Patent Description:
An electro-luminescence display apparatus may receive an image signal and may display an image in a display area. The electro-luminescence display apparatus may be implemented with the technologies of a micro light emitting diode (micro LED) that is an electro-luminescence diode, an organic light emitting diode (OLED), a quantum-dot light emitting diode (QLED) and the like.

A conventional electro-luminescence display apparatus includes a polarizing plate capable of absorbing external light on a display surface on which an image is displayed, to solve the problem of lower quality of images, which is caused by external light reflectance. <CIT> discloses an electroluminescence display device wherein a metal thin film having light transmission properties is formed on upper surfaces of an organic compound layer and a partition wall in a cathode, and an antireflection film having optical absorptivity is formed to prevent external light from being reflected on the upper surface of the metal thin film. <CIT> discloses a display device including a substrate; a pixel defining layer defining a pixel region on the substrate; a first electrode on the pixel region; a light emitting layer on the first electrode; a second electrode on the light emitting layer; a thin film encapsulation layer on the second electrode; a metal pattern on the thin film encapsulation layer and overlapping the pixel defining layer; and a multi-layer thin film layer on the metal pattern and the thin film encapsulation layer. <CIT> discloses a top emission type organic electro-luminescence device comprising a driving thin film transistor formed on a first substrate, an organic light emitting diode formed on the driving thin film transistor and including an organic light emitting layer provided between first and second electrodes and a second substrate spaced apart from the first substrate, wherein an outer light blocking layer is formed on the outer side of the second substrate and includes a first refractive layer and a second refractive layer. <CIT> discloses an organic light emitting display panel that comprises a substrate having an emission area and a non-emission area; a black matrix disposed on the non-emission area and comprising at least one open area that exposes at least a portion of a pattern formed on the substrate, wherein the pattern or the exposed portion of the pattern comprises a multi-layer structure comprising a conductive layer and at least one low reflective layer. <CIT> discloses a display device including a plurality of pixels where a plurality of gate lines cross a plurality of data lines, respectively, each of the pixels including a thin film transistor (TFT) region and a display region; a TFT formed in the TFT region; light emitting elements formed in the display region for displaying images based on signals from the TFT; a metallic layer disposed in the TFT region for electrical connection of the TFT; and a light absorbing layer disposed on the metallic layer and configured to absorb at least part of light propagating toward the metallic layer.

<CIT> discloses a sealing film of an organic light emitting display device which includes an adhesive layer sealing an organic light emitting device, a plurality of metal layers disposed on the adhesive layer, and a plurality of organic layers. In the sealing film of the organic light emitting display device, the plurality of metal layers and the plurality of organic layers are alternately disposed on the adhesive layer, which improves a barrier characteristic of water permeability.

The inventors of the present invention have performed research into improvement in quality of images, which is lowered due to surface reflection of a display apparatus by external light.

Conventionally, a circular polarizer is attached to a display surface of an electro-luminescence display apparatus to effectively reduce reflection of external light. However, the polarizer is thick and is not flexible. Accordingly, it is difficult to apply the polarizer to a thin electro-luminescence display apparatus, a flexible display apparatus, a rollable display apparatus, a foldable display apparatus and the like.

One objective of the present disclosure is to provide an electro-luminescence display apparatus in which an electro-luminescence display panel can reduce reflectance of external light on its own.

Another objective of the present disclosure is to provide an electro-luminescence display apparatus that can reduce reflectance of external light with a cathode of the electro-luminescence display panel and that can have a small thickness.

Yet another objective of the present disclosure is to provide an electro-luminescence display apparatus in which the electro-luminescence display panel can reduce reflectance of external light and a polarizing plate can be removed, thereby improving luminance.

Objectives of the present disclosure are not limited to what has been described. Additionally, other objectives that have not been mentioned may be clearly understood from the following description by one having ordinary skill in the art to which the present disclosure pertains.

These objects are solved by the subject-matter of the independent claim. Further advantageous embodiments and refinements are described in the respective dependent claims.

The electro-luminescence display apparatus is a bottom-emission type electro-luminescence display apparatus that is configured to emit light toward the transparent substrate. The surface of the transparent substrate via which the light is emitted may be referred to as the rear surface of the transparent substrate. That is, the electro-luminescence display apparatus may be configured to display an image through the rear surface of the transparent substrate.

The external light-absorbing layer may be configured to absorb visible light. The external light-absorbing layer may include at least one or more of pigment black, black resins, graphite, gravure ink, black spray, black enamel, chromium, and low reflective metal.

The electro-luminescence diode may be configured to emit first light toward the first electrode and to emit second light toward the second electrode. The external light-absorbing layer may be configured to absorb the second light, and external light that passes through the transparent substrate.

The external light-absorbing layer may be configured to absorb at least <NUM> % or more of the second light.

The external light-absorbing layer may be configured to absorb external light that is input to the transparent substrate.

The electro-luminescence display apparatus further includes an adhesive layer that is placed on the external light-absorbing layer, and a second substrate that is placed on the adhesive layer. The second substrate comprises opaque metal.

The first electrode may have at least <NUM> % or more of visible light transmittance, and the second electrode may have at least <NUM> % or more of visible light transmittance.

A rear surface of the transparent substrate may be directly exposed to external light.

External light reflectance of a display area of the electro-luminescence display apparatus may be at least <NUM> % or less.

The electro-luminescence display apparatus may further include a bank that is placed on the first electrode and that is overlapped with an edge of the first electrode. The bank may be configured to absorb at least <NUM> % or more of visible light.

The thin-film transistor array of the electro-luminescence display apparatus may include at least a first metallic layer and a second metallic layer, and may further include a light-absorbing layer that is placed on a rear surface of at least one or more of the first metallic layer and the second metallic layer. The rear surfaces of the at least one or more of the first metallic layer and the second metallic layer may face in the same direction as the rear surface of the transparent substrate. In other words, the light-absorbing layer may be arranged between at least one or more of the first metallic layer and the second metallic layer and the transparent substrate.

The electro-luminescence display apparatus may further include a phase-correction layer that is placed between at least one or more metallic layers and the light-absorbing layer.

The light-absorbing layer may include one of copper oxide, nickel oxide, molybdenum oxide, and oxide of an alloy that includes two or more of copper/nickel/molybdenum.

The phase-correction layer may include one of silicon nitride, IGZO and ITO.

A second encapsulation unit may be further placed on the external light-absorbing layer of the electro-luminescence display apparatus.

In some embodiments, a color filter may be further provided between the transparent substrate and the first electrode.

In some embodiments, an anti-reflection coating may be further provided on the rear surface of the transparent substrate.

In some embodiments, at least one or more buffer layers that consist of silicon oxide (SiO<NUM>) or silicon nitride (SiNx), which are an inorganic insulation material, may be further formed between the semiconductor layer and the transparent substrate.

The electro-luminescence display apparatus according to embodiments may include a thin-film transistor array that is formed on a transparent substrate, a first electrode on the thin-film transistor array, an electro-luminescence diode on the thin-film transistor array, a second electrode on the electro-luminescence diode, and an external light-absorbing layer that is placed on the second electrode and is configured to absorb external light passing through the transparent substrate, the first electrode, the electro-luminescence diode, and the second electrode so as to improve an ambient light contrast ratio.

The transparent substrate may be configured to display an image through the rear surface thereof. The transparent substrate may not include a polarizing plate on the rear surface thereof. The rear surface of the transparent substrate may be configured to contact air. The rear surface of the transparent substrate may be provided with an anti-reflection coating.

Details of other embodiments are included in the detailed description and the drawings.

The electro-luminescence display apparatus according to embodiments may improve quality of images because the external light-absorbing layer absorbs external light that is input through the transparent substrate.

Effects of the present disclosure are not limited to what is mentioned above, and various effects are included in the present disclosure.

Advantages and features of the present disclosure, and methods for implementing the advantages and features are clearly understood from the following detailed description of embodiments in conjunction with the attached drawings. The inventive subject matter of the present disclosure, however, may be embodied in various different forms, and should not be construed as being limited to the embodiments set forth hereunder. Rather, the embodiments are provided as examples so that the disclosure will be thorough and complete, and will fully convey the scope of the disclosure to one having ordinary skill in the art. The present disclosure should be defined only according to the scope of the appended claims.

The shapes, sizes, ratios, angles, and number of elements illustrated in the drawings for describing the embodiments are presented only as examples. Accordingly, the present disclosure is not limited to the drawings. Throughout the specification, like reference numerals denote like elements. Additionally, in describing the present disclosure, detailed description of the publicly-known technologies in relation to the disclosure is avoided if it is deemed to make the gist of the disclosure unnecessarily vague. When used in this specification, the terms "comprise", "have", "consist of" and the like imply the presence or addition of other elements. The singular forms "a", "an" and "the" are intended to include the plural forms as well, unless explicitly indicated otherwise.

When interpreted, elements should be interpreted as including a margin of error though not explicitly described.

When spacial terms such as "on", "above", "below", "next to" and the like are used to describe positions of two portions, one or more additional portions may be placed between the two portions unless the term "right" or "directly" is used.

When an element or a layer is described as being "on" another element or another layer, the element may or the layer may be placed right on another element or another layer, and an additional element may be interposed between the element or the layer and another element or another layer.

When used to describe various elements, the terms "first", "second" and the like are used herein only to distinguish one element from another element. The elements should not be limited by the terms. Thus, a below-mentioned first element may be a second element within the technical spirit of the present disclosure.

Through the specification, identical reference numerals denote identical elements.

The size and thickness of each of the elements illustrated in the drawings are illustrated for convenience of description, and the elements are not necessarily limited to the size and thickness illustrated in this specification.

Each of the features of various embodiments of the present disclosure may be partially or entirely coupled or combined. It will be apparent to those skilled in the art that the embodiments may be technically linked and operated in various ways and that each embodiment may be implemented independently and codependently.

Embodiments of the present disclosure are described below with reference to the attached drawings.

<FIG> is a sectional view schematically illustrating an electro-luminescence display apparatus according to an embodiment not falling within the scope of the invention.

Hereunder, the electro-luminescence display apparatus <NUM> according to an embodiment is described with reference to <FIG>. The electro-luminescence display apparatus <NUM> according to an embodiment may include a transparent substrate <NUM>, a thin-film transistor array <NUM> that is placed on the transparent substrate <NUM>, a first electrode <NUM> that is placed on the thin-film transistor array <NUM>, an electro-luminescence diode <NUM> that is placed on the first electrode <NUM>, a second electrode <NUM> that is placed on the electro-luminescence diode <NUM>, an encapsulation unit <NUM> that is placed on the second electrode <NUM>, and an external light-absorbing layer <NUM> that is placed on the encapsulation unit <NUM>.

The electro-luminescence display apparatus <NUM> may include a display area in which a plurality sub pixels, each sub pixel including the thin-film transistor array <NUM>, the first electrode <NUM>, the electro-luminescence diode <NUM>, and the second electrode <NUM> on the transparent substrate <NUM>, are arranged. The plurality of sub pixels may be grouped or arranged in a plurality of pixels. That is, the display area of the electro-luminescence display apparatus <NUM> may include a plurality of pixels, each pixel including a plurality of sub pixels. Each of the sub pixels may be configured to emit visible light in a range of specific wavelengths on the basis of an image signal that is supplied through the thin-film transistor array <NUM>. Accordingly, the electro-luminescence display apparatus <NUM> may display an image.

The transparent substrate <NUM> is configured to be transparent to visible light. Accordingly, light that displays an image may be displayed through the transparent substrate <NUM>. Additionally, external light may pass through the transparent substrate <NUM>. The transparent substrate <NUM> may be configured to include at least glass or plastics. The transparent substrate <NUM> may have the property of rigidity or flexibility. Thus, the transparent substrate <NUM> may transmit external light.

The thin-film transistor array <NUM> may include a semiconductor layer <NUM>, a first metallic layer <NUM> that is overlapped with the semiconductor layer <NUM> and that supplies a scanning signal, a first insulation layer <NUM> that electrically insulates the semiconductor layer <NUM> and the first metallic layer <NUM>, a second metallic layer <NUM> that is electrically connected with the semiconductor layer <NUM> and that is electrically insulated from the first metallic layer <NUM>, and a second insulation layer <NUM> that electrically insulates the first metallic layer <NUM> and the second metallic layer <NUM>.

The semiconductor layer <NUM> may consist of silicon, polysilicon, oxide semiconductor and the like. A part of the semiconductor layer <NUM> may be doped with impurities to become conductive. The area that becomes conductive may be referred to as a source or a drain. An area that does not become conductive may be referred to as a channel. However, in the present disclosure, a material of the semiconductor layer <NUM> is not restricted.

The first metallic layer <NUM> may be a part of a gate line, a data line or a bridge. For example, a part of the first metallic layer <NUM> may be configured to function as a gate line. The first metallic layer <NUM> may consist of a metallic material having the property of low resistance, i.e., any one of aluminum (Al), aluminum alloys (AlNd), copper (Cu), copper alloys, molybdenum (Mo), and molybdenum titanium (MoTi). However, the first metallic layer <NUM> is not limited to what has been described.

The first insulation layer <NUM> may be placed between the semiconductor layer <NUM> and the first metallic layer <NUM>. The first insulation layer <NUM> may consist of an inorganic insulation material. For example, the first insulation layer <NUM> may include silicon oxide (SiO<NUM>) or silicon nitride (SiNx). The first insulation layer <NUM> may be provided with a contact hole such that an electrically conductive material on the first insulation layer <NUM> is electrically connected with an electrically conductive material beneath the first insulation layer <NUM>. The first insulation layer <NUM>, for example, may be a gate insulation film. However, the first insulation layer <NUM> is not limited to what has been described.

The first insulation layer <NUM> is configured to be transparent to visible light. Accordingly, the transparent substrate <NUM> and the first insulation layer <NUM> may transmit external light.

The second metallic layer <NUM> may be a part of a gate line, a data line or a bridge. For example, a part of the second metallic layer <NUM> may be configured to function as a data line. The second metallic layer <NUM> may consist of a metallic material having the property of low resistance, i.e., any one of aluminum (Al), an aluminum-neodymium alloy (AlNd) , copper (Cu), a copper alloy, molybdenum (Mo), and molybdenum titanium (MoTi). However, the second metallic layer <NUM> is not limited to what has been described.

The second insulation layer <NUM> may be placed between the first metallic layer <NUM> and the second metallic layer <NUM>. The second insulation layer <NUM> may consist of an inorganic insulation material. For example, the second insulation layer <NUM> may include silicon oxide (SiO<NUM>) or silicon nitride (SiNx). The second insulation layer <NUM> may be provided with a contact hole such that an electrically conductive material on the second insulation layer <NUM> is electrically connected with an electrically conductive material beneath the second insulation layer <NUM>. However, the second insulation layer <NUM> is not limited to what has been described.

The second insulation layer <NUM> is configured to be transparent to visible light. Accordingly, the transparent substrate <NUM>, the first insulation layer <NUM>, and the second insulation layer <NUM> may transmit external light.

An organic layer <NUM> may be placed on the thin-film transistor array <NUM>. The organic layer <NUM> may be configured to compensate a stepped portion caused by patterning of various metallic layers of the thin-film transistor array <NUM>, and a stepped portion caused by patterning of the contact holes. Accordingly, a top surface of the organic layer <NUM> may be flatter than a rear surface of the organic layer <NUM>. The organic layer <NUM> is configured to be transparent to visible light. Accordingly, the transparent substrate <NUM>, the first insulation layer <NUM>, the second insulation layer <NUM>, and the organic layer <NUM> may transmit external light.

The first electrode <NUM> may be placed on the organic layer <NUM>. The first electrode <NUM> may be electrically connected with the thin-film transistor array <NUM>. The first electrode <NUM> may be supplied with voltage and/or electric current that correspond to an image signal from the thin-film transistor array <NUM>. For example, the first electrode <NUM> may be electrically connected with the second metallic layer <NUM>. The first electrode <NUM>, for example, may be an anode electrode. The first electrode <NUM> may be electrically connected with the second metallic layer <NUM> via a through-hole in the organic layer <NUM>.

As a transparent electrode, the first electrode <NUM> according to an embodiment may be a material that may have <NUM> % or more of visible light transmittance and that may be used as an anode electrode. Accordingly, the transparent substrate <NUM>, the first insulation layer <NUM>, the second insulation layer <NUM>, the organic layer <NUM>, and the first electrode <NUM> may transmit external light.

The first electrode <NUM>, for example, may include at least one or more of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and Al<NUM>O<NUM> doped ZnO (AZO).

A bank <NUM> may be placed on the first electrode <NUM>. The bank <NUM> may consist of an organic material and may be overlapped with an edge of the first electrode <NUM> in a way that encircles each of the sub pixels. That is, the bank <NUM> is configured to have an opened area that corresponds to a light-emitting area of each sub pixel. Additionally, the electro-luminescence diode <NUM> may be placed in the opened area. The bank <NUM>, for example, may include benzocyclobutene (BCB), polyimide resin, or photo acryl. However, the bank <NUM> is not limited to what has been described.

The bank <NUM> is configured to be transparent to visible light. Accordingly, the transparent substrate <NUM>, the first insulation layer <NUM>, the second insulation layer <NUM>, the organic layer <NUM>, and the bank <NUM> may transmit external light.

The electro-luminescence diode <NUM> may be placed on the first electrode <NUM>. The electro-luminescence diode <NUM> may be commonly formed in the display area or may be formed to correspond to each sub pixel. For example, when the electro-luminescence diode <NUM> is commonly formed in the display area, the electro-luminescence diode <NUM> may be configured to emit white light. In this case, the electro-luminescence diode <NUM> may be formed in the entire display area without an additional mask. When the electro-luminescence diode <NUM> is formed to correspond to the sub pixel, the electro-luminescence diode <NUM> may be configured to emit red light, green light, and blue light. In this case, a red electro-luminescence diode that emits red light, a green electro-luminescence diode that emits green light, and a blue electro-luminescence diode that emits blue light may be respectively formed using a fine metal mask. However, the red electro-luminescence diode, the green electro-luminescence diode, and the blue electro-luminescence diode are not limited to what has been described.

The electro-luminescence diode <NUM> includes a light-emitting layer. The electro-luminescence diode <NUM> may be formed in a single layer or in multiple layers and may further include at least one or more of a hole injection layer, a hole transport layer, and an electron transport layer to enhance performance of the electro-luminescence diode <NUM>. However, the electro-luminescence diode <NUM> is not limited to what has been described. The light-emitting layer may include host or dopant materials that are different for each sub pixel on the basis of wavelengths of emitted light. However, the light-emitting layer is not limited to what has been described.

The electro-luminescence diode <NUM> may be configured to emit light toward the first electrode <NUM> and the second electrode <NUM>. That is, the electro-luminescence diode <NUM> is configured to emit first light toward the first electrode <NUM> and to emit second light toward the second electrode <NUM>.

The electro-luminescence diode <NUM> is configured to be transparent to visible light. Accordingly, the transparent substrate <NUM>, the first insulation layer <NUM>, the second insulation layer <NUM>, the organic layer <NUM>, the first electrode <NUM>, and the electro-luminescence diode <NUM> may transmit external light.

The second electrode <NUM> may be placed on the electro-luminescence diode <NUM>. The second electrode <NUM> may be configured to cover the electro-luminescence diode <NUM>. The second electrode <NUM>, for example, may be a cathode electrode.

As a transparent electrode, the second electrode <NUM> according to an embodiment may be a material that may have <NUM> % or more of visible light transmittance and that may be used as a cathode electrode.

The second electrode <NUM>, for example, may include at least one or more of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and Al<NUM>O<NUM> doped ZnO (AZO). The electro-luminescence diode <NUM> is configured to be transparent to visible light. Accordingly, the transparent substrate <NUM>, the first insulation layer <NUM>, the second insulation layer <NUM>, the organic layer <NUM>, the first electrode <NUM>, the electro-luminescence diode <NUM>, and the second electrode <NUM> may transmit external light.

The encapsulation unit <NUM> may be placed on the electro-luminescence diode <NUM>. The encapsulation unit <NUM> may consist of an inorganic insulation material. For example, the encapsulation unit <NUM> may include at least silicon oxide (SiO<NUM>), silicon nitride (SiNx) or aluminum oxide (Al<NUM>O<NUM>). The encapsulation unit <NUM> protects the electro-luminescence diode <NUM> from oxygen and moisture. Accordingly, the encapsulation unit <NUM> may be thicker than the first insulation layer <NUM> and the second insulation layer <NUM> to enhance the performance of preventing oxygen and moisture. However, the encapsulation unit <NUM> is not limited to what has been described.

The encapsulation unit <NUM> may be formed in a single layer but may not be limited. The encapsulation unit <NUM> may have a structure in which at least one or more of inorganic insulation layers and at least one or more of organic insulation layers are stacked.

The encapsulation unit <NUM> is configured to be transparent to visible light. Accordingly, the transparent substrate <NUM>, the first insulation layer <NUM>, the second insulation layer <NUM>, the organic layer <NUM>, the first electrode <NUM>, the electro-luminescence diode <NUM>, the second electrode <NUM>, and the encapsulation unit <NUM> may transmit external light.

The external light-absorbing layer <NUM> may be placed on the encapsulation unit <NUM>. The external light-absorbing layer <NUM> may be configured to absorb external light that is transmitted up to the external light-absorbing layer <NUM> through the transparent substrate <NUM> and to reduce re-reflection of the external light toward the transparent substrate <NUM>. That is, the external light-absorbing layer <NUM> is configured to absorb visible light.

Preferably, the external light-absorbing layer <NUM> may be configured to absorb at least <NUM> % or more of visible light. More preferably, the external light-absorbing layer <NUM> may be configured to absorb at least <NUM> % or more of visible light.

The external light-absorbing layer <NUM>, for example, may include at least one or more of pigment black, black resins, graphite, black ink, gravure ink, black spray, black enamel, chromium (Cr), and low reflective metal.

Further, the electro-luminescence display apparatus <NUM> according to an embodiment may be a bottom-emission type electro-luminescence display apparatus that is configured to emit light toward the transparent substrate <NUM>.

In a conventional bottom-emission type electro-luminescence display apparatus, a conventional cathode electrode consists of a reflective material with high reflectance of visible light. This is to improve luminance of a conventional electro-luminescence display apparatus by reflecting second light that is emitted toward the conventional reflective cathode electrode toward the transparent substrate <NUM>. However, the conventional reflective cathode also reflects external light. Thus, a contrast ratio of external light drops, and the quality of images is reduced.

A greater amount of external light reflected from the display area of an electro-luminescence display apparatus <NUM> leads to a lower quality of images of the electro-luminescence display apparatus <NUM>. Additionally, brightness of external light that is reflected from the display area is much higher than maximum brightness of an image of the electro-luminescence display apparatus <NUM>. Accordingly, quality of the image recognized by a user is greatly affected by the amount of reflection of external light.

In the electro-luminescence display apparatus <NUM> according to an embodiment, the external light-absorbing layer <NUM> is configured to absorb second light that is emitted from the electro-luminescence diode <NUM> and at the same time, absorb external light that reaches the external light-absorbing layer <NUM> through the transparent substrate <NUM>.

That is, the external light-absorbing layer <NUM> is configured to simultaneously absorb second light that is output from the electro-luminescence diode <NUM>, and external light that passes through the transparent substrate <NUM>. Unlike the conventional reflective cathode electrode, the external light-absorbing layer <NUM> according to an embodiment may reduce maximum luminance of the electro-luminescence display apparatus <NUM> because light that would be reflected toward the transparent substrate <NUM> is absorbed, but may improve the quality of images, which is lowered due to reflection of external light.

That is, external light reflectance of the electro-luminescence display apparatus <NUM> may be effectively reduced because the external light-absorbing layer <NUM> according to an embodiment may effectively absorb external light that is input through the transparent substrate <NUM>. The external light-absorbing layer <NUM> may be configured to cover the entire display area of the electro-luminescence display apparatus <NUM>. Accordingly, the external light-absorbing layer <NUM> may absorb external light of the entire display area of the electro-luminescence display apparatus <NUM>. As a result, an ambient light contrast ratio may improve.

Additionally, when external light is absorbed by the external light-absorbing layer <NUM>, a polarizing plate provided on the rear surface of the transparent substrate <NUM> may not be required. Accordingly, the external light may be directly input to the transparent substrate <NUM> without passing through the polarizing plate. When the polarizing plate is removed, an increase in thickness of the electro-luminescence display apparatus, which is cause by the polarizing plate, may not occur, and manufacturing costs may be reduced.

Further, a conventional polarizing plate has about <NUM> % of visible light transmittance. Accordingly, luminance of a convention display apparatus is reduced due to the polarizing plate. Additionally, in the electro-luminescence display apparatus <NUM> according to the embodiments of the present disclosure, about <NUM> % of first light is output toward the first electrode <NUM>, and about <NUM> % of second light is output toward the second electrode <NUM>.

Accordingly, in comparison between luminance of a conventional display apparatus including a polarizing plate and luminance of the display apparatus including the external light-absorbing layer according to the embodiments of the present disclosure, the display apparatus including the external light-absorbing layer may achieve about <NUM>% of luminance on the basis of first light while the conventional display apparatus including a polarizing plate may achieve about <NUM>% of luminance on the basis of first light. Thus, the display apparatus of the present disclosure may provide luminance higher than that of the conventional display apparatus.

Further, the polarizing plate has low flexibility. Thus, when being bent, the polarizing plate may have a crack. As a result, the polarizing plate may reduce flexibility of the electro-luminescence display apparatus <NUM>. However, the electro-luminescence display apparatus <NUM> according to an embodiment does not require a polarizing plate. Thus, the electro-luminescence display apparatus <NUM> may be applied to a rollable display apparatus, a foldable display apparatus and the like.

<FIG> is a sectional view schematically illustrating an electro-luminescence display apparatus according to another embodiment not falling within the scope of the invention.

The electro-luminescence display apparatus <NUM> according to another embodiment is described below with reference to <FIG>. The electro-luminescence display apparatus <NUM> according to another embodiment is substantially similar to the electro-luminescence display apparatus <NUM> according to an embodiment. Accordingly, repetition of description is avoided for convenience of description.

Preferably, a bank <NUM> of the electro-luminescence display apparatus <NUM> according to another embodiment may be configured to absorb at least <NUM> % or more of visible light. More preferably, the bank <NUM> may be configured to absorb at least <NUM> % or more of visible light. The bank <NUM>, for example, may further include at least one or more of pigment black, black resins, graphite, black ink, gravure ink, black spray, and black enamel. With the above-described configuration, external light may be absorbed by the bank <NUM> before reaching the external light-absorbing layer <NUM>. Additionally, external light that passes through an opened area of the bank <NUM>, i.e., an area of the first electrode <NUM> may be absorbed by the external light-absorbing layer <NUM>. With the above-described configuration, an ambient light contrast ratio of the electro-luminescence display apparatus <NUM> may improve further.

A light-absorbing layer <NUM> may be further placed on rear surfaces of the first metallic layer <NUM> and the second metallic layer <NUM> of the electro-luminescence display apparatus <NUM> according to another embodiment. However, a position of the light-absorbing layeris not limited to what has been described. A phase-correction layer <NUM> may be further placed between the light-absorbing layer <NUM>, and the first and second metallic layers <NUM>,<NUM>.

The light-absorbing layer <NUM>, for example, may be applied to the rear surfaces of the first metallic layer <NUM> and the second metallic layer <NUM> but is not limited to what has been described. The light-absorbing layer <NUM> may also be provided in an area from which external light may be reflected.

The light-absorbing layer <NUM>, for example, may be copper oxide (CuOx), nickel oxide (NiOx), molybdenum oxide (MoOx), or oxide of an alloy that includes two or more of copper/nickel/molybdenum. The light-absorbing layer <NUM>, for example, may consist of metal oxide or alloy oxide, and the metal or the alloy may have an extinction coefficient of a complex refractive index of <NUM> or more. However, the light-absorbing layer <NUM> is not limited to what has been described. The light-absorbing layer <NUM> may consist of applicable metal oxide considering refractive indices, extinction coefficients and the like. With the above-described configuration, the light-absorbing layer <NUM> may absorb external light.

Additionally, the complex refractive index is calculated using n + ik. When a value that is calculated using n and k becomes grater, an amount of light that is absorbed by a material may become greater. In the complex refractive index, when the value k is greater than <NUM>, it means a material is transparent. In the present disclosure, metal oxides with the extinction coefficient k of the complex refractive index of <NUM> or greater is used for a light-absorbing layer, the light-absorbing layer may absorb external light of unpolarized light, thereby enhance the effect of low reflection. That is, when the extinction coefficient of the complex refractive index is <NUM> or greater, low reflection caused by refraction may increase.

The phase-correction layer <NUM>, for example, may be transparent oxide such as silicon nitride (SiNx), indium gallium zinc oxide (IGZO), indium tin oxide (ITO) and the like, which has a refractive index similar to a refractive index of copper oxide (CuOx). However, the phase-correction layer <NUM> is not limited what has been described.

The light-absorbing layer <NUM> and the phase-correction layer <NUM> may have a thickness of <NUM> to <NUM>Å. However, the light-absorbing layer <NUM> and the phase-correction layer <NUM> are not limited to what has been described.

When the phase-correction layer <NUM> is placed on the light-absorbing layer <NUM>, a phase difference may be compensated by destructive interference. Accordingly, phase difference interference is done to external light by the phase-correction layer <NUM> thereby reducing reflectance of the external light further. Specifically, when the light-absorbing layer <NUM> and the phase-correction layer <NUM> has a double-layer structure, reflectance of external light of the first metallic layer <NUM> and the second metallic layer <NUM> may be <NUM> % or less.

A second encapsulation unit <NUM> may be further placed on the external light-absorbing layer <NUM> of the electro-luminescence display apparatus <NUM> according to another embodiment. The second encapsulation unit <NUM> may consist of an inorganic insulation material. For example, the second encapsulation unit <NUM> may include at least silicon oxide (SiO<NUM>), silicon nitride (SiNx) or aluminum oxide (Al<NUM>O<NUM>). However, the second encapsulation unit <NUM> is not limited to what has been described. With the above-described configuration, the second encapsulation unit <NUM> protects the external light-absorbing layer <NUM> from oxygen and moisture, and even when the encapsulation unit <NUM> has a crack, may protect the electro-luminescence display apparatus <NUM>.

<FIG> is a sectional view schematically illustrating an electro-luminescence display apparatus according to an embodiment of the invention.

The electro-luminescence display apparatus <NUM> according to the embodiment is described below with reference to <FIG>. The electro-luminescence display apparatus <NUM> according to the embodiment is substantially similar to the electro-luminescence display apparatus <NUM> according to an embodiment. Accordingly, repetition of description is avoided for convenience of description.

An adhesive layer <NUM> and a second substrate <NUM> are further placed on the external light-absorbing layer <NUM> of the electro-luminescence display apparatus <NUM> according to the embodiment.

The adhesive layer <NUM> may fix the second substrate <NUM>. The adhesive layer <NUM> is placed on the external light-absorbing layer <NUM>. The adhesive layer <NUM> may be a heat-curing adhesive or a pressure-curing adhesive.

The second substrate <NUM> is an opaque metallic substrate, and for example, may be an alloy that includes aluminum (Al), copper (Cu), Invar or two or more metallic materials.

With the above-described configuration, the second substrate <NUM> may protect the electro-luminescence display apparatus <NUM> from external impact. Additionally, when the second substrate <NUM> consists of a material with a high Young's modulus, the second substrate <NUM> may be applied to a rollable display, and may allow the electro-luminescence display apparatus <NUM> to maintain flatness when the electro-luminescence display apparatus <NUM> is unrolled even in the case in which the electro-luminescence display apparatus <NUM> is rolled up for a long time. Further, when the second substrate <NUM> is opaque, the second substrate <NUM> may block external light from being input from a topsurface of the electro-luminescence display apparatus <NUM>. Furthermore, the second substrate <NUM> may protect the external light-absorbing layer <NUM> from oxygen and moisture, and even when the encapsulation unit <NUM> has a crack, may protect the electro-luminescence display apparatus <NUM>.

In some embodiments, a color filter may be further provided between the transparent substrate <NUM> and the first electrode <NUM>.

In some embodiments, an anti-reflection coating may be further provided on the rear surface of the transparent substrate <NUM>. The anti-reflection coating is a coating for reducing surface reflectance of the rear surface of the transparent substrate <NUM>. For example, a material such as MgF<NUM>, Al<NUM>O<NUM>/MgF<NUM>, TiO<NUM>/SiO<NUM>, and the like may be optionally used for the anti-reflection coating. However, the anti-reflection coating is not limited to what has been described.

In some embodiments, at least one or more buffer layers that consist of silicon oxide (SiO<NUM>) or silicon nitride (SiNx), which are an inorganic insulation material, may be further formed between the semiconductor layer <NUM> and the transparent substrate <NUM>. When at least one or more insulation material layers are provided beneath the semiconductor layer <NUM>, a negative effect of alkali ions released from the inside of the transparent substrate <NUM> on properties of the semiconductor layer <NUM> may be reduced. However, the buffer layer is not limited to what has been described.

Embodiments of the present disclosure may be described as follows.

The electro-luminescence display apparatus according to the embodiments may include a transparent substrate, a thin-film transistor array on the transparent substrate, a first electrode on the thin-film transistor array, an electro-luminescence diode on the first electrode, a second electrode on the electro-luminescence diode, an encapsulation unit on the second electrode, and an external light-absorbing layer on the encapsulation unit.

The electro-luminescence diode may be configured to emit first light toward the first electrode and to emit second light toward the second electrode, and the external light-absorbing layer may be configured to absorb the second light and external light that passes through the transparent substrate.

The electro-luminescence display apparatus may further include an adhesive layer that is placed on the external light-absorbing layer, and a second substrate that is placed on the adhesive layer. The second substrate may consist of opaque metal.

External light reflectance of the display area of the electro-luminescence display apparatus may be at least <NUM> % or less.

The electro-luminescence display apparatus may further include a bank that is placed on the first electrode and that is overlapped with an edge of the first electrode, and the bank may be configured to absorb at least <NUM> % or more of visible light.

The thin-film transistor array of the electro-luminescence display apparatus may include at least a first metallic layer and a second metallic layer, and may further include a light-absorbing layer that is placed on a rear surface of at least one or more of the first metallic layer and the second metallic layer.

The light-absorbing layer may include one of copper oxide (CuOx), nickel oxide (Ni-Ox), molybdenum oxide (MoOx), and oxide of an alloy that includes two or more of copper/nickel/molybdenum.

The phase-correction layer may include one of silicon nitride (SiNx), indium gallium zinc oxide (IGZO), and indium tin oxide (ITO).

The electro-luminescence display apparatus according to the embodiments may include a thin-film transistor array that is formed on a transparent substrate, a first electrode on the thin-film transistor array, an electro-luminescence diode on the thin-film transistor array, a second electrode on the electro-luminescence diode, and an external light-absorbing layer that is placed on the second electrode and is configured to absorb external light passing through the transparent substrate, the first electrode, the electro-luminescence diode, and the second electrode so as to improve an ambient light contrast ratio.

The above description is provided only to exemplarily describe the present disclosure.

Claim 1:
A bottom-emission type electro-luminescence display apparatus, comprising:
a transparent substrate (<NUM>), the display apparatus being configured to emit light toward the transparent substrate;
a thin-film transistor array (<NUM>) on the transparent substrate (<NUM>);
a transparent first electrode (<NUM>) on the thin-film transistor array (<NUM>);
an electro-luminescence diode (<NUM>) on the first electrode (<NUM>);
a transparent second electrode (<NUM>) on the electro-luminescence diode (<NUM>);
an encapsulation unit (<NUM>) on the second electrode (<NUM>); and
an external light-absorbing layer (<NUM>) on the encapsulation unit (<NUM>),
characterised in that
the electro-luminescence display apparatus further includes an adhesive layer (<NUM>) on the external light-absorbing layer (<NUM>), and a second substrate (<NUM>) on the adhesive layer (<NUM>), and
wherein the second substrate (<NUM>) comprises opaque metal.