JP6868311B2 - Light emitting device, display device and lighting device - Google Patents

Description

The present disclosure relates to a light emitting device, a display device, and a lighting device using an organic electroluminescent element or the like that emits light by an organic electroluminescence (EL) phenomenon.

In recent years, many proposals have been made for the structure of a light emitting device using an organic EL element (for example, Patent Documents 1 to 4). A light emitting device using an organic EL element is applied to, for example, a display device or a lighting device.

International Publication WO01 / 039554 Pamphlet Japanese Unexamined Patent Publication No. 2006-244713 Japanese Unexamined Patent Publication No. 2011-159431 Japanese Unexamined Patent Publication No. 2011-159433

In such a light emitting device, it is desired to improve the light distribution characteristics.

It is desirable to provide a light emitting device, a display device and a lighting device capable of improving the light distribution characteristics.

The light emitting device according to the embodiment of the present disclosure includes a first light emitting element region, a second light emitting element region, a first reflecting interface provided in the first light emitting element region and the second light emitting element region, and a first reflection. The light extraction surface facing the interface, the first light emitting layer provided between the first reflection interface and the light extraction surface of the first light emitting element region, and the first reflection interface and the light extraction surface of the second light emitting element region. The second light emitting layer provided between the first light emitting layer, each of the first light emitting layer and the second light emitting layer, and the light extraction surface are provided, and the reflection thereof is the light emission spectrum of the first light emitting layer and the second light emitting layer. A second reflection interface configured to strengthen each other with respect to the center wavelength of the light is provided between the second reflection interface and the light extraction surface, and the reflection is with respect to the center wavelength of the light emission spectrum of the first light emitting layer. with destructive, in which a third reflecting surface that is configured to constructively with respect to the center wavelength of the emission spectrum of the second light-emitting layer.

The display device according to the embodiment of the present disclosure includes a light emitting device and a driving element for driving the light emitting device for each pixel, and the light emitting device includes the light emitting device according to the embodiment of the present disclosure. Is.

The lighting device according to the embodiment of the present disclosure includes the light emitting device according to the embodiment of the present disclosure.

The light emitting device according to an embodiment of the present disclosure, the display device and a lighting device, with reflection on the third reflecting boundary surfaces, destructive with respect to the center wavelength of the emission spectrum of the first light-emitting layer, the second light-emitting layer It is configured to strengthen each other with respect to the central wavelength of the emission spectrum of. Thus, between the first light-emitting element region and the second light emitting element region, it is possible to vary the reflection condition of the third reflection boundary surface, to the light-emitting element for each region, the light emitting state is adjusted.

The light emitting device according to an embodiment of the present disclosure, according to the display device and a lighting device, between the first light-emitting element region and the second light emitting element region, so as to vary the reflection condition of the third reflection boundary surface Therefore, the light emitting state can be adjusted for each light emitting element region. Therefore, it is possible to improve the light distribution characteristics. The effects described here are not necessarily limited, and may be any of the effects described in the present disclosure.

It is sectional drawing which shows the schematic structure of the light emitting device which concerns on one Embodiment of this disclosure. It is sectional drawing which shows the structure of the red organic EL element shown in FIG. It is sectional drawing which shows the structure of the blue organic EL element shown in FIG. It is a figure which shows the transmittance of the light reflected by the 1st reflection interface shown in FIG. 2A. FIG. 3 is a diagram showing the transmittance of light reflected by the first reflection interface and the second reflection interface in an superimposed manner. It is sectional drawing which shows the other example (1) of the 2nd reflection interface shown in FIG. 2A. It is sectional drawing which shows the other example (2) of the 2nd reflection interface shown in FIG. 2A. It is a figure which shows the transmittance of the light reflected by the 1st reflection interface to the 3rd reflection interface shown in FIG. 2A. It is a figure which standardizes and represents the transmittance of the vertical axis shown in FIG. 7A. It is a figure which shows the transmittance of the light reflected by the 1st reflection interface to the 4th reflection interface shown in FIG. 2A. It is a figure which standardizes and represents the transmittance of the vertical axis shown in FIG. 8A. It is a figure which shows the transmittance of the light reflected by the 1st reflection interface to the 4th reflection interface shown in FIG. 2B. It is a figure which standardizes and represents the transmittance of the vertical axis shown in FIG. 9A. It is sectional drawing for demonstrating operation | movement of the light emitting device shown in FIG. It is a figure which shows an example of the change of the chromaticity by the viewing angle of the light emitting device shown in FIG. It is a figure which shows an example of the change of the luminance by the viewing angle of the light emitting device shown in FIG. It is sectional drawing which shows the schematic structure of the red organic EL element which concerns on modification 1. FIG. It is a figure which shows the spectral reflectance of the red organic EL element shown in FIG. It is sectional drawing which shows the schematic structure of the red organic EL element which concerns on modification 2. It is sectional drawing which shows the other example (1) of the red organic EL element shown in FIG. It is sectional drawing which shows the other example (2) of the red organic EL element shown in FIG. It is sectional drawing which shows the other example (3) of the red organic EL element shown in FIG. It is sectional drawing which shows the schematic structure of the light emitting device which concerns on modification 3. FIG. 5 is a cross-sectional view schematically showing the configuration of a display device to which the light emitting device shown in FIG. 1 and the like is applied. It is sectional drawing which shows the other example of the display device shown in FIG. It is a block diagram which shows the structure of the display device shown in FIG. It is a block diagram which shows the structure of the electronic device to which the display device and the like shown in FIG. 22 are applied. FIG. 3 is a perspective view showing an example of the appearance of a lighting device to which the light emitting device shown in FIG. 1 and the like is applied.

Embodiments of the present disclosure will be described in detail in the following order with reference to the drawings.
1. 1. Embodiment (Example of a top light emitting type light emitting device having the first to fourth reflection interfaces)
2. Deformation example 1 (example using a metal layer)
3. 3. Modification 2 (Example having a fifth reflection interface)
4. Modification 3 (Example of bottom light emitting type light emitting device)
5. Application example 1 (Example of display device and electronic device)
6. Application example 2 (Example of lighting device)

<Embodiment>
[Constitution]
FIG. 1 shows a cross-sectional configuration of a main part of a light emitting device (light emitting device 1) according to an embodiment of the present disclosure. The light emitting device 1 has a substrate 11, and the substrate 11 is provided with a red light emitting element region 11R (first light emitting element region), a green light emitting element region 11G, and a blue light emitting element region 11B (second light emitting element region). Has been done. The light emitting device 1 has a red organic EL element 10R in a red light emitting element region 11R, a green organic EL element 10G in a green light emitting element region 11G, and a blue organic EL element 10B in a blue light emitting element region 11B, respectively.

The red organic EL element 10R, the green organic EL element 10G, and the blue organic EL element 10B are provided on the substrate 11. The red organic EL element 10R includes a first electrode 12, a red light emitting layer 131R, a semitransparent reflective layer 14R, a first transparent layer 15R, a second transparent layer 16R, and a third transparent layer 17R on a substrate 11. Are in this order. The green organic EL element 10G includes a first electrode 12 and a green light emitting layer 131G on a substrate 11, a green organic layer 13G, a semitransparent reflective layer 14G, a first transparent layer 15G, a second transparent layer 16G, and a third transparent layer 17G. Are in this order. The blue organic EL element 10B includes a first electrode 12 and a blue light emitting layer 131B on a substrate 11, a blue organic layer 13B, a semitransparent reflective layer 14B, a first transparent layer 15B, a second transparent layer 16B, and a third transparent layer 17B. Are in this order.

The red organic EL element 10R emits light in the red wavelength region (red light LR) generated by the red light emitting layer 131R from the third transparent layer 17R side. The green organic EL element 10G emits light in the green wavelength region (green light LG) generated by the green light emitting layer 131G from the third transparent layer 17G side. The blue organic EL element 10B emits light in the blue wavelength region (blue light LB) generated by the blue light emitting layer 131B from the third transparent layer 17B side. The light emitting device 1 uses the light emitted from the red light emitting layer 131R, the green light emitting layer 131G, and the blue light emitting layer 131B with the first electrode 12, the third transparent layer 17R, the third transparent layer 17G, and the third transparent layer 17B. It is configured to take out light by multiple reflections between them. That is, the light emitting device 1 is a top light emitting device having a resonator structure.

The substrate 11 is a plate-shaped member for supporting the red organic EL element 10R, the green organic EL element 10G, and the blue organic EL element 10B, and is composed of, for example, a transparent glass substrate or a semiconductor substrate. The substrate 11 may be composed of a flexible substrate (flexible substrate).

The first electrode 12 is not only an anode electrode but also has a function as a reflective layer. The first electrode 12 is provided in common to, for example, the red light emitting element region 11R, the green light emitting element region 11G, and the blue light emitting element region 11B. For the first electrode 12, for example, a light-reflecting material such as aluminum (Al) and an alloy thereof, platinum (Pt), gold (Au), chromium (Cr), or tungsten (W) can be used. The first electrode 12 may be formed by laminating a transparent conductive material and a light-reflecting material. The thickness of the first electrode 12 is preferably in the range of 100 nm to 300 nm.

The red organic layer 13R has, for example, a hole injection layer, a hole transport layer, a red light emitting layer 131R, an electron transport layer, and an electron injection layer in this order from a position close to the first electrode 12. The green organic layer 13G has, for example, a hole injection layer, a hole transport layer, a green light emitting layer 131G, an electron transport layer, and an electron injection layer in this order from a position close to the first electrode 12. The blue organic layer 13B has, for example, a hole injection layer, a hole transport layer, a blue light emitting layer 131B, an electron transport layer, and an electron injection layer in this order from a position close to the first electrode 12.

The hole injection layer is a layer for preventing leakage, and is composed of, for example, hexaazatriphenylene (HAT) or the like. The thickness of the hole injection layer is, for example, 1 nm to 20 nm. The hole transport layer is composed of, for example, α-NPD [N, N'-di (1-naphthyl) -N, N'-diphenyl- [1,1'-biphenyl] -4,4'-diamine]. There is. The thickness of the hole transport layer is, for example, 15 nm to 100 nm.

The red light emitting layer 131R, the green light emitting layer 131G, and the blue light emitting layer 131B are configured to emit light of a predetermined color by combining holes and electrons, and have a thickness of, for example, 5 nm to 50 nm. There is. The red light emitting layer 131R emits light in the red wavelength region, and is composed of, for example, rubrene doped with a pyrromethene boron complex. At this time, rubrene is used as a host material. The green light emitting layer 131G emits light in the green wavelength region, and is composed of, for example, Alq3 (trisquinolinol aluminum complex). The blue light emitting layer 131B emits light in the blue wavelength region, and is composed of, for example, ADN (9,10-di (2-naphthyl) anthracene) doped with a diaminochrysene derivative. At this time, ADN is deposited on the hole transport layer as a host material with a thickness of, for example, 20 nm, and the diaminochrysene derivative is doped as a dopant material at a relative film thickness ratio of 5%.

The electron transport layer is composed of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline). The thickness of the electron transport layer is, for example, 15 nm to 200 nm. The electron injection layer is composed of, for example, lithium fluoride (LiF). The thickness of the electron injection layer is, for example, 15 nm to 270 nm.

The translucent reflective layers 14R, 14G, 14B are provided between the red organic layer 13R, the green organic layer 13G, the blue organic layer 13B, and the first transparent layers 15R, 15G, 15B. The translucent reflective layers 14R, 14G, and 14B may be provided as needed, or may be omitted. A transparent reflective layer may be provided instead of the semitransparent reflective layers 14R, 14G, and 14B. The translucent reflective layers 14R, 14G, and 14B preferably have a thickness of 5 nm or more, and are composed of, for example, magnesium (Mg), silver (Ag), or an alloy thereof. The translucent reflective layers 14R, 14G, and 14B may have a function as a second electrode (cathode electrode) paired with the first electrode 12. By providing the translucent reflective layers 14R, 14G, and 14B having high reflectance, the effect of the resonator structure can be enhanced and the light extraction efficiency can be improved. As a result, the power consumption can be suppressed, and the life of the red organic EL element 10R, the green organic EL element 10G, and the blue organic EL element 10B can be extended.

The first transparent layers 15R, 15G, 15B, the second transparent layers 16R, 16G, 16B and the third transparent layers 17R, 17G, 17B are provided on the light extraction side of the light emitting device 1. The thickness of the first transparent layers 15R, 15G, 15B is, for example, 30 nm to 450 nm, the thickness of the second transparent layers 16R, 16G, 16B is 30 nm to 380 nm, and the thickness of the third transparent layers 17R, 17G, 17B is. For example, 500 nm to 10000 nm.

For the first transparent layers 15R, 15G, 15B, the second transparent layers 16R, 16G, 16B and the third transparent layers 17R, 17G, 17B, for example, a transparent conductive material or a transparent dielectric material can be used. Examples of the transparent conductive material include ITO (Indium Tin Oxide) and an oxide of indium and zinc (IZO). Examples of the transparent dielectric material include silicon oxide (SiO ₂ ), silicon oxynitride (SiON), silicon nitride (SiN) and the like. The first transparent layers 15R, 15G, 15B, the second transparent layers 16R, 16G, 16B and the third transparent layers 17R, 17G, 17B may have a function as a second electrode (cathode electrode), or , It may be made to function as a passivation film. The first transparent layers 15R, 15G, 15B, the second transparent layers 16R, 16G, 16B and the third transparent layers 17R, 17G, 17B function as passivation films, and the red light emitting layer 131R, the green light emitting layer 131G, and the blue light emitting layer 131B are allowed to function. A second electrode (cathode electrode) may be provided between the first transparent layer 15R, 15G, and 15B. It is also possible to use a low refractive index material such as MgF or NaF for the first transparent layers 15R, 15G, 15B, the second transparent layers 16R, 16G, 16B and the third transparent layers 17R, 17G, 17B.

It is preferable that the upper layer of the third transparent layer 17R, 17G, 17B is provided with a layer of 1 μm or more. The layer of 1 μm or more is made of, for example, a transparent conductive material, a transparent insulating material, a resin material, glass, or the like. It can also be configured with air. By providing such a layer, it is possible to prevent external interference with the resonator structure formed between the first electrode 12 and the third transparent layers 17R, 17G, and 17B.

The resonator structures of the red organic EL element 10R, the green organic EL element 10G, and the blue organic EL element 10B will be described with reference to FIGS. 2A and 2B.

As shown in FIG. 2A, the red organic EL element 10R has a first reflection interface S1R, a second reflection interface S2R, a third reflection interface S3R, a fourth reflection interface S4R, and a light extraction surface SDR from the substrate 11 side. Have in order. A light emitting center OR of the red light emitting layer 131R is provided between the first reflecting interface S1R and the second reflecting interface S2R. In other words, the red light emitting layer 131R is provided between the first reflection interface S1R facing each other and the light extraction surface SDR. For example, the first electrode 12 faces the red light emitting layer 131R with the first reflection interface S1R in between, and the first transparent layer 15R is provided between the red light emitting layer 131R and the light extraction surface SDR.

As shown in FIG. 2B, the blue organic EL element 10B has the first reflection interface S1B, the second reflection interface S2B, the third reflection interface S3B, the fourth reflection interface S4B, and the light extraction surface SDB from the substrate 11 side. Have in order. A light emitting center OB is provided between the first reflection interface S1B and the second reflection interface S2B. In other words, the blue light emitting layer 131B is provided between the first reflection interface S1B and the light extraction surface SDB facing each other. For example, the first electrode 12 faces the blue light emitting layer 131B between the first reflection interfaces S1B, and the first transparent layer 15B is provided between the blue light emitting layer 131B and the light extraction surface SDB.

Although not shown, the green organic EL element 10G also has a first reflection interface, a second reflection interface, a third reflection interface, a fourth reflection interface, and light extraction, similarly to the red organic EL element 10R and the blue organic EL element 10B. The surfaces are provided in this order, and a light emitting center is provided between the first reflection interface and the second reflection interface. That is, the first reflection interface, the light emission center, the second reflection interface, the third reflection interface, the fourth reflection interface, and the light extraction surface are in this order over the red light emitting element region 11R, the green light emitting element region 11G, and the blue light emitting element region 11B. It is provided. The first reflection interface to the fourth reflection interface are formed by, for example, interfaces having a refractive index difference of 0.15 or more.

The first reflection interface S1R is, for example, the interface between the first electrode 12 and the red organic layer 13R. The first reflection interface S1B is, for example, the interface between the first electrode 12 and the blue organic layer 13B. The first reflective interfaces S1R and S1B are formed by the difference in refractive index between the constituent materials of the first electrode 12 and the constituent materials of the red organic layer 13R and the blue organic layer 13B. For example, the refractive index of aluminum (Al) constituting the first electrode 12 is 0.73, the extinction coefficient is 5.91, and the refractive indexes of the red organic layer 13R and the blue organic layer 13B are 1.75. The first reflection interface S1R is arranged at an optical distance L11 from the light emitting center OR. The first reflection interface S1B is arranged at an optical distance L21 from the light emitting center OB.

The optical distances L11 and L21 refer to the light having the center wavelength λ1 of the emission spectrum of the red light emitting layer 131R and the light having the center wavelength λ2 of the emission spectrum of the blue light emitting layer 131B with the first reflection interfaces S1R and S1B and the emission centers OR and OB. It is set to strengthen each other by interference with.

Specifically, the optical distances L11 and L21 are configured to satisfy the following equations (1), (5), (9), and (13). The optical distance L11 is, for example, 125 nm, and the optical distance L21 is, for example, 88 nm.

2L11 / λ11 + a1 / (2π) = m1 (however, m1 ≧ 0) ... (1)
λ1-150 <λ11 <λ1 + 80 ... (5)
2L21 / λ21 + c1 / (2π) = n1 (where n1 ≧ 0) ... (9)
λ2-150 <λ21 <λ2 + 80 ... (13)
However, the unit of m1, n1: integers λ1, λ11, λ2 and λ21: nm
a1: Phase change when light of each wavelength emitted from the red light emitting layer 131R is reflected at the first reflection interface S1R c1: Light of each wavelength emitted from the blue light emitting layer 131B is reflected at the first reflection interface S1B. Phase change

The a1 and c1 are the complex refractive index N = n0-jk (n0: refractive index, k: extinction coefficient) n0, k of the constituent material of the first electrode 12, and the red organic layer 13R and the blue organic layer 13B. It can be calculated using the index of refraction (see, for example, Principles of Optics, Max Born and Emil Wolf, 1974 (PERGAMON PRESS)). The refractive index of each constituent material can be measured using a spectroscopic ellipsometry measuring device.

If the values of m1 and n1 are large, the so-called microcavity (microresonator) effect cannot be obtained. Therefore, it is preferable that m1 = 0 and n1 = 0. For example, the optical distance L11 satisfies both the following equations (17) and (18).

2L11 / λ11 + a1 / (2π) = 0 ... (17)
λ1-150 = 450 <λ11 = 600 <λ1 + 80 = 680 ... (18)

FIG. 3 shows the transmittance (broken line) of light obtained by reflection at the first reflection interface S1R together with the emission spectrum (solid line) of the red light emitting layer 131R. Since the first reflection interface S1R satisfying the formula (17) is provided at the position of the 0th-order interference, it exhibits high transmittance over a wide wavelength band. Therefore, as shown in the equation (18), it is possible to greatly shift λ11 from the center wavelength λ1.

The second reflection interface S2R is provided between the light emitting center OR (red light emitting layer 131R) and the light extraction surface SDR, and is formed by, for example, a thin film translucent reflecting layer 14R. The second reflection interface S2B is provided between the light emitting center OB (blue light emitting layer 131B) and the light extraction surface SDB, and is formed by, for example, a thin film translucent reflecting layer 14B. The second reflective interfaces S2R and S2B are formed by the difference in refractive index between the constituent materials of the red organic layer 13R and the blue organic layer 13B and the constituent materials of the translucent reflective layers 14R and 14B. For example, the refractive index of the red organic layer 13R and the blue organic layer 13B is 1.75, the refractive index of silver (Ag) constituting the translucent reflective layers 14R and 14B is 0.13, and the extinction coefficient is 3.96. Is. The second reflection interface S2R is arranged at an optical distance L12 from the light emitting center OR. The second reflection interface S2B is arranged at an optical distance L22 from the light emitting center OB.

The optical distances L12 and L22 refer to the light having the center wavelength λ1 of the emission spectrum of the red light emitting layer 131R and the light having the center wavelength λ2 of the emission spectrum of the blue light emitting layer 131B with the second reflection interfaces S2R and S2B and the emission centers OR and OB. It is set to strengthen each other by interference with.

Specifically, the optical distances L12 and L22 are configured to satisfy the following equations (2), (6), (10), and (14). The optical distance L12 is, for example, 390 nm, and the optical distance L22 is, for example, 230 nm.

2L12 / λ12 + a2 / (2π) = m2 ... (2)
λ1-80 <λ12 <λ1 + 80 ... (6)
2L22 / λ22 + c2 / (2π) = n2 ... (10)
λ2-80 <λ22 <λ2 + 80 ... (14)
However, m2, n2: Units of integers λ1, λ12, λ2 and λ22: nm
a2: Phase change when light of each wavelength emitted from the red light emitting layer 131R is reflected at the second reflection interface S2R c2: Light of each wavelength emitted from the blue light emitting layer 131B is reflected at the second reflection interface S2B. Phase change

The above a2 and c2 can be obtained by the same method as a1 and c1.

If the values of m2 and n2 are large, the so-called microcavity (microcavity) effect cannot be obtained, so that m2 = 1 and n2 = 1 are preferable.

FIG. 4 shows the light transmittance (dashed line) obtained by reflection at the second reflection interface S2R added to FIG. Both the first reflection interface S1R and the second reflection interface S2R are configured to intensify the light generated by the red light emitting layer 131R with the light emission center OR. Due to this amplification effect, a peak of transmittance is generated in the vicinity of 620 nm.

As shown in FIG. 5, the second reflective interface S2R (or the second reflective interface S2B) is formed with the red organic layer 13R (or the blue organic layer 13B) and the first transparent without providing the semitransparent reflective layers 14R and 14B. It may be formed by the interface with the layer 15R (first transparent layer 15B).

As shown in FIG. 6, a fourth transparent layer (fourth transparent layer 18R) is located between the first transparent layer 15R (or the first transparent layer 15B) and the second transparent layer 16R (or the second transparent layer 16B). The second reflective interface S2R (or the second reflective interface S2B) may be formed by the interface between the fourth transparent layer 18R and the first transparent layer 15R.

The third reflection interface S3R is provided between the second reflection interface S2R and the light extraction surface SDR, and is, for example, an interface between the first transparent layer 15R and the second transparent layer 16R. The third reflection interface S3B is provided between the second reflection interface S2B and the light extraction surface SDB, and is, for example, an interface between the first transparent layer 15B and the second transparent layer 16B. The third reflective interfaces S3R and S3B are formed by the difference in refractive index between the constituent materials of the first transparent layers 15R and 15B and the constituent materials of the second transparent layers 16R and 16B. For example, the refractive index of silicon nitride (SiN) constituting the first transparent layers 15R and 15B is 1.95, and the refractive index of silicon oxynitride (SiON) constituting the second transparent layers 16R and 16B is 1.65. Is. The first transparent layers 15R and 15B may be made of IZO having a refractive index of 2.0. The third reflection interface S3R is arranged at an optical distance L13 from the light emitting center OR. The third reflection interface S3B is arranged at an optical distance L23 from the light emitting center OB. The third reflection interfaces S3R and S3B are preferably arranged at positions of 450 nm or less in optical distance from the second reflection interfaces S2R and S2B. This is because if the distance between the second reflection interfaces S2R and S2B and the third reflection interfaces S3R and S3B is large, the effect of the resonator structure cannot be obtained.

As shown in FIG. 6, the third reflection interface S3R may be the interface between the fourth transparent layer 18R and the second transparent layer 16R.

The fourth reflection interface S4R is provided between the third reflection interface S3R and the light extraction surface SDR, and is, for example, an interface between the second transparent layer 16R and the third transparent layer 17R. The fourth reflection interface S4B is provided between the third reflection interface S3B and the light extraction surface SDB, and is, for example, an interface between the second transparent layer 16B and the third transparent layer 17B. The fourth reflective interfaces S4R and S4B are formed by the difference in refractive index between the constituent materials of the second transparent layers 16R and 16B and the constituent materials of the third transparent layers 17R and 17B. The refractive index of silicon oxynitride (SiON) constituting the second transparent layers 16R and 16B is 1.65, and the refractive index of silicon nitride (SiN) constituting the third transparent layers 17R and 17B is 1.95. .. The fourth reflection interface S4R is arranged at an optical distance L14 from the light emitting center OR. The fourth reflection interface S4B is arranged at an optical distance L24 from the light emitting center OB. The fourth reflection interfaces S4R and S4B are preferably arranged at positions of 380 nm or less in optical distance from the second reflection interfaces S2R and S2B. This is because if the distance between the second reflection interfaces S2R and S2B and the fourth reflection interfaces S4R and S4B is large, the effect of the resonator structure cannot be obtained.

The third reflective interface S3R, S3B and the fourth reflective interface S4R, S4B may be formed by laminating metal thin films having a thickness of, for example, 5 nm or more.

In the light emitting device 1 of the present embodiment, the optical distance L13 is set so that the light having the center wavelength λ1 of the light emitting spectrum of the red light emitting layer 131R is weakened by interference between the third reflection interface S3R and the light emitting center OR. At the same time, the optical distance L23 is set so that the light having the center wavelength λ2 of the emission spectrum of the blue light emitting layer 131B is strengthened by interference between the third reflection interface S3B and the emission center OB.

Further, the optical distance L14 is set so that the light having the center wavelength λ1 of the emission spectrum of the red light emitting layer 131R is weakened by interference between the fourth reflection interface S4R and the emission center OR, and the optical distance L24 is set. , The light having the center wavelength λ2 of the emission spectrum of the blue light emitting layer 131B is set to be strengthened by interference between the fourth reflection interface S4B and the emission center OB.

Specifically, the optical distances L13, L23, L14, and L24 are given by the following equations (3), (4), (7), (8), (11), (12), (15), (16). It is configured to meet.

2L13 / λ13 + a3 / (2π) = m3 + 1/2 ... (3)
2L14 / λ14 + a4 / (2π) = m4 + 1/2 ... (4)
λ1-150 <λ13 <λ1 + 150 ... (7)
λ1-150 <λ14 <λ1 + 150 ... (8)
2L23 / λ23 + c3 / (2π) = n3 ... (11)
2L24 / λ24 + c4 / (2π) = n4 ... (12)
λ2-150 <λ23 <λ2 + 150 ... (15)
λ2-150 <λ24 <λ2 + 150 ... (16)
However, m3, m4, n3, n4: Units of integers λ1, λ13, λ14, λ2, λ23 and λ24: nm
a3: Phase change when light of each wavelength emitted from the red light emitting layer 131R is reflected at the third reflection interface S3R a4: Light of each wavelength emitted from the red light emitting layer 131R is reflected at the fourth reflection interface S4R. Phase change at the time c3: Phase change when light of each wavelength emitted from the blue light emitting layer 131B is reflected at the third reflection interface S3B c4: Light of each wavelength emitted from the blue light emitting layer 131B is reflected at the fourth reflection interface Phase change when reflecting by S4B

The above a3, c3, a4 and c4 can be obtained by the same method as a1 and c1.

Although the details will be described later, the reflection conditions at the third reflection interfaces S3R and S3B and the fourth reflection interfaces S4R and S4B can be made different between the red organic EL element 10R and the blue organic EL element 10B. The light emitting state can be adjusted for each light emitting element region (red light emitting element region 11R, green light emitting element region 11G, blue light emitting element region 11B).

7A and 7B show the transmittance of light obtained by reflection at the first reflection interface S1R to the third reflection interface S3R of the red light emitting element region 11R. In FIGS. 7A and 7B, the transmittance of light obtained by reflection at the first reflection interface S1R to the third reflection interface S3R is represented by a solid line, and the light obtained by reflection at the first reflection interface S1R and the second reflection interface S2R is shown by a solid line. The transmittance of is represented by a broken line. In FIG. 7B, the transmittance of the peak (wavelength 620 nm) of FIG. 7A is set to 1, and the transmittance standardized based on this is shown on the vertical axis. The addition of reflection at the third reflection interface S3R weakens the light generated by the red light emitting layer 131R and widens the half width of the spectrum.

8A and 8B are obtained by adding the transmittance of light obtained by reflection at the fourth reflection interface S4R to FIGS. 7A and 7B. In FIGS. 8A and 8B, the transmittance of light obtained by reflection at the first reflection interface S1R to the fourth reflection interface S4R is represented by a solid line, and the light obtained by reflection at the first reflection interface S1R to the third reflection interface S3R is shown by a solid line. The transmittance of light is represented by a single point chain line, and the transmittance of light obtained by reflection at the first reflection interface S1R and the second reflection interface S2R is represented by a broken line. By adding the reflection at the fourth reflection interface S4R, the light generated in the red light emitting layer 131R is further weakened, and the half width of the spectrum is further widened. By smoothing the vicinity of the peak of the spectrum in this way, it is possible to suppress abrupt changes in brightness and hue depending on the angle.

9A and 9B show the transmittance of light obtained by reflection at the first reflection interface S1B to the fourth reflection interface S4B of the blue light emitting element region 11B. In FIGS. 9A and 9B, the transmittance of light obtained by reflection at the first reflection interface S1B to the fourth reflection interface S4B is represented by a solid line, and the light obtained by reflection at the first reflection interface S1B to the third reflection interface S3B is shown by a solid line. The transmittance of light is represented by a single point chain line, and the transmittance of light obtained by reflection at the first reflection interface S1B and the second reflection interface SB2 is represented by a broken line. In FIG. 9B, the transmittance of the peak (wavelength 468 nm) of FIG. 9A is set to 1, and the normalized transmittance is shown on the vertical axis. By adding the reflection at the fourth reflection interface S4B, the light generated in the blue light emitting layer 131B is strengthened and the peak becomes large. By having a steep peak in this way, the light extraction efficiency can be improved. It is also possible to improve the chromaticity point. In FIGS. 9A and 9B, the positions of the peaks of the spectrum formed at the first reflection interface S1B and the second reflection interface S2B and the positions of the peaks of the spectrum formed at the third reflection interface S3B and the fourth reflection interface S4B are shown. I tried to match them, but you may shift them. By doing so, it is possible to expand the wavelength band in which the effect of the resonator structure can be obtained, and to suppress abrupt changes in brightness and hue.

The green organic EL element 10G has a first reflection interface to a fourth reflection interface, which are configured in the same manner as the blue organic EL element 10B, for example. Specifically, the first reflection interface to the fourth reflection interface are configured to strengthen each other with respect to the center wavelength of the emission spectrum of the green light emitting layer 131G.

Such a light emitting device 1 has a first electrode 12, an organic layer (red organic layer 13R, green organic layer 13G, blue organic layer 13B), translucent reflective layers 14R, 14G, 14B, and a first transparent layer on the substrate 11. It can be produced by forming the layers 15R, 15G, 15B, the second transparent layers 16R, 16G, 16B and the third transparent layers 17R, 17G, 17B in this order. The red organic layer 13R, the green organic layer 13G, and the blue organic layer 13B may be formed by a vapor deposition method or may be formed by printing. In other words, the red organic layer 13R, the green organic layer 13G, and the blue organic layer 13B may be printed layers. The first transparent layers 15R, 15G, 15B, the second transparent layers 16R, 16G, 16B and the third transparent layers 17R, 17G, 17B are common layers, respectively, and the red light emitting element region 11R, the green light emitting element region 11G, and the blue light emitting element are emitted. In the element region 11B, they may be formed of the same constituent material and the same thickness.

[Action, effect]
In the light emitting device 1 as described above, the first electrode is attached to each light emitting layer (red light emitting layer 131R, green light emitting layer 131G, blue light emitting layer 131B) of the red organic EL element 10R, the green organic EL element 10G, and the blue organic EL element 10B. When a drive current is injected through the 12 and the first transparent layers 15R, 15G, and 15B, holes and electrons are recombined in each light emitting layer to generate an exciter, and light emission occurs.

As shown in FIG. 10, the light emitted from each light emitting layer is multiplexed between the first reflection interface (first reflection interface S1R, S1B) and the fourth reflection interface (fourth reflection interface S4R, S4B). It is reflected and taken out from the light extraction surface (light extraction surface SDR, SDB). In the red organic EL element 10R, the red light LR is taken out from the light extraction surface SDR, in the green organic EL element 10G, the green light LG is taken out from the light extraction surface, and in the blue organic EL element 10B, the blue light LB is taken out. It is taken out from the surface SDB. Various colors are expressed by the additive mixing of these red light LR, green light LG, and blue light LB.

However, in a light emitting device having such a resonator structure, although various structures have been proposed, it is difficult to improve the light distribution characteristics.

For example, a method has been proposed in which the film thickness between the translucent electrode and the reflective electrode is set so that light of a desired wavelength resonates, thereby increasing the luminous efficiency (see, for example, Patent Document 1). Attempts have also been made to control the balance of attenuation of the three primary colors (red, green, and blue) by controlling the film thickness of the organic layer, and to improve the viewing angle characteristics of white chromaticity points (for example, Patent Document 4). reference).

However, since such a resonator structure functions as an interference filter having a narrow half-value width with respect to the spectrum of the extracted light, the wavelength of the light shifts significantly when the light extraction surface is viewed from an oblique direction. .. For this reason, the emission intensity is lowered depending on the viewing angle, and the viewing angle dependence becomes high.

Further, Patent Document 2 proposes a structure for reducing a change in hue due to a viewing angle. However, although this structure may be applicable to a single color and reduce the viewing angle dependence of luminance, it is difficult to apply to a sufficiently wide wavelength band. It is conceivable to increase the reflectance in order to widen the applicable wavelength band, but in this case, the light extraction efficiency is significantly reduced.

As described above, a method of reducing the angle dependence by adjusting the positional relationship in the resonator structure, the light emitting position, and the like can be considered, but this method may make adjustment difficult. For example, there is a case where the wavelength dispersion of the refractive index occurs depending on the spectrum of light emitted from each light emitting layer. In the wavelength dispersion of the refractive index, since the refractive index of the constituent material differs depending on each wavelength, the effect of the resonator structure differs among the red organic EL element, the green organic EL element, and the blue organic EL element. For example, in the red organic EL element, the peak of the extracted red light becomes too steep, and in the blue organic EL element, the peak of the extracted blue light becomes too gentle. As described above, when the effect of the resonator structure is significantly different for each element region, the angle dependence of the luminance and the hue becomes large, and the light distribution characteristic deteriorates.

On the other hand, in the light emitting device 1, the influence of the third reflection interface S3R and the fourth reflection interface S4R on the light generated by the red light emitting layer 131R and the light generated by the blue light emitting layer 131B are the first. The effects of the 3 reflection interface S3B and the 4th reflection interface S4B are different from each other. Specifically, the light generated by the red light emitting layer 131R and the light generated by the blue light emitting layer 131B are as follows.

The light generated in the red light emitting layer 131R is weakened by the interference between the light emitting center OR of the red light emitting layer 131R and the third reflection interface S3R and the fourth reflection interface S4R of the red light emitting element region 11R. On the other hand, the light generated in the blue light emitting layer 131B is strengthened by the interference between the light emitting center OB of the blue light emitting layer 131B and the third reflection interface S3B and the fourth reflection interface S4B of the blue light emitting element region 11B.

As a result, in the red light emitting element region 11R, the red light LR having a gentle peak vicinity is extracted from the light extraction surface SDR (see FIGS. 8A and 8B), and in the blue light emitting element region 11B, a steep peak is generated from the light extraction surface SDB. The blue light LB to have is taken out (see FIGS. 9A and 9B). Therefore, the difference between the effect of the resonator structure of the red light emitting element region 11R and the effect of the resonator structure of the blue light emitting element region 11B becomes small, and the angle dependence of the brightness and the hue becomes small. Therefore, the light distribution characteristics can be improved. Further, the light emitting device 1 having high light distribution characteristics is also suitable for a display device requiring high image quality, and the productivity of the display device can be improved.

FIGS. 11 and 12 show the viewing angle characteristics. FIG. 11 shows the change in chromaticity depending on the viewing angle, and FIG. 12 shows the change in brightness depending on the viewing angle. The light emitting device 1 can maintain Δuv ≦ 0.015 and a brightness of 60% or more even at a viewing angle of 45 °, and can realize high image quality.

As described above, in the light emitting device 1 of the present embodiment, the third reflection interface S3R and the fourth reflection interface S4R of the red light emitting element region 11R are provided so as to weaken the light generated in the red light emitting layer 131R. On the other hand, the third reflection interface S3B and the fourth reflection interface S4B of the blue light emitting element region 11B are provided so as to enhance the light generated in the blue light emitting layer 131B. As a result, the effect of the resonator structure can be adjusted for each element region, so that the light distribution characteristics can be improved.

Further, since high light transmittance can be obtained over a wide wavelength band, the light extraction efficiency can be improved. This also makes it possible to reduce power consumption.

When the third reflection interfaces S3R and S3B and the fourth reflection interfaces S4R and S4B are formed by laminating metal thin films having a thickness of 5 nm or more, high light transmittance can be obtained over a wide wavelength band.

Further, semitransparent reflective layers 14R, 14G, 14B are provided, and the interface between the organic layer (red organic layer 13R, blue organic layer 13B) and the semitransparent reflective layer 14R, 14G, 14B provides a second reflective interface (second reflective interface). By forming S2R, S2B), it is possible to enhance the amplification effect of the resonator structure and further improve the light extraction efficiency.

In addition, the light emitting device 1 is suitable when the organic layer (red organic layer 13R, blue organic layer 13B) is a printing layer. The organic layer tends to have a large or small thickness depending on the region due to undergoing a drying step or the like. That is, a film thickness distribution is likely to occur in the organic layer. In the light emitting device 1, it is possible to adjust the difference in the effect of the resonator structure for each element region due to this film thickness distribution.

Hereinafter, a modified example of the present embodiment will be described, but in the following description, the same components as those of the above embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

<Modification example 1>
FIG. 13 schematically shows the cross-sectional configuration of the red organic EL element (red organic EL element 50R) according to the first modification of the embodiment. In the red organic EL element 50R, the second reflection interface S2R is composed of an interface between the red organic layer 13R and the metal layer 51. Except for this point, the red organic EL element 50R has the same configuration as the red organic EL element 10R of the above embodiment, and its action and effect are also the same.

For the metal layer 51, for example, magnesium (Mg), silver (Ag) or an alloy thereof can be used. The thickness of the metal layer 51 is preferably 5 nm or more. By forming the second reflection interface S2R using such a metal layer 51, external light reflection can be suppressed. This will be described below.

FIG. 14 shows the spectral reflection characteristics of the red light emitting element region 11R when the metal layer 51 is provided. It is preferable to provide a color filter (for example, the color filter layer 74 of FIG. 21 described later) together with the metal layer 51. In the red light emitting element region 11R, this color filter transmits light in the red wavelength region and absorbs light in the green wavelength region and the blue wavelength region. By providing the metal layer 51 together with the color filter in this way, multiple reflections due to the extinction coefficient of the metal thin film occur, so that external light reflection can be suppressed. Therefore, the amplification effect of the resonator structure and the suppression effect of external light reflection can be obtained at the same time.

For example, the green organic EL element and the blue organic EL element (blue organic EL element 50B) are also provided with the metal layer 51.

<Modification 2>
FIG. 15 schematically shows the cross-sectional configuration of the red organic EL element (red organic EL element 60R) according to the second modification of the above embodiment. The red organic EL element 60R has a fifth reflection interface (fifth reflection interface S5R) in addition to the first reflection interface S1R to the fourth reflection interface S4R. Except for this point, the red organic EL element 60R has the same configuration as the red organic EL element 10R of the above embodiment, and its action and effect are also the same.

The fifth reflection interface S5R is provided between, for example, the second reflection interface S2R and the third reflection interface S3R. The fifth reflective interface S5R is, for example, an interface between the first transparent layer 15R and the fifth transparent layer 61, and is formed by the difference in refractive index between the constituent material of the first transparent layer 15R and the constituent material of the fifth transparent layer 61. Has been done. The fifth transparent layer 61 is provided between, for example, the first transparent layer 15R and the second transparent layer 16R.

16 to 18 show another example of the cross-sectional configuration of the red organic EL element 60R.

As shown in FIG. 16, the fifth reflection interface S5R may be provided between the third reflection interface S3R and the fourth reflection interface S4R. At this time, the fifth transparent layer 61 is provided between, for example, the second transparent layer 16R and the third transparent layer 17R.

As shown in FIG. 17, the fifth reflection interface S5R may be provided between the fourth reflection interface S4R and the light extraction surface SDR. At this time, the fifth reflection interface S5R is preferably arranged at a position of 1200 nm or less in optical distance from the second reflection interface S2R. This is because if the distance between the second reflection interfaces S2R and S2B and the fourth reflection interfaces S4R and S4B is large, the effect of the resonator structure cannot be obtained. The fifth transparent layer 61 is provided on, for example, the third transparent layer 17R.

As shown in FIG. 18, a plurality of fifth reflection interfaces S5R may be provided. For example, the fifth reflection interface S5R may be provided between the second reflection interface S2R and the third reflection interface S3R and between the third reflection interface S3R and the fourth reflection interface S4R. Alternatively, it may be between the second reflection interface S2R and the third reflection interface S3R, or between the fourth reflection interface S4R and the light extraction surface SDR, and the third reflection interface S3R and the fourth reflection interface S4R. It may be between the fourth reflection interface S4R and the light extraction surface SDR (not shown). Alternatively, three or more fifth reflection interfaces S5R may be provided.

The reflection at the fifth reflection interface S5R may be configured to weaken each other with respect to the center wavelength λ1 of the emission spectrum of the red light emitting layer 131R, or may be configured to strengthen each other. When there are a plurality of fifth reflection interfaces S5R, all of them may be configured to weaken each other with respect to the center wavelength λ1 of the emission spectrum of the red light emitting layer 131R, or may be configured to strengthen each other. Good. When there are a plurality of fifth reflection interfaces S5R, a part thereof may be configured to weaken each other with respect to the center wavelength λ1 of the emission spectrum of the red light emitting layer 131R, and the other part may be configured to strengthen each other. ..

For example, the green organic EL element and the blue organic EL element (blue organic EL element 50B) are also provided with a fifth reflection interface.

By providing the fifth reflection interface S5R, the effect of the resonator structure can be finely adjusted. A plurality of fifth reflection interfaces S5R shown in FIGS. 15 to 18 may be combined.

<Modification example 3>
FIG. 19 schematically shows a cross-sectional configuration of a light emitting device (light emitting device 1A) according to the third modification of the above embodiment. The light emitting device 1A is a bottom light emitting device, and has a third transparent layer 17R, 17B, a second transparent layer 16R, 16B, a first transparent layer 15R, 15B, and an organic layer (red organic layer) on the substrate 11. 13R, the blue organic layer 13B) and the first electrode 12 are provided in this order. In other words, the light extraction surface SDR, the fourth reflection interface S4R, the third reflection interface S3R, the second reflection interface S2R, and the first reflection interface S1R are provided in this order from the substrate 11 side. Except for this point, the light emitting device 1A has the same configuration as the light emitting device 1 of the above embodiment, and its action and effect are also the same.

<Application example 1>
The light emitting devices 1 and 1A described in the above embodiments can be applied to, for example, a display device (display device 2 in FIG. 20 described later). By applying the light emitting devices 1 and 1A having high light distribution characteristics to the display device, the angle dependence of the brightness and the hue becomes small, and high image quality can be realized.

FIG. 20 shows a schematic cross-sectional configuration of a display device (display device 2) to which the light emitting devices 1 and 1A are applied. The display device 2 is an active matrix type display device and has a drive board 71. The display device 2 has a sealing substrate 72 facing the driving substrate 71, and between the driving substrate 71 and the sealing substrate 72, a red organic EL element 10R (or a red organic EL element 50R, 60R), green. It has an organic EL element 10G and a blue organic EL element 10B (or a blue organic EL element 50B, 60B). The outer peripheral portions of the drive substrate 71 and the sealing substrate 72 are sealed with the sealing agent 73. In the display device 2, for example, an image is displayed on the sealing substrate 72 side. The display device 2 may be a black-and-white display or a color display.

The drive substrate 71 has a thin film transistor as a drive element for each pixel. The drive substrate 71 has a scanning line, a current supply line, and a data line for driving each thin film transistor together with the thin film transistor. A display signal corresponding to each display pixel is supplied to the thin film transistor of each pixel, and the pixel is driven according to the display signal to display an image.

As shown in FIG. 21, the display device 2 may be provided with the color filter layer 74. The color filter layer 74 is provided on, for example, one surface of the sealing substrate 72 (the surface facing the drive substrate 71). The color filter layer 74 is provided with color filters corresponding to each of the colors of red, green, and blue, for example, for each pixel.

FIG. 22 shows the functional block configuration of the display device 2.

The display device 2 displays a video signal input from the outside or a video signal generated internally as a video, and is applied to, for example, a liquid crystal display in addition to the above-mentioned organic EL display. The display device 2 includes, for example, a timing control unit 21, a signal processing unit 22, a drive unit 23, and a display pixel unit 24.

The timing control unit 21 has a timing generator that generates various timing signals (control signals), and performs drive control of the signal processing unit 22 and the like based on these various timing signals. For example, the signal processing unit 22 performs a predetermined correction on a digital video signal input from the outside, and outputs the video signal obtained by the correction to the drive unit 23. The drive unit 23 includes, for example, a scanning line drive circuit and a signal line drive circuit, and drives each pixel of the display pixel unit 24 via various control lines. The display pixel unit 24 includes an organic EL element (red organic EL element 10R, green organic EL element 10G, blue organic EL element 10B) and a pixel circuit for driving the organic EL element for each pixel. There is. Of these, for example, the drive unit 23 is composed of the drive board 71.

(Example of electronic device)
The display device 2 can be used for various types of electronic devices. FIG. 23 shows the functional block configuration of the electronic device 3. Examples of the electronic device 3 include a television device, a personal computer (PC), a smartphone, a tablet PC, a mobile phone, a digital still camera, a digital video camera, and the like.

The electronic device 3 has, for example, the above-mentioned display device 2 and an interface unit 30. The interface unit 30 is an input unit to which various signals, power supplies, and the like are input from the outside. The interface unit 30 may also include a user interface such as a touch panel, a keyboard, or operation buttons.

<Application example 2>
The light emitting devices 1 and 1A described in the above-described embodiment and the like can be applied to, for example, a lighting device (lighting unit 410 in FIG. 24 described later). The light emitting devices 1 and 1A can be applied to a light source of a lighting device in all fields such as a tabletop or floor-standing lighting device or an indoor lighting device.

FIG. 24 shows the appearance of an indoor lighting device to which the light emitting devices 1 and 1A are applied. This lighting device has, for example, a lighting unit 410 configured to include an organic EL element (red organic EL element 10R, green organic EL element 10G, blue organic EL element 10B). The lighting units 410 are arranged on the ceiling 420 of the building in an appropriate number and at intervals. The lighting unit 410 can be installed not only in the ceiling 420 but also in an arbitrary place such as a wall 430 or a floor (not shown) depending on the application.

In these lighting devices, the lighting is performed by the light from the light emitting devices 1 and 1A having high light distribution characteristics. As a result, it is possible to realize lighting having excellent color rendering properties.

Although the embodiments and application examples have been described above, the present disclosure is not limited to the above-described embodiments and the like, and various modifications can be made. For example, the numerical values, structures, shapes, materials, production methods, etc. described in the above-described embodiments are examples, and different ones may be used.

Further, in the above-described embodiment and the like, the case where the green organic EL element 10G has the same resonator structure as the blue organic EL element 10B has been described, but the green organic EL element 10G is the same as the red organic EL element 10R. It may have a resonator structure.

It should be noted that the effects described in the present specification are merely examples and are not limited, and other effects may be obtained.

In addition, the present disclosure may have the following structure.
(1)
The first light emitting element region and the second light emitting element region,
With the first light emitting element region and the first reflection interface provided in the second light emitting element region,
The light extraction surface facing the first reflection interface and
A first light emitting layer provided between the first reflection interface of the first light emitting element region and the light extraction surface, and
A second light emitting layer provided between the first reflection interface of the second light emitting element region and the light extraction surface, and
It is provided between each of the first light emitting layer and the second light emitting layer and the light extraction surface, and its reflection enhances with respect to the central wavelength of the light emitting spectra of the first light emitting layer and the second light emitting layer. With the second reflective interface configured as
It is provided between the second reflection interface and the light extraction surface, and its reflection weakens with respect to the center wavelength of the emission spectrum of the first light emitting layer, and at the same time, it becomes the center wavelength of the emission spectrum of the second light emitting layer. With a third reflective interface configured to strengthen each other,
It is provided between the third reflection interface and the light extraction surface, and its reflection weakens with respect to the center wavelength of the emission spectrum of the first light emitting layer, and at the same time, it becomes the center wavelength of the emission spectrum of the second light emitting layer. A light emitting device having a fourth reflective interface configured to strengthen each other.
(2)
The light emitting device according to (1) above, wherein the first reflecting interface is configured to strengthen each other with respect to the center wavelength of the light emitting spectra of the first light emitting layer and the second light emitting layer.
(3)
The optical distance between the first reflection interface and the light emitting center of the first light emitting layer is L11, the optical distance between the second reflection interface and the light emitting center of the first light emitting layer is L12, and the third reflection interface and the first light emitting layer. When the optical distance from the light emitting center of the first light emitting layer is L13, the optical distance between the fourth reflection interface and the light emitting center of the first light emitting layer is L14, and the central wavelength of the light emitting spectrum of the first light emitting layer is λ1. , L11, L12, L13 and L14 are the light emitting devices according to (2) above, which satisfy all of the following formulas (1) to (8).
2L11 / λ11 + a1 / (2π) = m1 (however, m1 ≧ 0) ... (1)
2L12 / λ12 + a2 / (2π) = m2 ... (2)
2L13 / λ13 + a3 / (2π) = m3 + 1/2 ... (3)
2L14 / λ14 + a4 / 2π = m4 + 1/2 ... (4)
λ1-150 <λ11 <λ1 + 80 ... (5)
λ1-80 <λ12 <λ1 + 80 ... (6)
λ1-150 <λ13 <λ1 + 150 ... (7)
λ1-150 <λ14 <λ1 + 150 ... (8)
However, m1, m2, m3, m4: Units of integers λ1, λ11, λ12, λ13 and λ14: nm
a1: Phase change when light of each wavelength emitted from the first light emitting layer is reflected at the first reflection interface a2: When light of each wavelength emitted from the first light emitting layer is reflected at the second reflection interface Phase change a3: Phase change when light of each wavelength emitted from the first light emitting layer is reflected at the third reflection interface a4: Light of each wavelength emitted from the first light emitting layer is reflected at the fourth reflection interface Phase change (4)
The light emitting device according to (3) above, wherein m1 = 0 and m2 = 1.
(5)
The optical distance between the first reflection interface and the light emitting center of the second light emitting layer is L21, the optical distance between the second reflection interface and the light emitting center of the second light emitting layer is L22, and the third reflection interface and the first light emitting layer. 2 When the optical distance from the light emitting center of the light emitting layer is L23, the optical distance between the fourth reflection interface and the light emitting center of the second light emitting layer is L24, and the central wavelength of the light emitting spectrum of the second light emitting layer is λ2. , L21, L22, L23 and L24 are the light emitting devices according to any one of (2) to (4) above, which satisfy all of the following formulas (9) to (16).
2L21 / λ21 + c1 / (2π) = n1 (where n1 ≧ 0) ... (9)
2L22 / λ22 + c2 / (2π) = n2 ... (10)
2L23 / λ23 + c3 / (2π) = n3 ... (11)
2L24 / λ24 + c4 / (2π) = n4 ... (12)
λ2-150 <λ21 <λ2 + 80 ... (13)
λ2-80 <λ22 <λ2 + 80 ... (14)
λ2-150 <λ23 <λ2 + 150 ... (15)
λ2-150 <λ24 <λ2 + 150 ... (16)
However, n1, n2, n3, n4: Units of integers λ2, λ21, λ22, λ23 and λ24: nm
c1: Phase change when light of each wavelength emitted from the second light emitting layer is reflected at the first reflection interface c2: When light of each wavelength emitted from the second light emitting layer is reflected at the second reflection interface Phase change c3: Phase change when light of each wavelength emitted from the second light emitting layer is reflected at the third reflection interface c4: Light of each wavelength emitted from the second light emitting layer is reflected at the fourth reflection interface Phase change (6)
The light emitting device according to (5) above, wherein n1 = 0 and n2 = 1.
(7)
Further, at least one of the second reflection interface and the third reflection interface, the third reflection interface and the fourth reflection interface, and the fourth reflection interface and the light extraction surface. The light emitting device according to any one of (1) to (6) above, which has a fifth reflection interface in one.
(8)
Further, it has a first electrode and a second electrode provided in the first light emitting element region and the second light emitting element region and facing each other with the first light emitting layer and the second light emitting layer in between.
The first electrode faces the first light emitting layer and the second light emitting layer with the first reflection interface in between.
The light emitting device according to any one of (1) to (7), wherein the second electrode is provided between the first light emitting layer and the second light emitting layer and a light extraction surface.
(9)
In addition, including the substrate,
The light emitting device according to (8), wherein the first electrode, the first light emitting layer, the second light emitting layer, and the second electrode are provided in order from a position closer to the substrate.
(10)
In addition, including the substrate,
The light emitting device according to (8), wherein the second electrode, the first light emitting layer, the second light emitting layer, and the first electrode are provided in order from a position closer to the substrate.
(11)
Further, the first organic layer including the first light emitting layer and
The light emitting device according to any one of (1) to (10), which has a second organic layer including the second light emitting layer.
(12)
The light emitting device according to (11), wherein the first light emitting layer and the second light emitting layer are printing layers.
(13)
Further, it has a semitransparent reflective layer or a transparent reflective layer provided in the first light emitting element region and the second light emitting element region.
The light emitting device according to any one of (1) to (12), wherein the second reflective interface is formed of the translucent reflective layer or the transparent reflective layer.
(14)
Further, it has a metal layer and a color filter provided in the first light emitting element region and the second light emitting element region.
The light emitting device according to (11) or (12), wherein the second reflective interface is an interface between each of the first organic layer and the second organic layer and the metal layer.
(15)
The light emitting device according to (14), wherein the thickness of the metal layer is 5 nm or more.
(16)
A light emitting device and a driving element for driving the light emitting device for each pixel are provided.
The light emitting device is
The first light emitting element region and the second light emitting element region,
With the first light emitting element region and the first reflection interface provided in the second light emitting element region,
The light extraction surface facing the first reflection interface and
A first light emitting layer provided between the first reflection interface of the first light emitting element region and the light extraction surface, and
A second light emitting layer provided between the first reflection interface of the second light emitting element region and the light extraction surface, and
It is provided between each of the first light emitting layer and the second light emitting layer and the light extraction surface, and its reflection enhances with respect to the central wavelength of the light emitting spectra of the first light emitting layer and the second light emitting layer. With the second reflective interface configured as
It is provided between the second reflection interface and the light extraction surface, and its reflection weakens with respect to the center wavelength of the emission spectrum of the first light emitting layer, and at the same time, it becomes the center wavelength of the emission spectrum of the second light emitting layer. With a third reflective interface configured to strengthen each other,
It is provided between the third reflection interface and the light extraction surface, and its reflection weakens with respect to the center wavelength of the emission spectrum of the first light emitting layer, and at the same time, it becomes the center wavelength of the emission spectrum of the second light emitting layer. A display device having a fourth reflective interface configured to strengthen each other.
(17)
Equipped with a light emitting device
The light emitting device is
The first light emitting element region and the second light emitting element region,
With the first light emitting element region and the first reflection interface provided in the second light emitting element region,
The light extraction surface facing the first reflection interface and
A first light emitting layer provided between the first reflection interface of the first light emitting element region and the light extraction surface, and
A second light emitting layer provided between the first reflection interface of the second light emitting element region and the light extraction surface, and
It is provided between each of the first light emitting layer and the second light emitting layer and the light extraction surface, and its reflection enhances with respect to the central wavelength of the light emitting spectra of the first light emitting layer and the second light emitting layer. With the second reflective interface configured as
It is provided between the second reflection interface and the light extraction surface, and its reflection weakens with respect to the center wavelength of the emission spectrum of the first light emitting layer, and at the same time, it becomes the center wavelength of the emission spectrum of the second light emitting layer. With a third reflective interface configured to strengthen each other,
It is provided between the third reflection interface and the light extraction surface, and its reflection weakens with respect to the center wavelength of the emission spectrum of the first light emitting layer, and at the same time, it becomes the center wavelength of the emission spectrum of the second light emitting layer. An illuminating device with a fourth reflective interface configured to strengthen each other.

1,1A ... light emitting device, 2 ... display device, 3 ... electronic device, 10R, 50R, 60R ... red organic EL element, 10G ... green organic EL element, 10B, 50B, 60B ... blue organic EL element, 11 ... substrate, 12 ... 1st electrode, 13R ... red organic layer, 13G ... green organic layer, 13B ... blue organic layer, 131R ... red light emitting layer, 131G ... green light emitting layer, 131B ... blue light emitting layer, 14R, 14G, 14B ... translucent Reflective layer, 15R, 15G, 15B ... 1st transparent layer, 16R, 16G, 16B ... 2nd transparent layer, 17R, 17G, 17B ... 3rd transparent layer, 18R ... 4th transparent layer, 21 ... Timing control unit, 22 ... Signal processing unit, 23 ... Drive unit, 24 ... Display pixel unit, 30 ... Interface unit, 51 ... Metal layer, 61 ... Fifth transparent layer, 71 ... Drive substrate, 72 ... Encapsulation substrate, 73 ... Encapsulant, 74 ... Color filter layer, S1R, S1B ... 1st reflection interface, S2R, S2B ... 2nd reflection interface, S3R, S3B ... 3rd reflection interface, S4R, S4B ... 4th reflection interface, S5R, S5B ... 5th reflection interface , SDR, SDB ... Optical extraction surface.

Claims (16)

The first light emitting element region and the second light emitting element region,
With the first light emitting element region and the first reflection interface provided in the second light emitting element region,
The light extraction surface facing the first reflection interface and
A first light emitting layer provided between the first reflection interface of the first light emitting element region and the light extraction surface, and
A second light emitting layer provided between the first reflection interface of the second light emitting element region and the light extraction surface, and
It is provided between each of the first light emitting layer and the second light emitting layer and the light extraction surface, and its reflection enhances with respect to the central wavelength of the light emitting spectra of the first light emitting layer and the second light emitting layer. With the second reflective interface configured as
It is provided between the second reflection interface and the light extraction surface, and its reflection weakens with respect to the center wavelength of the emission spectrum of the first light emitting layer, and at the same time, it becomes the center wavelength of the emission spectrum of the second light emitting layer. light-emitting device and a third reflecting surface that is configured to constructively against. The light emitting device according to claim 1, wherein the first reflecting interface is configured to strengthen each other with respect to the center wavelength of the light emitting spectra of the first light emitting layer and the second light emitting layer. The optical distance between the first reflection interface and the light emitting center of the first light emitting layer is L11, the optical distance between the second reflection interface and the light emitting center of the first light emitting layer is L12, and the third reflection interface and the first light emitting layer. 1 an optical distance between the emission center of the light-emitting layer L13, when the center wavelength of the emission spectrum before Symbol first light-emitting layer was set to λ1, L11, L12 and L13 satisfy all the following formulas (1) to (6) The light emitting device according to claim 2.
2L11 / λ11 + a1 / (2π) = m1 (however, m1 ≧ 0) ... (1)
2L12 / λ12 + a2 / (2π) = m2 ... (2)
2L13 / λ13 + a3 / (2π) = m3 + 1/2 ... (3 )
λ1-150 <λ11 <λ1 + 80 ... ( 4 )
λ1-80 <λ12 <λ1 + 80 ... ( 5 )
λ1-150 <λ13 <λ1 + 150 ... ( 6)
However, m1, m2, m 3: Units of integers λ1, λ11, λ12 and λ13 : nm
a1: Phase change when light of each wavelength emitted from the first light emitting layer is reflected at the first reflection interface a2: When light of each wavelength emitted from the first light emitting layer is reflected at the second reflection interface phase change a3: phase changes when the light of each wavelength emitted from the first light-emitting layer is reflected by the third reflection interface The light emitting device according to claim 3, wherein m1 = 0 and m2 = 1. The optical distance between the first reflection interface and the light emitting center of the second light emitting layer is L21, the optical distance between the second reflection interface and the light emitting center of the second light emitting layer is L22, and the third reflection interface and the first light emitting layer. the optical distance between the emission center of the second luminescent layer L23, when the center wavelength of the emission spectrum before Symbol second light-emitting layer was set to λ2, L21, L22 and L23 satisfy all the following formulas (7) - (12) The light emitting device according to claim 2.
2L21 / λ21 + c1 / (2π) = n1 (where n1 ≧ 0) ... ( 7 )
2L22 / λ22 + c2 / (2π) = n2 ... ( 8 )
2L23 / λ23 + c3 / (2π) = n3 ... ( 9)
λ2-150 <λ21 <λ2 + 80 ... ( 10 )
λ2-80 <λ22 <λ2 + 80 ... ( 11 )
λ2-150 <λ23 <λ2 + 150 ... ( 12)
However, n1, n2, n3: number of integer <br/> λ2, λ21, λ22 and λ23 units: nm
c1: Phase change when light of each wavelength emitted from the second light emitting layer is reflected at the first reflection interface c2: When light of each wavelength emitted from the second light emitting layer is reflected at the second reflection interface phase change c3: phase changes when the light of each wavelength emitted from the second light-emitting layer is reflected by the third reflection interface The light emitting device according to claim 5, wherein n1 = 0 and n2 = 1. Further, it has a first electrode and a second electrode provided in the first light emitting element region and the second light emitting element region and facing each other with the first light emitting layer and the second light emitting layer in between.
The first electrode faces the first light emitting layer and the second light emitting layer with the first reflection interface in between.
The light emitting device according to claim 1, wherein the second electrode is provided between the first light emitting layer and the second light emitting layer and a light extraction surface. In addition, including the substrate,
The light emitting device according to claim 7 , wherein the first electrode, the first light emitting layer, the second light emitting layer, and the second electrode are provided in order from a position closer to the substrate. In addition, including the substrate,
The light emitting device according to claim 7 , wherein the second electrode, the first light emitting layer, the second light emitting layer, and the first electrode are provided in order from a position closer to the substrate. Further, the first organic layer including the first light emitting layer and
The light emitting device according to claim 1, further comprising a second organic layer including the second light emitting layer. The light emitting device according to claim 10, wherein the first light emitting layer and the second light emitting layer are printing layers. Further, it has a semitransparent reflective layer or a transparent reflective layer provided in the first light emitting element region and the second light emitting element region.
The light emitting device according to claim 1, wherein the second reflective interface is formed of the translucent reflective layer or the transparent reflective layer. Further, it has a metal layer and a color filter provided in the first light emitting element region and the second light emitting element region.
The light emitting device according to claim 10, wherein the second reflective interface is an interface between each of the first organic layer and the second organic layer and the metal layer. The light emitting device according to claim 13 , wherein the thickness of the metal layer is 5 nm or more. A light emitting device and a driving element for driving the light emitting device for each pixel are provided.
The light emitting device is
The first light emitting element region and the second light emitting element region,
With the first light emitting element region and the first reflection interface provided in the second light emitting element region,
The light extraction surface facing the first reflection interface and
A first light emitting layer provided between the first reflection interface of the first light emitting element region and the light extraction surface, and
A second light emitting layer provided between the first reflection interface of the second light emitting element region and the light extraction surface, and
It is provided between each of the first light emitting layer and the second light emitting layer and the light extraction surface, and its reflection enhances with respect to the central wavelength of the light emitting spectra of the first light emitting layer and the second light emitting layer. With the second reflective interface configured as
It is provided between the second reflection interface and the light extraction surface, and its reflection weakens with respect to the center wavelength of the emission spectrum of the first light emitting layer, and at the same time, it becomes the center wavelength of the emission spectrum of the second light emitting layer. display device and a third reflecting surface that is configured to constructively against. Equipped with a light emitting device
The light emitting device is
The first light emitting element region and the second light emitting element region,
With the first light emitting element region and the first reflection interface provided in the second light emitting element region,
The light extraction surface facing the first reflection interface and
A first light emitting layer provided between the first reflection interface of the first light emitting element region and the light extraction surface, and
A second light emitting layer provided between the first reflection interface of the second light emitting element region and the light extraction surface, and
It is provided between each of the first light emitting layer and the second light emitting layer and the light extraction surface, and its reflection enhances with respect to the central wavelength of the light emitting spectra of the first light emitting layer and the second light emitting layer. With the second reflective interface configured as
It is provided between the second reflection interface and the light extraction surface, and its reflection weakens with respect to the center wavelength of the emission spectrum of the first light emitting layer, and at the same time, it becomes the center wavelength of the emission spectrum of the second light emitting layer. lighting apparatus that includes a third reflection surface that is configured to constructively against.

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