Display device

Abstract

A display device is disclosed which can display an image in a transmissive part and can improve the uniformity of the display in both the emissive part and the transmissive part, thereby improving the efficiency of the device and increasing the lifespan.

Description

Technical Field

[0001] The present invention relates to a display device, and more particularly, to a display device having improved efficiency and lifespan of the device. The display device can display images in an emission part and a transmission part, and can improve display uniformity in the emission part and the transmission part by changing the structure of a cover layer. Background Art

[0002] As we have recently entered the information age, the field of displays that visually display electrical information signals has developed rapidly, and to meet this development, various flat panel display devices with excellent performance (such as thinness, light weight and low power consumption) are being developed and rapidly replacing traditional cathode ray tubes (CRTs).

[0003] As examples of flat panel display devices, there are liquid crystal display (LCD) devices, plasma display panel (PDP) devices, field emission display (FED) devices, organic light emitting diode (OLED) display devices, quantum dot display devices, and the like.

[0004] Among the above examples, self-luminous display devices such as an organic light emitting diode display device and a quantum dot display device, which do not require a separate light source and achieve compactness and clear color display, are considered to be competitive applications.

[0005] The self-luminous display device includes a plurality of pixels located above a substrate, and each pixel includes a light emitting diode including an anode and a cathode disposed opposite to each other and a light emitting layer disposed between the anode and the cathode.

[0006] Since the self-luminous display device uses the light emitted by the light-emitting diode to display an image, it is important to effectively use the light extracted from the light-emitting diode. Therefore, efforts have been made to reduce the thickness of the cathode located in the light-emitting direction to improve the transmittance and to improve the reliability of the cathode and the elements disposed adjacent thereto to stabilize the performance of the display device.

[0007] In the top emission structure currently used, for example, the anode of the light emitting device includes a reflective metal, and the cathode of the light emitting device includes a semi-transmissive reflective metal. Therefore, light emitted from the light emitting layer located between the anode and the cathode is reflected by the reflective anode, resonates multiple times between the anode and the cathode, and emits light of a specific wavelength according to the distance between the anode and the cathode. In this structure, in order to further improve the transmittance, efforts are made to reduce the thickness of the cathode.

[0008] Furthermore, there is now an increasing demand for a transparent display device that can transmit light through its front and rear surfaces and display an image without obstructing a field of view.

[0009] The transparent display device changes the arrangement of light emitting diodes in the self-luminous area and the transmissive part, and thus can obtain both the transparent display effect and the luminous display effect.

[0010] However, since the self-luminous area and the transmission part respectively regard the increase of luminous efficiency and transmittance as important, the self-luminous area and the transmission part have different purposes and thus require different structures, and thus it is difficult to adopt a common structure to implement the self-luminous area and the transmission part.

[0011] That is, for the transparent display devices that have been proposed so far, it is difficult to have high transmittance and uniform color efficiency according to wavelength. Summary of the invention

[0012] Accordingly, the present invention is directed to a transparent display device that substantially obviates one or more problems due to limitations and disadvantages of the related art.

[0013] An object of the present invention is to provide a display device which can display images even in an emissive part and a transmissive part and can improve the uniformity of the display in both the emissive part and the transmissive part, thereby improving the efficiency of the device and increasing the lifespan.

[0014] Other advantages, purposes and features of the present invention will be partially described in the following description, and will become apparent to those skilled in the art when reading the following, or may be obtained through the practice of the present invention. The purposes and other advantages of the present invention may be realized and obtained through the structures specifically pointed out in the written description and claims and the accompanying drawings.

[0015] To achieve these objects and other advantages, and in accordance with the purpose of the present invention, as embodied and broadly described herein, a display device includes a first covering structure having destructive interference characteristics in a transmission portion and a second covering structure having constructive interference characteristics in an emission portion. Thus, the emission portion maintains a strong cavity characteristic and emits light generated from a light emitting element, and the transmission portion reduces the amount of light that is totally reflected inside the first covering structure and improves light transmittance by having a reflective characteristic at an interface of the first covering structure.

[0016] According to an embodiment of the present invention, a display device may include: a plurality of emitting parts and a plurality of transmitting parts located on a substrate; a light-emitting layer located in the emitting parts; a reflective electrode structure, which is located between the light-emitting layer and the substrate in each of the emitting parts; a transmitting electrode, which is located above the light-emitting layer on the entire emitting part and the transmitting part of the substrate; and a covering stack located on the transmitting electrode, the covering stack including a first covering structure above the transmitting part and a second covering structure above the emitting part, the second covering structure being different from the first covering structure.

[0017] According to different embodiments of the present invention, a display device may include: a plurality of red emission parts, a plurality of green emission parts, a plurality of blue emission parts and a plurality of transmission parts located on a substrate; a dam located between the red emission parts, the green emission parts, the blue emission parts and the transmission parts; a light-emitting element located in each of the red emission parts, the green emission parts and the blue emission parts, the light-emitting element having a reflective electrode structure, a light-emitting layer and a transmission electrode; a through electrode located in each of the transmission parts, the through electrode extending from the transmission electrode; and a covering stack located on the transmission electrode and the through electrode, the covering stack including a first covering structure located on at least a portion of the transmission parts and a second covering structure located on at least a portion of the red emission parts, the green emission parts and the blue emission parts, the second covering structure being different from the first covering structure.

[0018] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are included to provide a further understanding of the present invention, are included in and constitute a part of this application, illustrate embodiments of the present invention, and together with the description are used to explain the principle of the present invention. In the drawings:

[0020] Figure 1 is a plan view of a display device according to the present invention;

[0021] Figure 2A is a plan view of a display device according to a first embodiment of the present invention;

[0022] Figure 2B is along Figure 2A A cross-sectional view taken along line II' in FIG.

[0023] Figure 2C is a view showing the resonance principle of the cover stack;

[0024] Figure 3 It shows that when Figure 2B A graph of transmittance according to wavelength when the cover layer structures of the first to third experimental examples are applied in the transmission part of the display device in FIG.

[0025] Figure 4 It shows that when Figure 2B A graph of EL spectra (blue wavelength) when the cover layer structures of the first to third experimental examples are applied in the transmission portion of the display device in FIG.

[0026] FIG. 5A to FIG. 5C It shows that when Figure 2B Graphs of EL spectra of blue, green and red when the cover layer structures of the first, fourth and fifth experimental examples are applied in the emission portion of the display device in FIG.

[0027] Figure 5D is a graph showing transmittance characteristics of a blue filter, a green filter, and a red filter;

[0028] Figure 6 is a plan view of a display device according to a second embodiment of the present invention;

[0029] Figure 7 is a plan view of a display device according to a third embodiment of the present invention;

[0030] Fig. 8A and Figure 8B are a plan view and a cross-sectional view showing a display device according to a fourth embodiment of the present invention;

[0031] Figure 8C is a cross-sectional view showing the interface reflection of light in the cover stack of the display device according to the fourth embodiment of the present invention;

[0032] Fig. 9 is a plan view of a display device according to a fifth embodiment of the present invention;

[0033] Fig.10 is a plan view of a display device according to a sixth embodiment of the present invention;

[0034] Fig.11 is a plan view of a display device according to a seventh embodiment of the present invention;

[0035] Fig.12 is a plan view of a display device according to an eighth embodiment of the present invention;

[0036] Fig.13 is a plan view of a display device according to a ninth embodiment of the present invention;

[0037] Fig.14is a plan view of a display device according to a tenth embodiment of the present invention;

[0038] Fig.15 is a plan view of a display device according to an eleventh embodiment of the present invention;

[0039] Fig.16 is a graph showing the transmittance of wavelengths of an application region of a second cover layer in a transmission portion of a display device according to fourth to eleventh embodiments;

[0040] Fig.17 is a graph showing wavelength transmittance of an application area of ​​a second cover layer in a transmission portion of a display device according to fourth to eleventh embodiments when an upper structure of a cover laminate is applied as an encapsulation laminate;

[0041] 18A to 18D are cross-sectional views showing sixth to ninth experimental examples in which the upper configuration of the cover laminate is different in the transmission portion;

[0042] Fig.19A and Fig.19B is a graph showing transmittance of wavelengths in an emission part and a transmission part according to sixth and seventh experimental examples;

[0043] Fig. 20 is a graph showing transmittance of wavelengths according to a ninth experimental example when a second cover layer is applied or not applied in a transmission portion;

[0044] Fig.21 is a cross-sectional view showing a display device according to an embodiment of the present invention;

[0045] Fig. 22 is a cross-sectional view showing a display device according to a twelfth embodiment of the present invention. DETAILED DESCRIPTION

[0046] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are shown in the accompanying drawings. However, the present invention may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein, and embodiments of the present invention are provided only to fully disclose the present invention and fully inform those skilled in the art of the scope of the invention. In addition, the names of the elements used in the following description of the embodiments of the present invention are selected with consideration given to the convenience of writing the specification, and therefore may be different from the names of the components of the actual product.

[0047] The shapes, sizes, ratios, angles, quantities, etc. disclosed in the accompanying drawings for describing the embodiments of the present invention are only exemplary and do not limit the present invention. In the following description of the embodiments and the accompanying drawings, the same or similar elements are represented by the same reference numerals, even if they are illustrated in different drawings. In the following description of the embodiments of the present invention, when the subject matter of the present invention may be unclear, the detailed description of the known functions and structures contained in this article will be omitted. In the following description of the embodiments, the terms "including", "having", "consisting of...", etc. will be interpreted as indicating the existence of one or more other features, quantities, steps, operations, elements or parts or their combinations described in the specification, and do not exclude the existence of features, quantities, steps, operations, elements, parts or their combinations, or the possibility of adding the above features, quantities, steps, operations, elements, parts or their combinations, unless the term "only" is used. It should be understood that, unless otherwise specified, the singular expression of an element also includes the plural expression of the element.

[0048] When explaining elements included in various embodiments of the present invention, it will be interpreted that the elements include a range of errors even if there is no explicit description.

[0049] In the following description of embodiments, it will be understood that when expressing a positional relationship, for example, when an element is located "on", "above", "below", "beside", etc., another element, the two elements may be in direct contact with each other, or one or more other elements may be inserted between the two elements, unless the terms "only" or "directly" are used.

[0050] In the following description of the embodiments, it will be understood that, for example, when expressing a temporal relationship, terms expressing the order of events, such as "after," "successfully after," "after," or "before," may include a continuous relationship between these events or a discontinuous relationship between these events, unless the terms "only" or "directly" are used.

[0051] In the following description of the embodiments, it will be understood that when the terms "first", "second", etc. are used to describe various elements, these terms are only used to distinguish the same or similar elements. Therefore, unless otherwise specified, within the technical scope of the present invention, the element modified by the term "first" may be the same as the element modified by the term "second".

[0052] The features of the various embodiments of the present invention may be partially or completely connected or combined with each other and may be driven in a variety of technical ways and interlocked with each other, and the various embodiments may be implemented independently or together in combination with each other.

[0053] Figure 1is a plan view of a display device according to the present invention. Figure 2A is a plan view of a display device according to a first embodiment of the present invention. Figure 2B is along Figure 2A A cross-sectional view taken along line II' in FIG. Figure 2C is a view showing the resonance principle of the cover stack. Figure 3 It shows that when Figure 2B Graphs of transmittance according to wavelength when the cover layer structures of the first to third experimental examples are applied in the transmission part of the display device in FIG. Figure 4 It shows that when Figure 2B Graphs of EL spectra (blue wavelength) when the cover layer structures of the first to third experimental examples are applied in the transmissive portion of the display device in FIG.

[0054] like Figure 1 As shown, in the display device of the present invention, a plurality of pixels (each pixel including an emission portion E and a transmission portion T) are two-dimensionally repeated in horizontal and vertical lines in the active area AA of the substrate 100. That is, in the active area AA, a plurality of pixels are arranged in rows and columns, and thus a plurality of emission portions E and a plurality of transmission portions T are arranged in the substrate 100.

[0055] Each pixel can have an emissive part E and a transmissive part T, or Figure 1 As shown, each pixel may have first to third color emission parts E1, E2, and E3 emitting different color lights, and one transmission part T. The combined first, second, and third color emission parts E1, E2, and E3 in each pixel may emit white light.

[0056] The emitting parts E (E1, E2 and E3) and the transmissive part T can be as follows Figure 1 and Figure 2A The emitting parts E (E1, E2 and E3) and the transmissive parts T may have a rectangular shape, for example, as shown in FIG. Figure 1 and Figure 2B . But it is not limited thereto. The emission part E (E1, E2 and E3) and the transmission part T may have a polygonal or elliptical shape different from a rectangular shape. Or at least one of the emission part E (E1, E2 and E3) and the transmission part T may have at least one corner having a rounded shape. In some cases, the edges of the emission part E (E1, E2 and E3) and the transmission part T may be spaced at regular intervals.

[0057] In addition, the emission parts E (E1, E2 and E3) and the transmission part T may have different shapes. The sizes of the emission parts E1, E2 and E3 that emit light of different colors may be different. If the display device has a specific color directivity, the size of the specific color emission part (of a specific color) may be larger than the size of other emission parts.

[0058] In addition, the transmissive portion T may be larger than each of the first to third color emitting portions E1, E2, and E3 to improve the transmittance of the display device.

[0059] The bank 150 may be disposed between the emission portion E ( E1 , E2 , E3 ) and the transmission portion T to define the area thereof. The bank 150 may overlap at least one edge of the reflective electrode structure 111 .

[0060] In addition, each emitting portion E (E1, E2, E3) has a light emitting element including opposing electrodes and a light emitting layer interposed therebetween (refer to Figure 2B In contrast, the transmissive portion T may not have the light emitting element OLED. The transmissive portion T may have at least one layer of the light emitting element OLED other than the light emitting layer.

[0061] The display device has a feature in the structure of the cover stack 170. The cover stack 170 is used to protect the light emitting element and improve the light emitting effect toward the upper part. In particular, the cover stack 170 is characterized in that it includes a first cover structure C1 on at least a part of the transmission part. The first cover structure C1 has a first optical path. In addition, the first cover structure C1 has a transmittance with a destructive interference characteristic.

[0062] The display device also has a second covering structure C2 on at least a portion of the emitting portion E. The second covering structure C2 has different optical properties from the first covering structure C1. That is, the second covering structure C2 has a different optical path from the first covering structure C1. The second covering structure C2 has constructive interference characteristics. In the display device, the first covering structure C1 and the second covering structure C2 have different vertical structures. In the display device of the present invention, the first covering structure C1 and the second covering structure C2 are applied together in the covering stack 170, and the transmittance of the transmission portion T and the light efficiency of the emitting portion E are increased.

[0063] Various configurations of the cover laminate 170 according to embodiments will be described later.

[0064] The substrate 100 is formed of a transparent material (e.g., a glass substrate or a transparent plastic film) sufficient to transmit light through its rear surface. Although, if the transparent display device is permanently or requires flexibility during use, the substrate 100 is formed of a transparent plastic film, a glass substrate with a small thickness may be used as the substrate 100.

[0065] The arrangement of the first to third emission parts E1, E2, E3 provided in the emission part E may include, for example, the order of a blue emission part, a green emission part, and a red emission part, but is not limited thereto, and the order of the colors may be changed. The emission part E may also include a white emission part. Alternatively, the arrangement of the blue emission part, the green emission part, and the red emission part may be replaced by another arrangement including, for example, a cyan emission part, a magenta emission part, and a yellow emission part, or another arrangement including a combination of other color emission parts is possible. Depending on the composition of the light-emitting layer, the light-emitting diode in the emission part E may be an organic light-emitting diode or an inorganic light-emitting diode.

[0066] Although the case of using an organic light emitting diode will be mainly described below, the emission part E may include, for example, a quantum dot light emitting diode (QLED) by replacing the organic light emitting layer with a layer including a quantum dot light emitting layer.

[0067] Hereinafter, a display device of the present invention will be described in detail according to embodiments.

[0068] First embodiment

[0069] like Figures 1 to 2C As shown, the display device according to the first embodiment of the present invention includes: a plurality of emission parts E (E1, E2, E3) and a plurality of transmission parts T located on a substrate 100; light-emitting layers 132a, 132b, 132c arranged in each of the emission parts E1, E2, E3; a light-emitting element OLED having a structure of a transmission electrode 140 and a reflective electrode structure 111, the light-emitting layers 132a, 132b, 132c being inserted between the structure of the transmission electrode 140 and the reflective electrode structure 111; a through electrode 140a located in each of the transmission parts T, the through electrode 140a extending from the structure of the transmission electrode 140; and a covering stack 170 located on the structure of the transmission electrode 140 and the through electrode 140a.

[0070] The structure of the transmission electrode 140 and the through electrode 140a can be integrally provided without any disconnection or any separation in the active area AA. The transmission electrode 140 and the through electrode 140a can be transparent electrodes or semi-transmissive reflective metals. In each of the emission parts E1, E2, and E3, light is generated in the light emitting element OLED, and the light from the light emitting element OLED can be directly emitted to the outside through the structure of the transmission electrode 140. In addition, after repeated resonance between the reflective electrode structures 111, the light from the light emitting element OLED can be transmitted to the outside within a specific wavelength range with a strong cavity.

[0071] If the structure of the transmission electrode 140 is a transparent electrode, the structure of the transmission electrode 140 may include a transparent oxide electrode, such as at least one of ITO (indium tin oxide), IZO (indium zinc oxide), or ITZO (indium tin zinc oxide). If the structure of the transmission electrode 140 includes a semi-transmissive reflective electrode, the structure of the transmission electrode 140 may be formed of a silver (Ag) alloy (e.g., AgMg), or other semi-transmissive reflective metal alloys to have both reflective and transmissive properties. If the structure of the transmission electrode 140 includes a semi-transmissive reflective electrode, since the structure of the transmission electrode 140 and the through electrode 140a are integrally formed, the structure of the transmission electrode 140 may have a thickness of about 100 mm for the transparency of the transmission portion. to In some cases, for transparency in the transmission portion T, the structure of the transmission electrode 140 is thinner in the transmission portion T than in the emission portion E.

[0072] The structure of the transmissive electrode 140 may further include a transition metal layer for preventing the internal alloy components from coagulating and stability to external environments such as ultraviolet rays or heat. The transition metal layer may be disposed below or above the structure of the transmissive electrode 140 (transparent electrode or semi-transmissive reflective electrode). The transition metal layer is provided with a thickness thinner than the structure of the transmissive electrode 140 (transparent electrode or semi-transmissive reflective electrode) so as not to affect the performance of the light emitting element OLED.

[0073] The light generated by the light emitting element OLED is transmitted to the outside through the structure of the transmission electrode 140. In order to improve the light emitting effect, a cover stack 170 is provided on the structure of the transmission electrode 140. The cover stack 170 includes a first cover layer 171 having a first cover structure C1 with a destructive interference property as a single layer on at least a portion of the transmission portion T, and a second cover structure C2 of the first cover layer 171 and the second cover layer 172 as a double layer having a constructive interference property on at least a portion of the emission portion E. The first cover structure C1 and the second cover structure C2 have different optical paths, and the different optical paths have different interference properties.

[0074] The first covering layer 171 has an optical path having destructive interference characteristics according to the conditional equation "2n1d1cosθ=m1λ" (n1 is the refractive index of the first covering layer, d1 is the thickness of the first covering layer, m1 is an integer, λ is the destructive interference wavelength, and θ is the angle of incidence). The first covering layer 171 exhibits destructive interference in the wavelength range of about 400-600nm, which mainly includes blue wavelengths. That is, the first covering structure C1 having the first covering layer 171 alone has destructive interference for light mainly including blue wavelengths. In the transmission portion T, light that travels back and forth in the first covering layer 171 and passes through the through-electrode 140a from the light-emitting element OLED destructs at the bottom surface of the first covering layer 171, so the amount of light transmitted through the through-electrode 140a as the transparent light enters the rear surface of the substrate 100 can be increased. This is because each of the reflected waves of the two interfaces of the first covering layer 171 constituting the first covering structure C1 has an opposite phase, thereby destructively interfering. In this case, most of the light transmitted from the rear surface of the substrate 100 to the upper portion is incoherent with the phase of the reflected wave of the first cover layer 171, so most of the light transmitted from the rear surface of the substrate 100 is emitted at the upper portion of the first cover structure C1 in the transmission portion T without forming a reflection at the interface of the first cover layer 171. In some embodiments, destructive interference occurs when the maximum values ​​of the two waves differ by 180°. For example, the positive displacement of one wave is exactly offset by the negative displacement of the other wave, so the amplitude of the composite wave is zero.

[0075] And the second covering structure C2 has an optical path having constructive interference characteristics according to the conditional equation "2ndcosθ=(m2+1 / 2)λ" (n is the refractive index of the first covering layer and the second covering layer, d is the total thickness of the first covering layer and the second covering layer, m2 is an integer, λ is the wavelength, and θ is the incident angle). The second covering structure C2 is formed by stacking the first covering layer 171 and the second covering layer 172. In some embodiments, constructive interference occurs when the maximum / minimum values ​​of two waves are added (the two waves are in phase). Therefore, the amplitude of the composite wave is equal to the sum of the individual amplitudes.

[0076] Meanwhile, in the display device of the present invention, the wavelength λ required to define the optical distance "nd" of the first covering structure C1 and the second covering structure C2 may be determined according to the most sensitive blue wavelength in the display device.

[0077] The first cover layer 171 and the second cover layer 172 may be made of the same material, so the first cover layer 171 and the second cover layer 172 may have the same refractive index. However, not limited thereto, the first cover layer 171 and the second cover layer 172 are made of different materials, so there is a difference between the refractive indices. Even if the first cover layer 171 and the second cover layer 172 have different refractive indices, the difference in refractive index between the first cover layer 171 and the second cover layer 172 is small, and in the second cover structure C2, there is almost no interface reflection between the first cover layer 171 and the second cover layer 172. Reflection of the bottom surface of the first cover layer 171 from which light enters and reflection of the upper surface of the second cover layer 172 affect the emission of light passing through the structure of the transmissive electrode 140. There is a light emitting element OLED in the emission portion E. Therefore, light resonates between the reflective electrode structure 111 of the light emitting element OLED and the structure of the transmissive electrode 140, and then passes through the structure of the transmissive electrode 140 for emission. The reflection at the upper and lower interfaces of the second cover structure C2 (reflection at the lower surface of the first cover layer 171 and the upper surface of the second cover layer 172) has constructive interference on the light from the light emitting element OLED. Therefore, for example, each of the blue light, red light and green light is emitted from each light emitting layer 132a, 132b, 132c in each light emitting element OLED, respectively, to have a strong cavity of a specific wavelength.

[0078] In this way, the first cover structure C1 is formed of a single layer of the first cover layer 171 having a destructive interference property, and the second cover structure C2 is formed of the first cover layer 171 and the second cover layer 172 stacked for a different optical path from the first cover structure C1. For different optical paths (n1d1 and n2d2) in the first cover layer 171 and the second cover layer 172, the second cover layer 172 may have a material different from that of the first cover layer 171 or may have a thickness different from that of the first cover layer 171. By further having the second cover layer 172 on the first cover layer 171, the second cover structure C2 has a constructive interference property.

[0079] The first covering layer 171 is continuous over the emission portion E and the transmission portion T. In addition, the first covering layer 171 may be provided where the bank 150 exists between the emission portion E and the transmission portion T. In this case, the first covering layer 171 may be formed by using a common mask that opens the entire active area AA. The common mask for forming the first covering layer 171 may be the same as any one of the common masks for forming the structure of the common layers 131, 133, and 134 or the transmission electrode 140 included in the light emitting element OLED. In consideration of a process margin, the first covering layer 171 may have an area larger than the entire active area AA.

[0080] In contrast, the second cover layer 172 is selectively formed at a specific region on the first cover layer 171. At least a portion of the transmission portion T has the first cover layer 171 of the first cover structure C1 alone without the second cover layer 172. Therefore, according to the destructive interference characteristic, the internal light from the light emitting element OLED is reflected at both surfaces of the first cover layer 171 and then destructively reflected, and the external light entering through the substrate 100 is transmitted through the first cover structure C1 with high transmittance.

[0081] In this case, the deposition mask forming the second capping layer 172 has a shielding portion for the first capping structure C1 and an opening portion for the second capping structure C2.

[0082] The first covering structure C1 and the second covering structure C2 have different interference characteristics and are located in different regions. The positions of the first covering structure C1 and the second covering structure C2 are determined by providing the second covering layer 172. Since the second covering layer 172 is further provided, the second covering structure C2 has a height higher than the first covering structure C1.

[0083] like Figure 1 As shown, the emission parts E (E1, E2 and E3) and the transmission parts T can be parallel to each other in different rows, and each emission part in the emission parts E includes the first to third color emission parts E1, E2 and E3 in the same row. For example, the first to third color emission parts E1, E2 and E3 can be a blue emission part, a red emission part and a green emission part, respectively, but are not limited thereto. In some cases, the emission parts E and the transmission parts T can be arranged in a column direction and be parallel to each other in different columns.

[0084] The second cover structure C2 in the cover stack 170 may be along Figure 1 The length direction of the transmissive portion T shown in FIG extends longitudinally, and may even be formed in a region where the bank 150 is disposed between adjacent transmissive portions T. Alternatively, the width of the second covering structure C2 may be widened to overlap at least a portion of the emitting portion E (E1, E2, E3).

[0085] In any case, the cover stack 170 includes a first cover structure C1 in at least a portion of the transmission portion T and a second cover structure C2 in at least a portion of the emission portion E (E1, E2, and E3). Therefore, the cover stack 170 can improve the transmittance through the first cover structure C1 in the transmission portion T, and improve the efficiency of the device through the second cover structure C2 in the emission portion E (E1, E2, and E3).

[0086] In addition, in the display device according to the present invention, the first cover layer 171 having a destructive interference characteristic contacts the upper part of the structure of the transmissive electrode 140 and has a first refractive index n1 of 1.8 or more. Since the first cover layer 171 has a high refractive index, when an encapsulation stack or an air gap is provided on the cover stack 170, the first refractive index of the first cover layer 171 is higher than the refractive index of the lowest inorganic encapsulation layer by 0.2 or more and there will be interface reflection at the upper and lower surfaces of the first cover layer 171. Therefore, among the light having a resonance effect inside the first cover layer 171 and the light passing through the electrode 140a, the internal light caused by the light emitting element OLED destructs and the transmittance of the external light in the first cover structure C1 can be increased. The difference in refractive index between the first cover layer 171 and the lowest inorganic encapsulation layer of the encapsulation stack or the air gap is preferably 0.2 or more. More preferably, the interface reflection can be increased by making the difference in refractive index between the first cover layer 171 and the lowest inorganic encapsulation layer of the encapsulation stack 0.3 or more.

[0087] Here, the first refractive index n1 of the first cover layer 171 may be 1.8 to 2.7, and the second refractive index n2 of the second cover layer 172 may be the same as the first refractive index or may have a difference of less than 0.2. As long as the first cover layer 171 and the second cover layer 172 have the above-mentioned refractive index and interference characteristics, the first cover layer 171 and the second cover layer 172 may be any one of an organic material, an inorganic material, and an organic / inorganic hybrid material.

[0088] In the configuration of the light emitting element OLED, the reflective electrode structure 111 and the light emitting layers 132a, 132b, 132c are provided only in the emission parts E1, E2, and E3, and the structure of the transmissive electrode 140 and the common layers 131, 133, and 134 are common in the emission parts E1, E2, and E3 and the transmissive part T. The structure of the light emitting element OLED except for the electrodes (the structure of the reflective electrode structure 111 and the transmissive electrode 140) is referred to as an organic stack EL, and the common layers 131, 133, and 134 except for the light emitting layers 132a, 132b, and 132c are formed together on the transmissive part T.

[0089] In the case where the light emitting element OLED is disposed in the emission part E (E1, E2 and E3), the light emitting element OLED includes a light emitting layer 132a, 132b or 132c and a reflective electrode structure 111 between a first surface of the light emitting layer 132a, 132b or 132c (a lower surface of the light emitting layer 132a, 132b or 132c) and the substrate 100. In addition, a structure of a transmissive electrode 140 is disposed on a second surface of the light emitting layer 132a, 132b or 132c (an upper surface of the light emitting layer 132a, 132b or 132c) in common over a plurality of pixels in the active area AA. A plurality of reflective electrode structures 111 are respectively disposed in the color emission parts E1, E2 and E3 and are spaced apart from each other.

[0090] The first common layer 131 may have a hole injection property and / or a hole transport property, and the second common layer 133 and the third common layer 134 may have an electron transport property and an electron injection property, respectively. The first common layer 131 is disposed between the reflective electrode structure 111 and the light emitting layer 132a, 132b or 132c, and the second common layer 133 and the third common layer 134 are stacked and disposed between the light emitting layer 132a, 132b or 132c and the structure of the transmissive electrode 140.

[0091] In some cases, the third common layer 134 may be omitted, and thus the second common layer 133 may be disposed solely between the light emitting layer 132a, 132b, or 132c and the structure of the transmissive electrode 140. Each of the first common layer 131, the second common layer 133, and the third common layer 134 may be disposed as a single layer or multiple layers.

[0092] In some cases, a transparent electrode may be further disposed above and / or below the reflective electrode.

[0093] The display device of the present invention selectively includes a reflective electrode structure 111 only in the emission portion E (E1, E2, E3), and the reflective electrode structure 111 reflects light generated by the light-emitting layers 132a, 132b, 132c and returns it from the upper surface of the reflective electrode structure 111 at the upper part.

[0094] The reflective electrode structure 111 is divided into a plurality of color emission parts E1, E2 and E3 for each color, and thus a sub-pixel can be defined for each color emission part E1, E2 and E3. At least one thin film transistor TFT1, TFT2, TFT3 is provided at each sub-pixel. The thin film transistors TFT1, TFT2, TFT3 are connected to the reflective electrode structure 111 of each sub-pixel.

[0095] In the active area AA, the structures of the first common layer 131, the second common layer 133, and the third common layer 134 and the transmissive electrode 140 are continuous without any disconnection over the emission part E (E1, E2, and E3) and the transmissive part T. The first common layer 131 may be a hole transport layer HTL, the second common layer 133 may be an electron transport layer ETL, and the third common layer 134 may be an electron injection layer EIL or an interface compensation layer.

[0096] The structure including the structure from the reflective electrode structure 111 to the transmissive electrode 140 on the emission part E (E1, E2, E3) is called a light-emitting element OLED. In particular, the light-emitting layer 132a, 132b or 132c included therein is an organic light-emitting layer, and the structure from the reflective electrode structure 111 to the transmissive electrode 140 on the emission part E (E1, E2, E3) can be called an organic light-emitting device. The experiments and characteristic comparisons described below are based on the application of organic light-emitting devices to light-emitting elements. However, the light-emitting element of the display device of the present invention is not limited to the example of applying the light-emitting element as the organic light-emitting device, and the light-emitting element can be a quantum dot light-emitting device using a quantum dot light-emitting layer.

[0097] The emission part E (E1, E2, E3) has thin film transistors TFT1, TFT2, TFT3 electrically connected to the reflective electrode structure 111 and each light emitting element OLED connected to the thin film transistors TFT1, TFT2, TFT3, and the light emitting element OLED located on the thin film transistor is selectively driven by turning on and off the thin film transistors TFT1, TFT2, TFT3.

[0098] In the transmission part T in which the rear surface of the substrate 100 can be seen, in order to ensure the transparency of the transmission part T, the thin film transistors TFT1, TFT2 and TFT3, the reflective electrode structure 111 and the organic light emitting layers 132a, 132b and 132c disposed in the emission part E are not disposed in the transmission part T. Here, the first common layer 131, the second common layer 133 and the third common layer 134 are commonly disposed in the emission part E and the transmission part T, may be layers having transparency and form an organic stack EL. External light from the rear surface of the substrate 100 is transmitted through the organic stack EL without being shielded due to their transparency.

[0099] In the display device according to the first embodiment of the present invention, the structure of the transmissive electrode 140 is shared by the emission part E and the transmission part T. This means that in the entire active area including a plurality of pixels displaying an image, a single structure of the transmissive electrode 140 to which a common voltage or a ground voltage is applied is formed. If the structure of the transmissive electrode 140 is selectively removed in the transmission part T, the resistance around the area in the transmission part T where the structure of the transmissive electrode 140 is removed increases, and thus a voltage drop may occur in the structure of the transmissive electrode 140. Therefore, the structure of the transmissive electrode 140 may be formed in the emission part E and the transmission part T in common. In addition, the structure of the transmissive electrode 140 may be formed by a deposition process using a common mask for forming any one of the common layers 131, 133, 134 in the organic stack EL, and thus organic damage caused when a sputtering process is applied may be prevented. In addition, in the display device of the present invention having the structure of the transmissive electrode 140, the device may be integrated, so that productivity may be improved and the process will be simplified. In addition, since the metal mask may be deformed due to high temperature, during the metal deposition process, it is difficult to apply the metal mask including the shielding part for the active area AA due to high temperature. Furthermore, if a transmissive electrode is formed using a metal mask having a plurality of shielding portions for an active region, sheet resistance in the patterned transmissive electrode tends to increase as the thickness of the transmissive electrode becomes thinner, and reliability of the transmissive electrode tends to decrease due to a high temperature of a deposition process.

[0100] In the display device of the present invention, the structure of the transmissive electrode 140 can utilize one process without any division in the active area AA, and thus can be formed to fully maintain the reflective characteristics and the transmissive characteristics. That is, the deposition mask forming the structure of the transmissive electrode 140 has one opening area for the active area AA, and it can prevent the reliability from being reduced due to equipment fluctuations or mask fluctuations. The structure of the transmissive electrode 140 can be formed with a thin thickness in one process, and also has high transmittance, low resistivity, and high reliability. The display device of the present invention is characterized in that the configuration of the cover stack 170 is changed as described above so as to adjust the luminous efficiency of the emission side.

[0101] The structure of the transmissive electrode 140 is formed of a silver (Ag) alloy such as AgMg to exhibit light transmission characteristics of the transmission part T and resonance characteristics of the emission part E, and thus may have both reflective characteristics and transmissive characteristics. In addition, the structure of the transmissive electrode 140 may be a transparent electrode formed of IZO or ITO. If the structure of the transmissive electrode 140 is formed of a metal having both reflective characteristics and transmissive characteristics, the thickness of the structure of the transmissive electrode may be 1000 Å. or less, more preferably or less, so that due to the characteristics of the structure of the transmission electrode 140 commonly provided in the transmission part T and the emission part E, the transmission part T has a transmittance of a specified value or more.

[0102] Reference Figure 3 and Figure 4 , the transmittance and EL spectrum characteristics in the transmission part of the display device of the present invention will be described.

[0103] The inventors of the present invention conducted experiments by applying a first covering layer structure that distinguishes optical paths in the transmission portion T for the first to third experimental examples (A, B, C). For the first covering layer structure, the first to third experimental examples A, B, and C use different materials or use different thicknesses. For the first covering layer structure as a single layer, an optical path with destructive interference characteristics is applied in the first experimental example A, an optical path with constructive interference characteristics is applied in the third experimental example C, and an optical path with intermediate characteristics between destructive interference and constructive interference is applied in the second experimental example B.

[0104] Meanwhile, the transmittance described in the present specification refers to a value obtained by multiplying an opening ratio of the transmission portion T according to an area ratio of the transmission portion T provided in the substrate 100 and a transmittance according to components of the transmission portion T.

[0105] Figure 3 In the first experimental example A showing the destructive interference characteristics, the transmittance is about 87% or more in the visible light wavelength of 430nm to 655nm. In particular, in the first experimental example A, the transmittance is 90% or more in the wavelength of 430nm to 600nm.

[0106] In contrast, in the third experimental example C of the constructive interference characteristic, it was shown that the transmittance in all visible light wavelengths from 430 nm to 655 nm was less than 90%.

[0107] Furthermore, in the second experimental example B of intermediate characteristics between destructive interference and constructive interference, it was shown that the transmittance in the visible light wavelength of 430 nm to 655 nm was in the range of 75% to 93%.

[0108] Reference Figure 3 It can be seen that, as in the third experimental example C and the second experimental example B, in the case of fully or partially having constructive interference characteristics, the transmittance decreases significantly in the blue wavelength.

[0109] In contrast, as in the first experimental example A, in the case of having destructive interference, it can be seen that a transmittance of 90% or more is obtained in the wavelength range of at least 430 nm to 620 nm. This means that when the optical path of the first cover layer 171 (of the cover stack 170) is adjusted to have destructive interference characteristics in the transmission portion T, it can be expected that the transmittance can be improved in the visible light wavelength range.

[0110] Similarly, refer to Figure 4 , from the third experimental example C to the first experimental example A, it can be seen that for the blue wavelength, the full width at half maximum FWHM of the spectrum increases, and a shoulder is observed on the right side of the relatively longer wavelength in the graph. This means that from the third experimental example C to the first experimental example A, it loses the microcavity characteristics and has light transmission characteristics in a wider wavelength range. That is, as in the first experimental example A, when the first covering structure C1 is applied as the first covering layer 171 having a destructive interference characteristic, the amount of blocking of external light passing through the rear surface of the substrate 100 is reduced, and thus the transmittance of external light can be improved.

[0111] Figure 4 The EL spectrum of the blue wavelength having the highest sensitivity among the wavelengths in the visible light range is shown. Figure 3 As shown, in the first experimental example A of the first cover layer having destructive interference characteristics in the transmission portion T, a transmittance of 90% or more can be obtained for green wavelengths (510nm to 590nm) and red wavelengths (605nm to 635nm).

[0112] That is, refer to Figure 3 and Figure 4 In the case where a single-structured first covering structure C1 having a first covering layer 171 having destructive interference characteristics relative to the transmission portion T is applied to the display device of the present invention, it can be seen that when external light transmitted from the rear surface of the substrate 100 passes through the first covering structure C1, the effects of increased transmittance and improved transparency of the external light can be obtained.

[0113] In the first embodiment of the present invention, specifically for the first color emission portion E1, the second color emission portion E2, and the third color emission portion E3, a first covering structure C1 including a first covering layer with destructive interference characteristics is applied relative to the entire area of ​​the transmission portion T, and a second covering structure C2 is applied relative to other areas of the transmission portion T. Even when the second covering structure C2 is applied in an island shape along the respective shapes of the first color emission portion E1, the second color emission portion E2, and the third color emission portion E3, the same optical effect as in the first embodiment of the present invention can be obtained.

[0114] The wavelength of red emission may correspond to 600 nm to 650 nm described in the present specification, the wavelength of blue emission may correspond to 430 nm to 460 nm, and the wavelength of green emission may correspond to 510 nm to 590 nm.

[0115] In the display device according to the present invention, a covering stack 170 is provided to protect the light emitting element OLED, assist in the extraction of light in the emission portion E and improve the transmittance of the transmission portion T. To this end, a covering stack 170 having a constructive interference characteristic is formed by stacking a first covering layer 171 and a second covering layer 172. When light from the light emitting element OLED passes through the second covering structure C2 in the emission portion E, the light from the light emitting element OLED is transmitted while maintaining a strong cavity characteristic. And in the transmission portion T, the first covering structure C1 having a destructive interference characteristic causes the light inside the display device to destruct and destroy the internal resonance in the first covering structure C1, thereby minimizing the loss of external light from the lower portion of the substrate 100, and the external light is transmitted as is.

[0116] Despite Figure 2B As shown, the bank is omitted due to the focus on the internal structure, but the bank can be provided between the transmission part T and the color emission parts E1, E2 and E3, and can be provided between the transmission part T and the color emission parts E1, E2 and E3, as shown in FIG. Figure 2A shown.

[0117] The above-mentioned first experimental example A has the same structure as the first embodiment of the present invention.

[0118] Hereinafter, various selective applications of the first cover structure and the second cover structure of the display device of the present invention will be described, and improved efficiency of the device will be examined according to the various selective applications of the first cover structure and the second cover structure.

[0119] FIG. 5A to FIG. 5C It shows that when Figure 2B Graphs of EL spectra of blue, green and red when the cover layer structures of the first, fourth and fifth experimental examples are applied to the emission portion of the display device in FIG. Figure 5D is a graph showing transmittance characteristics of a blue color filter, a green color filter, and a red color filter.

[0120] The inventors of the present invention conducted experiments on the first experimental example A, the fourth experimental example D, and the fifth experimental example E. The first experimental example A and the fourth experimental example D have different optical paths, respectively, by making the second covering structure C2 of the covering stack 170 in the emission portion E. In the fifth experimental example E, color filters B, G, and R according to the wavelengths of the color emission portions BE, GE, and RE are further applied to the second covering structure C2 of the fourth experimental example D. The first experimental example A has the covering stack 170 by stacking the first covering layer 171 and the second covering layer 172 to have a constructive interference characteristic in the emission portion, such as FIG. 2A to FIG. 2C In contrast, the fourth experimental example D and the fifth experimental example E each have a covering structure with destructive interference characteristics.

[0121] Reference FIG. 5A to FIG. 5D 1 and Table 1, the EL emission spectra and efficiencies of the first experimental example A, the fourth experimental example D, and the fifth experimental example E were examined.

[0122] [Table 1]

[0123]

[0124] In Table 1, "DCI (Digital Cinema Initiative)" described in the color gamut refers to the satisfaction of the color gamut that can be expressed in the application of digital cinema. In contrast, BT2020 is the 4K / UHD standard recommended by the ITU of the International Broadcasting Standards Organization, and BT709 is the standard for HD supported color gamut. Turning to BT709, DCI, BT2020, stricter standards are applied, and the color expression area is larger.

[0125] Increasing each value in the area ratio of DCI means that a wider variety of colors can be achieved than in a large area and high resolution display, and has the effect of providing clear image quality. In addition, increasing each value in the overlap rate of DCI means that the area overlapping with the standard of the color gamut is large, and it is more in line with the standard of the display.

[0126] In addition, the white efficiency is the efficiency measured in the color coordinates (0.313, 0.329).

[0127] like FIG. 5A to FIG. 5C As shown in , the fourth experimental example of destructive interference characteristics shows shoulders or blue, green, and red emission portions in the EL spectrum on the right side of the graph due to the low efficiency of the microcavity.

[0128] Table 1 shows that the blue coordinate, green coordinate and red coordinate of the fourth experimental example deviate from the pure blue coordinate, pure green coordinate and pure red coordinate. In particular, the CIEy of the blue coordinate has risen, so the fourth experimental example cannot achieve dark blue display. And this means that it is difficult to achieve pure green and pure red in the fourth experimental example.

[0129] In particular, the fourth experimental example shows that the area ratio is 82% and the overlap ratio is 76% in the DCI standard, and thus the color reproduction rate is not very satisfactory.

[0130] In order to compensate for the microcavity characteristics in the fourth experimental example, as in the fifth experimental example Figure 5D As shown in , a blue filter B-CF, a green filter G-CF, and a red filter R-CF, which filter light away from blue, green, and red wavelengths, are applied on top of the cover stack in the fourth experimental example.

[0131] The fifth experimental example has the same cover stack as the fourth experimental example. Therefore, as in the fourth experimental example, the same driving voltage is applied to the light emitting elements located under the cover stack of the blue emission part BE, the green emission part GE, and the red emission part RE. FIG. 5A to FIG. 5C As shown in , by applying a color filter in the fifth experimental example, it can be seen that the right shoulder of the graph can be removed by the filtering effect of the color filter, and the EL spectrum of each color graph has a narrower FWHM than the fourth experimental example. As shown in Table 1, the fifth experimental example has CIE characteristics similar to the pure color CIE characteristics, and satisfies the area ratio and overlap ratio of the DCI standard. However, the fifth experimental example E does not use the amount of light properly due to the filtering effect of the color filter, so it has lower efficiency than the fourth experimental example D, and its combined white spectrum of red, green and blue has a brightness of 33.8Cd / A, which is lower than 44.5Cd / A of the fourth experimental example D.

[0132] On the contrary, FIG. 2A to FIG. 2C As shown, if the cover stack 170 has a second cover structure C2 with constructive interference characteristics for each color emission portion, the display device of the present invention has the same FIG. 5A to FIG. 5C The similar narrow FWHM shown in the fifth experimental example of . This means that pure color display is possible similar to the structure with a color filter. In addition, the display device of the present invention has an area ratio of 105% of the DCI standard and an overlap ratio of 98%. This means that the present invention almost meets the DCI standard, so the light-emitting element in the emission part of the display device has excellent color reproducibility. In addition, as FIG. 5A to FIG. 5CAs shown, the display device of the present invention has better blue intensity, green intensity and red intensity than the fourth experimental example D and the fifth experimental example E. It can be confirmed that in Table 1, the white brightness of the present invention is 54.2Cd / A, and the efficiency is the highest. Although it has excellent brightness characteristics, it can be seen that the driving voltage used to drive each color emission part is lower than that of the fourth experimental example D. When the corresponding color brightness is driven under the same conditions, this reduction in driving voltage requires a low driving voltage, so an increase in life can be expected.

[0133] In the fourth experimental example D and the first experimental example A, each efficiency of the blue emission part BE can be measured by comparing the efficiency of pure blue by considering not only the measured brightness value (Cd / A) but also the conversion efficiency obtained by dividing the measured brightness by the CIEy value. The conversion efficiency of the fourth experimental example D is 12.4 / 0.102, which is equal to 122, and the conversion efficiency of the first experimental example A is 12.1 / 0.062, which is equal to 195, and it can be confirmed that the pure blue efficiency in the first experimental example A will be improved.

[0134] That is, through the above experiments, as in the display device of the present invention, at least a portion of the transmission part T has the first covering structure C1 of destructive interference characteristics, and at least a portion of the emission part E has the second covering structure C2 of constructive interference characteristics, so that the transmittance is increased in the transmission part T. And the effects of improving the luminous efficiency and reducing the driving voltage can be expected, and the effect of improving the color reproducibility in the emission part E can be improved.

[0135] Meanwhile, the above-mentioned first experimental example A to fifth experimental example E have been described for a structure in which an air gap exists in the upper structure of the cover stack. The first experimental example A to fifth experimental example E may use the display device according to the first embodiment of the present invention. For example, the first experimental example A to fifth experimental example E may have a space including an air gap, wherein a packaging substrate (not shown) is located above the cover stack 170. In the first experimental example A to fifth experimental example E, the difference in refractive index at the interface between air having a low refractive index of 1.0 and the upper surface of the cover stack 170 having a relatively high refractive index (1.8 or more) is large, so that reflection can occur at the upper surface of the cover stack 170, and thus the internal resonance of the cover stack 170 can be used.

[0136] Hereinafter, various embodiments of the arrangement of the first covering structure C1 and the second covering structure C2 of the present invention will be described.

[0137] Compared with the first covering structure, the second covering structure C2 further has a second covering layer. In the following embodiments, various arrangements of the emission part and the transmission part and the selective arrangement relationship of the second covering structure are described.

[0138] Second embodiment

[0139] Figure 6 is a plan view of a display device according to a second embodiment of the present invention.

[0140] like Figure 6 As shown in, in the covering stack 170 of the display device according to the second embodiment of the present invention, the blue emission part BE, the red emission part RE and the green emission part GE that emit different color lights are arranged along the row direction, the second covering structure C2 is applied to overlap with each color emission part BE, RE and GE, and the first covering structure C1 is applied to overlap with the remaining area (including the transmission part T).

[0141] In this case, the second covering structure C2 fully covers each color emission part BE, RE and GE that are continuous in the row direction and the embankment 150 between the color emission parts BE, RE and GE. If the display device has multiple rows of emission parts, the second covering structure C2 is applied to cover the multiple rows of emission parts and be parallel to each other. The area in the covering stack 170 where the second covering structure C2 is not provided is defined as the first covering structure C1.

[0142] As described above, the first covering structure C1 has the first covering layer 171 having a single destructive interference characteristic, and the second covering structure C2 having a constructive interference characteristic by stacking the first covering layer 171 and the second covering layer 172 .

[0143] In the second embodiment, compared with the first embodiment, the second covering structure C2 is continuously arranged instead of being arranged in an island shape, and the second covering layer 172 is arranged in a line so as to be parallel to the length direction of the transmission part T. Therefore, the deposited opening area forming the second covering layer 172 can be set to be long to overlap with the color emission part in the row direction, so that the deposition mask has a grid type with an opening area in one line. Therefore, a deposition mask for forming the second covering layer 172 is provided. In addition, since the deposition mask is not affected by the left alignment and the right alignment during the alignment process, the second embodiment of the present invention has advantages in the process compared with the first embodiment.

[0144] In addition, as described in the first embodiment, even in the second embodiment of the present invention, the transmittance in the transmission part T is improved, and each color efficiency of the color emission parts BE, RE and GE is improved, so the color filter can be omitted. In addition, in the second embodiment, there are advantages such as a reduction in driving voltage and an improvement in color gamut. Optically, the first embodiment and the second embodiment can have the same effect.

[0145] Third embodiment

[0146] Figure 7 is a plan view of a display device according to a third embodiment of the present invention.

[0147] like Figure 7 As shown, the display device according to the third embodiment of the present invention expands the width of the second cover structure C2, so that the second cover structure C2 can overlap a portion of the transmissive portion T, compared with the second embodiment.

[0148] That is, in this case, the width of the second covering structure C2 can be set to be larger than "the length of the color emission parts BE, RE and GE in the column direction + the width of the upper and lower banks of the color emission parts BE, RE and GE", and overlap with the predetermined transmission part T of the adjacent color emission parts BE, RE and GE. In this case, the second covering structure C2 having constructive interference characteristics can be set in the transmission part T according to a certain width of the area overlapping with the second covering structure C2. By partially setting the second covering structure C2 in the transmission part T, the transmittance in the long wavelength range can be supplemented and improved compared with the first and second embodiments.

[0149] Here, the area of ​​the transmission part T to which the second covering structure C2 is applied is set to a level of 50% or less of the total area of ​​the transmission part T, thereby improving the transmittance obtained from the remaining first covering structure C1. That is, the first covering structure C1 corresponds to at least 50% or more of the area of ​​the transmission part T, thereby marking the transmittance of the entire wavelength at a level of 90% or more.

[0150] Fourth embodiment

[0151] Fig. 8A and Figure 8B are a plan view and a cross-sectional view showing a display device according to a fourth embodiment of the present invention. Figure 8C 4 is a cross-sectional view showing the interface reflection of light in the cover laminate of the display device according to the fourth embodiment of the present invention.

[0152] like FIG. 8A to FIG. 8C As shown, in the display device according to the fourth embodiment of the present invention, the covering stack 170 includes a second covering structure C2 in the blue emission part BE and the red emission part RE and a portion adjacent to the blue emission part BE and the red emission part RE in the transmission part T, and a first covering structure C1 in the remaining area.

[0153] In the fourth embodiment and the fifth and eleventh embodiments described below, the transmissive portion T has a portion of the second cover structure C2. Figure 8B A cross-sectional view is provided for understanding.

[0154] like Figure 8C As shown, the first cover structure C1 corresponds to the green emission portion GE and the remaining transmission portion T. In this case, the second cover structure C2 is formed by stacking the first cover layer 171 and the second cover layer 172, and the second cover layer is selectively disposed in the region of the second cover structure C2. In this case, the second cover layer 172 may have an island shape and be uniformly disposed in a pixel unit consisting of the disposed blue emission portion, the red emission portion, and the green emission portion and one transmission portion T.

[0155] like FIG. 8A to FIG. 8C As shown, if the second covering structure C2 corresponds to a partial area of ​​the transmission part T, the long wavelength transmittance at the transmission part T can be improved. In addition, by setting the second covering structure C2 to overlap with the blue emission part BE and the red emission part RE of the emission material having high sensitivity and low efficiency, in the color emission parts BE and RE to which the second covering structure C2 is applied, the color efficiency, color gamut (color reproducibility) and device characteristics can be improved.

[0156] exist Figure 8B , the bank 150 is shown between each color portion BE, RE, and GE, and between the color portions BE, RE, and GE and the transmission portion T. The bank 150 may define the region of each color emission portion BE, RE, and GE before forming the organic stack EL of the light emitting element OLED. The bank 150 may be disposed to overlap with at least one edge of the reflective electrode structure 111. The reflective electrode structure 111 serves as an anode. The organic stack EL may be deposited on the bank 150, or the organic stack EL may be relatively thinly deposited on the side surface of the bank 150 rather than on the flat surface of the bank 150. Optionally, the organic stack EL may be partially separated from other organic stacks EL on the side surface of the bank 150. As shown in FIG. Figure 8B As shown, the bank 150 may have a vertical side, or may have a forward tapered shape to have an acute angle with respect to the upper surface of the reflective electrode structure 111 .

[0157] In the display device of the present invention, the structure of the transmission electrode 140 is shared by the emission part E and the transmission part T. This means that in the entire active area including a plurality of pixels displaying an image, a single structure of the transmission electrode 140 to which a common voltage or a ground voltage is applied is formed. If the structure of the transmission electrode 140 is selectively removed in the transmission part T, the resistance around the area of ​​the transmission part T increases, and thus a voltage drop may occur in the structure of the transmission electrode 40. Therefore, the structure of the transmission electrode 140 may be formed in the emission part E and the transmission part T together. In addition, the structure of the transmission electrode 140 may be formed by a deposition process using a common mask for forming any one of the common layers 131, 133, 134 of the organic stack EL, and thus organic damage when a sputtering process for a metal layer is applied may be prevented. In addition, in the display device of the present invention having the structure of the transmission electrode 140, the device may be integrated, so that productivity may be improved and the process may be simplified. Meanwhile, since the metal mask may be deformed due to high temperature, during the metal deposition process, it is difficult to apply the metal mask including the shielding part for the active area AA due to high temperature. Furthermore, if a transmissive electrode is formed using a metal mask having a plurality of shielding portions for an active region, sheet resistance in the patterned transmissive electrode tends to increase as the thickness of the transmissive electrode becomes thinner, and reliability of the transmissive electrode tends to decrease due to a high temperature of a deposition process.

[0158] However, in the display device of the present invention, even in the structure of the transmissive electrode 140 formed thinly to maintain the reflective transmittance, the structure of the transmissive electrode at the entire active area AA can be formed in a unified process using a deposition mask with one opening area for the entire active area AA without a separate area, thereby preventing the reliability from being reduced due to equipment fluctuations or mask fluctuations. In addition, the display device of the present invention can obtain high transmittance, low resistance, and high reliability. To this end, the device of the present invention is characterized in that the configuration of the cover stack 170 is changed as described above so as to adjust the emission efficiency of the emission side.

[0159] The structure of the transmissive electrode 140 of the present invention may be formed of a silver (Ag) alloy such as AgMg as a semi-transmissive reflective electrode, or may be formed of other semi-transmissive reflective electrodes having both reflective and transmissive characteristics. Alternatively, the structure of the transmissive electrode 140 may be formed of a transparent electrode such as IZO or ITO. If the structure of the transmissive electrode 140 includes a semi-transmissive reflective electrode, the structure of the transmissive electrode 140 may have a thickness of approximately to thickness to obtain high transmittance.

[0160] Fifth embodiment

[0161] Fig. 9It is a plan view of a display device according to a fifth embodiment of the present invention.

[0162] like Fig. 9 As shown in, in the display device of the fifth embodiment of the present invention, the covering stack 170 has a second covering structure C2 that intersects the length direction of the transmission part T and the first covering structure C1 in the remaining area. In this case, the second covering structure C2 is arranged longitudinally along the column direction. Since the blue light-emitting material has the lowest efficiency so far among the red emission material, the green emission material and the blue emission material, and the user's visual recognition amount is small, it is most necessary to improve the light-emitting efficiency of the blue among various light-emitting colors. In this regard, the fifth embodiment of the present invention applies a second covering structure C2 with constructive interference characteristics so as to overlap only with the blue emission part BE.

[0163] Even in the fifth embodiment, the second covering structure C2 is applied to a portion of the transmission portion T to improve the transmittance in the long wavelength range. In addition, the second covering structure C2 corresponds to the overlap with the blue emission portion BE of the luminescent material having high sensitivity and low efficiency, so that the color efficiency and color gamut (color reproducibility) of the blue emission portion BE corresponding to the second covering structure C2 can be improved.

[0164] Sixth Embodiment

[0165] Fig.10 It is a plan view of a display device according to a sixth embodiment of the present invention.

[0166] like Fig.10 As shown in , in the display device of the sixth embodiment of the present invention, the cover stack 170 includes a second cover structure C2 located in a portion adjacent to the red emission portion RE in the blue emission portion BE, the red emission portion RE, and the transmission portion T. The second cover structure C2 having a constructive interference characteristic includes an island portion C21 to the blue emission portion BE, and a portion C22 overlapping with a portion of the red emission portion RE and the transmission portion T in a line crossing the length direction of the transmission portion. The cover stack 170 also includes a first cover structure C1 in the remaining area except the second cover structure C2.

[0167] Even in the sixth embodiment, the second covering structure C2 is applied to a portion of the transmission portion T to improve the transmittance in the long wavelength range. In addition, the second covering structure C2 corresponds to the blue emission portion BE and the red emission portion RE overlapping with the luminescent material having high sensitivity and low efficiency, so that the color efficiency and color gamut (color reproducibility) of the blue emission portion BE and the red emission portion RE corresponding to the second covering structure C2 can be improved.

[0168] Seventh embodiment

[0169] Fig.11 It is a plan view of a display device according to a seventh embodiment of the present invention.

[0170] like Fig.11 As shown in , in the display device of the seventh embodiment of the present invention, the cover stack 170 includes a blue emission part BE, a green emission part GE, and a red emission part RE, and a second cover structure C2 in a portion adjacent to the red emission part RE in the transmission part T. The second cover structure C2 having a constructive interference characteristic includes island portions C21 and C23 to the blue emission part BE and the green emission part GE, and a portion C22 overlapping with a portion of the red emission part RE and the transmission part T in a line crossing the length direction of the transmission part. The cover stack 170 also includes a first cover structure C1 in the remaining area except the second cover structure C2.

[0171] Even in the seventh embodiment, a second covering structure C2 is applied to a portion of the transmission portion T to improve the transmittance in the long wavelength range. In addition, the second covering structure C2 corresponds to the overlap with the blue emission portion BE, the green emission portion GE, and the red emission portion RE, so that the color efficiency, color gamut, and device characteristics of each color light can be improved.

[0172] Eighth Embodiment

[0173] Fig.12 It is a plan view of a display device according to an eighth embodiment of the present invention.

[0174] like Fig.12 As shown in, in the display device of the eighth embodiment of the present invention, compared with the first embodiment, the cover stack 170 also corresponds to the second cover structure C2, thereby partially overlapping with the transmission part T along the length direction of the transmission part T. That is, the second cover structure C2 includes an island portion C2A in the blue emission part BE, the green emission part BE and the red emission part RE along the length direction of the transmission part T (in the row direction) and a linear portion C2B partially overlapping with the transmission part T. The second cover structure C2 has a constructive interference characteristic. The cover stack 170 also includes a first cover structure C1 in the remaining area except the second cover structure C2.

[0175] Since the second cover structure C2 is applied on a portion of the transmission portion T, transmittance in a long wavelength range may be improved.

[0176] Ninth embodiment

[0177] Fig.13 It is a plan view of a display device according to a ninth embodiment of the present invention.

[0178] like Fig.13As shown in, compared with the eighth embodiment, in the display device of the ninth embodiment of the present invention, the island-shaped second covering structure of the green emission part GE is removed. That is, in the ninth embodiment of the present invention, the second covering structure C2 includes an island-shaped portion C2C in the blue emission part BE and the red emission part RE along the length direction (in the row direction) of the transmission part T and a linear portion C2B partially overlapping the transmission part T. The second covering structure C2 has a constructive interference characteristic. The covering stack 170 also includes a first covering structure C1 with a destructive interference characteristic in the remaining area except the second covering structure C2.

[0179] Since the second cover structure C2 is applied on a portion of the transmission portion T, transmittance in a long wavelength range may be improved.

[0180] Tenth embodiment

[0181] Fig.14 It is a plan view of a display device according to a tenth embodiment of the present invention.

[0182] like Fig.14 As shown in, in the display device of the tenth embodiment of the present invention, the covering stack 170 includes a second covering structure C2 and a first covering structure C1, the second covering structure C2 is island-shaped relative to the blue emission part BE and the transmission part T at the periphery of the blue emission part BE, and the first covering structure C1 is used for the remaining area (including the green emission part GE and the red emission part RE and other transmission parts T that do not overlap with the second covering structure C2).

[0183] Since the second cover structure C2 is applied on a portion of the transmission portion T, transmittance in a long wavelength range may be improved.

[0184] Meanwhile, in the above-mentioned embodiment, the color emission parts E1, E2, E3 and BE, RE, GE and the transmission part T are shown to have a rectangular shape, but are not limited thereto. That is, the color emission parts E1, E2, E3 and BE, RE, GE and the transmission part T may have other polygonal shapes, ellipses or rounded corners. In addition, the color emission parts E1, E2, E3 and BE, RE, GE and the transmission part T may have the same shape or different shapes in some cases.

[0185] Hereinafter, examples of configurations different from the shapes of the color emitting portion and the transmissive portion will be described.

[0186] Eleventh Embodiment

[0187] Fig.15 It is a plan view of a display device according to an eleventh embodiment of the present invention.

[0188] like Fig.15As shown in, in the eleventh embodiment of the present invention, the blue emission part BE and the green emission part GE have a rhombus shape. The red emission part RE is arranged between the blue emission part BE and the green emission part GE in a rectangular shape smaller than each size of the blue emission part BE and the green emission part GE. The blue emission part, the red emission part and the green emission part are repeated in the row direction, and the blue emission part, the red emission part and the green emission part are arranged in multiple rows. (One or more) transmission parts T can be arranged between different rows where the color emission parts BE, RE and GE are arranged. The transmission part T has a polygonal shape, such as a hexagon, a square, an octagon or another polygon. Alternatively, the corners of the transmission part T can be rounded. The transmission part T can be located on the same column line as the red emission part RE. In addition, the transmission part T is located between the blue emission part BE and the green emission part GE arranged diagonally relative to the transmission part T. In the eleventh embodiment of the present invention, each area of ​​the blue emission part BE and the green emission part GE is larger than the area of ​​the red emission part RE. This is why the blue emission part BE has a relatively high sensitivity among the color emission parts and the green emission part BE contributes the most to controlling the white brightness of the display device.

[0189] The shapes of the transmission part T and the color emission parts BE, RE and GE are not limited thereto and may be changed to have the same Fig.15 The polygons shown in are different polygons.

[0190] In the display device of the eleventh embodiment of the present invention, the cover stack 170 has a second cover structure C2 and a first cover structure C1, the second cover structure C2 includes an island-shaped first area C24 and a second area C25 overlapping each of the blue emission part BE and the green emission part GE, and a linear third area C26 intersecting the length direction of the transmission part T and overlapping the red emission part RE, and the first cover structure C1 is in the remaining area. In this case, the third area C26 is longitudinally arranged along the column direction. The third area C26 completely overlaps each red emission part RE and partially overlaps the transmission part T adjacent to the red emission part RE. The third area C26 may have the same width in the red emission part RE and the transmission part T, so the third area C26 in the transmission part T occupies a part of the transmission part T. The second cover structure C2 has a constructive interference characteristic, and the first cover structure C1 has a destructive interference characteristic.

[0191] The third region C26 of the second covering structure C2 may have the same width as the red emission portion, which has a relatively smaller width than the other color emission portions. Compared with the first covering structure C1, the second covering structure C2 also includes a second covering layer 172. In this case, the second covering layer 172 may be formed by a deposition mask having a linear opening region for the third region C26. Since the transmission portion T has the second covering structure C2 with constructive interference characteristics and the first covering structure C1 with destructive interference characteristics having the same width as the red emission portion RE in the remaining region, high transmittance and an increase in transmittance in the transmission portion T are expected in the long wavelength range.

[0192] Also, by providing the second cover structure C2 in each of the color emission parts BE, RE, and GE, effects of improving light emission efficiency and reducing driving voltage and effects of improving color reproducibility can be expected.

[0193] In the above-mentioned second to eleventh embodiments, the color emission parts E1, E2 and E3 are formed sequentially from the left as the blue emission part BE, the red emission part RE and the green emission part GE. However, this is only an example. And the arrangement order of the color emission parts can be changed, and / or the area of ​​the specific color emission part can be made larger, or the number of the specific color emission parts can be made more.

[0194] Through the above experiments and the above embodiments, the inventors have confirmed that, in particular, when the second covering structure C2 of constructive interference characteristics at least in the blue emission part BE is applied between the color emission parts, deep blue color can be displayed in the display device.

[0195] The effect of improving the transparency of the first covering structure C1 having the destructive interference characteristic provided in the transmission part T can be obtained as the area ratio of the first covering structure C1 occupied in the transmission part T. In addition, the structure partially including the second covering structure C2 having the constructive interference characteristic in the transmission part T can have the effect of improving the transmittance for all wavelengths. In particular, the structure partially including the second covering structure C2 having the constructive interference characteristic in the transmission part T can further improve the transmittance of the structure of the transmission part T having only the first covering structure C1 at a longer wavelength.

[0196] Fig.16 : is a graph showing the transmittance of the wavelength of the application area of ​​the second cover layer in the transmission part of the display device according to the fourth to eleventh embodiments.

[0197] The display devices of the fourth to eleventh embodiments have the second cover structure C2 of constructive interference characteristics not only in the emission parts E1, E2, and E3 but also in a partial region of the transmission part T. That is, the transmission part T has both the first cover structure C1 and the second cover structure C2.

[0198] Reference Fig.16 , the transmittance of the transmission part is examined according to the ratio of the application area of ​​the second covering structure C2 with respect to the wavelength.

[0199] like Fig.16 As shown in , in the case of only the first cover structure C1 having destructive interference characteristics in the transmission portion T without the second cover structure C2, the transmittance of the blue wavelength is high, but the transmittance of the red wavelength which is a longer wavelength is 90% or less.

[0200] In contrast, in a structure where the second covering structure C2 of constructive interference characteristics is applied to the entire area of ​​the transmission portion T, the lower transmittance at a blue wavelength is about 87% or less, and the high transmittance is 90% or more for a wavelength of about 540nm or longer.

[0201] And in the structure in which the second covering structure C2 with constructive interference characteristics is applied in 30% and 50% of the entire area of ​​the transmission part T, as the second covering structure C2 is increased relative to the entire transmission part T, the transmittance tends to increase at longer wavelengths and the transmittance tends to decrease at shorter wavelengths, compared with the structure in which the first covering structure C1 with only destructive interference characteristics is applied in the transmission part T.

[0202] Fig.16 It is shown that the structure of the second covering structure C2 applying the constructive interference characteristic in 30% and 50% of the entire area of ​​the transmission portion T has uniform superiority for the visible light wavelength without being biased to a specific wavelength.

[0203] Right now, Fig.16 It is shown that the second cover structure C2 having the constructive interference characteristic partially provided in the transmission portion T has uniform and excellent transmittance over the entire range of the visible light wavelength of 440 nm to 650 nm.

[0204] On the other hand, as in the first to third embodiments of the present invention, a significant increase in transmittance in blue wavelengths can be expected even in the case where only the first covering structure C1 having destructive interference characteristics is provided in the transmission portion T. This embodiment is meaningful in a transparent display device in which blue light emission characteristics are important.

[0205] Reference Fig.16It can be seen that when the application area of ​​the constructive interference characteristics for the transmission portion T is 50% or less of the total area of ​​the transmission portion T, improved transmission uniformity is obtained for the full visible light wavelength.

[0206] Fig.16 is a result of a structure in which air gaps exist in the upper structure of the cover stack 170. For example, referring to Figure 2B In the structure of the first embodiment, an air space exists on the cover laminate 170 , so that reflection occurs at the upper surface of the cover laminate 170 .

[0207] In the display device of the present invention, the structure above the cover stack 170 is not limited to the structure having an air gap. Hereinafter, the encapsulation stack is applied on the cover stack 170 so that the inorganic encapsulation layer at the bottom surface of the cover stack 170 and the encapsulation stack can contact each other. The transmittance will be examined for the structure that distinguishes the application area of ​​the second cover structure C2 from the transmission portion T.

[0208] Fig.17 : is a graph showing the wavelength transmittance of the application area of ​​the second cover layer in the transmission part of the display device according to the fourth to eleventh embodiments when the upper structure of the cover laminate is applied as the encapsulation laminate.

[0209] like Fig.17 As shown in , when the encapsulation stack is applied in the upper structure of the covering stack, regardless of the area difference of the second covering structure C2 of the constructive interference characteristic, the transmittance is high in the green wavelengths of 500nm to 580nm, and the transmittance tends to decrease in the remaining blue wavelengths and red wavelengths. However, according to the area difference of the second covering structure C2, different trends are shown in the blue wavelengths and the red wavelengths. That is, in the blue wavelength, as the area of ​​the second covering structure C2 decreases, the transmittance increases. On the contrary, in the red wavelength, as the area of ​​the second covering structure increases, the transmittance increases.

[0210] like Fig.17 As shown in , even in a structure where an encapsulation stack is applied right above the encapsulation stack, by providing the second cover structure C2 of 50% or less of the total area of ​​the transmission portion T, uniformity of transmittance for all visible light wavelengths can be expected.

[0211] The encapsulation stack on the cover stack may include at least one inorganic encapsulation layer and at least one organic encapsulation layer. The inorganic encapsulation layers and the organic encapsulation layers are stacked alternately. If the encapsulation stack is included in a display device, the encapsulation substrate can be omitted, thereby having the advantage that the display device can be made thinner. In the encapsulation stack, the inorganic encapsulation layer and the organic encapsulation layer each have a thickness of 1 μm or more, so that the optical refraction and interference characteristics at each internal interface between the inorganic encapsulation stack and the organic encapsulation stack are almost negligible. That is, in the display device of the present invention, there is almost no optical influence inside the encapsulation stack.

[0212] In the following, the effects of the cover stack and the superstructure will be examined experimentally.

[0213] 18A to 18D are cross-sectional views showing sixth to ninth experimental examples in which the upper configuration of the cover laminate is different in the transmission portion. Fig.19A and Fig.19B is a graph showing transmittances of wavelengths in the emission part and the transmission part according to the sixth and seventh experimental examples.

[0214] 18A to 18D The sixth to ninth experimental examples in the common ground include Figure 2B The transmission part T is shown. The transmission part includes an organic stack EL including common layers 131, 133 and 134 extending from the emission part E, and a through electrode 140a extending from the structure of the transmission electrode 140. Under the organic stack EL, there is a substrate 100 including a transparent protective layer.

[0215] The common layer included in the organic stack EL may be, for example, a hole injection layer, a hole transport layer, an electron blocking layer, an electron transport layer, and an electron injection layer. Among these common layers, any common layer that can be formed by a deposition mask having one opening area corresponding to the entire active area may be formed in the transmission portion T and even in the emission portion E.

[0216] Each of the sixth to ninth experimental examples includes an interface compensation layer 139 including a transition metal on the uppermost layer of the organic stacked layer EL. The interface compensation layer 139 may be provided for interface compensation with the structure of the transmission electrode 140. The interface compensation layer 139 has a configuration common to the emission portion E and the transmission portion T. The interface compensation layer 139 may be formed in, for example, a deposition process of forming a common layer of the organic stacked layer EL.

[0217] In the sixth to ninth experimental examples, an electrode having a transflective electrode such as an AgMg alloy was used for the structure of the transmissive electrode 140 .

[0218] The sixth to ninth experimental examples have differences in the covering structure on the structure of the transmissive electrode and the upper structure thereon, and the differences will be described below.

[0219] like Fig.18A As shown, the sixth experimental example F includes a cover layer 71 having a refractive index of 1.8 on the through electrode 140a and an air gap on the cover layer 71 in the transmission portion T. In experimental example F, there is a large refractive index difference (1.8-1.0) at the interface between the cover layer 71 and the air gap, and thus, interface reflection in the light traveling direction is introduced, and thus, output light can be emitted without light loss.

[0220] In this case, even though the cover layer 71 has the same refractive index of 1.8, the sixth experimental example F has different transmittance tendencies depending on whether the cover layer 71 has the destructive interference characteristic F1 and the constructive interference characteristic F2. In the structure of the sixth experimental example, when the cover layer 71 has the destructive interference characteristic F1, it has the same tendency as the above-mentioned first experimental example A: the transmittance is at least 90% in the blue and green wavelength ranges, and the transmittance tends to be slightly lower in the red wavelength range.

[0221] In the structure of the sixth experimental example, when the cover layer 71 has the constructive interference characteristic F2, it has the same tendency as the above third experimental example C. The transmittance tends to increase from shorter wavelengths to longer wavelengths, but the transmittance is generally maintained at a level less than 90% throughout the visible light wavelength.

[0222] That is, in the sixth experimental example F, by forming the cover layer 71 of destructive interference characteristics in the transmission part T and forming Figure 2B The light-emitting element OLED in the transmission part T can improve the transparency and improve the color efficiency and color reproducibility in the emission part E.

[0223] The seventh experimental example G, the eighth experimental example H, and the ninth experimental example I are structures in which a package stack is applied on a cover layer, respectively.

[0224] like Fig.18B As shown in FIG. 1 , the seventh experimental example G includes a cover layer 71 and an encapsulation stack 190, the cover layer 71 is on the through electrode 140a and has a refractive index of 1.8, and the encapsulation stack 190 includes at least one pair of an inorganic encapsulation layer 191a and an organic encapsulation layer 192 on the cover layer 71 in the transmission portion T. The inorganic encapsulation layer 191a has a refractive index of 1.8, and the organic encapsulation layer 192 covering the particles has a refractive index of 1.5.

[0225] like Fig.18BAs shown in , in the case where there is no difference in refractive index between the cover layer 71 and the inorganic encapsulation layer 191a, no refraction or reflection occurs at the interface between the cover layer 71 and the inorganic encapsulation layer 191a, and therefore, regardless of whether the cover layer 71 has the destructive interference characteristic G1 or the constructive interference characteristic G2, no internal resonance is generated in the cover layer 71. Therefore, regardless of whether the cover layer 71 has the destructive interference characteristic G1 or the constructive interference characteristic G2, the seventh experimental example G tends to have similar high transmittance at the green wavelength and low transmittance at the red wavelength.

[0226] That is, in the seventh experimental example (G: G1, G2), slight refraction and interface reflection occur between the inorganic encapsulation layer 191a and the organic encapsulation layer 192, but the thickness of the inorganic encapsulation layer 191a is thicker than the thickness of the covering layer 71, and therefore, the slight refraction is not affected, and the interface reflection occurring between the inorganic encapsulation layer 191a and the organic encapsulation layer 192 cannot optically affect the covering layer 71. This means that the constructive interference characteristics or destructive interference characteristics according to the optical path of the covering layer 71 do not affect the luminous characteristics of the device.

[0227] In addition, in the structure of the seventh experimental example (G: G1, G2), even if the inorganic encapsulation layer 191a and the organic encapsulation layer 192 have interface reflection, it will not affect the transmittance of the transmission part T caused by the interface reflection between the inorganic encapsulation layer 191a and the organic encapsulation layer 192.

[0228] like Fig.18C As shown in , the eighth experimental example H includes a cover layer 71 and an encapsulation stack 190, the cover layer 71 is on the through electrode 140a and has a refractive index of 1.8, and the encapsulation stack 190 includes at least one pair of an inorganic encapsulation layer 191b and an organic encapsulation layer 192 on the cover layer 71 in the transmission portion T. In the eighth experimental example H, the inorganic encapsulation layer 191b has a refractive index of 1.5, and the organic encapsulation layer 192 covering the particles has a refractive index of 1.5.

[0229] Here, the capping layer 71 and the inorganic encapsulation layer 191 b have a refractive index difference of 0.3, and reflection occurs due to the refractive index difference.

[0230] For reference, the reflectivity of the interface between two layers with different refractive indices n1 and n2 corresponds to (θ i is the incident angle, θ t is the exit angle).

[0231] Considering the incident and outgoing angles of each layer in the normal direction, the incident angle θ i and the exit angle θ t It can be 0°, with forward visibility being most effective in the direction of the normal.

[0232] In this case, the reflectivity between the capping layer 71 and the inorganic encapsulation layer 191 b is at a level of 1%.

[0233] In the eighth experimental example H, regardless of whether the covering layer 71 has the destructive interference characteristic H1 or the constructive interference characteristic H2, refraction or reflection occurs at the interface between the covering layer 71 and the inorganic encapsulation layer 191b, but the amount of interface reflection is small, and the increase in transmittance is small when using the internal resonance of the covering layer 71. However, even in the structure of the eighth experimental example (H: H1, H2), when the covering layer 71 having the destructive interference characteristic is applied, the transmittance is improved at the blue wavelength, and when the covering layer 71 having the constructive interference characteristic is applied, the transmittance is improved at the red wavelength.

[0234] like Fig.18D As shown in the ninth experimental example I, the ninth experimental example I includes a covering layer 371 and an encapsulation stack 190, the covering layer 371 is on the through electrode 140a and has a refractive index of, for example, 2.2, and the encapsulation stack 190 includes at least one pair of an inorganic encapsulation layer 191b and an organic encapsulation layer 192 on the covering layer 371 in the transmission portion T. In the ninth experimental example I, the inorganic encapsulation layer 191b has a refractive index of 1.5, and the organic encapsulation layer 192 covering the particles has a refractive index of 1.5.

[0235] Compared with the sixth experimental example F, the seventh experimental example G, and the eighth experimental example H, by applying the cover layer 371 having a high refractive index, the difference in refractive index between the inorganic encapsulation layer 191b and the cover layer 371 increases, and thus the interface reflectivity between the cover layer 371 and the inorganic encapsulation layer 191b increases to 4.6%. Therefore, the effect of increasing the transmittance in the transmission portion T due to the internal resonance of the cover layer 371 can be expected.

[0236] In the seventh experimental example G, for example, SiNx having a refractive index of 1.8 is used in the inorganic encapsulation layer 191a. In the eighth experimental example H and the ninth experimental example I, for example, SiON having a refractive index of 1.5 is used in the inorganic encapsulation layer 191b.

[0237] For reference, the organic encapsulation layer 192 used in the seventh experimental example G, the eighth experimental example H, and the ninth experimental example I collectively have a refractive index of 1.5. However, each of the organic encapsulation layer 192 and the inorganic encapsulation layer 191a / 191b in the encapsulation stack 190 is thicker than the light-emitting element OLED and any component in the cover stack. Therefore, even if there is a difference in refractive index between the organic encapsulation layer 192 and the inorganic encapsulation layer 191a / 191b, there is almost no effect on the interface reflection occurring at the internal interface between the organic encapsulation layer 192 and the inorganic encapsulation layer 191a / 191b. Therefore, if there is no optical effect on the function of emitting light from the light-emitting element, the inorganic encapsulation layer 191a / 191b and the organic encapsulation layer 192 can be changed to various materials.

[0238] exist Fig.18D In the structure of the ninth experimental example I, the high refractive index cover layer 371 can be formed as FIG. 2A to FIG. 2C The first cover layer 171 of destructive interference characteristics is shown. In this case, in the emission part, a second cover layer 172 may be further provided. In this configuration, the effects of improving the transmittance in the transmission part T and improving the light emission efficiency will be described below with reference to experimental contents.

[0239] Fig. 20 is a graph showing transmittance of wavelengths according to a ninth experimental example when the second cover layer is applied or not applied in the transmission portion.

[0240] like Fig. 20 As shown in, in the structure of the ninth experimental example I, in the case I2 when the second covering layer is not applied in the transmission part T and the covering layer 371 having a separate destructive interference characteristic with a high refractive index is applied, it can be seen that the transmittance of the entire visible light wavelength is 90% or greater, compared with the case where the second covering layer is provided so that the constructive interference characteristic is applied even in the transmission part T.

[0241] As described above, with reference to the results of the ninth experimental example I (I1 and I2), the display device of the present invention can be applied not only to a structure in which an air gap exists in the upper structure of the covering stack, but also to a structure in which a packaging stack or a surface seal is provided on the covering stack. In one example, when the packaging stack is applied to the top of the covering stack, the bottommost inorganic packaging layer of the packaging stack contacts the covering stack. In this structure, the driving voltage, brightness, conversion efficiency, and FWHM are checked by Table 2 based on the application of constructive interference characteristics in the emission portion E.

[0242] In the ninth experimental example I, the following effect when the cover stack has constructive interference characteristics in the emission portion E will be described.

[0243] Here, DI refers to a first covering structure C1 having a destructive interference characteristic, and CI refers to a second covering structure C2 having a constructive interference characteristic.

[0244] [Table 2]

[0245]

[0246] From Table 2, even in a structure in which the encapsulation stack is directly applied on top of the covering structure, it can be confirmed that when the constructive interference (CI) characteristic is applied to the emission parts BE, GE and RE, the FWHM (full width at half maximum) can be reduced and thus the cavity characteristics can be improved. It can also be confirmed that, compared with the structure of the covering stack having the destructive interference (DI) characteristic, when the constructive interference (CI) characteristic is applied to the emission parts BE, GE and RE, the FWHM (full width at half maximum) can be reduced and thus the driving voltage can be relatively reduced, so that pure colors (blue, green and red) can be displayed. In particular, it can be seen that the blue conversion efficiency has an improvement of 15% or more.

[0247] Reference Fig.21 , describes a specific example in which a light-emitting element and a cover stack are provided on a substrate of a display device of the present invention.

[0248] Fig.21 is a cross-sectional view showing a display device according to an embodiment of the present invention.

[0249] Reference Fig.21 As an example, in the display device of the present invention, the blue emission part E1, the red emission part E2 and the green emission part E3 adjacent to each other in the row direction and the transmission part T are included in the next row parallel thereto. Therefore, it can be called a pixel P, and the pixel P is arranged on the substrate 100 in a plurality of rows and a plurality of columns. And thin film transistors TFT1, TFT2, TFT3 are arranged at each color emission part E1, E2 and E3, so that each color emission part can be used as a sub-pixel driven independently.

[0250] A blue light emitting layer 132a is disposed at the blue emission portion BE. A red light emitting layer 132b is disposed at the red emission portion RE. A green light emitting layer 132c is disposed at the green emission portion GE.

[0251] The first thin film transistor TFT1 in the emission portion E (RE, GE, BE) includes a first gate electrode 1120 formed in the same layer as the scan line SL, a first semiconductor layer 1110 provided with a channel region overlapping the first gate electrode 1120, and a first source electrode 1140 and a first drain electrode 1160 connected to both sides of the first semiconductor layer 1110. In addition, the first gate electrode 1120 may be formed as a protruding pattern protruding from the scan line SL to be formed integrally with the scan line SL. The first source electrode 1140 may be formed as a protruding pattern protruding from the data line DL, and the first drain electrode 1160 is spaced apart from the first source electrode 1140 and connected to the reflective anode 1100 of the organic light emitting diode OLED through the first connection portion CT1.

[0252] Reference Fig.21 , the layered structure of the display device will be described in detail below.

[0253] The buffer layer 105 is disposed above the transparent substrate 100, and the first semiconductor layer 1110, the second semiconductor layer 1111, and the third semiconductor layer are disposed above the buffer layer 105. The buffer layer 105 is used to prevent impurities remaining in the transparent substrate 100 from being introduced into the semiconductor layers 1110 and 1111. The semiconductor layers 1110 and 1111 may be amorphous or crystalline silicon semiconductor layers, or transparent oxide semiconductor layers. In addition, both sides of the first semiconductor layer 1110 connected to the first and second source electrodes 1140 and the first and second drain electrodes 1160, and the entire region of the second semiconductor layer 1111 may be regions where impurities are injected, and the intrinsic region of the first semiconductor layer 1110 between the impurity-injected regions may be used as a channel region.

[0254] The second semiconductor layer 1111 may be disposed to overlap the storage electrodes 1121 and 1141 to be formed thereon and may serve as an auxiliary storage electrode which, if impurities are injected, increases the capacitance of the storage capacitor STC. Otherwise, the third semiconductor layer may be omitted as the case requires.

[0255] Furthermore, a gate insulating film 106 is provided to cover the first semiconductor layer 1110 and the second semiconductor layer 1111 , and a gate electrode 1120 and a first storage electrode 1121 are formed to overlap intrinsic regions of the first semiconductor layer 1110 and the second semiconductor layer 1111 , respectively.

[0256] A first interlayer insulating film 107 is provided to cover the first and second semiconductor layers 1110 and 1111 , the gate electrode 1120 , and the first storage electrode 1121 .

[0257] A contact hole is formed by selectively removing the first interlayer insulating film 107 and the gate insulating film 106 from both sides of the first semiconductor layer 1110, a first source electrode 1140 and a first drain electrode 1160 are connected to the first semiconductor layer 1110, and a second source electrode 1161 and a second drain electrode 1142 are connected to the second semiconductor layer 1112 through the contact hole. In the same process, a second storage electrode 1141 is formed over the first interlayer insulating film 107 overlapping the first storage electrode 1121.

[0258] Here, the first thin film transistor TFT for driving the light emitting element OLED set in the emission part E (E1, E2 and E3) includes a first semiconductor layer 1110 stacked in sequence from below, a first gate electrode 1120 provided with a channel region overlapping the first semiconductor layer 1110, and a first source electrode 1140 and a first drain electrode 1160 connected to both sides of the first semiconductor layer 1110.

[0259] In addition, the storage capacitor STC includes a first storage electrode 1121 and a second storage electrode 1141 overlapping each other with a first interlayer insulating film 107 interposed therebetween.

[0260] The second interlayer insulating film 108 is formed to cover the first and second thin film transistors TFT1 and TFTS and the storage capacitor STC.

[0261] Here, the first thin film transistor TFT and the storage capacitor STC include a light shielding metal layer and are arranged not to overlap the transmission portion T, and therefore, the thin film transistor TFT may be arranged to overlap the emission portion E (E1, E2, E3) or a region for forming the bank 150. Here, the bank 150 may be located between the transmission portion T and the emission portion E, or between emission regions of the emission portion E spaced apart from each other. In the emission portion E, the reflective anode 1100 makes the metal layer disposed thereunder invisible, and in the region where the bank 150 is disposed, the thick bank 150 makes the elements disposed thereunder invisible.

[0262] In addition, a planarization film 109 may be formed to planarize the surface of the second interlayer insulating film 108 while covering the second interlayer insulating film 108, a first connection portion CT1 and a second connection portion CT2 may be formed by selectively removing the planarization film 109 and the second interlayer insulating film 108, and the thin film transistor TFT may be connected to the reflective anode 1100 and the transparent electrode 1200 through the first connection portion CT1 and the second connection portion CT2.

[0263] The display device according to the present invention may further include a partition wall (not shown) in a designated area of ​​a portion where the transmission part T and the emission part E are not provided, and the partition wall divides the adjacent transmission part T or the emission part E. The partition wall prevents a deposition mask (not shown) for depositing an organic material when forming the organic stack 130 and 130' from directly contacting the bank 150, and thus maintains the shape of the bank 150 without the bottom 150 collapsing.

[0264] The partition wall may include a first layer and a second layer, the first layer being formed in the same layer as the bank 150, and the second layer having a specified height from an upper surface of the first layer so as to cover the first layer. In order to prevent a deposition mask required for forming an organic common layer or a light emitting layer from directly contacting the bank 150 or sagging after forming the bank 150, the second layer may be formed in the same layer as a spacer (not shown) formed above the bank 150.

[0265] In the emission portion E, the structures of the reflective anode 1100 and the transmissive electrode 140 are disposed opposite to each other. Here, the reflective anode 1100 is shown as having a three-layer structure having a reflective electrode layer 111 and an upper transparent electrode layer 112b and a lower transparent electrode layer 112a, but is not limited thereto. That is, one or both of the transparent electrode layers 112b and 112a may be omitted, or a plurality of transparent electrode layers 112b and 112a and a plurality of reflective electrode layers 111 may be provided. If the reflective anode 1100 includes at least one transparent electrode layer, the transparent electrode 1200 in the transmission portion T may be formed by the same process as the transparent electrode layer.

[0266] Although the above example describes the organic light emitting diode OLED disposed in the emission portion E as a single stack including a single organic light emitting layer in each sub-pixel, an organic light emitting diode including a plurality of stacks each including a light emitting layer may be applied to the display device according to the present invention.

[0267] Hereinafter, an exemplary embodiment in which an organic stacked layer between electrodes of a light emitting element is formed as a plurality of stacked layers will be described.

[0268] Fig. 22 is a cross-sectional view showing a display device according to a twelfth embodiment of the present invention.

[0269] like Fig. 22 As shown, the display device according to the twelfth embodiment of the present invention has two stacked layers on the substrate 200. Each stacked layer is divided by the charge generation layer 235. The display device including the spirit of the present invention is not only an example including the two stacked layers shown, but an example having more than three stacked layers is possible.

[0270] A plurality of insulating layers including thin film transistors may be further included between the substrate and the light emitting element. In the illustrated example, description of the remaining configuration is omitted to focus on the relationship between the internal configuration of the light emitting element and the cover stack.

[0271] First, the transmission part E (RE, GE and BE) will be described.

[0272] In each emission part E (RE, GE, and BE), a reflective anode (eg, a reflective electrode anode) 1100 and a transmissive electrode cathode 240 are opposite to each other, and a plurality of stacked layers are disposed therebetween.

[0273] The reflective anode 1100 may have transparent electrodes 112a and 112b below and above the reflective electrode 111. The transparent electrode of the transparent electrodes 112a and 112b may be omitted. In some cases, the reflective anode 1100 may be formed separately.

[0274] In addition, the transmission electrode cathode 240 may have a reflective transmittance. The transmission electrode cathode 240 may be formed of, for example, an AgMg alloy. Light may be resonated between the reflective electrode anode 1100 and the transmission electrode cathode 240, and by repeating the resonance a plurality of times, light may be transmitted to a high degree within an optimal wavelength range with a narrow FWHM. In the spirit of the display device of the present invention, the transmission electrode cathode 240 may be replaced with a transparent electrode such as ITO or IZO.

[0275] Each stack may be divided by the charge generation layer 235 .

[0276] Each stack basically includes hole transport layers 232 and 236, light emitting layers 233a, 233b or 233c / 237a, 237b or 237c, electron transport layers 234 and 238. A hole injection layer 231 may be further disposed on a side close to the reflective electrode anode 1100, and an electron injection layer or interface compensation layer 239 may be further disposed adjacent to the transmissive electrode cathode 240.

[0277] In this embodiment, an example is described in which organic light emitting layers 233a, 233b and 233c / 237a, 237b and 237c emitting light of the same color are applied to each stack to improve the color efficiency of the red emission part RE, the green emission part GE and the blue emission part BE. However, this is an example, and in some cases, light emitting layers may be provided with light emitting layers of different colors in different stacks so that various colors can be expressed even in one light emitting region.

[0278] In the light emitting element, other layers except the reflective electrode anode 1100 and the light emitting layers 233a, 233b and 233c / 237a, 237b and 237c may be formed indiscriminately in the active region, so the other layers may be formed in the transmission part T and the emission part E.

[0279] That is, the hole injection layer 231, the hole transport layers 232 and 236, the electron transport layers 234 and 238, the charge generation layer 235 (p-type charge generation layer (235a), n-type charge generation layer (235b)), the interface compensation layer or the electron injection layer 239, and the transmission electrode cathode 240 are common layers without dividing the emission part E and the transmission part T.

[0280] exist Fig. 22 In order to clarify the difference in the layered structure between the respective color emission parts RE, GE and BE and the transmission part T, the bank is not shown (see Figure 1 150 in the figure). However, in the twelfth embodiment, the bank may also be applied between the respective color emission parts RE, GE and BE and the transmission part T. In this case, the bank may be provided between the reflective electrode anode 1100 and the hole injection layer 231 by overlapping the edges of the reflective electrode anode 1100.

[0281] In the display device according to the present invention, a first covering structure C1 having a destructive interference characteristic is disposed in a portion of the transmission portion T, and a second covering structure C2 having a constructive interference characteristic is disposed in the emission portion E. The first covering structure C1 includes a single first covering layer 171, and the second covering structure C2 includes a stacked first covering layer 171 and a second covering layer 172. The first covering layer 171 is completely formed in the active region, and the second covering layer 172 is selectively formed in the active region.

[0282] In some cases, the second cover structure C2 may occupy 50% or more of the entire area of ​​the transmissive portion T, thereby improving the uniformity of transparency in all visible light wavelengths by increasing the transmittance in the longer wavelength range.

[0283] In some cases, the first portion as an island may be applied in a portion of the emission portion E and the second portion may be applied in the transmission portion T using the second covering structure C2 having constructive interference characteristics and the first covering structure C1 having destructive interference characteristics in the remaining region. In this case, a hybrid deposition mask of a groove type and / or a grid type may be used to form the second covering layer 172 included in the second covering structure C2.

[0284] Even in the twelfth embodiment of the display device, the first covering structure C1 having destructive interference characteristics may be provided in the transmission part T, and the second covering structure C2 having constructive interference characteristics may be provided in the emission part E. Therefore, the above-mentioned effects of improving the transmittance of the transmission part and improving the color efficiency, improving the color reproducibility, and reducing the driving voltage of the emission part are expected together, and further extension of the life can be obtained.

[0285] Other aspects of the present disclosure may be provided. A display device according to an embodiment of the present invention may include: a plurality of emitting portions and a plurality of transmissive portions on a substrate; a light emitting layer in the emitting portions; a reflective electrode structure located between the light emitting layer and the substrate in each of the emitting portions; a transmissive electrode located above the light emitting layer over the entire emitting portions and the transmissive portions of the substrate; and a cover stack located on the transmissive electrode, the cover stack including a first cover structure over the transmissive portion and a second cover structure over the emitting portion, the second cover structure being different from the first cover structure.

[0286] The first cover structure may have a first optical path through which light passing through the transmissive electrode is destructively interfered and transmitted, and the second cover structure may have a second optical path through which light passing through the transmissive electrode is constructively interfered and transmitted.

[0287] The cover stack may include a first cover layer continuous on the emitting portion and the transmissive portion and a second cover layer selectively located on the first cover layer in a second cover structure.

[0288] In the cover stack, the first cover layer may have destructive interference properties, and the stack of the first cover layer and the second cover layer may have constructive interference properties.

[0289] The first cover structure may include a first cover layer of destructive interference characteristics. And, the second cover structure may include a first cover layer and a second cover layer on the first cover layer and having a different optical path from the first cover layer. The first cover layer may be continuous on the emission portion and the transmission portion.

[0290] The cover laminate may further include a second cover layer at a portion of the transmission portion, and a step portion between a region having the second cover layer and a region having only the first cover layer in the transmission portion.

[0291] The emission part and the transmission part may be parallel, and the emission part may include a blue emission part, a red emission part, and a green emission part.

[0292] The second capping layer may be disposed on at least the blue emission portion.

[0293] The blue emission parts and the green emission parts may be alternately arranged with the red emission parts interposed therebetween, and an area of ​​the red emission parts may be smaller than an area of ​​each of the blue emission parts and the green emission parts.

[0294] The second covering layer may overlap the emission portion and extend to a portion of the transmission portion adjacent to the emission portion.

[0295] The second cover layer of the cover stack may overlap a portion of the blue emission portion, the red emission portion, the green emission portion, and the transmission portion adjacent to the blue emission portion, the red emission portion, and the green emission portion on the substrate.

[0296] The display device may further include an inorganic protective layer on the cover stack, the inorganic protective layer having a refractive index different from that of the first cover layer by 0.2 or more.

[0297] The plurality of emission parts and the plurality of transmission parts have different shapes.

[0298] The sizes of the plurality of emission portions emitting different colors are different from each other.

[0299] The transmissive electrode includes a transparent oxide electrode and a transition metal layer disposed under the transparent oxide electrode or on the transparent oxide electrode.

[0300] The display device further includes a transparent electrode disposed above and / or below the emitting electrode structure.

[0301] The transmissive electrode includes at least one of a silver alloy, IZO, or ITO.

[0302] According to different embodiments of the present invention, a display device may include: a plurality of red emission parts, a plurality of green emission parts, a plurality of blue emission parts and a plurality of transmission parts located on a substrate; a dam located between the red emission parts, the green emission parts, the blue emission parts and the transmission parts; a light-emitting element located in each of the red emission parts, the green emission parts and the blue emission parts, the light-emitting element having a reflective electrode structure, a light-emitting layer and a transmission electrode; a through electrode located in each of the transmission parts, the through electrode extending from the transmission electrode; and a covering stack located on the transmission electrode and the through electrode, the covering stack including a first covering structure located on at least a portion of the transmission part and a second covering structure located on at least a portion of the red emission parts, the green emission parts and the blue emission parts, the second covering structure being different from the first covering structure.

[0303] The capping stack may include a second capping structure on at least the blue emitting portion.

[0304] The second covering structure may overlap the entirety of the blue emission portion and the transmission portion adjacent to the blue emission portion, and the second covering structure may further overlap at least one of the green emission portion and the red emission portion.

[0305] The display device may further include an air gap on the cover structure.

[0306] The display device may further include an inorganic protective layer on the cover stack, the inorganic protective layer having a refractive index different from that of the first cover layer by 0.2 or more.

[0307] In the cover stack, the first cover structure may have destructive interference characteristics and the second cover structure may have constructive interference characteristics.

[0308] The first cover structure may include a first cover layer of destructive interference characteristics. And, the second cover structure may include a first cover layer and a second cover layer on the first cover layer and having a different optical path from the first cover layer. The first cover layer may be continuous on the emission portion and the transmission portion.

[0309] The cover stack may include a first cover layer integrally disposed on the transmission electrode and the passing electrode over the emission part and the transmission part, and a second cover layer selectively on the first cover layer in the second cover structure.

[0310] The transmission electrode and the passing electrode may include at least one of a transflective metal and a transparent metal.

[0311] The display device may further include a third cover layer in a portion of the transmission portion on the same layer as the second cover layer, the third cover layer being parallel to at least one of arrangement directions of the red, green, and blue emission portions.

[0312] The red emission part, the green emission part, and the blue emission part may be arranged in a first direction. The first covering layer may be integral over the red emission part, the green emission part, the blue emission part, and the transmission part, and the second covering layer may overlap the blue emission part and further include a plurality of emission covering parts spaced apart from each other in the first direction.

[0313] The second cover layer may further include at least one transmissive cover portion parallel to the emissive cover portion by crossing the transmissive portion.

[0314] The blue emission parts and the transmission parts are alternately arranged in the second direction, and the second covering layer may include a plurality of emission covering parts spaced apart from each other in the second direction, each emission covering part overlapping at least one of the blue emission parts.

[0315] Each emission covering portion of the second covering layer may overlap at least one of the blue emission portion and the transmission portion, the portion adjacent to the blue emission portion in the second direction.

[0316] The display device of the present invention has a covering structure including constructive interference characteristics in the emission part, thereby improving the cavity characteristics of the EL spectrum of each color wavelength even in a structure without a color filter. At the same time, the display device of the present invention has a covering structure including destructive interference characteristics in the transmission part, thereby improving transparency and transmittance in the transmission part.

[0317] Furthermore, the display device of the present invention can improve color purity and cavity characteristics in the emission portion, and can reduce the driving voltage of the device, thereby increasing the life of the display device.

[0318] As is apparent from the above description, the display device according to the present invention has the following effects.

[0319] First, the cover stack includes a first cover structure having constructive interference characteristics in the emission part to enhance the cavity characteristics of each wavelength in red, green and blue, and a second cover structure having destructive interference characteristics in the transmission part to improve the transmittance. That is, by applying the hybrid cover structure, the cover stack in the display device can improve the color purity of red, green and blue without a color filter, while improving the transmittance in the transmission part.

[0320] Second, in the emission section, device efficiency can be improved by improving color purity and cavity characteristics, which can reduce driving voltage and thus improve lifetime.

[0321] Third, by increasing the efficiency of the emitting part, the area of ​​the emitting part can be reduced. As a result, the transmissive part can be increased, thereby increasing the transmittance of the structure itself.

[0322] Fourth, the covering structure of the transmission part is a single layer with destructive interference characteristics. That is, in the covering structure, the light transmittance can be improved by reducing or minimizing the amount of light totally internally reflected in the covering structure and increasing the amount of light emitted. Therefore, in the same structure, the transmittance can be improved without increasing the area of ​​the transmission part in the display device and without changing the area of ​​the emission part in the display device.

[0323] Various modifications and variations can be made to the present invention without departing from the spirit or scope of the present invention, which will be apparent to those skilled in the art. Therefore, the present invention is intended to include modifications and variations of the present invention as long as they fall within the scope of the appended claims and their equivalents.

[0324] This application claims the benefit of Korean Patent Application No. 10-2019-0109924, filed on September 5, 2019, which is hereby incorporated by reference as if fully set forth herein.

Claims

1. A display device, comprising: a plurality of emitting parts and a plurality of transmitting parts, the plurality of emitting parts and the plurality of transmitting parts being on a substrate; a light-emitting layer in the emitting portion; a reflective electrode structure located between the light emitting layer and the substrate in each of the emitting portions; a transmissive electrode located above the light emitting layer in the entirety of the emitting portion and the transmissive portion of the substrate; as well as a covering stack on the transmissive electrode, the covering stack comprising a first covering structure above the transmissive portion and a second covering structure above the emitting portion, the second covering structure being different from the first covering structure, wherein, in the cover stack, the first cover structure has destructive interference characteristics, and the second cover structure has constructive interference characteristics, and Wherein, the covering stack comprises: a first cover layer over the emitting portion and the transmissive portion; and A second covering layer is selectively located on the first covering layer in the second covering structure.

2. The display device according to claim 1, wherein: The first covering structure has a first optical path through which light passing through the transmissive electrode is destructively interfered and transmitted, and The second covering structure has a second optical path, and the light passing through the transmissive electrode is constructively interfered and transmitted through the second optical path.

3. The display device according to claim 1, wherein: The cover laminate further includes a second cover layer at a portion of the transmission portion, and a step portion between a region having the second cover layer and a region having only the first cover layer in the transmission portion. 4 . The display device of claim 1 , further comprising an air gap or an encapsulation stack on the cover stack. 5 . The display device according to claim 1 , further comprising an inorganic protective layer on the cover stack, the inorganic protective layer having a refractive index different from that of the first cover layer by 0.2 or more.

6. The display device according to claim 1, wherein: The transmissive electrode includes a transparent oxide electrode and a transition metal layer disposed under the transparent oxide electrode or on the transparent oxide electrode.

7. A display device, comprising: a plurality of red emission parts, a plurality of green emission parts, a plurality of blue emission parts and a plurality of transmission parts, the red emission parts, the green emission parts, the blue emission parts and the transmission parts being on a substrate; a bank between the red emission portion, the green emission portion, the blue emission portion, and the transmission portion; a light emitting element in each of the red emission portion, the green emission portion, and the blue emission portion, the light emitting element having a reflective electrode structure, a light emitting layer, and a transmissive electrode; a through electrode in each of the transmissive portions, the through electrode extending from the transmissive electrode; as well as a covering stack, the covering stack being on the transmission electrode and the passing electrode, the covering stack comprising a first covering structure over at least a portion of the transmission portion and a second covering structure over at least a portion of the red emission portion, the green emission portion, and the blue emission portion, the second covering structure being different from the first covering structure, wherein, in the cover stack, the first cover structure has destructive interference characteristics, and the second cover structure has constructive interference characteristics, and Wherein, the covering stack comprises: a first covering layer integrally disposed on the transmission electrode and the passing electrode over the emission portion and the transmission portion; and A second covering layer is selectively on the first covering layer in the second covering structure.

8. The display device according to claim 7, wherein: The capping stack includes a second capping stack on at least the blue emitting portion.

9. The display device according to claim 8, wherein: The second covering structure overlaps the entirety of the blue emitting portion and the transmissive portion adjacent to the blue emitting portion, and The second covering structure also overlaps with at least one of the green emission portion and the red emission portion.

10. The display device of claim 7, further comprising an air gap or an encapsulation stack on the cover stack. 11 . The display device according to claim 7 , further comprising an inorganic protective layer on the cover stack, the inorganic protective layer having a refractive index different from that of the first cover layer by 0.2 or more.

12. The display device according to claim 7, wherein: The transmissive electrode includes a transparent oxide electrode and a transition metal layer disposed under the transparent oxide electrode or on the transparent oxide electrode.

13. The display device according to claim 7, wherein: The transmission electrode and the passing electrode include at least one of a semi-transmissive reflective electrode and a transparent electrode.

14. The display device according to claim 7, wherein: The red emission portion, the green emission portion, and the blue emission portion are arranged in a first direction, and Wherein, the first covering layer is integrated over the red emission part, the green emission part, the blue emission part and the transmission part, and the second covering layer overlaps with the blue emission part and also includes a plurality of emission covering parts spaced apart from each other in the first direction.

15. The display device according to claim 14, wherein: The second cover layer further includes at least one transmissive cover portion parallel to the emissive cover portion by crossing the transmissive portion.

16. The display device according to claim 7, wherein: The blue emitting parts and the transmissive parts are alternately arranged in a second direction, and The second covering layer includes a plurality of emission covering portions spaced apart from each other in the second direction, each emission covering portion overlapping at least one of the blue emission portions.

17. The display device according to claim 16, wherein: Each emission covering portion overlaps at least one blue emission portion and a portion of the transmissive portion adjacent to the blue emission portion in the second direction.

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