = n eml × sin(θ eml + ψ) (10)

[0069] Here, θ eml is the emission angle at the light-emitting point. In Figure 6A where λ on = λ PL , θ eml = 0°, and in Figure 6B where λ off = λ PL , θ eml = Θ eml . As can be seen from Figures 6A, 6B, and equation (10), in the light-emitting device according to the present invention, as shown in Figure 6B, since light of λ PL is incident obliquely on the inclined portion, light of λ PL can be refracted more toward the wide-angle side. The maximum value of the refraction angle derived from the total reflection condition of equation (10) is for the case where λ on = λ PL and for the case where λ off = λ PLIn this case, they are expressed by equations (11) and (12), respectively. θ0=π / 2-sin -1 (n0 / n eml ) (11) θ0'=π / 2+Θ eml -sin -1 (n0 / n eml ) =θ0+Θ eml (12)

[0070] That is, the interference peak resonance wavelength λ in the direction inclined with respect to the main surface of the substrate off is the PL peak wavelength λ PL By setting the optical interference condition of the organic light-emitting element close to Θ, the refraction direction is eml It is possible to shift the angle to the wide-angle side by a certain amount. In this embodiment, it can be said that the angle adjustment range by microlens shift can be wider than in the conventional configuration. If it is possible to emit light to the wider-angle side, it can be applied to a shorter-focus optical system with a smaller display device while increasing the FOV. In other words, it becomes possible to miniaturize head-mounted displays, etc.

[0071] In at least a partial region of the light emitting device, the distance between the center position of the light extraction structure and the center position of the pixel opening in the in-plane direction of the substrate may be adjusted as appropriate.

[0072] 7A and 7B are plan views showing that the relative positions of the microlenses and pixels vary depending on the position in the display area. FIG. 7A is a plan view of the display area. FIG. 7B is a schematic cross-sectional view taken along line E-E' in FIG. 7A. FIG. 7B shows the relationship between the relative positions of the centers of the microlenses 10 and the light-emitting regions 22 and the positions of the light-emitting elements in the display area. At the center of the display area 1, the centers of the microlenses and the light-emitting regions coincide. That is, ΔML23 is 0. The distance between the center of the microlens and the center of the light-emitting region increases toward the left side of the figure. That is, ΔML24 is greater than delta ML23, and ΔML25 is greater than ΔML24. In FIG. 7B, ΔML26 is the largest distance between the center of the microlens and the center of the light-emitting region. The distance between the center of the microlens and the center of the light-emitting region shown in the figure is merely an example. ΔML may increase from the center to the edges of the display area as shown in the figure, or it may decrease from the center to the edges of the display area. ΔML may be formed to change continuously macroscopically with respect to the position in the display area. As long as it is continuous macroscopically, ΔML may be changed for each light-emitting element, or may be changed stepwise for each of a plurality of light-emitting elements. Alternatively, a configuration in which ΔML is changed for each light-emitting element and a configuration in which ΔML is changed stepwise for each of a plurality of light-emitting elements may be combined. In this embodiment, ΔML23 at the center of the display area is set to 0, but it does not have to be 0. ΔML within the display area may also be constant.

[0073] [Other embodiments] 8A to 8D are diagrams showing other configuration examples of a light emitting device according to one embodiment of the present invention. Fig. 8A is a cross-sectional schematic diagram of a light emitting device according to one embodiment of the present invention. In this embodiment, the light extraction structure is, for example, a microlens. The light extraction structure only needs to have a certain inclination angle with respect to the main surface of the insulating layer, and may be, in addition to a microlens, an aspherical microlens, a conical microlens, a cylindrical microlens, or a digital microlens.

[0074] FIG. 8A shows a light-emitting device in which a light-emitting element 3 on a substrate 5 includes a reflective layer 6, a pixel separation layer 21 covering the edges of the reflective layer, an organic layer 7 containing a light-emitting material, a semi-transparent electrode 8, a protective layer 9, and a microlens 10. The portion of the reflective layer 6 not covered by the pixel separation layer 21 is the light-emitting region 22. The portion of the reflective layer 6 not covered by the pixel separation layer 21 is also called a pixel opening. The pixel separation layer 21 is a so-called bank and is an insulating layer. The reflective layer 6 and the semi-transparent electrode 8 are also called a lower electrode and an upper electrode, respectively, based on their positions. Furthermore, to maintain the characteristics of the outermost light-emitting element, dummy pixels 3′ are arranged outside the display region 1. Multiple columns and rows of dummy pixels 3′ may be formed. The dummy pixels may have the same components as the light-emitting elements. The dummy pixels may have the same configuration as the light-emitting elements, except that no current is supplied to the dummy pixels.

[0075] An insulating layer (not shown) may be provided on the substrate 5. The insulating layer may be formed of an oxide layer, a nitride layer, an organic layer, or the like. The insulating layer is also called a planarizing layer due to its function. For example, the insulating layer may have the role of reducing the influence of unevenness of a transistor formed on the substrate on the electrodes.

[0076] The organic layer 7 may be composed of multiple layers. The multiple layers include a light-emitting layer, which contains a light-emitting substance. A light-emitting layer emitting a single emitted light color may be formed on the entire surface between the light-emitting elements. Alternatively, to enable the display device to display at least two or more colors, light-emitting layers emitting different colors may be stacked on the entire surface between the light-emitting elements, or light-emitting layers emitting different colors for each light-emitting element may be patterned. When the organic layer is composed of a light-emitting layer emitting white light, a color filter may be provided between the light-emitting element and the microlens.

[0077] The protective layer 9 is a layer for protecting the light emitting element, and may be made of an inorganic layer such as silicon nitride, silicon oxynitride, silicon oxide, or aluminum oxide, or an organic layer such as acrylic resin, epoxy resin, or polyimide resin.

[0078] Light emitted from the light-emitting element is incident on the microlens 10. A planarizing layer (not shown) may be provided between the microlens and the protective layer. The planarizing layer may also serve as an adhesive layer. The planarizing layer may be made of the same resin as the microlens.

[0079] 8A shows the distance L from the semi-transparent electrode 8 to the microlens, the height h of the microlens, the radius φ of the microlens, the distance D between the vertex of one microlens and the vertex of the adjacent microlens, the refractive index n2 of the protective layer, the refractive index n1 of the microlens, and the external refractive index n0. The distance D does not have to be constant. More specifically, the distance D may be increased or decreased as the distance approaches the edge of the display area. In this embodiment, the height is the distance in the vertical direction of the paper.

[0080] 8B is a cross-sectional schematic diagram of a light-emitting device further including a color filter. A color filter 27 is further provided between the protective layer 9 and the microlens 10. A color filter is a filter that transmits a specific wavelength. For example, it may be a filter that transmits R of RGB. As shown in FIG. 8B, three types of color filters that transmit each of RGB may be provided.

[0081] FIG. 8C is a cross-sectional schematic diagram of a light-emitting device having a different color filter and microlens configuration. Unlike the other embodiments, the microlens 10' has a convex shape extending downward in the plane of the paper. The downward direction in the plane of the paper can also be interpreted as the direction from the semi-transparent electrode to the reflective layer. The space between the microlens 10' and the protective layer 9 may be empty or filled with another substance. A resin layer may be provided between the color filter 27 and the microlens 10'.

[0082] A protective glass 28 is provided on the color filter 27. An organic layer such as an adhesive layer may be provided between the protective glass 28 and the color filter 27. The protective glass 28 is located opposite the substrate 5, and is therefore also called an opposing substrate.

[0083] FIG. 8D is a cross-sectional schematic diagram of a light-emitting device in which the optical interference distance of the light-emitting element is varied for each emitted color. An optical adjustment layer 29, a transparent electrode 30, an organic layer 7, a semi-transparent electrode 8, a protective layer 9, a filling layer 31, a color filter 27, and a microlens 10 are arranged on the reflective layer 6. The color filters 27 are labeled 27R, 27G, and 27B, corresponding to their transmitted colors, and are red, green, and blue, respectively. The optical distance between the reflective layer 6 and the semi-transparent electrode 8 varies depending on the thickness of the optical adjustment layer 29. From the right in the figure, the light-emitting elements are shown as a blue-enhancing light-emitting element, a green-enhancing light-emitting element, and a red-enhancing light-emitting element. In this embodiment, the optical adjustment layer of the first light-emitting element is thicker than that of the second light-emitting element. This configuration allows for optimal optical interference distances for each emitted color. In this embodiment, the optical adjustment layer under the transparent electrode is used to change the optical interference distance for each color. However, the optical adjustment layer may also be provided on the semi-transparent electrode. In addition, the thickness of the organic layer can be changed for each light-emitting element to optimize the optical interference distance for each light-emitting element. When the thickness of the organic layer is changed for each light-emitting element, it is preferable to change the thickness of the organic layer on the reflective layer side of the light-emitting layer.

[0084] The wavelength range transmitted by the color filter may include the PL peak wavelength of the luminescent material. When the PL peak of the luminescent material has a first peak and a second peak smaller than the first peak, if priority is given to the brightness of the light-emitting device, the first peak wavelength and the second peak wavelength may be included in the wavelength range transmitted by the color filter. When the PL peak of the luminescent material has a first peak and a second peak smaller than the first peak, if priority is given to the color purity of the light-emitting device, only the first peak may be included in the wavelength range transmitted by the color filter.

[0085] This is preferable when used in devices that place importance on brightness, such as head-mounted displays and AR glasses.

[0086] [Light-emitting element configuration] The light-emitting element is provided by forming an insulating layer, a first electrode, an organic compound layer, and a second electrode on a substrate. A protective layer, a color filter, a microlens, etc. may be provided on the cathode. When a color filter is provided, a planarizing layer may be provided between the color filter and the protective layer. The planarizing layer may be made of acrylic resin or the like. The same applies when a planarizing layer is provided between the color filter and the microlens.

[0087] [substrate] Examples of the substrate include quartz, glass, a silicon wafer, a resin, and a metal. Furthermore, the substrate may be provided with a switching element such as a transistor and wiring, and an insulating layer thereon. Any material can be used for the insulating layer, as long as it allows for the formation of a contact hole so that wiring can be formed between the first electrode and the insulating layer, and ensures insulation from wiring that is not connected. For example, resins such as polyimide, silicon oxide, silicon nitride, etc. can be used.

[0088] [Light-emitting element] The light-emitting element has a first electrode, a second electrode, and a light-emitting layer disposed between the first and second electrodes and containing a light-emitting substance. The light-emitting layer may be an organic compound layer or an inorganic compound layer. The electrode may also serve as a reflective layer. The light-emitting substance may be fluorescent or phosphorescent.

[0089] [electrode] A pair of electrodes can be used. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a higher potential is the anode, and the other is the cathode. It can also be said that the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode. The electrodes may be formed across multiple light-emitting elements, or may be formed separately for each light-emitting element. For example, an anode may be formed separately for each light-emitting element, and a cathode may be formed across multiple light-emitting elements.

[0090] The anode material should have as high a work function as possible. Examples include simple metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, tungsten, and silicon, mixtures containing these metals, alloys of these metals, and metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and zinc indium oxide. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

[0091] These electrode materials may be used alone or in combination of two or more. The anode may be composed of one layer or multiple layers.

[0092] When used as a reflective layer, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates thereof can be used. The above materials can also function as a reflective layer without functioning as an electrode. When used as a transparent electrode, transparent conductive oxide layers such as indium tin oxide (ITO) and indium zinc oxide can be used, but are not limited to these. Photolithography techniques can be used to form the electrode. The reflective layer preferably has a reflectance of 70% or more at the emission wavelength. The reflective layer may also serve as an electrode.

[0093] On the other hand, materials with a low work function are preferred for the cathode. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, and metals such as aluminum, titanium, manganese, silver, lead, and chromium, as well as mixtures containing these metals. Alternatively, alloys combining these metals can be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials can be used alone or in combination. The cathode can have either a single-layer or multi-layer structure. Among these, silver is preferred, and a silver alloy is even more preferred to reduce silver aggregation. The alloy ratio is not critical as long as silver aggregation can be reduced. For example, the silver:other metal ratio can be 1:1, 3:1, or the like.

[0094] The cathode may be a top-emission element using an oxide conductive layer such as ITO, or a bottom-emission element using a reflective layer such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but DC and AC sputtering methods are more preferred because they provide good film coverage and make it easier to reduce resistance.

[0095] When used as a semi-transparent electrode, a metal that transmits part of the incident light and reflects part of it is used. A semi-transparent electrode can also be made by forming a sufficiently thin metal layer. For example, a semi-transparent electrode can be made by forming a silver layer about 10 nm thick.

[0096] [Organic layer] The organic layer may be formed as a single layer or as multiple layers. When multiple layers are present, they may be called hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, electron injection layer, or charge generation layer depending on their functions. The organic layer is mainly composed of organic compounds, but may also contain inorganic atoms or compounds. For example, the organic layer may contain copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, etc.

[0097] The organic layer may be an organic layer having a plurality of light-emitting layers. Any of the light-emitting layers may contain a red light-emitting material, a green light-emitting material, or a blue light-emitting material, and white light can be obtained by mixing the respective light-emitting colors. Any of the light-emitting layers may contain light-emitting materials of complementary colors, such as a blue light-emitting material and a yellow light-emitting material. The light-emitting material may be a fluorescent material, a phosphorescent material, a delayed fluorescent material, or a quantum dot such as CdS or perovskite. Furthermore, different colors may be emitted by changing the material or composition contained in the light-emitting layer for each light-emitting element. A light-emitting layer may be formed for each light-emitting element. The organic compound layer may be disposed between the first electrode and the second electrode, or may be disposed in contact with the first electrode and the second electrode.

[0098] [Protective layer] The protective layer is an insulating layer, and preferably contains an inorganic material that is translucent and has low permeability to oxygen and moisture from the outside. The protective layer can be made of inorganic materials such as silicon nitride (SiN), silicon oxynitride (SiON), silicon oxide (SiOx), aluminum oxide (Al2O3, etc.), and titanium oxide (TiO2). It may be provided directly on the cathode, or an organic resin layer may be provided between them. The organic resin layer may be made of, for example, polyacrylate, polyimide, polyester, epoxy, etc.

[0099] Furthermore, by bonding glass provided with a moisture absorbent to the cathode, it is possible to reduce the penetration of water and other substances into the organic layer and reduce the occurrence of display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the cathode to reduce the penetration of water and other substances into the organic compound layer. For example, after forming the cathode, the cathode may be transferred to another chamber without breaking the vacuum, and a 2 μm-thick silicon nitride film may be formed by CVD to serve as a protective layer. A protective layer may be formed using atomic layer deposition (ALD) after the CVD film formation. The material of the film formed by ALD is not limited, and may be silicon nitride, silicon oxide, aluminum oxide, or the like. Silicon nitride may be further formed on the film formed by ALD by CVD. The film formed by ALD may have a thickness smaller than that of the film formed by CVD. Specifically, the thickness may be 50% or less, or even 10% or less.

[0100] [Color Filter] A color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element may be provided on a separate substrate and then bonded to the substrate on which the organic light-emitting element is provided, or a color filter may be patterned on the protective layer described above using photolithography technology. The color filter may be made of a polymer.

[0101] [Planarization layer] A planarization layer may be provided between the color filter and the protective layer. The planarization layer is provided for the purpose of reducing the unevenness of the underlying layer. It may also be called a resin layer without limiting its purpose. The planarization layer may be composed of an organic compound, and may be either a low molecular weight or a high molecular weight, but is preferably a high molecular weight.

[0102] The planarizing layer may be provided above or below the color filter, and may be made of the same or different materials, such as polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0103] [Microlens] The organic light-emitting device may have an optical component such as a microlens on its light-emitting side. The microlens may be made of acrylic resin, epoxy resin, or the like. The microlens may be used to increase the amount of light extracted from the organic light-emitting device and to control the direction of the extracted light. The microlens may have a hemispherical shape. When the microlens has a hemispherical shape, among the tangents to the hemisphere, there is a tangent that is parallel to the insulating layer, and the point of contact between this tangent and the hemisphere is the vertex of the microlens. The vertex of the microlens can be determined in the same way in any cross-sectional view. In other words, among the tangents to the semicircle of the microlens in the cross-sectional view, there is a tangent that is parallel to the insulating layer, and the point of contact between this tangent and the semicircle is the vertex of the microlens.

[0104] It is also possible to define the midpoint of a microlens. In the cross section of the microlens, a line segment is imagined from the point where an arc shape ends to the point where another arc shape ends, and the midpoint of this line segment can be called the midpoint of the microlens. The cross section for determining the vertex and midpoint may be a cross section perpendicular to the insulating layer.

[0105] Microlenses can be formed by adjusting the exposure and development processes. Specifically, a film (photoresist film) made of a material for forming the microlenses is formed, and the photoresist film is exposed and developed using a mask with continuous gradation changes. Such a mask can be a gray mask or an area gradation mask, which allows light irradiation with continuous gradations on the imaging plane by changing the density distribution of dots made of a light-shielding film below the resolution of the exposure device.

[0106] Furthermore, the lens shape can be adjusted by etching back the microlenses formed by the exposure and development process. The shape of the microlenses only needs to have an inclined portion that can refract the emitted light, and they may be spherical or have an asymmetric cross-sectional shape.

[0107] [Counter substrate] An opposing substrate may be provided on the planarization layer. The opposing substrate is called an opposing substrate because it is provided at a position corresponding to the aforementioned substrate. The constituent material of the opposing substrate may be the same as that of the aforementioned substrate. When the aforementioned substrate is defined as a first substrate, the opposing substrate may be a second substrate.

[0108] [Formation of organic layer] The organic compound layers (hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, electron injection layer, charge generation layer, etc.) constituting the organic light-emitting device according to one embodiment of the present invention are formed by the method shown below.

[0109] The organic compound layer constituting the organic light-emitting device according to one embodiment of the present invention can be formed by dry processes such as vacuum deposition, ionization deposition, sputtering, plasma, etc. Alternatively to the dry process, a wet process can be used in which the compound is dissolved in an appropriate solvent and a layer is formed by a known coating method (for example, spin coating, dipping, casting, LB method, inkjet method, etc.).

[0110] Here, when a layer is formed by a vacuum deposition method or a solution coating method, crystallization is unlikely to occur and the layer has excellent stability over time. When a film is formed by a coating method, the film can be formed by combining with an appropriate binder resin.

[0111] Examples of the binder resin include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0112] These binder resins may be used singly or in combination as homopolymers or copolymers, and may further contain known additives such as plasticizers, antioxidants, and ultraviolet absorbers, if necessary.

[0113] [Pixel circuit] The light-emitting device may have a pixel circuit connected to the light-emitting element. The pixel circuit may be an active matrix type that controls the emission of the first light-emitting element and the second light-emitting element independently. The active matrix type circuit may be voltage-programmed or current-programmed. The drive circuit has a pixel circuit for each pixel. The pixel circuit may have a light-emitting element, a transistor that controls the emission brightness of the light-emitting element, a transistor that controls the emission timing, a capacitor that holds the gate voltage of the transistor that controls the emission brightness, and a transistor for connecting to GND without going through the light-emitting element.

[0114] The light-emitting device has a display region and a peripheral region arranged around the display region. The display region has pixel circuits, and the peripheral region has a display control circuit. The mobility of a transistor constituting the pixel circuit may be lower than the mobility of a transistor constituting the display control circuit.

[0115] The slope of the current-voltage characteristics of the transistors that make up the pixel circuit may be smaller than the slope of the current-voltage characteristics of the transistors that make up the display control circuit. The slope of the current-voltage characteristics can be measured using the so-called Vg-Ig characteristics.

[0116] The transistors that make up the pixel circuit are transistors connected to light-emitting elements such as the first light-emitting element.

[0117] [Pixels] An organic light emitting device includes a plurality of pixels, each of which includes sub-pixels that emit different colors, for example, RGB colors.

[0118] The pixel emits light from an area called the pixel aperture. This area is the same as the first area. The pixel aperture may be 15 μm or less, or 5 μm or more. More specifically, it may be 11 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc.

[0119] The distance between the subpixels may be 10 μm or less, and specifically may be 8 μm, 7.4 μm, or 6.4 μm.

[0120] The pixels may be arranged in a known manner in a plan view. For example, they may be in a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the subpixels in a plan view may be any known shape. For example, they may be rectangular, quadrilaterals such as diamonds, or hexagons. Of course, a shape that is close to a rectangle, rather than an exact shape, is included in the rectangle. The shape of the subpixels and the pixel arrangement may be used in combination. [Example]

[0121] Example 1 Next, specific effects of the present invention will be described using examples. In these examples, a monochromatic organic light-emitting element was used. Table 1 shows the microlens height h / D, microlens radius Φ / D, and color filter upper surface height L2 / D normalized by the pixel pitch D.

[0122] As described above, the effect of the present invention is not dependent on whether the display is monochrome or white, and a color filter or the like may be separately disposed.

[0123] [Table 1]

[0124] Figure 9 is a diagram showing the relationship between the radiation angle and the relative light intensity in the light-emitting layer, as determined by ray tracing. As shown in the figure, ray tracing for the configuration shown in Table 1 showed that the maximum relative light intensity was observed at angles of 10° to 15° in the front direction. In Example 1, the reflective layer was an Al electrode, the semi-transparent electrode was 15 nm thick MgAg, and the protective layer was a SiN film. The microlenses were formed using a material with a refractive index of n = 1.5. Figure 10 shows the PL spectrum PL1 of the light-emitting material used in Example 1. The maximum peak wavelength of the PL spectrum was 523 nm.

[0125] [Table 2]

[0126] The results of the study are shown in Table 2. In this example, the study was carried out under the condition that the interference order m between the reflective layer and the light-emitting point described in formula (4) is 1, and the interference order m' from the light-emitting point to the semi-transparent electrode is 0. Comparative example D001 has an interference peak resonance wavelength λ on is λ PL and the interference peak resonance wavelength λ in the direction inclined with respect to the substrate main surface off is λ PL In the embodiment, D101 and D102 are positioned on the short wave side of λ on Under the condition that the wavelengths are 545 nm and 552 nm, the interference peak resonance wavelength λ in the direction inclined with respect to the main surface of the substrate off is λ PL The relative radiant intensity in Table 2 is the value normalized by the radiance of the comparative example for the configurations without and with microlenses.

[0127] First, the characteristics of the organic light-emitting device without a microlens are compared. The interference conditions of D101 and D102 with respect to D001 are as follows: EL spectrum peak intensity λ EL (0) is λ PL On the other hand, with the microlens, the EL peak wavelength λ increases to 1.36 and 1.4 for D101 and D102, respectively, and the relative radiant intensity is shifted to the longer wavelength side. EL 529nm and 530nm and λ PL This is due to the component around Θeml, which has the highest contribution from the component refracted in the front direction at the inclined part of the microlens shown in Figure 5(b). For D101 and D102, the difference between the interference peak resonance wavelength in the front direction and the PL peak wavelength |λ off -λ PL | is the difference between the EL peak wavelength and the PL peak wavelength for 22 nm and 29 nm, respectively. EL -λ PL In this way, in an organic light-emitting element having a light extraction structure, |λ off -λ PL for |λ EL -λPL By adjusting the optical interference of the organic EL element so that | is small, the radiance in the front direction can be increased.

[0128] <Example 2> Example 2 is the same as Example 1, except that the spectral shape of the luminescent material is double-peaked. Double-peaked means that the emission spectrum has a first peak and a second peak.

[0129] [Table 3]

[0130] Table 3 shows the λ PL , λ on , λ off , and the front radiation intensity are listed. λ PL , λ EL , λ on The comparison example D002 shows the difference between the front interference peak resonance wavelength λ under the above conditions. on λ PL The interference peak resonance wavelength λ in the direction inclined with respect to the substrate main surface is off is λ PL The examples D103 and D104 are configured to be positioned on the short-wave side with respect to λ on Under the condition that the wavelengths are 545 nm and 552 nm, the interference peak resonance wavelength λ in the direction inclined with respect to the main surface of the substrate off is λ PL The relative radiant intensity in Table 3 is a value normalized by the radiance of D002.

[0131] First, a comparison is made with a configuration without a microlens. The interference conditions for D103 and D104 with respect to D002 are as follows: EL spectrum peak intensity λ EL (0) is λ PLThe EL peak wavelength λ shifts to 542nm and 549nm, respectively, compared to 523nm, and the relative radiance decreases to 1 and 0.98. On the other hand, with the microlens, the relative radiance of D103 and D104 increases to 1.4 and 1.45, respectively. EL are both 524 nm, and λ PL This is due to the component around Θeml, which has the highest contribution of the component refracted in the front direction at the inclined part of the microlens shown in Figure 5(b). In D103 and D104, the interference peak resonance wavelength λ in the front direction on and PL peak wavelength difference |λ off -λ PL | is the difference between the EL peak wavelength and the PL peak wavelength for 22 nm and 29 nm, respectively. EL -λ PL The present invention was found to be useful for light-emitting dopants having a PL spectrum shape with a second peak, such as PL2.

[0132] Example 3 Example 3 is the same as Example 2, except that the interference order m between the reflective layer and the light-emitting point is set to 0 and the semi-transparent electrode is set to 23 nm. Table 4 explains the results of the study on Example 3.

[0133] [Table 4]

[0134] In the comparative example D003, under the above conditions, the front interference peak resonance wavelength λ on λ PL The interference peak resonance wavelength λ in the direction inclined with respect to the substrate main surface is off is λ PL The embodiment D105 is configured to be located on the short wave side of λ on is 539 nm, the interference peak resonance wavelength λ in the direction inclined to the substrate main surface off 524nm and λ PLThe relative radiance intensities in Table 4 are values ​​normalized by the radiance of D003.

[0135] First, we compare the configuration without a microlens. The interference condition for D105 against D003 is the EL spectrum peak intensity λ in the front direction without a microlens. EL (0) is λ PL = 523nm and 528nm, respectively, and the relative radiance decreases to 0.9. On the other hand, with a microlens, the relative radiance of D105 increases to 1.36. Also, the EL peak wavelength λ EL are both 524 nm, and λ PL This is due to the component around Θeml, which has the highest contribution of the component refracted in the front direction at the inclined part of the microlens shown in Figure 5(b). In D105, the interference peak resonance wavelength λ on and PL peak wavelength difference |λ off -λ PL | is the difference between the EL peak wavelength and the PL peak wavelength, |λ EL -λ PL It was found that the present invention can be effective even when the interference order m between the reflective layer and the light-emitting point is set to 0.

[0136] Example 4 Example 4 is the same as Example 2 except that the interference order m' between the semi-transparent electrode and the light-emitting point is set to 1. Table 5 explains the results of the study on Example 4.

[0137] [Table 5]

[0138] In the comparative example D004, under the above conditions, the front interference peak resonance wavelength λ on is λ PL The interference peak resonance wavelength λ in the direction inclined with respect to the substrate main surface is off is λ PLThe embodiment D106 is configured to be located on the short wave side of λ on is 538 nm, the interference peak resonance wavelength λ in the direction inclined to the substrate main surface off 520nm and λ PL The relative radiant intensity in Table 5 is a value normalized by the radiance of D004.

[0139] First, we compare the configuration without a microlens. The interference condition for D106 against D004 is the EL spectrum peak intensity λ in the front direction without a microlens. EL (0) is λ PL = 523nm and 528nm, respectively, shift to the longer wavelength side. Also, the relative radiance decreases to 0.84. On the other hand, with the microlens, the relative radiance of D105 increases to 1.13. Also, the EL peak wavelength λ EL are both 524 nm, and λ PL This is due to the component around Θeml, which has the highest contribution of the component refracted in the front direction at the inclined surface of the microlens shown in Figure 5(b). In D106, the interference peak resonance wavelength λ on and PL peak wavelength difference |λ off -λ PL | is the difference between the EL peak wavelength and the PL peak wavelength, |λ EL -λ PL It was found that the present invention can be effective even when the interference order m between the semitransparent electrode and the light-emitting point is set to 1.

[0140] As described above, it has been shown that the effect of the present invention does not depend on the shape of the PL spectrum of the light-emitting dopant or the interference order.

[0141] [Use of the organic light-emitting device according to one embodiment of the present invention] The organic light-emitting device according to one embodiment of the present invention can be used as a component of a display device or a lighting device, and can also be used as an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, a light-emitting device having a white light source and a color filter, etc.

[0142] The display device may be an image information processing device that has an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, etc., has an information processing unit that processes the input information, and displays the input image on the display unit.

[0143] The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of this touch panel function may be an infrared method, a capacitance method, a resistive film method, or an electromagnetic induction method, and is not particularly limited. The display device may also be used in the display unit of a multifunction printer.

[0144] Next, the display device according to this embodiment will be described with reference to the drawings.

[0145] The light-emitting element according to one embodiment of the present invention may be used in an image-forming apparatus, which includes a photoreceptor, an exposure light source, a developing unit, a charging unit, a transfer unit, a transport roller, and a fixing unit.

[0146] Light is irradiated from the exposure light source, and an electrostatic latent image is formed on the surface of the photosensitive member. This exposure light source has the organic light-emitting element according to the present invention. The developing unit has toner, etc. The charging unit charges the photosensitive member. The transfer device transfers the developed image to a recording medium. The transport unit transports the recording medium. The recording medium is, for example, paper. The fixing unit fixes the image formed on the recording medium.

[0147] The exposure light source may have a plurality of light-emitting units arranged on a long substrate. The row direction in which the organic light-emitting elements are arranged may be the axial direction of the photoreceptor. This row direction is the same as the direction of the axis about which the photoreceptor rotates. This direction may also be called the long axis direction of the photoreceptor.

[0148] The light-emitting portions may be arranged alternately in the column direction in each of the first and second columns, and the first and second columns are arranged at different positions in the row direction.

[0149] The first column may include a plurality of light-emitting units arranged at intervals. The second column may include light-emitting units at positions corresponding to the intervals between the light-emitting units in the first column. That is, the plurality of light-emitting units may also be arranged at intervals in the row direction. The light-emitting elements may be arranged, for example, in a grid pattern, a houndstooth pattern, or a checkerboard pattern.

[0150] 11 is a schematic diagram illustrating an example of a light-emitting device according to this embodiment. A display device 1000 may include 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 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. The light-emitting device is included in the display panel.

[0151] The display device according to this embodiment may have color filters having red, green, and blue colors, which may be arranged in a delta arrangement.

[0152] The display device according to the present embodiment may be used as a display unit of a mobile terminal. In this case, the display device may 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. The display device may have a display control unit that controls the image to be displayed.

[0153] The light-emitting device according to this embodiment may be used in a display unit of an imaging device having an optical unit with a plurality of 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 located within a viewfinder. The imaging device may be a digital camera or a digital video camera.

[0154] 12A is a schematic diagram showing an example of an imaging device according to this embodiment. 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 have a light-emitting device according to this embodiment. In this case, the display device may display not only the image to be captured, but also environmental information, imaging instructions, and the like. 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, and the like.

[0155] Since the optimum timing for capturing an image is very short, it is better to display information as quickly as possible. Therefore, it is preferable to use the organic light-emitting device of the present invention, because organic light-emitting elements have a fast response speed. The organic light-emitting device can be used more preferably than devices requiring high display speed, such as liquid crystal display devices.

[0156] 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.

[0157] FIG. 12B is a schematic diagram illustrating an example of an electronic device according to this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. 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. Examples of the electronic device include a smartphone and a laptop computer.

[0158] 13A and 13B are schematic diagrams illustrating an example of a light-emitting device according to this embodiment. FIG. 13A illustrates 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 light-emitting device according to this embodiment may be used in the display unit 1302.

[0159] It 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. 4A. The bottom side of the frame 1301 may also serve as the base.

[0160] 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.

[0161] FIG. 13B is a schematic diagram illustrating another example of a light-emitting device according to this embodiment. Display device 1310 in FIG. 13B is configured to be bendable, and is a so-called foldable display device. Display device 1310 has first display unit 1311, second display unit 1312, housing 1313, and bending point 1314. First display unit 1311 and second display unit 1312 may include a light-emitting device according to this embodiment. First display unit 1311 and second display unit 1312 may be a single, seamless display device. First display unit 1311 and second display unit 1312 can be separated by the bending point. First display unit 1311 and second display unit 1312 may display different images, or the first and second display units may display a single image.

[0162] The light-emitting device according to the present invention may be used in a lighting device. The lighting device may have a housing, a light source, a circuit board, an optical film, and a light diffusion unit. The light source may have the light-emitting device according to this embodiment. The optical filter may be a filter that improves the color rendering of the light source. The light diffusion unit can effectively diffuse light from the light source, such as for lighting up, and deliver the light over a wide area. The optical filter and the light diffusion unit may be provided on the light output side of the lighting. If necessary, a cover may be provided on the outermost part.

[0163] The lighting device is, for example, a device for illuminating a room. The lighting device may emit white, daylight white, or any other color from blue to red. It may have a dimming circuit for dimming these colors. The lighting device may have the organic light-emitting element of the present invention and a power supply circuit connected thereto. The power supply circuit is a circuit for converting AC voltage to DC voltage. Furthermore, white has a color temperature of 4200K, and daylight white has a color temperature of 5000K. The lighting device may have a color filter.

[0164] The lighting device according to this embodiment may also include a heat dissipation unit, which dissipates heat from within the device to the outside, and may be made of a material such as a metal with a high specific heat capacity or liquid silicon.

[0165] The light-emitting device according to the present invention may be used in a moving body such as an automobile. The automobile has a tail lamp, which is an example of a lamp. The automobile may have a tail lamp that is turned on when braking or the like is performed.

[0166] A tail lamp may include the light-emitting device according to this embodiment. The tail lamp may include a protective member for protecting the organic light-emitting element. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but is preferably made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

[0167] An automobile may have a body and a window attached thereto. The window may be a transparent display as long as it is not a window for checking the front and rear of the automobile. The transparent display may have an organic light-emitting device according to this embodiment. In this case, constituent materials of the electrodes and the like of the organic light-emitting element are made of transparent materials.

[0168] The moving body according to this embodiment may be a ship, an aircraft, a drone, or the like. The moving body may have a body and a lighting device provided on the body. The lighting device may emit light to indicate the position of the body. The lighting device has the organic light-emitting element according to this embodiment.

[0169] 14A and 14B, application examples of the display devices according to the above-described embodiments will be described. The display device can be applied to systems that can be worn as wearable devices, such as smart glasses, HMDs, and smart contact lenses. The image capturing and display device used in such application examples includes an image capturing device capable of photoelectrically converting visible light and a display device capable of emitting visible light.

[0170] 14A illustrates 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. Furthermore, a display device according to any of the above-described embodiments is provided on the back side of the lens 1601.

[0171] 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.

[0172] FIG. 14B illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 include a control device 1612, which is equipped with an imaging device equivalent to the imaging device 1602 and a display device. A lens 1611 includes an optical system for projecting light emitted from the imaging device and 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 include a gaze detection unit that detects the gaze of the wearer. Infrared light may be used for gaze detection. The infrared light emitter 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 that reduces light from the infrared light emitter to the display unit in a planar view reduces degradation of image quality.

[0173] 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.

[0174] 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.

[0175] A display device according to an embodiment of the present invention 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.

[0176] Specifically, the display device determines a first field of view area where the user gazes and a second field of view area other than the first field of view area based on the 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. In the display area of ​​the display device, the display resolution of the first field of view area may be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area may be lower than that of the first field of view area.

[0177] 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.

[0178] Note that AI may be used to determine the first field of view area and areas 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 an image of the eyeball, using as training data an image of the eyeball and the direction in which the eyeball in the image was actually looking. The AI ​​program may be included in the display device, the imaging device, or an external device. If included in an external device, it is transmitted to the display device via communication.

[0179] 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.

[0180] As described above, by using a device using the organic light-emitting element according to this embodiment, it is possible to provide a stable display with good image quality even over a long period of time.

[0181] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are appended to apprise the public of the scope of the present invention. [Explanation of symbols]

[0182] 1 Display area 2 Edges of the display area 3 Light-emitting element 3' dummy pixel 4 Optical Components 5. Substrate 6 reflective layer 7 Organic layer 8 Semi-transparent electrode 9 Protective layer 10 Microlenses 11 Light-emitting point 12 Synchrotron Radiation 13 Slope 14 Distance from the center of the pixel to the light-emitting position 15 Luminous area 16 Light extraction surface 17 Tilt angle 18 Luminous area 19 Light extraction surface 20 Light-emitting area that emits light in the forward direction 21 Pixel isolation layer 22 Light-emitting area 23 to 26 ΔML 27 Color Filter 28 Protective Glass 29 Optical adjustment layer 30 Transparent electrode 31 Filled bed 1000 display devices 1001 Top cover 1002 Flexible Printed Circuit 1003 Touch Panel 1004 Flexible Printed Circuit 1005 Display panel 1006 frames 1007 Circuit Board 1008 Battery 1009 Lower cover 1100 Imaging device 1101 Viewfinder 1102 Rear display 1103 Operation unit 1104 Case 1200 Electronic equipment 1201 Display section 1202 Operation unit 1203 Case 1300 display device 1301 Picture Frame 1302 Display section 1303 Foundation 1310 Display device 1311 First display section 1312 Second display section 1313 Case 1314 bending point 1600 Smart Glasses 1601 Lens 1602 Imaging device 1603 Control device 1610 Smart Glasses 1611 Lens 1612 control device

Claims

1. The present invention provides a light-emitting device comprising an insulating layer, a light-emitting element including a luminescent material and having a resonator structure, the light-emitting element being disposed on a main surface of the insulating layer, and a lens provided on the light-emitting element, the PL spectrum of the luminescent material having a wavelength λ within a visible light region. ＰＬ a light emitting device having a first peak which is the light-emitting device has an electrode between a main surface of the insulating layer and the light-emitting material, the electrode supplying electric charges to the light-emitting material, and one end and the other end of the electrode are covered with a pixel separation layer; In the resonator structure, a resonance peak wavelength λ of an interference spectrum that intensifies light emitted in a direction perpendicular to the main surface ｏｎ and the peak wavelength λ of the EL light emitted through the lens. ＥＬ and the λ ＰＬ and satisfy the following formula (1): |l ＥＬ -l ＰＬ | < |λ ｏｎ -l ＰＬ | (1)

2. 2. The light emitting device according to claim 1, wherein in the PL spectrum, the first peak is a maximum intensity peak in the visible light region.

3. PL peak wavelength λ ＰＬ is the λ in the PL spectrum ｏｎ 3. The light emitting device according to claim 1, wherein the wavelength of the peak light is closest to the wavelength of the peak light.

4. The present invention provides a light-emitting device comprising an insulating layer, a light-emitting element including a luminescent material and having a resonator structure, the light-emitting element being disposed on a main surface of the insulating layer, and a lens provided on the light-emitting element, the PL spectrum of the luminescent material having a wavelength λ within a visible light region. ＰＬ A light emitting device having a first peak of the light-emitting device has an electrode between a main surface of the insulating layer and the light-emitting material, the electrode supplying electric charges to the light-emitting material, and one end and the other end of the electrode are covered with a pixel separation layer; In the resonator structure, a resonance peak wavelength λ of an interference spectrum that intensifies light emitted in a direction perpendicular to the main surface ｏｎ and a resonance peak wavelength λ of an interference spectrum that intensifies light emitted in a direction perpendicular to the main surface due to refraction in the lens. ｏｆｆ and the λ ＰＬ and satisfy the following formula (2): |l ｏｆｆ -l ＰＬ | < |λ ｏｎ -l ＰＬ | (2)

5. The PL spectrum of the luminescent material has a luminescence intensity lower than the first peak and a wavelength λ ＰＬ２ and the light-emitting device according to claim 4, wherein the second peak is: |l ｏｆｆ -l ＰＬ | ≦ |λ ｏｎ -l ＰＬ２ | (3)

6. 6. The light emitting device according to claim 5, wherein in the PL spectrum, the first peak is a peak with the highest intensity in the visible light region, and the second peak is a peak with the second highest intensity after the first peak.

7. PL peak wavelength λ ＰＬ is the λ in the PL spectrum ｏｎ 7. The light emitting device according to claim 4, wherein the wavelength of the peak is closest to the wavelength of the light emitting element.

8. Said λ ｏｎ is the λ ＰＬ 8. The light emitting device according to claim 1, wherein the wavelength of the light emitted from the light source is longer than that of the light emitted from the light source.

9. the lens has an inclined portion inclined with respect to the main surface, 9. The light emitting device according to claim 1, wherein the inclined portion refracts light traveling in a direction inclined to the main surface in a direction perpendicular to the main surface.

10. 10. The light emitting device according to claim 9, wherein the inclined portion has an inclination angle of 9 degrees or more and 60 degrees or less with respect to the main surface.

11. 11. The light emitting device according to claim 9, wherein the light refracted in the forward direction at the inclined portion of the lens has a radiation angle Θeml with respect to the main surface of the light emitting layer of the light emitting element that is greater than 0° and less than 30°.

12. 12. The light emitting device according to claim 9, wherein the light refracted in the forward direction at the inclined portion of the lens has a radiation angle Θeml of 5° or more and 20° or less with respect to the main surface of the light emitting layer of the light emitting element.

13. In the light-emitting element, 13. The light-emitting device according to claim 1, wherein in a cross section perpendicular to the main surface of the insulating layer, the midpoint of the lens in a direction parallel to the main surface and the midpoint between the end of the pixel separation layer and the other end do not overlap in a planar view.

14. the display area has a first area including a central portion of the display area and a second area disposed outside the first area, the first region includes a third light-emitting element, and the second region includes a fourth light-emitting element; The light-emitting device described in claim 13, characterized in that the distance between the midpoint of the lens in the fourth light-emitting element and the midpoint between the end of the pixel isolation layer and the other end is greater than the distance between the midpoint of the lens in the third light-emitting element and the midpoint between the end of the pixel isolation layer and the other end.

15. a light-emitting portion containing the light-emitting material, In a cross section of the insulating layer taken in a direction perpendicular to the main surface, when a midpoint of the lens in a direction parallel to the main surface and a midpoint between an end of the pixel separation layer and the other end do not overlap in a plan view, Said λ ｏｆｆ 15. The light emitting device according to claim 13, wherein the optical distance is a distance between the light emitting portion and a curved surface of the lens that is farthest from the light emitting portion in the cross section.

16. 16. The light-emitting device according to claim 1, further comprising a second light-emitting element having a different resonator structure from the light-emitting element, wherein the second light-emitting element intensifies light of a wavelength different from that of the light-emitting element.

17. The light-emitting device of claim 16, characterized in that the light-emitting element has a first optical adjustment layer, the second light-emitting element has a second optical adjustment layer, and the layer thickness of the first optical adjustment layer is smaller than the layer thickness of the second optical adjustment layer.

18. 18. The light emitting device according to claim 1, further comprising a second light emitting element different from the light emitting element, the second light emitting element not satisfying the formula (1).

19. 5. The light emitting device according to claim 4, further comprising a second light emitting element different from the light emitting element, the second light emitting element not satisfying the formula (2).

20. the emission spectrum of the luminescent material has a first full width at half maximum; the second light-emitting element has a second light-emitting material; the emission spectrum of the second luminescent material has a second full width at half maximum; 20. The light emitting device of claim 16, wherein the second full width at half maximum of the second luminescent material is greater than the first full width at half maximum of the luminescent material.

21. 21. The light emitting device of claim 20, wherein the second luminescent material is a phosphorescent material.

22. 22. The light-emitting device according to claim 1, wherein the light-emitting substance of the light-emitting element is a fluorescent material.

23. a second light-emitting element different from the light-emitting element, and a second lens different from the lens and onto which light from the second light-emitting element is incident; 23. The light-emitting device according to claim 1, wherein the distance in a direction parallel to the main surface between the midpoint of the light-emitting region of the light-emitting element and the midpoint of the lens in a cross section perpendicular to the main surface is greater than the distance in a direction parallel to the main surface between the midpoint of the light-emitting region of the second light-emitting element and the midpoint of the second lens in a cross section perpendicular to the main surface.

24. a third light-emitting element different from the second light-emitting element; and a third lens different from the second lens and onto which light from the third light-emitting element is incident; 24. The light-emitting device of claim 23, wherein the distance in a direction parallel to the main surface between the midpoint of the light-emitting region of the second light-emitting element and the midpoint of the lens in a cross section perpendicular to the main surface is greater than the distance in a direction parallel to the main surface between the midpoint of the light-emitting region of the third light-emitting element and the midpoint of the third lens in a cross section perpendicular to the main surface.

25. A display device comprising: a light-emitting device according to claim 1; and a display control unit connected to the light-emitting device.

26. an optical unit having a plurality of lenses, an image pickup element that receives light that has passed through the optical unit, and a display unit that displays an image picked up by the image pickup element; An imaging device, wherein the display unit comprises the light-emitting device according to claim 1 .

27. 25. An electronic device comprising: a display unit having the light-emitting device according to claim 1; a housing in which the display unit is provided; and a communication unit provided in the housing for communicating with an external device.

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