Display and electronic apparatus

Abstract

To provide a display that can suppress reduction in a color viewing angle and a luminance viewing angle.SOLUTION: A display comprises: an organic layer that has a luminescent layer containing an organic luminescent material; a reflection layer that reflects light generated in the luminescent layer; a transparent first electrode; a transparent second electrode; and an optical adjustment layer that adjusts an optical distance between the reflection layer and the second electrode. The reflection layer, the optical adjustment layer, the first electrode, the organic layer, and the second electrode are arranged side by side in order. Reflectance of a first boundary between the organic layer and the first electrode, and reflectance of a second boundary between the organic layer and the second electrode are both 11% or less.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a display device and an electronic device. [Background technology]

[0002] 2. Description of the Related Art Devices having light-emitting elements such as organic EL (electroluminescence) elements are known.

[0003] Patent Document 1 discloses an organic EL element used in an organic EL light-emitting device. The organic EL element includes a substrate, a reflective layer, an optical path length adjustment layer, a first electrode, an organic EL layer, and a second electrode. The substrate, the reflective layer, the optical path length adjustment layer, the first electrode, the organic EL layer, and the second electrode are stacked in this order from the substrate.

[0004] In the organic EL element described in Patent Document 1, the optical path length adjustment layer, the first electrode, and the organic EL layer form a resonator structure. The optical path length adjustment layer is provided between the reflective layer and the first electrode to increase the optical path length of the resonator structure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-8515 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in a device having a resonator structure as described in Patent Document 1, the color or brightness of the display appears to differ depending on the viewing direction of the device. In other words, the device as described in Patent Document 1 has a problem in that the color viewing angle and the brightness viewing angle are reduced. [Means for solving the problem]

[0007] In order to solve the above problems, a display device according to a preferred embodiment of the present disclosure comprises an organic layer having an emission layer containing an organic emission material, a reflective layer that reflects light generated in the emission layer, a transparent first electrode, a transparent second electrode, and an optical adjustment layer that adjusts the optical distance between the reflective layer and the second electrode, wherein the reflective layer, the optical adjustment layer, the first electrode, the organic layer, and the second electrode are arranged in order, and the reflectance of a first interface between the organic layer and the first electrode and the reflectance of a second interface between the organic layer and the second electrode are each 11% or less. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view illustrating a display device according to a first embodiment. [Diagram 2] 2 is an equivalent circuit diagram of the sub-pixel shown in FIG. [Diagram 3] FIG. 2 is a plan view showing a part of the display device of FIG. [Figure 4] 2 is a schematic diagram showing a partial cross section of the display device of FIG. 1. [Diagram 5] 5 is a diagram for explaining the path of light in the display device of FIG. 4. [Figure 6] FIG. 13 is a diagram showing a display device according to a modified example. [Figure 7] FIG. 2 is a diagram illustrating a configuration of a display device of Comparative Example 1. [Figure 8] FIG. 13 is a diagram illustrating a configuration of a display device of Comparative Example 2. [Figure 9] FIG. 13 is a diagram illustrating a configuration of a display device of Comparative Example 3. [Figure 10] FIG. 1 is a diagram illustrating a schematic view of a part of a virtual image display device that is an example of an electronic device. [Figure 11] FIG. 1 is a perspective view showing a personal computer as an example of an electronic device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the dimensions and scale of each part in the drawings may differ from the actual ones, and some parts are shown diagrammatically to facilitate understanding. In addition, the scope of the present disclosure is not limited to these forms unless otherwise specified in the following description to the effect that the present disclosure is limited.

[0010] 1.Display device 100 1-1. Basic configuration of the display device 100 FIG. 1 is a plan view showing a display device 100 of the first embodiment. For convenience of explanation, the following description will be given using the mutually orthogonal X-axis, Y-axis, and Z-axis as appropriate. Also, one direction along the X-axis is the X1 direction, and the opposite direction to the X1 direction is the X2 direction. Similarly, one direction along the Y-axis is the Y1 direction, and the opposite direction to the Y1 direction is the Y2 direction. One direction along the Z-axis is the Z1 direction, and the opposite direction to the Z1 direction is the Z2 direction. Viewing in the Z1 direction or Z2 direction is referred to as "planar view."

[0011] The display device 100 shown in FIG. 1 displays an image using organic electroluminescence (EL). The image includes an image that displays only text information. The display device 100 is used, for example, as a microdisplay that displays color images in a head-mounted display. The head-mounted display will be described in detail later.

[0012] The display device 100 is divided into a display area A10 and a peripheral area A20 in a plan view. The display area A10 is an area where an image is displayed. The peripheral area A20 is an area where peripheral circuits are arranged. The display area A10 is rectangular. The peripheral area A20 is a rectangular frame that surrounds the display area A10.

[0013] A plurality of pixels P are provided in the display area A10. Each pixel P has a sub-pixel PR that obtains light in a red wavelength range, which is a "first wavelength range," a sub-pixel PG that obtains light in a green wavelength range, which is a "second wavelength range," and a sub-pixel PB that obtains light in a blue wavelength range, which is a "third wavelength range." The red wavelength range is greater than 580 nm and less than 700 nm. The green wavelength range is greater than 500 nm and less than 580 nm. The blue wavelength range is greater than 400 nm and less than 500 nm. The sub-pixels PB, PG, and PR form one pixel P of a color image. In the following, when the sub-pixels PB, PG, and PR are not distinguished from each other, they are referred to as sub-pixels P0. The sub-pixels P0 are the smallest units that are independently controlled. The sub-pixels P0 are arranged in a matrix along the X-axis and the Y-axis.

[0014] Furthermore, in the display region A10, M scanning lines 11 extending along the X-axis and N signal lines 12 extending along the Y-axis are provided. Sub-pixels P0 are formed at intersections between the M scanning lines 11 and the N signal lines 12. Although not shown in detail, a plurality of dummy pixels that do not contribute to image display are provided in a portion of the display region A10 close to the peripheral region A20.

[0015] The peripheral area A20 is provided with a control circuit 201, a scanning line driving circuit 202, a signal line driving circuit 203, and a plurality of external terminals 204. The control circuit 201 controls the display of an image. The control circuit 201 generates a control signal based on a synchronization signal supplied from a higher-level circuit (not shown), and supplies the control signal to the scanning line driving circuit 202 and the signal line driving circuit 203. The control circuit 201 also generates an analog image signal based on image data supplied from a higher-level circuit (not shown), and supplies the analog image signal to the signal line driving circuit 203. The scanning line driving circuit 202 is also connected to M scanning lines 11. The scanning line driving circuit 202 generates a scanning signal for sequentially selecting the M scanning lines 11 one by one based on the control signal, and outputs the scanning signal to the M scanning lines 11. The signal line driving circuit 203 is also connected to N signal lines 12. The signal line driving circuit 203 generates a data signal according to a gradation to be displayed based on the image signal and the control signal, and outputs the data signal to the N signal lines 12. An FPC (Flexible Printed Circuits) board or the like for electrical connection to a higher-level circuit (not shown) is connected to the external terminal 204. In addition, a power supply circuit (not shown) is electrically connected to the peripheral area A20.

[0016] 1-2. Electrical configuration of the display device 100 Fig. 2 is an equivalent circuit diagram of the sub-pixel P0 shown in Fig. 1. One sub-pixel P0 and its corresponding elements are representatively illustrated in Fig. 2. As shown in Fig. 2, the sub-pixel P0 includes a light-emitting element 20 and a pixel circuit 30.

[0017] The light emitting element 20 is disposed on a path connecting the first constant potential wiring 13 and the second constant potential wiring 14. A high-level power supply potential Vel is supplied to the first constant potential wiring 13 from a power supply circuit (not shown). A low-level power supply potential Vct is supplied to the second constant potential wiring 14 from a power supply circuit (not shown). The light emitting element 20 is composed of an OLED (organic light emitting diode). The light emitting element 20 includes a light emitting layer 220, a first electrode 21, and a second electrode 23. The light emitting layer 220 includes an organic light emitting material and is interposed between the first electrode 21 and the second electrode 23. The first electrode 21 functions as an anode, and the second electrode 23 functions as a cathode. The first electrode 21 is formed individually for each sub-pixel P0 and is controlled independently of the other first electrodes 21. The second electrode 23 is continuous across a plurality of sub-pixels P0. In the light emitting element 20, holes supplied from the first electrode 21 and electrons supplied from the second electrode 23 recombine in the light emitting layer 220. This causes the light emitting layer 220 to emit light.

[0018] The pixel circuit 30 has a driving transistor 31, a selection transistor 32, and a capacitance element 33. The driving transistor 31 generates a driving current whose amount corresponds to the gate-source or gate-drain voltage. The driving transistor 31 is disposed in series with the light emitting element 20 on a path connecting the first constant potential wiring 13 and the second constant potential wiring 14. Specifically, one of the source and the drain of the driving transistor 31 is electrically connected to the first constant potential wiring 13, and the other is electrically connected to the first electrode 21.

[0019] The selection transistor 32 functions as a switch that controls conduction and non-conduction between the signal line 12 and the gate of the driving transistor 31. The gate of the selection transistor 32 is electrically connected to the scanning line 11. One of the source and the drain of the selection transistor 32 is electrically connected to the signal line 12, and the other is electrically connected to the gate of the driving transistor 31.

[0020] The capacitance element 33 is a storage capacitor that holds a voltage between the gate and source or between the gate and drain of the driving transistor 31. One electrode of the capacitance element 33 is connected to the gate of the driving transistor 31, and the other electrode is connected to the first constant potential wiring 13.

[0021] In the display device 100, the signal line driving circuit 203 supplies a data signal corresponding to a gradation designated for each sub-pixel P0 to the multiple signal lines 12 in parallel for each writing period. The scanning line driving circuit 202 sequentially selects the multiple scanning lines 11 for each writing period by outputting a scanning signal to each scanning line 11. When the selection transistor 32 of the sub-pixel P0 corresponding to the scanning line 11 selected by the scanning line driving circuit 202 is turned on, a gradation potential corresponding to the data signal is supplied to the gate of the driving transistor 31, and a voltage corresponding to the gradation potential is held in the capacitive element 33. Therefore, a driving current corresponding to the gradation potential is supplied from the driving transistor 31 to the light emitting element 20. As described above, each light emitting element 20 emits light at a luminance corresponding to the gradation potential, and an arbitrary image designated by the image signal is displayed in the display area A10. Even after the writing period ends, a driving current corresponding to the voltage held in the capacitive element 33 is supplied from the driving transistor 31 to the light emitting element 20. Therefore, each light emitting element 20 maintains light emission at a luminance corresponding to the gradation potential.

[0022] Note that the configuration of the pixel circuit 30 shown in Fig. 2 is just an example, and the pixel circuit 30 may have a configuration other than that shown in Fig. 2. For example, the pixel circuit 30 may further include another transistor that controls conduction between the first electrode 21 and the driving transistor 31.

[0023] 1-3. Pixel P of the display device 100 Fig. 3 is a plan view showing a part of the display device 100 of Fig. 1. In the following, elements of one pixel P are representatively illustrated. In the following, the reference numerals of elements related to the subpixel PR are suffixed with "R", the reference numerals of elements related to the subpixel PG are suffixed with "G", and the reference numerals of elements related to the subpixel PB are suffixed with "B".

[0024] 3, in the display device 100, light-emitting elements 20R, 20G, and 20B are provided for each pixel P. The light-emitting element 20R is a light-emitting element 20 provided in the sub-pixel PR. The light-emitting element 20G is a light-emitting element 20 provided in the sub-pixel PG. The light-emitting element 20B is a light-emitting element 20 provided in the sub-pixel PB.

[0025] The light emitting element 20R has an opening region AR through which light in the red wavelength region is emitted. The light emitting element 20G has an opening region AG through which light in the green wavelength region is emitted. The light emitting element 20B has an opening region AB through which light in the blue wavelength region is emitted. As described above, the first electrode 21 is formed individually for each sub-pixel P0. Therefore, the light emitting element 20R has a first electrode 21R. The light emitting element 20G has a first electrode 21G. The light emitting element 20B has a first electrode 21B.

[0026] In FIG. 3, the three sub-pixels P0 of one pixel P are arranged in a stripe shape. However, the arrangement of the sub-pixels P0 is not limited to a stripe shape, and may be a rectangle shape, a delta shape, or the like. In FIG. 3, one pixel P has three sub-pixels P0, but the number of sub-pixels P0 of one pixel P is not limited to three. For example, one pixel P may have four sub-pixels P0. In the example shown in FIG. 3, the shape of each of the opening regions AR, AG, and AB in a plan view is a rectangle, but is not limited to this, and may be another polygon, such as an octagon.

[0027] In this specification, the pixel size means the size of the pixel P in a planar view, or the size of the sub-pixel P0 in a planar view. In this embodiment, the planar area of ​​the rectangular region S0 surrounding the aperture regions AR, AG, and AB corresponds to the pixel size of the pixel P. The pixel size of the pixel P is, for example, 25 μm 2 ~100μm 2 The plane area of ​​the aperture region AR corresponds to the pixel size of the sub-pixel PR, the plane area of ​​the aperture region AG corresponds to the pixel size of the sub-pixel PG, and the plane area of ​​the aperture region AB corresponds to the pixel size of the sub-pixel PB.

[0028] 1-4. Partial configuration of the display device 100 Fig. 4 is a diagram showing a schematic partial cross section of the display device 100 of Fig. 1. In Fig. 4, elements of one pixel P are representatively shown.

[0029] 4, the display device 100 includes a substrate 41, a circuit layer 42, a reflective layer 43, an optical adjustment layer 44, a first electrode 21, an organic layer 22, a second electrode 23, a sealing film 45, a color filter 46, and a cover 47. The organic layer 22 includes the above-mentioned light-emitting layer 220. The substrate 41 and the circuit layer 42 form a wiring board 40. The circuit layer 42, the reflective layer 43, the optical adjustment layer 44, the first electrode 21, the organic layer 22, the second electrode 23, the sealing film 45, the color filter 46, and the cover 47 are stacked in this order starting from the substrate 41.

[0030] The substrate 41 is formed of a semiconductor material such as silicon. In this embodiment, the display device 100 has a top emission structure that emits light in the Z1 direction, and the substrate 41 does not need to be light-transmitting. Instead of a silicon substrate, for example, a glass substrate, a resin substrate, or a ceramic substrate may be used. The substrate 41 may be light-transmitting. In this specification, the term "light-transmitting" refers to transparency to visible light, and preferably refers to a visible light transmittance of 50% or more.

[0031] The pixel circuit 30 described above is formed in the circuit layer 42. Specifically, the circuit layer 42 has a plurality of insulating layers formed of silicon oxide or the like, and each element and various wirings of the pixel circuit 30 are formed between the insulating layers. Examples of materials for each element and various wirings of the pixel circuit 30 include conductive materials such as polysilicon, metal, metal silicide, and metal compound. Although not shown in detail, each of the transistors described above of the pixel circuit 30 may be any of MOS transistors, thin film transistors, and field effect transistors. When the transistors of the pixel circuit 30 are MOS transistors having an active layer, the active layer may be formed on the substrate 41. Therefore, a part of the pixel circuit 30 may be formed on the substrate 41.

[0032] The reflective layer 43 has light reflectivity that reflects light generated in the light emitting layer 220. The material of the reflective layer 43 is, for example, a metal having high reflectivity, such as aluminum (Al) or silver (Ag), or an alloy thereof. The reflective layer 43 may be composed of one metal layer, or may be a laminate including a plurality of metal layers. The reflective layer 43 may be common to the three sub-pixels P0, or may be provided for each sub-pixel P0. The reflective layer 43 may also function as a wiring that is electrically connected to the pixel circuit 30.

[0033] The optical adjustment layer 44 has light transmissivity and adjusts the optical distance between the reflective layer 43 and the light emitting layer 220. The optical adjustment layer 44 includes a first optical adjustment portion 44R, a second optical adjustment portion 44G, and a third optical adjustment portion 44B. The first optical adjustment portion 44R is provided in the sub-pixel PR. The second optical adjustment portion 44G is provided in the sub-pixel PG. The third optical adjustment portion 44B is provided in the sub-pixel PB.

[0034] The thickness of the optical adjustment layer 44 is not particularly limited, but is 50 nm or more and 500 nm or less. The optical adjustment layer 44 has a different thickness for each emitted color. Specifically, the longer the wavelength, the thicker the optical adjustment layer 44. Therefore, the thickness of the first optical adjustment portion 44R, the thickness of the second optical adjustment portion 44G, and the thickness of the third optical adjustment portion 44B are thicker in this order.

[0035] The material of the optical adjustment layer 44 is, for example, silicon oxide, silicon oxynitride, or silicon nitride. The optical adjustment layer 44 may be composed of one layer, or may be a laminate of multiple layers. For example, when the optical adjustment layer 44 is a laminate, the optical adjustment layer 44 is formed of a laminate of silicon oxide and silicon nitride.

[0036] The first electrode 21 is a transparent pixel electrode, and is provided for each sub-pixel P0. In this specification and the like, "transparent" means that the reflectance of visible light is 20% or less. The material of the first electrode 21 is, for example, a transparent conductive material such as ITO (Indium Tin Oxide) and IZO (Indium Xinc Oxide). The thickness of the first electrode 21 is not particularly limited, but is, for example, 10 nm or more and 200 nm or less. In addition, the thickness of the first electrode 21 may be different for each sub-pixel P0, or may be the same.

[0037] The organic layer 22 includes at least a light-emitting layer 220. The light-emitting layer 220 includes an organic light-emitting material that emits light when a current is supplied. The organic light-emitting material is a light-emitting organic compound. In this embodiment, the light-emitting layer 220 includes a layer including a blue light-emitting material, a layer including a green light-emitting material, and a layer including a red light-emitting material. Blue light is generated from the layer including the blue light-emitting material, green light is generated from the layer including the green light-emitting material, and red light is generated from the layer including the red light-emitting material. The organic layer 22 includes the light-emitting layer 220 from which each of the blue, green, and red light colors can be obtained, thereby realizing white light emission. In this embodiment, in addition to the light-emitting layer 220, the organic layer 22 includes a hole injection layer (HIL), a hole transport layer (HTL), an electron injection layer (EIL), and an electron transport layer (ETL). In the organic layer 22, holes injected from the hole injection layer and electrons transported from the electron transport layer are recombined in the light-emitting layer 220. Each layer of the organic layer 22 is formed by, for example, a gas phase process. The organic layer 22 may have any configuration, and any of the layers described above may be omitted from the organic layer 22, or any layer may be added thereto.

[0038] The light emitting layer 220 has a first light emitting section 22R, a second light emitting section 22G, and a third light emitting section 22B. The first light emitting section 22R emits light in a wavelength range including light in a red wavelength range, which is the "light in the first wavelength range". The second light emitting section 22G emits light in a wavelength range including light in a green wavelength range, which is the "second wavelength range" longer than the first wavelength range. The third light emitting section 22B emits light in a wavelength range including light in a blue wavelength range, which is the "third wavelength range" longer than the second wavelength range. Although not shown in detail, the first light emitting section 22R corresponds to the first optical adjustment section 44R and overlaps with the first optical adjustment section 44R in a planar view. The second light emitting section 22G corresponds to the second optical adjustment section 44G and overlaps with the second optical adjustment section 44G in a planar view. The third light-emitting portion 22B corresponds to the third optical adjustment portion 44B, and overlaps with the third optical adjustment portion 44B in a plan view.

[0039] The second electrode 23 is a common electrode provided in common to the plurality of sub-pixels P0. The second electrode 23 is a transparent electrode similar to the first electrode 21. The material of the second electrode 23 is, for example, a transparent conductive material such as ITO or IZO. The thickness of the second electrode 23 is not particularly limited, but is, for example, 10 nm or more and 200 nm or less.

[0040] The reflectance of the first interface 221 between the organic layer 22 and the first electrode 21 and the reflectance of the second interface 222 between the organic layer 22 and the second electrode 23 are each 11% or less. Furthermore, the first electrode 21 and the second electrode 23 are each transparent. Therefore, the display device 100 does not have an optical resonator between the reflective layer 43 and the second electrode 23.

[0041] Specifically, the reflectance of the first interface 221 is the reflectance of light traveling from the organic layer 22 to the first interface 221. Specifically, the reflectance of the second interface 222 is the reflectance of light traveling from the organic layer 22 to the second interface 222. The first interface 221 and the second interface 222 have unevenness because the thickness of the optical adjustment layer 44 differs for each sub-pixel P0.

[0042] The sealing film 45 seals the light-emitting element 20. By providing the sealing film 45, the light-emitting element 20 can be protected from moisture in the atmosphere. The sealing film 45 also functions as a planarizing film that planarizes the upper surface of the light-emitting element 20. Therefore, the upper surface of the sealing film 45 is flat. The sealing film 45 is translucent. The material of the sealing film 45 is, for example, silicon oxide, silicon oxynitride, or silicon oxide. The thickness of the sealing film 45 is not particularly limited, but is, for example, 10 nm or more and 2000 nm or less. The sealing film 45 may be composed of one layer or multiple layers.

[0043] The color filter 46 selectively transmits light in a predetermined wavelength range. The color filter 46 has a coloring layer 46R, a coloring layer 46G, and a coloring layer 46B. The coloring layer 46R is provided in the sub-pixel PR and selectively transmits light in a red wavelength range from the light from the light emitting element 20R. The coloring layer 46G is provided in the sub-pixel PG and selectively transmits light in a green wavelength range from the light from the light emitting element 20G. The coloring layer 46B is provided in the sub-pixel PB and selectively transmits light in a blue wavelength range from the light from the light emitting element 20B. By providing the color filter 46, the color purity of the light emitted from each sub-pixel P0 can be increased compared to a case where the color filter 46 is not provided. The material of the color filter 46 is, for example, a resin material such as an acrylic photosensitive resin material containing a color material. The color material is a pigment or a dye.

[0044] The cover 47 is bonded to the color filter 46 via, for example, an adhesive layer (not shown). The adhesive layer is, for example, a transparent adhesive using a resin material such as an epoxy resin or an acrylic resin. The cover 47 protects the elements provided below the cover 47, particularly the light emitting element 20 and the color filter 46. The cover 47 is formed of, for example, a glass substrate or a quartz substrate.

[0045] As described above, the display device 100 includes the organic layer 22 including the light-emitting layer 220, the reflective layer 43, the optical adjustment layer 44, the first electrode 21, and the second electrode 23. The first electrode 21 and the second electrode 23 are transparent. The reflectance of the first interface 221 between the organic layer 22 and the first electrode 21 and the reflectance of the second interface 222 between the organic layer 22 and the second electrode 23 are each 11% or less. Therefore, the light emitted by the light-emitting layer 220 does not resonate between the reflective layer 43 and the second electrode 23. That is, as described above, the display device 100 does not have an optical resonator.

[0046] By having an optical resonator, the light extraction efficiency and color purity may be improved. However, when an optical resonator is included, the characteristics of the display device 100 in the front direction are improved, but the angle dependency is large, and the color change and the brightness change tend to be large when the observation direction of the display device 100 is changed. In contrast, since the display device 100 of the present embodiment does not have an optical resonator, the color change and the brightness change when the observation direction is changed can be reduced. In other words, the decrease in the color viewing angle and the brightness viewing angle can be suppressed.

[0047] Moreover, the display device 100 includes an optical adjustment layer 44 that adjusts the optical distance between the reflective layer 43 and the light emitting layer 220. This makes it possible to increase the light extraction efficiency and improve the color purity.

[0048] FIG. 5 is a diagram for explaining the path of light in the display device 100 of FIG. 4. As described above, the optical adjustment layer 44 is provided to adjust the optical distance between the reflective layer 43 and the light emitting layer 220. Furthermore, the light LL1 emitted by the light emitting layer 220 is constructively coupled with the light LL2 reflected by the reflective layer 43. In other words, the optical adjustment layer 44 is provided so that the light LL1 is constructively coupled with the light LL2 reflected by the reflective layer 43. The light LL1 is light emitted from the light emitting layer 220 toward the cover 47. The light LL2 is light that is emitted from the light emitting layer 220 toward the reflective layer 43, reflected by the reflective layer 43, and directed toward the cover 47. By aligning the phases of the light LL1 and the light LL2, the light extraction efficiency can be increased and the color purity can be improved. In other words, the light of the required color can be efficiently extracted and the light of the unnecessary color becomes relatively weak, thereby improving the color purity. For this reason, a wide color gamut can be realized.

[0049] As described above, in this embodiment, the display device 100 can display a color image, and the thickness of the optical adjustment layer 44 is adjusted for each emitted color. Specifically, the thickness of the first optical adjustment section 44R, the thickness of the second optical adjustment section 44G, and the thickness of the third optical adjustment section 44B are different from each other. In this embodiment, the thickness of the first optical adjustment section 44R, the thickness of the second optical adjustment section 44G, and the thickness of the third optical adjustment section 44B are thicker in this order. By making these thicknesses thicker in the above order, the light extraction efficiency can be effectively increased for each emitted color, and the color purity can be improved.

[0050] In addition, when the thickness of the first optical adjustment unit 44R, the thickness of the second optical adjustment unit 44G, and the thickness of the third optical adjustment unit 44B are different from each other, these thicknesses do not have to be thicker in this order. For example, when the refractive indexes of the first optical adjustment unit 44R, the second optical adjustment unit 44G, and the third optical adjustment unit 44B are different, the thicknesses of the first optical adjustment unit 44R, the second optical adjustment unit 44G, and the third optical adjustment unit 44B do not have to be thicker in this order. However, from the viewpoint of ease of manufacture, it is preferable that the first optical adjustment unit 44R, the second optical adjustment unit 44G, and the third optical adjustment unit 44B are formed of the same material. Therefore, when the material is the same, it is preferable that the thickness of the first optical adjustment unit 44R, the thickness of the second optical adjustment unit 44G, and the thickness of the third optical adjustment unit 44B are thicker in this order from the viewpoint of improving color purity.

[0051] The material of the first electrode 21 and the material of the second electrode 23 may be the same, but preferably are different. By using the most suitable material for each electrode, the necessary action of each electrode can be fully exerted. For example, in this embodiment, it is preferable that the first electrode 21 is ITO and the second electrode 23 is IZO. By using IZO for the second electrode 23, the optical characteristics of the second electrode 23 are suppressed from changing even if heat is applied during the deposition of the sealing film 45, compared to the case where ITO is used. In addition, ITO has a larger work function than IZO, and holes can be easily injected into the organic layer. For this reason, it is preferable to use ITO.

[0052] In addition, in the display device 100, the pixel size of the sub-pixel P0 is 5 μm2 This is particularly useful when the optical properties of the lens are less than 5 μm. Wearable devices such as smart glasses are 2 A minute pixel size of 5 μm or less is required. For example, unlike a television, the viewing angle of smart glasses changes significantly depending on the bone structure and eye movements of the person using the display device 100. Therefore, when the display device 100 is used in smart glasses, it is desirable that the viewing angle be wider than when it is used in a television. As described above, the display device 100 has excellent color viewing angles and luminance viewing angles. For this reason, the pixel size of the sub-pixel P0 is set to 5 μm 2 By using the display device 100 of this embodiment in the following cases, it is possible to improve the performance of a device including the display device 100.

[0053] According to the display device 100 described above, a wide color gamut, color viewing angle, and luminance viewing angle can be achieved.

[0054] 6 is a diagram showing a modified display device 100A. The display device 100A shown in FIG. 6 has a lens layer 48 and a light-transmitting layer 49 in addition to the elements of the display device 100 shown in FIG.

[0055] The color filter 46, the lens layer 48, the light-transmitting layer 49, and the cover 47 are arranged in this order. The lens layer 48 is light-transmitting and has a plurality of microlenses 480. The microlenses 480 are provided for each sub-pixel P0. The microlenses 480 are convex lenses that protrude from the color filter 46 in the Z1 direction and have a convex lens surface.

[0056] The light-transmitting layer 49 is transparent and contacts the convex lens surface. In this embodiment, the refractive index of the light-transmitting layer 49 is lower than that of the lens layer 48. In this case, the light passing through the light-transmitting layer 49 converges. Therefore, by providing the lens layer 48 and the light-transmitting layer 49, it is possible to improve the luminance efficiency compared to a case where these layers are not provided. In other words, it is possible to reduce the power consumption when outputting the same luminance.

[0057] The refractive index of the light-transmitting layer 49 may be higher than the refractive index of the lens layer 48. In this case, the light passing through the light-transmitting layer 49 diverges. In this case, the viewing angle characteristics can be improved.

[0058] According to the display device 100A described above, it is possible to achieve high luminance efficiency, as well as a wide color gamut, color viewing angle, and luminance viewing angle. EXAMPLES

[0059] Specific examples of the present embodiment will be described below based on the following examples. Note that the present disclosure is not limited to the following examples.

[0060] The following Tables 1, 2, and 3 are tables showing specific examples of the display device 100 of this embodiment and the modified example 100A, etc. Table 1 shows the layer configuration in the subpixel PR, Table 2 shows the layer configuration in the subpixel PG, and Table 3 shows the layer configuration in the subpixel PB. Note that Example 1, Example 2, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4 each have a substrate, a circuit substrate, a cover, and an organic layer. The substrate, circuit substrate, cover, and organic layer are all the same in each Example and Comparative Example, so descriptions thereof will be omitted.

[0061] [Table 1]

[0062] [Table 2]

[0063] [Table 3]

[0064] Example 1 is a specific example of the display device 100 shown in FIG. 4. As shown in Tables 1, 2, and 3, in each subpixel P0, the material of the reflective layer 43 is AlCu (aluminum-copper alloy), and the thickness of the reflective layer 43 is 150 nm. The material of the first electrode 21 is ITO, and the thickness of the first electrode 21 is 20 nm. The material of the second electrode 23 is IZO, and the thickness of the second electrode 23 is 70 nm. Also, as shown in Table 1, the first optical adjustment unit 44R has a SiO2 layer with a thickness of 30 nm, a SiN layer with a thickness of 60 nm, and a SiO2 layer with a thickness of 100 nm. The SiO2 layer with a thickness of 30 nm, the SiN layer with a thickness of 60 nm, and the SiO2 layer with a thickness of 100 nm are stacked in this order from the reflective layer 43. As shown in Table 2, the second optical adjustment unit 44G has a SiO2 layer with a thickness of 30 nm, a SiN layer with a thickness of 60 nm, and a SiO2 layer with a thickness of 20 nm. A 30 nm thick SiO2 layer, a 60 nm thick SiN layer, and a 20 nm thick SiO2 layer are stacked in this order starting from the reflective layer 43. As shown in Table 3, the third optical adjustment unit 44B has a 30 nm thick SiO2 layer and a 60 nm thick SiN layer. A 30 nm thick SiO2 layer and a 60 nm thick SiN layer are stacked in this order starting from the reflective layer 43.

[0065] In Example 1, the reflectance of light traveling from the organic layer 22 to the second interface 222 is 1% or more and 11% or less. Therefore, in Example 1, the reflectance of the second interface 222 is 11% or less.

[0066] Example 2 is a specific example of the display device 100A shown in Fig. 6. Example 2 has the same configuration as Example 1, except that it has a lens layer 48 and a light-transmitting layer 49.

[0067] FIG. 7 is a diagram showing a schematic configuration of a display device 100a of Comparative Example 1. Note that FIG. 7 shows one subpixel P0 as a representative. In the display device 100a shown in FIG. 7, the reflective layer 43 and the optical adjustment layer 44 of the display device 100 shown in FIG. 4 are omitted. As shown in FIG. 7, the display device 100a of Comparative Example 1 has a substrate 41, a circuit layer 42, a first electrode 21a, an organic layer 22, a second electrode 23, a sealing film 45, a color filter 46, and a cover 47. The circuit layer 42, the first electrode 21a, the organic layer 22, the second electrode 23, the sealing film 45, the color filter 46, and the cover 47 are laminated in this order from the substrate 41. In addition, the first electrode 21a has light reflectivity that reflects light from the light-emitting layer 220. In addition, in each subpixel P0, the material of the first electrode 21a is Al, and the thickness of the first electrode 21a is 150 nm. The material of the second electrode 23 is IZO, and the thickness of the second electrode 23 is 70 nm.

[0068] Fig. 8 is a diagram illustrating a schematic configuration of a display device 100b of Comparative Example 2. Note that Fig. 8 illustrates one sub-pixel P0 as a representative. The display device 100b of Comparative Example 2 has the same configuration as that of Comparative Example 1, except that it has a lens layer 48 and a light-transmitting layer 49.

[0069] FIG. 9 is a diagram showing a schematic configuration of a display device 100c of Comparative Example 3. Note that FIG. 9 shows one subpixel P0 as a representative. As shown in FIG. 9, the display device 100c has a substrate 41, a circuit layer 42, a reflective layer 43, an adjustment layer 44c, a first electrode 21, an organic layer 22, a second electrode 23c, and a cover 47. The circuit layer 42, the reflective layer 43, the adjustment layer 44c, the first electrode 21, the organic layer 22, the second electrode 23c, and the cover 47 are laminated in this order from the substrate 41. The second electrode 23c is a semi-transmissive semi-reflective film that reflects and transmits light from the light-emitting layer 220. An optical resonator is formed between the second electrode 23c and the reflective layer 43. The thickness of the adjustment layer 44c is set for each subpixel P0 so that light in a predetermined wavelength range resonates between the second electrode 23c and the reflective layer 43. In each subpixel P0, the material of the reflective layer 43 is AlCu, and the thickness of the reflective layer 43 is 150 nm. In each subpixel P0, the material of the first electrode 21 is ITO, and the thickness of the first electrode 21 is 20 nm. The material of the second electrode 23 is IZO, and the thickness of the second electrode 23 is 20 nm.

[0070] As shown in Table 1, the adjustment layer 44c provided in the subpixel PR has a SiO2 layer with a thickness of 30 nm, a SiN layer with a thickness of 45 nm, and a SiO2 layer with a thickness of 115 nm. The SiO2 layer with a thickness of 30 nm, the SiN layer with a thickness of 45 nm, and the SiO2 layer with a thickness of 115 nm are stacked in this order from the reflective layer 43. As shown in Table 2, the adjustment layer 44c provided in the subpixel PG has a SiO2 layer with a thickness of 30 nm, a SiN layer with a thickness of 45 nm, and a SiO2 layer with a thickness of 45 nm. The SiO2 layer with a thickness of 30 nm, the SiN layer with a thickness of 45 nm, and the SiO2 layer with a thickness of 45 nm are stacked in this order from the reflective layer 43. As shown in Table 3, the adjustment layer 44c provided in the subpixel PB has a SiO2 layer with a thickness of 30 nm, and a SiN layer with a thickness of 45 nm. The SiO2 layer with a thickness of 30 nm, and the SiN layer with a thickness of 45 nm are stacked in this order from the reflective layer 43.

[0071] In Comparative Example 3, the reflectance of light traveling from the organic layer 22 to the second interface 222 is 51% or more and 58% or less. Therefore, in Comparative Example 3, the reflectance of the second interface 222 exceeds 11%.

[0072] Comparative Example 4 is the same as Comparative Example 3, except that the material of the second electrode 23c is Al and the thickness of the second electrode 23c is 10 nm.

[0073] In Comparative Example 4, the reflectance of light traveling from the organic layer 22 to the second interface 222 is not less than 50% and not more than 55%. Therefore, in Comparative Example 4, the reflectance of the second interface 222 exceeds 11%.

[0074] The following evaluations were carried out for each of the Examples and Comparative Examples. The evaluation results are shown in Table 4 below.

[0075] [Table 4]

[0076] A. Luminous efficiency The luminance efficiency of Examples 1 and 2 and Comparative Examples 1 to 4 was evaluated. The luminance efficiency shown in Table 4 is a value obtained by dividing the luminance when the surface of the display device is observed from a direction of 0° by the amount of current, assuming that the direction perpendicular to the surface of the display device is 0°. Table 4 shows relative values ​​with Example 1 set to 100. The higher the luminance efficiency, the more the power consumption can be reduced when outputting the same luminance.

[0077] B. Color gamut The color gamuts of Examples 1 and 2 and Comparative Examples 1 to 4 were evaluated. The color gamut was evaluated in terms of the coverage rate of NTSC, which is one of the color gamut standards. In addition, when the direction perpendicular to the surface of the display device is set to 0°, the evaluation was performed when the surface of the display device was observed from a direction of 0° and when the surface of the display device was observed from a direction of 40°.

[0078] C. Color viewing angle The color viewing angle of Examples 1 and 2 and Comparative Examples 1 to 4 was evaluated. When the direction perpendicular to the surface of the display device was set as 0°, the color change Δu'v' of white light when the observation direction of the display device was changed from 0° to 40° was evaluated as the color viewing angle. The reference point of the color change is the luminescent color at which the surface of the display device can be observed from the direction of 0°. The closer the color viewing angle value shown in Table 4 is to 0, the better the color viewing angle is. In general, humans recognize that colors are different when the color viewing angle value exceeds 0.02. Therefore, it is preferable that the color viewing angle value is 0.02 or less.

[0079] D. Luminance viewing angle The luminance viewing angle was evaluated for Examples 1 and 2 and Comparative Examples 1 to 4. The luminance viewing angle was evaluated as a relative value of the change in luminance of white light when the observation direction of the display device was changed from 0° to 40°, with the direction perpendicular to the surface of the display device being 0°. Table 4 shown in Fig. 13 indicates the relative value when the observation direction is 40°, with the value being 1 when the observation direction is 0°.

[0080] As can be seen from Table 4, by adopting the structures of Examples 1 and 2, it is possible to realize a wide color gamut, color viewing angle, and luminance viewing angle with an NTSC ratio of 90% or more while exhibiting high luminance efficiency. In contrast, the structure of Comparative Example 1 has low luminance efficiency and a narrow color gamut. In other words, in the structure of Comparative Example 1, power consumption is high when displaying the same luminance as in the Examples, and the colors that can be expressed are limited, resulting in poor display quality. In addition, the structure of Comparative Example 2 has high luminance efficiency, but a narrow color gamut like Comparative Example 1. In addition, the structure of Comparative Example 3 has high luminance efficiency when the observation direction is 0°, but the color and luminance change significantly when the observation direction is changed. In particular, in applications such as smart glasses, if the luminance difference between the observation direction of 0° and the observation direction of 40° becomes large, the luminance unevenness in the screen becomes large.

[0081] 2.Electronic equipment The display device 100 of each of the above-described embodiments or modifications can be applied to various electronic devices.

[0082] 2-1. Head-mounted display Fig. 10 is a diagram showing a schematic view of a part of a virtual image display device 700, which is an example of an electronic device. The virtual image display device 700 shown in Fig. 10 is a head mounted display (HMD) that is worn on the head of a viewer to display an image. The virtual image display device 700 includes the above-mentioned display device 100, a collimator 71, a light guide 72, a first reflective volume hologram 73, a second reflective volume hologram 74, and a control unit 79. The light emitted from the display device 100 is emitted as image light LL.

[0083] The control unit 79 includes, for example, a processor and a memory, and controls the operation of the display device 100. The collimator 71 is disposed between the display device 100 and the light guide 72. The collimator 71 converts the light emitted from the display device 100 into parallel light. The collimator 71 is composed of a collimator lens and the like. The light converted into parallel light by the collimator 71 enters the light guide 72.

[0084] The light guide 72 is flat and extends in a direction intersecting the direction of the light incident through the collimator 71. The light guide 72 reflects and guides the light inside. A light inlet through which the light enters and a light outlet through which the light exits are provided on a surface 721 of the light guide 72 facing the collimator 71. A first reflection type volume hologram 73 as a diffractive optical element and a second reflection type volume hologram 74 as a diffractive optical element are provided on a surface 722 opposite to the surface 721 of the light guide 72. The first reflection type volume hologram 73 is provided closer to the light outlet side than the second reflection type volume hologram 74. The first reflection type volume hologram 73 and the second reflection type volume hologram 74 have interference fringes corresponding to a predetermined wavelength range and diffract and reflect light in the predetermined wavelength range.

[0085] In a virtual image display device 700 having such a configuration, the image light LL that enters the light guide 72 from the light inlet is repeatedly reflected and guided from the light outlet to the observer's pupil EY, allowing the observer to observe an image composed of a virtual image formed by the image light LL.

[0086] The virtual image display device 700 includes the display device 100 described above. The display device 100 described above is designed to reduce the risk of capacitance variation. Therefore, it is possible to achieve a wide color gamut, color viewing angle, and luminance viewing angle while exhibiting high luminance efficiency. Therefore, the display device 100 has good quality. Therefore, by including the display device 100, it is possible to provide a virtual image display device 700 with high display quality. The same applies when the display device 100A is used instead of the display device 100.

[0087] 2-2.Personal Computers FIG. 11 is a perspective view showing a personal computer 400, which is an example of the electronic device of the present invention. The personal computer 400 shown in FIG. 11 includes a display device 100, a main body 403 provided with a power switch 401 and a keyboard 402, and a control unit 409. The control unit 409 includes, for example, a processor and a memory, and controls the operation of the display device 100. The personal computer 400 can achieve a wide color gamut, color viewing angle, and luminance viewing angle while exhibiting high luminance efficiency. Therefore, the display device 100 has good quality. Therefore, by including the display device 100, a personal computer 400 with high display quality can be provided. The same applies when the display device 100A is used instead of the display device 100.

[0088] Examples of "electronic devices" equipped with the display device 100 include the virtual image display device 700 illustrated in FIG. 10 and the personal computer 400 illustrated in FIG. 11, as well as devices that are placed close to the eyes, such as digital scopes, digital binoculars, digital still cameras, and video cameras. "Electronic devices" equipped with the display device 100 are applied as mobile phones, smartphones, PDAs (Personal Digital Assistants), car navigation devices, and in-vehicle display units. "Electronic devices" equipped with the display device 100 are also applied as lighting that emits light, or sensors that use light.

[0089] Although the present disclosure has been described above based on the illustrated embodiments, the present disclosure is not limited thereto. In addition, the configuration of each part of the present disclosure can be replaced with any configuration that exhibits the same function as the above-mentioned embodiment, and any configuration can be added. In addition, the present disclosure may be configured to combine any configuration of each of the above-mentioned embodiments. [Explanation of symbols]

[0090] 11...scanning line, 12...signal line, 13...first constant potential wiring, 14...second constant potential wiring, 20...light-emitting element, 20B...light-emitting element, 20G...light-emitting element, 20R...light-emitting element, 21...first electrode, 21B...first electrode, 21G...first electrode, 21R...first electrode, 21a...first electrode, 22...organic layer, 22B...third light-emitting section, 22G...second light-emitting section, 22R...first light-emitting section, 23...second electrode, 23c...second electrode, 30...pixel circuit, 31...driving transistor 3. A substrate for a semiconductor device according to claim 1, wherein the first optical adjustment section includes a first optical adjustment section, a second optical adjustment section, and a third optical adjustment section. The substrate for a semiconductor device according to claim 1, wherein the first optical adjustment section includes a first optical adjustment section and a second optical adjustment section. The substrate for a semiconductor device according to claim 1, wherein the first optical adjustment section includes a first optical adjustment section and a second optical adjustment section. ...first reflection type volume hologram, 74...second reflection type volume hologram, 79...control unit, 100...display device, 100A...display device, 100a...display device, 100b...display device, 100c...display device, 201...control circuit, 202...scanning line driving circuit, 203...signal line driving circuit, 204...external terminal, 220...light emitting layer, 221...first interface, 222...second interface, 400...personal computer, 401...power switch, 402...key Board, 403...main body, 409...control unit, 430...top surface, 480...microlens, 700...virtual image display device, 721...surface, 722...surface, A10...display area, A20...peripheral area, AB...aperture area, AG...aperture area, AR...aperture area, EY...pupil, L1...first optical path length, L2...second optical path length, LL...image light, LL1...light, LL2...light, P...pixel, P0...subpixel, PB...subpixel, PG...subpixel, PR...subpixel, S0...area.

Claims

1. an organic layer having a light-emitting layer including an organic light-emitting material; a reflective layer that reflects light generated in the light emitting layer; A transparent first electrode; a transparent second electrode; an optical adjustment layer that adjusts an optical distance between the reflective layer and the second electrode; the reflective layer, the optical adjustment layer, the first electrode, the organic layer, and the second electrode are arranged in order, a reflectance of a first interface between the organic layer and the first electrode, and a reflectance of a second interface between the organic layer and the second electrode are each 11% or less; A display device comprising:

2. light emitted from the light emitting layer does not resonate between the reflective layer and the second electrode; The display device according to claim 1 .

3. The light emitted by the light emitting layer is constructively coupled with the light reflected by the reflective layer. The display device according to claim 1 .

4. The material of the first electrode and the material of the second electrode are different from each other. The display device according to claim 1 .

5. The pixel of the display device has a plurality of sub-pixels, the first electrode is provided for each of the sub-pixels, The pixel size of the sub-pixel is 5 μm ２ Below is the The display device according to claim 1 .

6. the light emitting layer has a first light emitting section that emits light in a first wavelength range, a second light emitting section that emits light in a second wavelength range that is shorter than the first wavelength range, and a third light emitting section that emits light in a third wavelength range that is shorter than the second wavelength range, the optical adjustment layer has a first optical adjustment portion through which light in the first wavelength range is transmitted, a second optical adjustment portion through which light in the second wavelength range is transmitted, and a third optical adjustment portion through which light in the third wavelength range is transmitted, The thickness of the first optical adjustment portion, the thickness of the second optical adjustment portion, and the thickness of the third optical adjustment portion are different from each other. The display device according to claim 1 .

7. a thickness of the first optical adjustment portion, a thickness of the second optical adjustment portion, and a thickness of the third optical adjustment portion are thicker in this order; The display device according to claim 6.

8. A display device according to claim 1 or 2; and a control unit for controlling an operation of the display device.

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