Patent Application
20240065078
The present invention relates to light-emitting apparatuses, display apparatuses, image pickup apparatuses, and electronic apparatuses.
Organic light-emitting elements (also referred to as organic electroluminescence (EL) elements or organic light-emitting diodes (OLEDs)) are electronic elements including 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 of the luminescent organic compound in the organic compound layer, and when the excitons return to the ground state, the organic light-emitting element emits light. The recent remarkable progress in the organic light-emitting elements has prompted a lower driving voltage, a variety of emission wavelengths, rapid response, and a decrease in the thickness and weight of light-emitting devices. In contrast, organic light-emitting elements trap light so that much light cannot be extracted to the outside, having low light extraction efficiency. To increase the light extraction efficiency, organic light-emitting elements may include a light extracting structure, such as microlenses. PTL 1 discloses an organic light-emitting device including microlenses as an outcoupling component to increase the amount of light extracted from the OLED. In the organic light-emitting device disclosed in PTL 1, the diameter of each microlens and the distance between the lens and the luminous region are defined to address the problem of low contrast due to back scattering.
PTL 1 Japanese Patent Laid-Open No. 2017-17013
However, the organic light-emitting device disclosed in PTL 1 does not define interference conditions, having no sufficient configuration for radiating desired light in a substrate normal direction (that is, a frontal direction).
The present invention is made in view the above problem, and its object is to provide an organic light-emitting element having high radiance in the frontal direction using a light extracting structure, such as microlenses, and using optical interference taking account of the light extracting structure.
An embodiment of the present invention provides a light-emitting apparatus including an insulating layer, a light-emitting element disposed on a main surface of the insulating layer, the light-emitting element containing a light-emitting material and having a resonator structure, a light extracting structure disposed above the light-emitting element, and an electrode between the main surface of the insulating layer and the light-emitting material, the electrode supplying electrical charge to the light-emitting material, a photoluminescence (PL) spectrum of the light-emitting material having a first peak with a wavelength λpl in a visible light range,
|λEL−λpl|<|λon−λpl| (1)
where λon is a resonance peak wavelength of an interference spectrum that reinforces light emitted in a direction perpendicular to the main surface and λEL is a peak wavelength of electroluminescence radiated via the light extracting structure.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
A light-emitting apparatus according to an embodiment of the present invention can reinforce the radiation intensity in the frontal direction of the organic EL element with a light extracting structure by including an organic-film interference structure matched to the inclined portion of the light extracting structure. This is because the light with the PL peak wavelength of the light-emitting material is effectively reinforced and is refracted in the frontal direction at the inclined portion of the light extracting structure. The light-emitting apparatus includes an electrode that supplies electrical charge to the light-emitting material between the main surface of the insulating layer and the light-emitting material, and one end and the other end of the electrode is covered with a pixel separating layer.
In other words, a light-emitting apparatus according to an embodiment of the present invention includes an insulating layer, a light-emitting element disposed on a main surface of the insulating layer, the light-emitting element containing a light-emitting material and having a resonator structure, and a light extracting structure disposed above the light-emitting element, a photoluminescence (PL) spectrum of the light-emitting material having a first peak with a wavelength λPL in a visible light range, wherein the resonator structure satisfies Exp. (1),
|λEL−λPL|<|λon−λPL| (1)
where λon is a resonance peak wavelength of an interference spectrum that reinforces light emitted in a direction perpendicular to the main surface and λEL is a peak wavelength of electroluminescence radiated via the light extracting structure.
A light-emitting apparatus according to an embodiment of the present invention may include an insulating layer, a light-emitting element disposed on a main surface of the insulating layer, the light-emitting element containing a light-emitting material and having a resonator structure, and a light extracting structure disposed above the light-emitting element, a photoluminescence (PL) spectrum of the light-emitting material having a first peak with a wavelength λPL in a visible light range, wherein the resonator structure satisfies Exp. (2),
|λoff−λPL|<|λon−λPL| (2)
where λon is a resonance peak wavelength of an interference spectrum that reinforces light emitted in a direction perpendicular to the main surface and λoff is a resonance peak wavelength of an interference spectrum that reinforces light emitted in the direction perpendicular to the main surface due to refraction in the light extracting structure.
In another embodiment, λoff may be set at the distance from the luminous area to the lower end of the upper electrode of the light-emitting element in the direction of the curve of the light extracting structure, and λon may be set at the distance from the luminous area to the lower end of the upper electrode of the light-emitting element in the direction perpendicular to the insulating layer. The use of the actual distances facilitates designing.
A light-emitting apparatus according to an embodiment of the present invention will be described hereinbelow with reference to the drawings. Known technology in the technical field is applicable to components that are not particularly illustrated or described in this specification. It is to be understood that the present invention is not limited to the embodiments described below.
This resonator structure has a resonance peak wavelength λon with an interference spectrum that reinforces light emitted in the direction perpendicular to the main surface of the substrate. The light emitted in the direction perpendicular to the main surface of the substrate is also referred to as light extracted in the direction perpendicular to the main surface of the substrate without the light extracting structure. In other words, the light is light emitted in the frontal direction of the substrate independently from refraction using the light extracting structure. The resonator structure has a peak wavelength λEL of electro luminescence (EL) radiated through the light extracting structure. The wavelength λEL is the wavelength of light emitted to front of the substrate in which optical interference due to the resonator structure and refraction due to the light extracting structure are taken into account. The PL and the PL spectrum are the behavior of the light-emitting material independent of the structure of the light-emitting element. The PL spectrum can be obtained by, for example, forming an emission layer containing the light-emitting material of an organic light-emitting element on the substrate and causing photoexcitation. The emission layer is preferably reproduced, but any solid-state membrane of a light-emitting material allows photoluminescence to be measured. In contrast, electroluminescence (EL) and an EL spectrum are luminescence characteristics in which the effects of the optical distance between the electrodes and the light extracting structure are taken into account.
The light-emitting apparatus according to this embodiment is a light-emitting apparatus in which λPL which is a first peaks of the light-emitting material, λEL, and λon satisfy Exp. (1). Satisfying Exp. (1) provides a light-emitting apparatus with preferable luminance in front of the substrate.
|λEL−λPL|<|λon−λPL| (1)
Satisfying Exp. (1) represents that the difference between the wavelength of electroluminescence and the first peak wavelength of the light-emitting material is less than the difference between the interference peak λon and the first peak wavelength of the light-emitting material.
The value |λon−λPL| may be less than the half width at half maximum of λPL.
The light-emitting apparatus according to this embodiment has, in the resonator structure, a resonance peak wavelength λoff of an interference spectrum that reinforces light emitted in the direction perpendicular to the main surface of the substrate due to refraction in the light extracting structure. The light emitted in the frontal direction of the substrate due to the refraction with the light extracting structure is light inclined with respect to the main surface of the substrate. In
The light-emitting apparatus according to this embodiment is a light-emitting apparatus in which λPL, λoff, and λon satisfy Exp. (2). Satisfying Exp. (2) provides a light-emitting apparatus with preferable luminance in front of the substrate.
|λoff−λPL|<|λon−λPL| (2)
Exp. (2) represents that the difference between interference peak λoff and the first peak wavelength of the light-emitting material is less than the difference between the interference peak λon and the first peak wavelength of the light-emitting material. In other words, the first peak wavelength of the light-emitting material is closer to the interference peak at which the light emitted in the frontal direction of the substrate is reinforced via the light extracting structure than the interference peak at which the light emitted in the substrate frontal direction is reinforced. In other words, the interference peak at which the light emitted at an angle to the substrate is reinforced is closer to the first peak of the light-emitting material. The first peak may be the maximum intensity peak in the PL spectrum of the light-emitting material in the visible range. If the PL spectrum has a second peak, the second peak may be a peak with the second highest intensity after the first peak. The light-emitting material is also referred to as luminescence dopant. The value |λon−λPL| may be less than or equal to the half width at half maximum of λPL.
If the second peak is present, Exp. (3) is preferably satisfied.
|λoff−λPL|≤|λon−λPL2| (3)
where λPL2 is the wavelength of the second peak.
Exp. (3) represents that the difference between the interference peak λoff and the first peak λPL is less than the difference between the interference peak λon and the second peak λPL2. In other words, the interference peaks may be designed putting the first peak on a higher priority than the second peak. The first peak may coincide with λoff, and the second peak may coincide with λon. Satisfying Exp. (3) is preferable because it increases the luminance in the frontal direction of the substrate. The value |λon−λPL2| may be less than or equal to the half width at half maximum of the second peak.
In contrast, the light-emitting apparatus may include a second light-emitting element different from the light-emitting element, and the second light-emitting element mat be an element that does not satisfy Exp. (1). The second light-emitting element may be an element that emits light of a different color from the light-emitting element. Since the second light-emitting element is a light-emitting element that emits light of a different color, the light-emitting element does not have to satisfy both of Exp. (1) and Exp. (2). The color of light emitted from the second light-emitting element that does not satisfy Exp. (1) and Exp. (2) may be determined in accordance with the balance of red, green, and blue (RGB) of the light-emitting apparatus and may be blue, green, or red or a combination thereof.
In the light-emitting apparatus according to an embodiment of the present invention, an element that puts a higher priority on frontal luminance may satisfy (1) or (2) and (3), and an element that puts a higher priority on chromatic purity may be an element that does not satisfy (3). The element that puts a higher priority on chromatic purity does not have to satisfy (1) and (2).
The element that puts a higher priority on frontal luminance may be an element that generates green, and the element that puts a higher priority on chromatic purity may be an element that generates blue. In another embodiment, the element that puts a higher priority on frontal luminance may be an element that generates blue, and the element that puts a higher priority on chromatic purity may be an element that generates green. In yet another embodiment, the element that puts a higher priority on frontal luminance may be an element that generates red, and the element that puts a higher priority on chromatic purity may be an element that generates green or blue.
The second light-emitting element may contain a second light-emitting material different from the light-emitting material of the first light-emitting element.
The half width at half maximum of the PL spectrum of the second light-emitting material may be larger than or equal to the half width at half maximum of the PL spectrum of the light-emitting material of the first light-emitting element.
The half width at half maximum of the PL spectrum refers to the width of the first peak at an intensity of 0.5, where the PL intensity of the first peak is 1. In a light-emitting material whose spectrum widths of the first peak and the second peak are large, the minimum value of the PL intensity in the boundary between the first peak and the second peak can be greater than or equal to 0.5. In this case, the spectrum width of a spectrum obtained by adding up the spectrum components of the first peak and the second peak at an intensity of 0.5 is a half width at half maximum. If the spectrum width of the first peak is extremely large, it appears as if no second peak is present. The half width at half maximum in this case refers to the width of the entire PL spectrum at an intensity of 0.5.
The light-emitting material with an emission spectrum having the first peak and the second peak may be a fluorescence emission material or a delayed fluorescence material. The delayed fluorescence may be of a thermally activated type. In contrast, the second light-emitting material that is assumed to have a small second peak or have no second peak may be a phosphorescence emission material.
In other words, the light-emitting element containing a fluorescent material may satisfy Exp. (1) or (2) in the specification, and the second light-emitting element containing a phosphorescent material may be in a form that does not satisfy either of Exps. (1) and (2) in this specification.
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 smaller than the width of the other light-emitting elements. This is for the purpose of preventing the wavelength of green, which sandwiched between blue and red, from overlapping with the other colors.
Since the interference peak resonant wavelength Aoff of the light-emitting apparatus according to this embodiment may reinforce the light of an emission angle of 15°, because light of an emission angle of 15° with respect to the substrate main surface tends to be reinforced.
To form the light-emitting apparatus according to this embodiment, specifically, the interference peak resonant wavelength in the frontal direction, which depends on the material and the thickness of the organic layer of the light-emitting element, is set closer to the long wavelength side than the PL peak wavelength of the light-emitting material. Setting the interference peak resonant wavelength closer to the long wavelength side allows the light near the PL peak wavelength with the highest intensity in the PL spectrum of the light-emitting material to be emitted toward the inclined portion of the light extracting structure. This inclined portion refracts the light in the frontal direction of the substrate, increasing the luminance in the frontal direction. The configuration of the light-emitting apparatus according to the present invention refers to an optical interference condition unique to the light-emitting element with the light extracting structure. Preferably, the inclined portion of the light extracting structure is at 0° or more and less than 90° with respect to the substrate main surface, and more preferably, at 9° or more and 60° or less. This range allows the luminance in the frontal direction of the substrate to be increased.
Reinforcing the optical interference condition refers to causing reinforcing interference by adjusting the distance d0 from the light emitting position of the emission layer to the reflecting surface of the light reflective material to d0=mλ/4n0 (i=1, 3, 5, . . . ). This results in an increase in a component in a particular direction in the radiation distribution of light with a wavelength λ, increasing the radiance at the particular angle.
The optical distance Lr between the light emitting position to the reflecting surface of the light reflecting layer, in reinforcing the wavelength λ together, is expressed as Exp. (4).
Lr=(2m−(ϕr/π))×(λ/4)×1/cos (Θeml) (4)
In Exp. (4), m is the order of interference between the luminous point and the reflecting layer, which is an integer greater than or equal to 0, and n0 is an effective refractive index of the layer from the light emitting position to the reflecting surface at a wavelength λ. Cases where m=0 and m=1 in an ideal case Φr=π are respectively referred to as an interference condition of λ/4 and an interference condition of 3λ/4, where ϕr[rad] is the sum of the phase shift amounts when light with a wavelength λ is reflected at the reflecting surface, and Θeml is an emission angle with respect to the direction of normal to the substrate in the emission layer. The optical distance Lr is the sum of the products of the refractive indices nj and the thicknesses dj of the individual layers of the organic compound layer. In other words, Lr can be expressed as Σnj×dj or n0×d0, where ϕ is a negative value.
The full thickness interference L, in reinforcing the wavelength λ, is expressed as Exp. (5), where Ls is the optical distance between the light emitting position and the reflecting surface of the electrode, and ϕs[rad] is the sum of the phase shifts when light with a wavelength λ is reflected at the reflecting surface of the light extracting electrode.
L=(Lr+Ls)=(2M−Φ/π)×(λ/4)×1/cos (θeml) (5)
where M is m+m′, m′ is the order of interference between the luminous point and the light extracting electrode, which is an integer greater than or equal to 0.
The value M is the sum of the order of interference m between the luminous point and the reflecting layer and the order of interference m′ between the luminous point and the light extracting electrode (M=m+m′), which is an integer greater than or equal to 0, and Φ is the sum of the phase shifts when the light with a wavelength λ is reflected at the light reflecting layer and the light extracting electrode (Φ=ϕr+ϕs). Exp. (5) expresses interference which is referred to as the full thickness interference of the organic compound layer.
In the case of an organic light-emitting element having no inclined surface of the light extracting structure, the thickness of the organic layer is designed so that Exp. (4) and Exp. (5) are satisfied on the condition that the frontal direction Θeml=0°.
The interference peak resonant wavelength in the frontal direction, λon (on-axis), at that time is expressed as Exp. (6).
λon=4πL/(2πM−Φ) (6)
For an organic light-emitting element without the inclined surface of the light extracting structure, the thickness and the material are designed so that the peak resonant wavelength λon in the frontal direction, expressed by Exp. (6), substantially coincides with the peak wavelength λPL of the PL spectrum of the luminescence dopant.
In contrast, with the light extracting structure, in other words, according to an embodiment of the present invention, the emission angle in the frontal direction in the organic light-emitting element changes depending on the pixel light emitting position in the pixel luminous region.
The distance X between the luminous point 11 from which the emission light 12 to be refracted in the frontal direction at the inclined portion 13 and the pixel center is expressed as Exp. (7). The emission angle Θeml of the emission light 41 in the emission layer is expressed as Exp. (8), where R is the distance between the inclined portion 13 of the microlens 10 with an angle of inclination of ψ to the main surface of the substrate and the pixel center in the direction parallel to the main surface of the substrate, and r is the distance between the inclined portion 13 and the luminous point 11 in the direction parallel to the main surface of the substrate. In this case, the pixel center may be a middle point in a cross section of the lower electrode perpendicular to the substrate main surface. If the lower electrode has an insulating layer at the ends, the pixel center may be a middle point of an opening of the insulating layer on the lower electrode in a cross section perpendicular to the substrate main surface.
The values di and ni are the thickness and the refractive index of the i-th layer, respectively. R(ψ) denotes a structural parameter indicating the relationship between the position and the angle of inclination of the light extracting structure. In the case of the spherical microlenses illustrated in
Next, the inclined portion with the highest contributing rate is defined, and the interference peak resonant wavelength in the direction of the emission angle Θeml corresponding to the inclination angle with the highest contributing rate will be described. The inclined portion with the highest contributing rate refers to an inclined portion with the maximum luminous area of a pixel emission range in which light refracted in the frontal direction at the inclined portion of the light extracting structure can be emitted.
Here, the emission angle Θeml corresponding to the inclined portion with the highest contributing rate is an emission angle at a luminous point of light emitted from the maximum luminous area, described above, and refracted in the frontal direction at the inclined portion with the highest contributing rate.
In
λoff=4πL/(2πM−Φ)×1/cos (Θeml) (9)
It is preferable to determine an optical interference condition for the organic light-emitting element so that the difference between the interference peak resonant wavelength λoff in Exp. (9) and the PL peak wavelength λPLof the light-emitting material is smaller than the difference between the interference peak wavelength λon in the frontal direction defined by Exp. (9) and λPL. The interference peak resonant wavelength λoff may be almost equal to the peak wavelength λEL of the EL spectrum of the light-emitting apparatus of this embodiment, which will be illustrated in the examples. In other words, the optical interference condition of the organic light-emitting element may be determined so that the difference between λEL and λPL is smaller than the difference between the interference peak wavelength λon in the frontal direction and λPL.
Next, the effect of the difference between the interference peak resonant wavelength λoff in an oblique direction in Exp. (9) and the PL peak wavelength λPL of the light-emitting material being smaller than the difference between the interference peak wavelength λon in the frontal direction defined by Exp. (6) and λPL will be described.
The value Θeml=0° in
With the conventional configuration in
In contrast, in the case where the difference between the interference peak resonant wavelength λoff in a direction inclined with respect to the substrate main surface and the PL peak wavelength λPL is smaller than the difference between the interference peak wavelength λon in the frontal direction of the substrate main surface and λPL, the region with high frontal-light extraction efficiency of the light extracting structure and the region with a high emission intensity of the PL spectrum coincide. In other words, the radiance of Θeml=15°, 25° in
Since the present invention is configured so that the interference peak wavelength λon in front of the substrate main surface of the organic light-emitting element with the light extracting structure is closer to the long wavelength side with respect to the PL peak wavelength λPL of the light-emitting material, the frontal radiance is high. In other words, setting the difference between the interference peak resonant wavelength λoff in a direction inclined with respect to the substrate main surface and the PL peak wavelength λPL smaller than the difference between the interference peak wavelength λon in the frontal direction and λPL remarkably increases the frontal radiance. As shown in
To increase the radiance in the frontal direction of the substrate main surface, λoff and λPL may be made to coincide. When the spectrum of the light-emitting material has the second peak λPL2 with lower intensity than λPL, λPL2 may be made to coincide with λon. In other words, the interference spectrum in a direction inclined with respect to the substrate main surface is close to λPL, and the interference spectrum in the frontal direction of the substrate main surface is close to λPL2. In comparison of them, λPL and λoff may be closer to each other than λPL2 and λon.
In this embodiment, the optical distance may be roughly estimated, with the refractive index of the organic layer assumed to be 1.9. In this case, a constant A that satisfies Exp. (A) is provided.
1.9 D<AλPL/4<1.9 D/cos θ (A)
where λPL is the emission wavelength of the light-emitting material, D is the interelectrode distance, and θ is the inclination angle of the emission light.
The value AλPL/4 may be closer to 1.9 D/cosθ than to 1.9 D. In other words, the interference spectrum inclined at an angle of θ contributes more to the interference of the emission wavelength λPL of the light-emitting material than the interference spectrum in the frontal direction of the substrate.
The light-emitting apparatus according to this embodiment may include a second light-emitting element different from the light-emitting element and a second light extracting structure that is different from the light extracting structure and that receives light from the second light-emitting element, in which the distance in the direction parallel to the substrate main surface between the middle point of the luminous region of the light-emitting element and the middle point of the light extracting structure in a cross section perpendicular to the substrate main surface may be smaller than the distance in the direction parallel to the substrate main surface between the middle point of the luminous region of the second light-emitting element and the middle point of the second light extracting structure in a cross section perpendicular to the substrate main surface.
The light-emitting apparatus according to this embodiment may further include a third light-emitting element different from the second light-emitting element and a third light extracting structure that is different from the second light extracting structure and that receives light from the third light-emitting element, in which the distance in the direction parallel to the substrate main surface between the middle point of the luminous region of the second light-emitting element and the middle point of the second light extracting structure in a cross section perpendicular to the substrate main surface may be smaller than the distance in the direction parallel to the substrate main surface between the middle point of the luminous region of the third light-emitting element and the middle point of the third light extracting structure in a cross section perpendicular to the substrate main surface.
In
n
0×sin (θ0+ψ)=neml×sin (θeml+ψ) (10)
where ψ (ψ′ in
The sign θeml denotes the emission angle at the luminous point. In
θ0=π/2−sin−1(n0/neml) (11)
θ0′=π/2+θeml−sin−1(n0/neml)=θ0+Θeml (12)
In other words, the refracting direction can be shifted to the wider angle by Θeml than with the conventional configuration with the optical interference condition for the organic light-emitting element for bringing the interference peak resonant wavelength λoff in a direction inclined with respect to the substrate main surface close to the PL peak wavelength λPL. In other words, the configuration of this embodiment can increase the angle adjustment range by shifting the microlens as compared with the conventional configuration. The wider angle emission allows application to a shorter focus optical part with a small display while increasing the field of view (FOV). In other words, for example, a head mount display can be reduced in size.
The distance in a substrate in-plane direction between the central position of the light extracting structure and the central position of the pixel opening may be adjusted as appropriate in at least some regions of the light-emitting apparatus.
An insulating layer (not shown) may be provided on the substrate 5. The insulating layer may be formed of, for example, an oxide layer, a nitride layer, or an organic layer. The insulating layer is also referred to as a planarizing layer because of its function. For example, the insulating layer may have the function of reducing the effect of the surface irregularities of the transistors formed on the substrate exerted on the electrodes.
The organic layer 7 may be constituted by a plurality of layers. The plurality of layers includes an emission layer, which contains a light-emitting material. An emission layer that emits light of a single color may be formed on the light-emitting elements and over the entire surface between the light-emitting elements. Alternatively, emission layers that emit light of different colors may be layered on the light-emitting elements and over the entire surface between the light-emitting elements so that the display apparatus can display at least two colors, or an emission layer that emits different colors of light for each light-emitting element may be patterned. If the organic layer is made of an emission layer that emits white light, a color filter may be provided between the light-emitting elements and the microlenses.
The protecting layer 9 is a layer for protecting the light-emitting elements and may be an inorganic layer, such as silicon nitride, silicon oxynitride, silicon oxide, or aluminum oxide, or an organic layer, such as an acrylate resin, an epoxy resin, or a polyimide resin.
The microlenses 10 receives light emitted from the light-emitting elements. A planarizing layer (not shown) may be provided between the microlenses and the protecting layer. The planarizing layer may also serve as an adhesion layer. The planarizing layer may be made of the same resin as the microlenses.
A protective glass 28 is provided on the color filter 27. An organic layer, such as an adhesion layer, may be disposed between the protective glass 28 and the color filter 27. The protective glass 28 is located at a position opposite to the substrate 5 and is therefore also referred to as an opposing substrate because of its placement position.
The region of wavelengths transmitted by the color filter may include the PL peak wavelength of the light-emitting material. When priority is given to the luminance of the light-emitting apparatus in the case where the PL peak of the light-emitting material includes a first peak and a second peak lower than the first peak, the first peak wavelength and the second peak wavelength may be included in the region of wavelengths transmitted by the color filter. When priority is given to the chromatic purity of the light-emitting apparatus in the case where the PL peak of the light-emitting material includes the first peak and the second peak lower than the first peak, only the first peak may be included in the region of wavelengths transmitted by the color filter.
This is preferable in application to devices that place importance on the luminance, for example, a head mount display and an augmented reality (AR) glass.
In this embodiment, the light-emitting element may include an electrode that supplies an electric charge to the light-emitting material and a pixel separating layer that covers one end and the other end of the electrode. The pixel separating layer may also be referred to as an insulating layer on the lower electrode. The insulating layer here is another layer different from the insulating layer under the lower electrode. The pixel separating layer is also referred to as a bank.
The middle point of the light extracting structure in the direction parallel to the main surface of the insulating layer and the middle point between one end and the other end of the pixel separating layer do not have to be superposed on each other in plan view in a cross section perpendicular to the main surface of the substrate.
The light-emitting apparatus includes a display area. The display area includes a first area including the central portion of the display area and a second area outside the first area in plan view.
The first area includes a third light-emitting element, and the second area includes a fourth light-emitting element. The distance between the middle point of the light extracting structure and the middle point between one end and the other end of the pixel separating layer of the fourth light-emitting element is larger than the distance between the middle point of the light extracting structure and the middle point between one end and the other end of the pixel separating layer of the third light-emitting element. In other words, the gap between the light extracting structure and the bank opening of the fourth light-emitting element is larger.
The light-emitting element includes an insulating layer, a first electrode, an organic compound layer, and a second electrode on a substrate. For example, a protecting layer, a color filter, and microlenses may be provided above the negative electrode. If a color filter is provided, a planarizing layer may be provided between the color filter and the protecting layer. The planarizing layer may be made of an acrylic resin or the like. This also applies to a planarizing layer provided between the color filter and the microlenses.
The substrate is made of quartz, glass, a silicon wafer, resin, metal, or the like. Switching elements, such as transistors, and wiring lines may be provided on the substrate, on which an insulating layer may be provided. The insulating layer may be made of any material that allows contact holes to be formed therein so that wiring lines can be formed between the insulating layer and the first electrode and that ensures insulation from unconnected wiring lines. Examples include resins, such as polyimide, silicon oxide, and silicon nitride.
The light-emitting element includes a first electrode, a second electrode, and an emission layer disposed between the first electrode and the second electrode and containing a light-emitting material. The emission layer may be either an organic compound layer or an inorganic compound layer. The electrode may also serve as a reflecting layer. The light-emitting material may be either a fluorescence emitting material or a phosphorescence emitting material.
The electrodes may be a pair of electrodes. The pair of electrodes may include a positive electrode and a negative electrode. When an electric field is applied in the direction in which the organic light-emitting element emits light, an electrode with a high potential is the positive electrode, and the other is the negative electrode. In other words, an electrode that supplies holes to the emission layer is the positive electrode, and an electrode that supplies electrons is the negative electrode. The electrodes may be formed across a plurality of light-emitting elements or separately formed for each light-emitting element. For example, the positive electrode may be separately formed for each light-emitting element, and the negative electrode may be formed across a plurality of light-emitting elements.
Preferably, a material for the positive electrode has the largest possible work function. Examples include single metals, such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, tungsten, and silicon, a mixture thereof, an alloy thereof, and metal oxides, such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide. Other examples include conductive polymers, such as polyaniline, polypyrrole, and polythiophene.
These electrode materials may be used alone or in combination of two or more materials. The positive electrode may be formed of one layer or a plurality of layers.
For use as a reflecting layer, chromium, aluminum, silver, titanium, tungsten, molybdenum, an alloy thereof, or a laminate thereof may be used. A reflecting layer not having the function of an electrode may be made of the above materials. Examples for use as a transparent electrode include, but are not limited to, oxide transparent conductive layers made of indium tin oxide (ITO) or indium zinc oxide. The electrodes may be formed using a photolithography technique. The reflecting layer preferably has a reflectance of 70% or more at an emission wavelength. The reflecting layer may also serve as an electrode.
In contrast, a material for the negative electrode preferably has a small work function. Examples include alkali metal, such as lithium, alkali earth metal, such as calcium, single metals, such as aluminum, titanium, manganese, silver, lead, and chromium, and a mixture thereof. Other examples include alloys of such single metals. Examples include a magnesium-silver alloy, an aluminum-lithium alloy, an aluminum-magnesium alloy, a silver-copper alloy, and a zinc-silver alloy. Metal oxide, such as indium tin oxide (ITO), may also be used. These electrode materials may be used alone or in combination of two or more materials. The negative electrode may be formed of one layer or multiple layers. Among them, silver is preferably used, and more preferably, a silver alloy is used to reduce silver agglomeration. Any alloy ratio that reduces silver agglomeration is possible. For example, the ratio of silver to another meal may be 1:1 or 3:1.
Examples of the negative electrode include, but are not limited to, a top emission element made of an oxide conductive layer, such as ITO, and a bottom emission element made of a reflecting layer, such as aluminum (Al). Examples of a method for forming the negative include, but are not limited to, direct-current sputtering and alternate-current sputtering, which more preferably provide large film coverage, enhancing ease of decreasing the resistance.
For use as a transflective electrode, metal that transmits part of incident light and reflects part of the incident light is used. A sufficiently thin metal layer may be used as the transflective electrode. For example, silver about 10 nm thick may be used as the transflective electrode.
The organic layer may be formed of one layer or multiple layers. The organic layer, if including multiple layers, may be referred to as a hole injection layer, a hole transport layer, an electron blocking layer, an emission layer, a hole blocking layer, an electron transport layer, an electron injection layer, or a charge generating layer depending on the function. The organic layer is mainly composed of an organic compound but may contain inorganic atoms or an inorganic compound containing, for example, copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, or zinc.
The organic layer may include multiple emission layers. Any of the emission layers may contain a red emitting material, a green emitting material, or a blue emitting material. Mixing the emitting materials allows emission of white light. Any of the emission layers may contain complementary color emitting materials, such as a blue emitting material and a yellow emitting material. The emitting material may be a fluorescent material, a phosphorescent material, a delayed fluorescence material, or CdS or perovskite quantum dots. Light of different colors may be emitted by changing the material or the configuration of the emission layer for each light-emitting element. The emission layer may be formed for each light-emitting element. The organic compound layer may be disposed between the first electrode and the second electrode and may be disposed in contact with the first electrode and the second electrode.
The protecting layer is an insulating layer and preferably contains a translucent inorganic material with low permeability of oxygen and moisture from the outside. The protecting layer can be formed of an inorganic material, such as silicon nitride (SiN), silicon oxynitride (SiON), silicon oxide (SiOx), aluminum oxide (Al2O3), or titanium oxide (TiO2). The protecting layer may be provided directly on the negative electrode or with an organic resin layer disposed therebetween. The organic resin layer may be made of, for example, polyacrylate, polyimide, polyester, or epoxy.
Bonding glass with absorbent to the negative electrode can reduce infiltration of water or the like into the organic layer, thereby reducing display defect. In another embodiment, a passivation film, such as silicon nitride, may be provided on the negative electrode to reduce infiltration of water or the like into the organic compound layer. For example, the protecting layer may be formed by forming a negative electrode and then conveying the negative electrode to another chamber with the vacuum kept, on which a silicon nitride film with a thickness of 2 μm is formed using a chemical vapor deposition method. The protecting layer may be formed using the CVD method and then an atom layer deposition method (ALD method). Examples of a material for the film using the ALD method include, but are not limited to, silicon nitride, silicon oxide, and aluminum oxide. Silicon nitride may be deposited using the CVD method on the film formed using the ALD method. The film formed using the ALD method may be thinner than the film formed using the CVD method. Specifically, the thickness may be 50% or less, or 10% or less.
A color filter may be provided on the protecting layer. For example, a color filter taking the size of the organic light-emitting element into account may be provided on another substrate, and the substrate may be bonded to the substrate of the organic light-emitting element or, alternatively, a color filter may be patterned on the protecting layer described above using a photolithography technique. The color filter may be made of a high polymer.
A planarizing layer may be provided between the color filter and the protecting layer. The planarizing layer is provided to reduce the surface irregularities of the lower layer. The planarizing layer may also be referred to as a resin layer without limitation on the purpose. The planarizing layer may be made of an organic compound, which may be either low molecular or high molecular, and preferably high molecular.
The planarizing layer may be provided on and under the color filter and may be made of the same material or different materials. Specific examples include a polyvinyl carbazole resin, a polycarbonate resin, a polyester resin, an acrylonitrile-butadiene-styrene (ABS) resin, an acrylic resin, a polyimide resin, a phenol resin, an epoxy resin, a silicon resin, and an urea resin.
The organic light-emitting apparatus may include an optical member, such as microlenses, on the light-exiting side. The microlenses can be made of, for example, an acrylic resin or an epoxy resin. The microlenses may be provided to increase the amount of light to be extracted from the organic light-emitting apparatus and to control the direction of the light to be extracted. The microlenses may have a hemispherical shape. In the case of the hemispherical shape, a contact point between, among tangents in contact with the hemisphere, a tangent parallel to the insulating layer and the hemisphere is the apex of the microlens. The apex of the microlens can be determined also in any cross-sectional view. In other words, the apex of the microlens is the contact point between a tangent, among tangents in contact with the hemisphere of the microlens in the cross-sectional view, parallel to the insulating layer and the hemisphere.
The middle point of the microlens can also be defined. Assuming a line segment from a point at which the circular arc ends to a point at which another circular arc ends in a cross section of the microlenses, the middle point of the line segment can be referred to as the middle point of the microlens. The cross section in which the apex and the middle point are determined may be a cross section perpendicular to the insulating layer.
The microlenses may be formed by adjusting the exposing and developing processes. Specifically, a film (photoresist film) made of a material for the microlenses is formed, and the photoresist film is subjected to exposure and development using a mask having continuous gradation. Examples of the mask include a gray mask and an area gradation mask, which allows light having continuous gradation to be applied to an imaging plane by changing the density distribution of dots formed of a light shielding layer with a resolution lower than or equal to the resolution of the exposure device.
Etching back the microlenses formed using the exposing and developing processes allows the lens shape to be adjusted. The microlenses may have any shape having an inclined portion that allows radiated light to be refracted and may be spherical or asymmetric in cross section.
An opposing substrate may be provided on the planarizing layer. The opposing substrate is named from the fact that it is provided at a position opposite to the substrate. The constituent material of the opposing substrate may be the same as that of the above substrate. Assuming that the above substrates is a first substrate, the opposing substrate may be referred to as a second substrate.
The organic compound layer (a hole injection layer, a hole transport layer, an electron blocking layer, an emission layer, a hole blocking layer, an electron transport layer, an electron injection layer, a charge generating layer, and so on) constituting the organic light-emitting element according to an embodiment of the present invention is formed using the following method.
The organic compound layer constituting the organic light-emitting element according to an embodiment of the present invention can be formed by means of a dry process, such as a vacuum deposition method, an ionized deposition method, sputtering, or plasma. Instead of the dry process, a wet process may be used for forming the layer by coating an organic compound dissolved in an appropriate solvent using a known coating method (for example, spin coating, dipping, a cast method, a Langmuir-Blodgett (LB) method, or an ink-jet method).
Using the vacuum deposition method or the solution coating method to form the layer makes crystallization or the like unlikely to occur, providing high temporal stability. In forming the film using the coating method allows the film to be formed in combination with an appropriate binder resin.
Examples of the binder resin include, but are not limited to, a polyvinyl carbazole resin, a polycarbonate resin, a polyester resin, an ABS resin, an acrylic resin, a polyimide resin, a phenol resin, an epoxy resin, a silicon resin, and an urea resin.
These binder resins may be used alone as a homopolymer or a copolymer or in combination of two or more kinds. In addition, additives, such as a known plasticizer, an antioxidant, and an ultraviolet absorber, may be used in combination as required.
The light-emitting apparatus may include a pixel circuit connected to the light-emitting element. The pixel circuit may be of an active-matrix type that controls the emission of the first light-emitting element and the second light-emitting element independently. The active-matrix circuit may employ voltage programming or current programming. The drive circuit includes a pixel circuit for each pixel. The pixel circuit may include a light-emitting element, a transistor for controlling the luminance of the light-emitting element, a transistor for controlling the emission timing, capacitance that holds the gate voltage of the transistor for controlling the luminance, and a transistor for connecting to the ground (GND) not via the light-emitting element.
The light-emitting apparatus includes a display area and a peripheral area around the display area. The display area includes the pixel circuit, and the peripheral area includes a display control circuit. The mobility of the transistors constituting the pixel circuit may be lower than the mobility of the transistors constituting the display control circuit.
The inclination of the current-voltage characteristics of the transistors constituting the transistor pixel circuit may be smaller than the inclination of the current-voltage characteristics of the transistors constituting the display control circuit. The inclination of the current-voltage characteristics can be measured from a so-called Vg-Ig characteristic.
The transistors constituting the pixel circuit are connected to the light-emitting element, for example, the first light-emitting element.
The organic light-emitting apparatus includes a plurality of pixels. The pixels include subpixels that emit light of different colors. The subpixels may individually have RGB emission colors.
Each pixel emits light from an area referred to as a pixel opening. This area is the same as the first area. The pixel opening may be 15 μm or less and 5 μm or more in size. More specifically, the pixel opening may be 11 μm, 9.5 μm, 7.4 μm, or 6.4 μm in size.
The distance between the subpixels may be 10 μm or less, specifically, 8 μm, 7.4 μm, or 6.4 μm.
The pixels can have a known arrangement in plan view. Examples include a stripe arrangement, a delta arrangement, a PenTile arrangement, and a Bayer arrangement. The subpixel may have any known shape in plan view. Examples include a quadrangular shape, such as a rectangular shape or a rhombus shape, and a hexagonal shape. Of course, the rectangular shape includes any nearly rectangular shape other than an exact shape. A combination of the shape of the subpixel and the pixel arrangement may be employed.
The specific effects of the present invention will be described using an example. In this example, a single-color organic light-emitting element was used. Table 1 shows microlenses height h/D, microlenses radius Φ/D, and height L2/D of the upper surface of the color filter, which are normalized by interpixel pitch D.
The effects of the present invention are independent of whether single color or white, as described above, and a color filter or the like may be separately provided.
Table 2 shows the test results. In this example, the test was conducted on the conditions that the order of interference m between the reflecting layer and the luminous point expressed by Exp. (4) was 1, and the order of interference m′ between the luminous point and the translucent electrode was 0. In Comparative Example D001, the interference peak resonant wavelength λon in the frontal direction coincided with λPL, and the interference peak resonant wavelength λoff in a direction inclined with respect to the substrate main surface was positioned closer to the short-wavelength side with respect to λPL on the above conditions. In Examples D101 and D102, the interference peak resonant wavelength λoff in a direction inclined with respect to the substrate main surface was closer to λPL on the condition that λon was 545 nm and 552 nm, respectively. The relative radiation intensities in Table 2 are values normalized by the radiance of Comparative Example for configurations with microlenses and without microlenses.
First, the characteristics of the organic light-emitting elements without microlenses were compared. The interference conditions of D101 and D102 as compared with D001 showed that the EL spectrum peak intensity λEL(0) in the frontal direction without microlenses shifted to the long-wavelength side with respect to λPL and that the relative radiation intensity was equal to 1 or decreased to 0.99. In contrast, with microlenses, D101 and D102 showed that the relative radiation intensity increased to 1.36 and 1.4, respectively, and the EL peak wavelength λEL was 529 nm and 530 nm, respectively, which are close to λPL=523 nm. This is due to the component around Θeml with the highest contributing rate of the components refracted in the frontal direction at the inclined portion of the microlens shown in
Example 2 is the same as Example 1 except that the spectrum shape of the light-emitting material has a double peak. The double peak means that the emission spectrum includes a first peak and a second peak.
Table 3 shows λPL, λon, λoff, and the front radiation intensity in Example 2, in which the difference between λPL, λEL, and λon under the individual conditions are listed. In Comparative Example D002, the interference peak resonant wavelength λon in the frontal direction coincided with λPL, and the interference peak resonant wavelength λoff in a direction inclined with respect to the substrate main surface was positioned closer to the short-wavelength side with respect to λPL on the above conditions. In Examples D103 and D104, the interference peak resonant wavelength λoff in a direction inclined with respect to the substrate main surface was closer to λPL on the condition that λon was 545 nm and 552 nm, respectively. The relative radiation intensities in Table 3 are values normalized by the radiance of D002.
First, comparison is made for the configuration without microlenses. The interference conditions of D103 and D104 as compared with D002 showed that the EL spectrum peak intensity λEL(0) in the frontal direction without microlenses shifted to 542 nm and 549 nm, respectively, to the long-wavelength side with respect to λPL=523 nm and that the relative radiation intensity was equal to 1 or decreased to 0.98. In contrast, with microlenses, D103 and D104 showed that the relative radiance increased to 1.4 and 1.45, respectively, and the EL peak wavelength λEL was 524 nm in both of D103 and D104, which is close to λPL=523 nm. This is due to the component around Θeml with the highest contributing rate of the components refracted in the frontal direction at the inclined portion of the microlens shown in
Example 3 is the same as Example 2 except that the order of interference m between the reflecting layer and the luminous point is 0 that the translucent electrode was 23 nm. Table 4 shows the test results of Example 3.
In Comparative Example D003, the interference peak resonant wavelength λon in the frontal direction coincided with λPL, and the interference peak resonant wavelength λoff in a direction inclined with respect to the substrate main surface was positioned closer to the short-wavelength side with respect to λPL on the above conditions. In Example D105, the interference peak resonant wavelength λoff in a direction inclined with respect to the substrate main surface was 534 nm, close to λPL=523 nm, on the condition that λon was 539 nm. The relative radiation intensity in Table 4 is a value normalized by the radiance of D003.
First, comparison is made for the configuration without microlenses. The interference conditions of D105 as compared with D003 showed that the EL spectrum peak intensity λEL(0) in the frontal direction without microlenses shifted to 528 nm to the long-wavelength side with respect to λPL=523 nm and that the relative radiation intensity was decreased to 0.9. In contrast, with microlenses, the relative radiance of D105 increased to 1.36, and the EL peak wavelength λEL was 524 nm, which is close to λPL=523 nm. This is due to the component around Θeml with the highest contributing rate of the components refracted in the frontal direction at the inclined portion of the microlens shown in
Example 4 is the same as Example 2 except that the order of interference m′ between the translucent electrode and the luminous point is 1. Table 5 shows the test results of Example 4.
In Comparative Example D004, the interference peak resonant wavelength λon in the frontal direction coincided with λPL, and the interference peak resonant wavelength λoff in a direction inclined with respect to the substrate main surface was positioned closer to the short-wavelength side with respect to λPL on the above conditions. In Example D106, the interference peak resonant wavelength λoff in a direction inclined with respect to the substrate main surface was 520 nm, close to λPL=523 nm, on the condition that λon was 538 nm. The relative radiation intensity in Table 5 is a value normalized by the radiance of D004.
First, comparison is made for the configuration without microlenses. The interference conditions of D106 as compared with D004 showed that the EL spectrum peak intensity λEL(0) in the frontal direction without microlenses shifted to 528 nm to the long-wavelength side with respect to λPL=523 nm and that the relative radiation intensity was decreased to 0.84. In contrast, with microlenses, the relative radiance of D106 increased to 1.13, and the EL peak wavelength λEL was 524 nm, which is close to λPL=523 nm. This is due to the component around eemi with the highest contributing rate of the components refracted in the frontal direction at the inclined portion of the microlens shown in
Thus, the effects of the present invention were independent of the shape of the PL spectrum of luminescence dopant and the order of interference.
The organic light-emitting element according to an embodiment of the present invention can be used as a component of a display apparatus or an illumination apparatus. Other applications include an exposing light source of an electrophotographic image forming apparatus, a backlight of a liquid crystal display apparatus, and a light-emitting apparatus having a color filter for a white light source.
The display apparatus may be an image-information processing apparatus including an image input unit that receives image information from an area charge-coupled device (CCD), a linear CCD, a memory card, or the like and an information processing unit that processes the input information and configured to display the input image on a display.
The display of an image pickup apparatus or an ink-jet printer may have a touch panel function. Examples of a driving method for the touch panel function include, but are not limited to, an infrared method, a capacitive sensing method, a resistive method, and an electromagnetic induction method. The display apparatus may be used as the display of a multifunction printer.
Next, the display apparatus according to this embodiment will be described with reference to the drawings.
The light-emitting element according to an embodiment of the present invention may be used in an image forming apparatus. The image forming apparatus includes a photosensitive member, an exposing light source, a developing unit, a charging unit, a transfer unit, a conveying roller, and a fixing unit.
Light is emitted from the exposing light source to form an electrostatic latent image on the surface of the photosensitive member. The exposing light source includes an organic light-emitting element according to the present invention. The developing unit includes toner or the like. The charging unit charges the photosensitive member. The transfer unit transfers a developed image to a printing medium. The conveying unit conveys the printing medium. One example of the printing medium is paper. The fixing unit fixes the image formed on the printing medium.
The exposing light source may include a plurality of light-emitting portions arranged on a long substrate. The column direction in which the organic light-emitting elements are arrayed may be the axial direction of the photosensitive member. The column direction is the same as the direction of the axis of rotation of the photosensitive member. This direction may also be referred to as the long axis direction of the photosensitive member.
The light-emitting portions may be arranged alternately in the column direction in the first column and the second column. The light-emitting portions in the first column and the second column are arranged at different positions in the row direction.
The first column may have a plurality of light-emitting portions arranged at intervals. The second column has light-emitting portions at the positions corresponding to the interval between the light-emitting portions in the first column. In other words, a plurality of light-emitting portions may be arranged at intervals also in the row direction. The light-emitting elements may be arranged, for example, in the form of a grid, in a staggered pattern, or in a checkerboard pattern.
The display apparatus according to this embodiment may include a color filter including red, green, and blue. The color filter may be arranged in a delta array of red, green, and blue.
The display apparatus according to this embodiment may be used as the display of a mobile terminal. In this case, the display apparatus may have both a display function and an operating function. Examples of the mobile terminal include a mobile phone, such as a smartphone, a tablet, and a head-mounted display. The display apparatus may include a display control unit that controls an image to be displayed.
The light-emitting apparatus according to this embodiment may be used for the display of an image pickup apparatus including an optical part including a plurality of lenses and an image sensor that receives light passing through the optical part. The image pickup apparatus may include a display that displays information acquired by the image sensor. The display may be exposed out of the image pickup apparatus or disposed in the finder. The image pickup apparatus may be either a digital camera or a digital video camera.
The information should be displayed as fast as possible because the best timing for image capturing is short. Accordingly, it is preferable to use the organic light-emitting apparatus according to the present invention. This is because the organic light-emitting element has a fast response speed. The organic light-emitting apparatus can be used more suitably for apparatuses that require high display speed than liquid crystal display apparatuses.
The image pickup apparatus 1100 includes an optical part (not shown). The optical part includes a plurality of lenses and forms an image on an image sensor housed in the casing 1104. Adjusting the relative positions of the plurality of lenses allows the focal point to be adjusted. This operation can be automatically performed. The image pickup apparatus may be referred to as a photoelectric conversion apparatus. The photoelectric conversion apparatus can adopt not sequential image capturing but a method of detecting the difference from the previous image, a method of clipping an image from regularly recorded images, and other image capturing methods.
The display apparatus 1300 includes a base 1303 that supports the frame 1301 and the display 1302. The shape of the base 1303 does not have to be he shape shown in
The frame 1301 and the display 1302 may be curved. The radius of curvature may be 5,000 mm or more and 6,000 mm or less.
The light-emitting apparatus according to this embodiment may be used in an illumination apparatus. The illumination apparatus may include a casing, a light source, a circuit board, an optical film, and a light diffusing unit. The light source may include the light-emitting apparatus according to this embodiment. The optical film may be a film that enhances the color rendering property of the light source. The light diffusing unit can diffuse the light from the light source efficiently, for example, light up, to deliver the light to a wide area. The optical film and the light diffusing unit may be disposed on the light emission side. A cover may be provided on the outermost periphery as needed.
An example of the illumination apparatus is an apparatus that illuminates the room. The illumination apparatus may emit any of white, natural white, and blue to red lights. The illumination apparatus may include a dimmer circuit that controls the light. The illumination apparatus may include the organic light-emitting element according to the present invention and a power circuit connected thereto. The power circuit converts an alternating-current voltage to a direct-current voltage. The white light has a color temperature of 4,200 K. The natural white light has a color temperature of 5,000 K. The illumination apparatus may include a color filter.
The illumination apparatus according to this embodiment may include a heat radiator. The heat radiator releases the heat in the apparatus to the outside. Examples include metal and liquid silicon with high specific heat.
The light-emitting apparatus according to the present invention may be used in a moving object, such as an automobile. The automobile includes a tail lamp, which is an example of lighting fixtures. The automobile may include a tail lamp and may be configured to light on the tail lamp at a brake operation or the like.
The tail lamp may include the light-emitting apparatus according to this embodiment. The tail lamp may include a protector that protects the organic light-emitting elements. The protector may be made of any transparent material with relatively high strength, preferably, polycarbonate. The polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.
The automobile may include a body and windows mounted thereto. The windows may include a transparent display if they are not for checking the front and back of the automobile. The transparent display may include the organic light-emitting apparatus according to this embodiment. In this case, the components of the organic light-emitting elements, such as electrodes, are made of transparent materials.
The moving object according to this embodiment may be a ship, an aircraft, a drone, or the like. The moving object may include a body and a lighting fixture provided on the body. The lighting fixture may emit light for indicating the position of the body. The lighting fixture includes the organic light-emitting element according to this embodiment.
Referring to
The pair of glasses 1600 further includes a control unit 1603. The control unit 1603 functions as a power source for supplying electricity to the image pickup apparatus 1602 and the display apparatus according to each embodiment. The control unit 1603 controls the operation of the image pickup apparatus 1602 and the display apparatus. The lens 1601 is provided with an optical part for collecting light to the image pickup apparatus 1602.
The gaze of the user at the displayed image is detected from the image of the eyeball using infrared light. The gaze detection using the image of the eyeball may use any known technique. An example is an eye-gaze tracking method based on Purkinje images obtained by the reflection of illuminated light on the cornea.
More specifically, a gaze tracking process based on pupil center corneal reflection is performed. The gaze of the user is detected by calculating a gaze vector indicating the orientation (rotation angle) of the eyeball on the basis the image of the pupil contained in the image of the eyeball and Purkinje images using pupil center corneal reflection.
A display apparatus according to an embodiment of the present invention may include an image pickup apparatus including a light receiving element and may control an image displayed on the display apparatus on the basis of user gaze information provided from the image pickup apparatus.
Specifically, the display apparatus determines a first view area at which the user gazes and a second view area other than the first view area on the basis of the gaze information. The first view area and the second view area may be determined by the control unit of the display apparatus or may be received from an external control unit. The display resolution of the first view area in the display area of the display apparatus may be set higher than the display resolution of the second view area. In other words, the resolution of the second view area may be set lower than the resolution of the first view area.
The display area includes a first display area and a second display area different from the first display area. A higher priority area is determined from the first display area and the second display area on the basis of the gaze information. The first view area and the second view area may be determined by the control unit of the display apparatus or may be received from an external control unit. The resolution of a higher priority area may be set higher than the resolution of the area other than the higher priority area. In other words, the resolution of the lower priority area may be set low.
The determination of the first view area and the higher priority area may use artificial intelligence (AI). The AI may be of a model configured to estimate the gaze angle and the distance from an image of the eyeball to the object of the gaze using the image of the eyeball and the direction of the actual gaze of the eyeball in the image as training data. An AI program may be installed in the display apparatus, the image pickup apparatus, or an external apparatus. The AI program, if installed in an external apparatus, is sent to the display apparatus via communication.
Display control based on visual recognition allows application to smartglasses that further includes an image pickup apparatus that captures an external image. Smartglasses can display captured external information in real time.
Thus, using an apparatus including the organic light-emitting element according to this embodiment allows stable display with high image quality even for long time display.
The present invention provides an organic light-emitting element having high radiance in the frontal direction using a light extracting structure and optical interference taking account of the light extracting structure.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-067635 | Apr 2021 | JP | national |
| 2022-018103 | Feb 2022 | JP | national |
This application is a Continuation of International Patent Application No. PCT/JP2022/015552, filed Mar. 29, 2022, which claims the benefit of Japanese Patent Application No. 2021-067635, filed Apr. 13, 2021 and No. 2022-018103, filed Feb. 8, 2022, all of which are hereby incorporated by reference herein in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2022/015552 | Mar 2022 | US |
| Child | 18486878 | US |
