KR102703676B1 - Organic light emitting display device - Google Patents

Abstract

An organic light-emitting display device according to an embodiment of the present invention includes a thin film transistor on a substrate, a planarization layer covering the thin film transistor, a first bank layer, a first electrode on the planarization layer and connected to the thin film transistor, a second bank layer on the first bank layer, an organic material layer on the first electrode, and an organic light-emitting layer, and a light-emitting portion including a second electrode on the light-emitting portion, wherein the first bank layer is formed of the same material as the planarization layer and in the same layer, and the second bank layer includes a black pigment.

Description

ORGANIC LIGHT EMITTING DISPLAY DEVICE

The present invention relates to an organic light emitting display device, and more specifically, to an organic light emitting display device in which reflection by external light can be minimized and an aperture ratio can be improved.

An organic light-emitting display (OLED) is a self-luminous display device that uses an organic light-emitting element that injects holes and electrons into the light-emitting layer from an electrode (anode) for hole injection and an electrode (cathode) for electron injection, respectively, and emits light when excitons formed by combining the injected holes and electrons drop from an excited state to a ground state.

Organic light-emitting display devices can be divided into top emission, bottom emission, and dual emission types depending on the direction in which light is emitted, and can be divided into passive matrix and active matrix types depending on the driving method.

Unlike liquid crystal displays (LCDs), organic light-emitting displays do not require a separate light source, so they can be manufactured as lightweight and thin. In addition, organic light-emitting displays are advantageous in terms of power consumption due to low-voltage operation, and are also excellent in color implementation, response speed, viewing angle, and contrast ratio (CR), so they are being studied as next-generation display devices.

An organic light-emitting display device includes an organic light-emitting element including a plurality of organic light-emitting layers emitting different colors between two electrodes. For example, the organic light-emitting layers may be configured such that a red light-emitting layer for emitting red light, a green light-emitting layer for emitting green light, and a blue light-emitting layer for emitting blue light are separately configured for a red sub-pixel, a green sub-pixel, and a blue sub-pixel, respectively. Each of the light-emitting layers may be pattern-deposited using a mask opened for each sub-pixel, such as a fine metal mask (FMM).

The organic light-emitting display device includes a bank layer for defining each sub-pixel, and the bank layer of the organic light-emitting display device may be made of a transparent material. The light transmitted from the outside through this transparent bank layer is reflected by the metal under the bank layer, causing a problem in that the reflection of the organic light-emitting display device due to external light increases.

Accordingly, the inventor of the present invention recognized the problems mentioned above and invented an organic light emitting display device capable of improving the aperture ratio while minimizing reflection due to external light.

The problem solved by an embodiment of the present invention is to provide an organic light-emitting display device capable of minimizing reflection by external light and improving the aperture ratio by improving the structure of a bank layer of the organic light-emitting display device.

The problems to be solved according to the embodiments of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

In order to solve the aforementioned problems, an organic light-emitting display device is provided that can minimize reflection by external light and improve aperture ratio.

An organic light-emitting display device according to an embodiment of the present invention includes a thin film transistor on a substrate, a planarization layer covering the thin film transistor, a first bank layer, a first electrode on the planarization layer and connected to the thin film transistor, a second bank layer on the first bank layer, an organic material layer on the first electrode, and an organic light-emitting layer, a light-emitting portion including a second electrode on the light-emitting portion, wherein the first bank layer is formed of the same material as the planarization layer and in the same layer, and the second bank layer includes a black pigment.

In another aspect, an organic light-emitting display device according to an embodiment of the present invention including an organic light-emitting layer between a first electrode and a second electrode on a substrate is configured to have a thin film transistor on the substrate, a planarization layer on the thin film transistor including a first region having a first thickness and a second region having a second thickness greater than the first thickness, and a bank layer made of a material including a black pigment on the second region of the planarization layer, so that surface reflection luminance due to external light is minimized compared to a conventional structure, so that outdoor visibility can be improved.

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

According to an organic light-emitting display device according to an embodiment of the present invention, the bank layer is configured to include a first bank layer made of the same material as a planarization layer on a thin film transistor and a second bank layer positioned on the first bank layer and including black pigment, thereby minimizing reflection by external light and reducing surface reflection luminance, thereby improving outdoor visibility of the organic light-emitting display device.

According to an organic light-emitting display device according to an embodiment of the present invention, the bank layer is configured to include a first bank layer made of the same material as a planarization layer on a thin film transistor and a second bank layer positioned on the first bank layer and including a black pigment, thereby improving the optical density of the bank layer, and thus providing an organic light-emitting display device capable of minimizing reflection by external light.

According to an organic light emitting display device according to an embodiment of the present invention, at least a portion of the first electrode is formed to be positioned on an inclined surface of the first bank layer, so that the width of the light emitting area of the organic light emitting display device increases, thereby improving the aperture ratio of the organic light emitting display device.

According to the organic light emitting display device according to an embodiment of the present invention, the manufacturing process of the organic light emitting display device can be simplified by simultaneously forming the first bank layer and the planarization layer by a halftone process.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

Since the content of the invention described in the problem to be solved, the means for solving the problem, and the effect described above does not specify the essential features of the claim, the scope of the claim's rights is not limited by the matters described in the content of the invention.

FIG. 1 is a drawing showing a cross-sectional structure of an organic light-emitting display device according to an embodiment of the present invention.
FIG. 2 is a drawing showing the cross-sectional structure of a light-emitting portion of an organic light-emitting display device according to an embodiment of the present invention.
FIG. 3 is a drawing showing a method for measuring reflection luminance of an organic light-emitting display device according to an embodiment of the present invention.
FIG. 4 is a drawing showing a cross-sectional structure of an organic light-emitting display device according to another embodiment of the present invention.
FIGS. 5A to 5E are drawings for explaining a method for manufacturing an organic light-emitting display device according to an embodiment of the present invention.

The advantages and features of the present invention, and the method for achieving them, will become clear with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and these embodiments are provided only to make the disclosure of the present invention complete and to fully inform a person having ordinary skill in the art to which the present invention belongs of the scope of the invention, and the present invention is defined only by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are exemplary, and therefore the present invention is not limited to the matters illustrated. Like reference numerals refer to like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. When the terms “includes,” “has,” “consists of,” etc. are used in this specification, other parts may be added unless “only” is used. When a component is expressed in singular, it includes a case where the plural is included unless there is a specifically explicit description.

In interpreting components, even if there is no separate explicit description, it is interpreted as including the error range. In the case of a description of a positional relationship, for example, if the positional relationship between two parts is described as 'on', 'above', 'below', 'next to', etc., one or more other parts may be located between the two parts unless 'right' or 'directly' is used.

Also, although the terms first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, a first component mentioned below may also be a second component within the technical concept of the present invention.

The individual features of the various embodiments of the present invention may be partially or wholly combined or combined with each other, and may be technically linked and driven in various ways, and each embodiment may be implemented independently of each other or implemented together in a related relationship.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a drawing showing a cross-sectional structure of an organic light-emitting display device according to an embodiment of the present invention.

Referring to FIG. 1, an organic light emitting display device (100) according to an embodiment of the present invention is configured to include a substrate (110), a thin film transistor (120) positioned on the substrate (110), and a light emitting portion (150) positioned between a first electrode (140) and a second electrode (160) and including a plurality of organic layers and an organic light emitting layer.

The organic light emitting display device (100) includes a plurality of sub-pixels. A sub-pixel refers to a minimum unit area where actual light is emitted. In addition, a plurality of sub-pixels may be gathered together to form a minimum group capable of expressing white light. For example, three sub-pixels may form one group, and a red sub-pixel, a green sub-pixel, and a blue sub-pixel may form one group. Alternatively, four sub-pixels may form one group, and a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel may form one group. However, the present invention is not limited thereto, and various sub-pixel designs are possible. In FIG. 1, only one sub-pixel among the plurality of sub-pixels of the organic light emitting display device (100) is illustrated for convenience of explanation.

In the organic light emitting display device (100) according to the embodiment of the present invention, the substrate (110) is formed of an insulating material to support various components of the organic light emitting display device (100). For example, the substrate (110) may be formed of not only glass, but also a plastic substrate such as PET (PolyEthylene Terephthalate), PEN (PolyEthylene Naphthalate), or polyimide. If the organic light emitting display device is a flexible organic light emitting display device, the substrate (110) may be formed of a flexible material such as plastic. In addition, when an organic light emitting element that is easy to implement in a flexible manner is applied to a vehicle lighting device or an automotive display device, the degree of freedom in the design and various designs of the vehicle lighting device can be secured according to the structure or exterior shape of the vehicle.

A buffer layer (131) may be formed on the substrate (110) to block the penetration of impure elements from the substrate (110) and the outside and to protect various components of the organic light-emitting display device (100). The buffer layer (131) may be formed as a single-layer or multi-layer structure of, for example, a silicon oxide film (SiOx) or a silicon nitride film (SiNx), but is not limited thereto. The buffer layer (131) may be omitted depending on the structure or characteristics of the organic light-emitting display device (100).

A thin film transistor (120) including a semiconductor layer (122), a gate electrode (121), a source electrode (123), and a drain electrode (124) is formed on the buffer layer (131).

Specifically, a semiconductor layer (122) is formed on a substrate (110), and a gate insulating layer (132) is formed on the semiconductor layer (122) to insulate the semiconductor layer (122) and the gate electrode (121). An interlayer insulating layer (133) is formed on the gate electrode (121) to insulate the gate electrode (121) from the source electrode (123) and the drain electrode (124). A source electrode (123) and a drain electrode (124) that are in contact with the semiconductor layer (122) are formed on the interlayer insulating layer (133). The source electrode (123) or the drain electrode (124) is electrically connected to the semiconductor layer (122) through a contact hole.

The semiconductor layer (122) may be formed of amorphous silicon (a-Si), polycrystalline silicon (poly-Si), an oxide semiconductor, or an organic semiconductor. When the semiconductor layer (122) is formed of an oxide semiconductor, it may be formed of any one of the following materials: IGZO (Indium Gallium Zinc Oxide), ZTO (Zinc Tin Oxide), IZO (Indium Zinc Oxide), or ITZO (Indium Tin Zinc Oxide), but is not limited thereto.

The gate insulating layer (132) may be formed as a single-layer or multi-layer structure made of an inorganic insulating material such as a silicon oxide film (SiOx), a silicon nitride film (SiNx), or the like, but is not limited thereto.

The gate electrode (121) performs the function of transmitting a gate signal to the thin film transistor (120), and may be made of at least one metal or alloy of aluminum (Al), molybdenum (Mo), titanium (Ti), and copper (Cu), and may be formed of a single-layer or multi-layer structure of the metal or material, but is not limited thereto.

The source electrode (123) and the drain electrode (124) serve to transmit an electrical signal transmitted from the outside from the thin film transistor (120) to the light emitting portion (150). The source electrode (123) and the drain electrode (124) may be formed of at least one metal or alloy of aluminum (Al), molybdenum (Mo), titanium (Ti), and copper (Cu), and may be formed of a single layer or multi-layer structure of the metal or material, but are not limited thereto.

For convenience of explanation, in this specification, only the driving thin film transistor (120) connected to the first electrode (140) among various thin film transistors that may be included in the organic light emitting display device (100) is illustrated. Each sub-pixel may further include a switching thin film transistor or a capacitor.

A protective layer (170) is formed on the thin film transistor (120). The protective layer (170) may be made of an inorganic insulating material. For example, the protective layer (170) may be made of a silicon oxide film (SiOx) or a silicon nitride film (SiNx), but is not limited thereto.

A planarization layer (134) is formed on the protective layer (170). The planarization layer (134) functions to planarize components such as a thin film transistor (120) on the substrate (110). The planarization layer (134) may be composed of a single layer or multiple layers, and may be made of an organic material. For example, the planarization layer (134) may be made of polyimide, photo acryl, or benzocyclobutene (BCB), but is not limited thereto. The protective layer (170) and the planarization layer (134) include a contact hole (135) for electrically connecting the thin film transistor (120) and the first electrode (140) in each sub-pixel.

Also, referring to FIG. 1, the planarization layer (134) of the organic light-emitting display device (100) according to the embodiment of the present invention may include a first region (R1) having a first thickness (A) and a second region (R2) having a second thickness (B) greater than the first thickness (A). The first thickness (A) may be a thickness from the upper surface of the protective layer (170) to the lower surface of the first electrode (140). And, the second thickness (B) may be a thickness from the upper surface of the protective layer (170) to the lower surface of the second bank layer (145).

An organic light emitting display device (100) according to an embodiment of the present invention includes an emission area (EA) and a non-emission area (NEA), and a first area (R1) of a planarization layer (134) may be positioned to correspond to the emission area (EA), and a second area (R2) may be positioned to correspond to the non-emission area (NEA). More specifically, the planarization layer (134) is formed to have a first thickness (A) in the first area (R1) and a second thickness (B) greater than the first thickness (A) in the second area (R2), so that the planarization layer (134) may be formed thicker in the non-emission area (NEA) than in the emission area (EA).

In addition, the first region (R1) of the planarization layer (134) corresponding to the light-emitting area (EA) of the organic light-emitting display device (100) according to the embodiment of the present invention is located between the second region (R2) of the planarization layer (134) corresponding to the non-light-emitting area (NEA). Therefore, the second region (R2) of the planarization layer (134) can play the role of the first bank layer (134b) defining the light-emitting area (EA) of the organic light-emitting display device (100).

In addition, a planarization layer (134) including a first region (R1) having a first thickness (A) and a second region (R2) having a second thickness (B) greater than the first thickness (A) can be formed through a halftone process using a halftone mask. The halftone mask is a mask having a light-shielding portion, a light-transmitting portion, and a semi-transmitting portion, wherein the light-shielding portion is a portion that blocks light, the light-transmitting portion is a portion that transmits light, and the semi-transmitting portion refers to a portion in which the amount of light transmitted is less than that of the light-transmitting portion. When such a halftone mask is used, patterns having different heights can be formed by differentially applying an amount of light.

That is, the first bank layer (134b) included in the planarization layer (134) may be formed of the same material in the same layer as the planarization layer region (134a), and may be simultaneously patterned through a halftone process. The first bank layer (134b) of the planarization layer (134) may be formed of one of polyimide, photoacryl, or benzocyclobutene (BCB), similarly to the planarization layer region (134a).

In addition, the permittivity of the first bank layer (134b) of the planarization layer (134) of the organic light-emitting display device (100) according to the embodiment of the present invention should be set in consideration of the leakage current to the adjacent sub-pixel. The leakage current is a phenomenon in which current flows to another neighboring sub-pixel through a common organic layer, such as a hole injection layer or a hole transport layer, when current is applied to drive a specific sub-pixel, since the organic layers constituting the light-emitting portion (150) are configured as a common layer to correspond to a plurality of sub-pixels. This leakage current causes other sub-pixels to emit light unintendedly, causing color mixing between the sub-pixels and reducing brightness. Therefore, the first bank layer (134b) of the planarization layer (134) of the organic light-emitting display device (100) according to the embodiment of the present invention should be configured of a material having a low permittivity, and specifically, it is preferable to be configured of a material having a permittivity of 7 F/m or less.

A first electrode (140) is formed on a planarization layer (134). The first electrode (140) may be an anode, and is formed of a conductive material having a relatively large work function value to supply holes to an organic light-emitting layer of a light-emitting portion (150). The first electrode (140) is electrically connected to a thin film transistor (120) through a contact hole (135) provided in a protective layer (170) and a planarization layer (134), and may be electrically connected to, for example, a source electrode (123) of the thin film transistor (120). In addition, the first electrode (140) is spaced apart from each other for each sub-pixel. The first electrode (140) is formed of a transparent conductive material, and may be formed of, for example, a material such as indium tin oxide (ITO), indium zinc oxide (IZO), or the like, but is not limited thereto.

In addition, when the organic light-emitting display device (100) according to an embodiment of the present invention is a top emission type, a reflective layer made of a metal material with excellent reflection efficiency, such as aluminum (Al) or silver (Ag), may be additionally formed on the upper or lower portion of the first electrode (140) so that the light emitted from the organic light-emitting layer of the light-emitting portion (150) can be reflected by the first electrode (140) and emitted more smoothly in the upward direction.

For example, the first electrode (140) may have a two-layer structure in which a transparent conductive layer and a reflective layer formed of a transparent conductive material are sequentially laminated, or a three-layer structure in which a transparent conductive layer, a reflective layer, and a transparent conductive layer are sequentially laminated. The reflective layer may be silver (Ag) or an alloy containing silver, for example, silver (Ag) or APC (Ag/Pd/Cu).

In explaining an embodiment of the present invention, the top emission method means a method in which light emitted from an organic light-emitting layer (153) is emitted in the direction of the second electrode (160), and the bottom emission method means a method in which light is emitted in the direction of the first electrode (140), which is the opposite direction to the top emission method.

Referring to FIG. 1, at least a part of the first electrode (140) of the organic light emitting display device (100) according to an embodiment of the present invention may be positioned on an inclined surface of the first bank layer (134b) of the planarization layer (134). In the case of a conventional organic light emitting display device, the first electrode is positioned below the bank layer, and thus the light emitting area of the conventional organic light emitting display device is limited to the width of the first electrode exposed below the bank layer. On the other hand, when at least a part of the first electrode (140) is positioned on the inclined surface of the first bank layer (134b) as described above, the width of the first electrode (140) can be expanded compared to the conventional structure, and the width of the light emitting area (EA) of the organic light emitting display device can be increased, so that the aperture ratio of the organic light emitting display device can be improved.

In the case of a conventional organic light emitting display device, since the bank layer is formed of a transparent material, light incident from the outside is transmitted through the transparent bank layer and reflected by the first electrode (140) located under the bank layer and including a layer made of a metal material. Therefore, the organic light emitting display device (100) has a problem of reflection due to external light. In addition, when the organic light emitting display device (100) is applied to a vehicle display device, it becomes difficult to apply it to the vehicle display device due to reflection due to external light. Therefore, in order to minimize reflection due to external light of the organic light emitting display device, the second bank layer (145) of the organic light emitting display device (100) according to an embodiment of the present invention should be composed of a material that minimizes reflection of external light.

Referring to FIG. 1, a second bank layer (145) including a black pigment may be arranged on a second region (R2), i.e., a first bank layer (134b), having a second thickness (B) of a planarization layer (134) of an organic light-emitting display device (100) according to an embodiment of the present invention. That is, a photoresist for forming the second bank layer (145) may be composed of a material including a black pigment. The black pigment may be composed of an organic material or an inorganic material.

The black pigment may be composed of carbon-based or metal oxide, etc. In addition, the photoresist may include a photosensitive compound including at least one of a polymer, a monomer, and a photoinitiator. In addition, the photoresist may include a solvent for dispersing the photosensitive compound.

Looking at the reaction mechanism, the photoresist before exposure has a form in which black pigment is dispersed in a photosensitive compound by a solvent. The solvent of the photoresist can be removed in a vacuum drying process or a curing process. Then, after exposure, a photoinitiator included in the photosensitive compound generates radicals by light. Then, the monomer included in the photoresist has a double bond, so it reacts with the radical of the photoinitiator to cross-link. Accordingly, a photoresist having a high molecular weight is formed after exposure, so it does not dissolve by a developer. Then, in the developing process using a developer, the part that is not dissolved by the developer becomes the second bank layer (145), and the part that is dissolved by the developer is removed. Therefore, the photoresist forming the second bank layer (145) can be called a negative photoresist.

And, in order to improve crosslinking after exposure, the photoinitiator included in the photoresist may include an imine-based photoinitiator. The imine-based photoinitiator may include, for example, at least one of an oxime and an oxime ester. The oxime or oxime ester is a long-wavelength photoinitiator and can improve crosslinking. Here, the long wavelength refers to 365 nm or more. And, the light source used during exposure is a high-pressure mercury lamp having multiple wavelengths. The multiple wavelengths may be 436 nm for the G-line, 405 nm for the H-line, and 365 nm for the I-line. Among these, the photolithography process is performed using the I-line of 365 nm or more.

In addition, since oxime or oxime ester can minimize by-products generated after exposure, it can minimize impurities generated when by-products react with other molecules in subsequent processes such as baking after cross-linking. In addition, since oxime or oxime ester is used together with black pigment, there is an effect of forming a second bank layer (145) with high light-shielding properties. Alternatively, acetophenone may be further included in the oxime or oxime ester as a photoinitiator.

For example, oxime can be represented by the chemical formula 1 below.

Here, R, R’ can be one of an alkyl group or a phenyl group having 1 to 15 carbon atoms.

For example, an oxime ester can be represented by the chemical formula 2 below.

Here, R is an aryl group, and R’ can be either an alkyl group having 1 to 15 carbon atoms or a phenyl group.

The monomer may include a 6-functional group, and may include, for example, DPHA (DiPentaerythritol HexaAcrylate). This DPHA has a double bond and can be quickly cured by light after cross-linking. Accordingly, the photoresist for forming the second bank layer (145) can be formed into a hard film, and the developing resistance is improved, so that the film is not washed away even in a developing process with a high concentration of a developer.

And, the polymer of the photoresist includes a cardo-based polymer. The cardo-based polymer has excellent heat resistance and compatibility with pigments, and excellent solubility. And, the polymer of the photoresist may further include epoxy acrylate. Therefore, the polymer of the photoresist including the cardo-based or epoxy acrylate improves dispersibility by allowing the black pigment to be well dispersed within the polymer. Dispersibility refers to the uniformity of the photoresist, and as the dispersibility improves, a more uniform second bank layer (145) can be formed.

For example, a polymer of the cardo series can be expressed by the chemical formula 3 below.

And, the developer can be, for example, TMAH (TetraMethylAmmoniumHydroxide) or KOH (Potassium Hydroxide).

In addition, since the second bank layer (145) includes a black pigment, the optical density (OD), which indicates the degree of light blocking, increases. If the optical density increases, reflection by external light can be minimized. However, if the optical density becomes excessively high, the dielectric constant increases and leakage current may occur to adjacent sub-pixels. Therefore, considering this, the optical density of the second bank layer (145) is preferably 4 or less.

In addition, since the second bank layer (145) is composed of a material including a black pigment, when the incident angle of the incident light is 45 degrees, the reflection luminance at a reflection angle of 30 degrees can be composed of 30 nits or less. Therefore, the reflection due to external light can be improved, and the reflection luminance can be reduced. The reflection luminance of the second bank layer (145) is measured by DMS803. Here, the reflection luminance can include the reflection luminance at the left and right of the organic light emitting display device. That is, the left and right reflection luminance can be 30 nits or less at a reflection angle of 30 degrees when the incident angle of the incident light is 45 degrees. In addition, when the organic light emitting display device is applied to a vehicle display device, a display device with minimized reflection due to external light can be provided. In addition, since the reflection due to external light of the organic light emitting display device can be minimized, the visual characteristics of the organic light emitting display device in the left and right directions can be improved.

In the case of a bank layer including black pigment, since the taper characteristic of the bank layer was not good during the formation process, patterning was not easy and it was difficult to increase the optical density. However, in the case of the organic light emitting display device (100) according to the embodiment of the present invention, by forming a first bank layer (134b) made of the same material in the same layer as the planarization layer (134) and forming a second bank layer (145) on the first bank layer (134b) of a material including black pigment, it is possible to provide an organic light emitting display device capable of forming a bank layer with improved optical density while minimizing leakage current.

Also, referring to FIG. 1, in order for a multi-layer bank layer to be stably formed, the width of the lower portion of the second bank layer (145) may be formed smaller than the width of the upper portion of the second region (R2) having the second thickness (B) of the flattening layer (134), i.e., the first bank layer (134b).

A light-emitting portion (150) is formed on the first electrode (140), the first bank layer (134b), and the second bank layer (145). The light-emitting portion (150) may include various organic layers as needed, and may also be configured to include a plurality of organic light-emitting layers. The organic layers may include at least one hole injection layer (151), a hole transport layer (152), and an electron transport layer (154). In addition, the plurality of organic layers included in the light-emitting portion (150) may have a common layer structure so as to correspond to all of the red sub-pixel (R), the green sub-pixel (G), and the blue sub-pixel (B).

A second electrode (160) is formed on the light-emitting portion (150). The second electrode (160) may be a cathode, and is formed of a conductive material having a low work function because it must supply electrons to the organic light-emitting layer of the light-emitting portion. More specifically, the second electrode (160) may be a metal material such as magnesium (Mg), silver-magnesium (Ag:Mg), etc., but is not limited thereto.

In addition, when the organic light emitting display device (100) according to the embodiment of the present invention is a top emission type, the second electrode (160) may be made of a transparent conductive oxide of the indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO), and tin oxide (TiO) series, but is not limited thereto.

That is, the organic light emitting display device (100) according to the embodiment of the present invention is configured such that the planarization layer (134) on the thin film transistor includes a first region (R1) having a first thickness (A) and a second region (R2) having a second thickness (B) greater than the first thickness (A), and includes a bank layer (145) made of a material including black pigment on the second region (R2) of the planarization layer (134), thereby minimizing reflection by external light compared to a conventional structure, thereby reducing surface reflection luminance, thereby improving the outdoor visibility of the organic light emitting display device. In addition, the organic light emitting display device (100) according to the embodiment of the present invention is configured such that at least a portion of the first electrode (140) is positioned on an inclined surface of the second region (R2), thereby increasing the width of the light emitting area (EA) of the organic light emitting display device (100), thereby improving the aperture ratio of the organic light emitting display device. In addition, in the organic light emitting display device (100) according to the embodiment of the present invention, the first bank layer (134b) can be formed simultaneously with the planarization layer (134) through a halftone process, so that the manufacturing process of the organic light emitting display device can be simplified.

FIG. 2 is a drawing showing the cross-sectional structure of a light-emitting portion of an organic light-emitting display device according to an embodiment of the present invention.

Referring to FIG. 2, the light emitting unit (150) of the organic light emitting display device (100) according to an embodiment of the present invention will be described in more detail.

Referring to FIG. 2, the light emitting part (150) of the organic light emitting display device (100) according to the embodiment of the present invention includes an organic emitting layer (EML) including a hole injection layer (151, Hole Injection Layer: HIL) disposed on a first electrode (140), a first hole transport layer (152a, 1st Hole Transport Layer: 1st HTL) disposed on the hole injection layer (151), a second hole transport layer (152b, 2nd Hole Transport Layer: 2nd HTL) and a third hole transport layer (152c, 3rd Hole Transport Layer: 3rd HTL) disposed on the first hole transport layer (152a), a red emitting layer (153a), a green emitting layer (153b), and a blue emitting layer (153c) disposed on the hole transport layers (152a, 152b, 152c), and an organic emitting layer (EML) disposed on the organic emitting layer. It includes a deployed electron transport layer (154, Electron Transport Layer: ETL).

The first electrode (140) is placed on the planarization layer (134) so as to correspond to each of the red sub-pixel region (R), the green sub-pixel region (G), and the blue sub-pixel region (B) defined on the substrate.

The hole injection layer (151) is placed on the first electrode (140) as a common layer so as to correspond to all of the red sub-pixel region (R), the green sub-pixel region (G), and the blue sub-pixel region (B).

The hole injection layer (151) can play a role in facilitating hole injection, and may be formed of HATCN (1,4,5,8,9,11-hexaazatriphenylene-hexanitrile), CuPc (cupper phthalocyanine), PEDOT (poly(3,4)-ethylenedioxythiophene), PANI (polyaniline), and NPD (N,N-dinaphthyl-N,N'-diphenylbenzidine), TPD (N,N′-Bis(3-methylphenyl)-N,N′-bis(phenyl)-benzidine), α-NPB (Bis[N-(1-naphthyl)-N-phenyl]benzidine), TDAPB (1,3,5-tris(4-diphenylaminophenyl)benzene), TCTA (Tris(4-carbazoyl-9-yl)triphenylamine), It may be composed of at least one substance selected from the group consisting of spiro-TAD (2,2′,7,7′-Tetrakis(N,N-diphenylamino)-9,9-spirobifluorene) and CBP (4,4′-bis(carbazol-9-yl)biphenyl), but is not limited thereto.

The hole injection layer (151) may also be formed by doping a p-type dopant into the material forming the first hole transport layer (152a). In this case, the hole injection layer (151) and the second hole transport layer (152a) may be formed in a continuous process using one process device. The p-type dopant may be formed of F4-TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinidimethane), but is not limited thereto.

The first hole transport layer (152a) is disposed on the hole injection layer (151) as a common layer so as to correspond to all of the red sub-pixel region (R), the green sub-pixel region (G), and the blue sub-pixel region (B). The first hole transport layer (152a) serves to facilitate the transport of holes, and may be formed of one or more of NPD (N,N-dinaphthyl-N,N'-diphenylbenzidine), TPD (N,N'-bis-(3-methylphenyl)-N,N'-bis-(phenyl)-benzidine), spiro-TAD (2,2′,7,7′-Tetrakis(N,N-diphenylamino)-9,9-spirobifluorene), and MTDATA (4,4',4"-Tris(N-3-methylphenyl-N-phenyl-amino)-triphenylamine), but is not limited thereto.

The second hole transport layer (152b) is disposed on the first hole transport layer (152a) of the red sub-pixel region (R). In addition, the third hole transport layer (152c) is disposed on the first hole transport layer (152a) of the green sub-pixel region (G).

The second hole transport layer (152b) and the third hole transport layer (152c) serve to smoothly transfer holes from the hole injection layer (151) to the red light-emitting layer (153a) and the green light-emitting layer (153b), respectively.

In addition, the thickness of each of the second hole transport layer (152b) and the third hole transport layer (152c) can form an optical distance of a micro cavity. More specifically, the thickness of each of the second hole transport layer (152b) and the third hole transport layer (152c) can be determined such that the red light-emitting layer (153a) forms a micro cavity structure between the first electrode (140) and the second electrode (160), and the green light-emitting layer (153b) forms a micro cavity structure between the first electrode (140) and the second electrode (160), thereby forming an optical distance of the micro cavity in the red sub-pixel region (R) and the green sub-pixel region (G), thereby improving the efficiency of the organic light-emitting display device (100).

The red light-emitting layer (153a) is arranged on the second hole transport layer (152b) of the red sub-pixel region (R). The red light-emitting layer (153a) may include a light-emitting material that emits red light, and the light-emitting material may be formed using a phosphorescent material or a fluorescent material.

More specifically, the red light-emitting layer (153a) may include a host material including CBP (carbazole biphenyl) or mCP (1,3-bis(carbazol-9-yl)benzene), and may be formed of a phosphorescent material including a dopant including at least one of Ir(btp)2(acac)(bis(2-benzo[b]thiophen-2-yl-pyridine)(acetylacetonate)iridium(III)), Ir(piq)2(acac)(bis(1-phenylisoquinoline)(acetylacetonate)iridium(III)), Ir(piq)3(tris(1-phenylquinoline)iridium(III)), and PtOEP(octaethylporphyrin platinum), and alternatively, may be formed of a fluorescent material including PBD:Eu(DBM)3(Phen) or Perylene, but is not limited thereto.

The green light-emitting layer (153b) is arranged on the third hole transport layer (152c) of the green sub-pixel region (G). The green light-emitting layer (153b) may include a light-emitting material that emits green light, and the light-emitting material may be formed using a phosphorescent material or a fluorescent material.

More specifically, the green light-emitting layer (153b) may include a host material including CBP or mCP, and may be formed of a phosphorescent material including a dopant material such as an iridium complex including Ir(ppy)3(tris(2-phenylpyridine)iridium(III)) or Ir(ppy)2(acaa)(bis(2-phenylpyridine)(acetylacetonate)iridium(III), or alternatively, may be formed of a fluorescent material including Alq3(tris(8-hydroxyquinolino)aluminium), but is not limited thereto.

The blue light-emitting layer (153c) is arranged on the first hole transport layer (152a) of the blue sub-pixel region (Bp). The blue light-emitting layer (153c) may include a light-emitting material that emits blue light, and the light-emitting material may be formed using a phosphorescent material or a fluorescent material.

More specifically, the blue light-emitting layer (153c) may include a host material including CBP or mCP, and may be formed of a phosphorescent material including a dopant material including FIrPic (bis(3,5,-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III)). In addition, it may be formed of a fluorescent material including any one of DPVBi(4,4'-bis[4-di-p-tolylamino)stryl)biphenyl), DSA(1-4-di-[4-(N,N-di-phenyl)amino]styryl-benzene), PFO(polyfluorene)-based polymer, and PPV(polyphenylenevinylene)-based polymer, but is not limited thereto.

The electron transport layer (154) is arranged on the red light-emitting layer (153a), the green light-emitting layer (153b), and the blue light-emitting layer (153c) so as to correspond to all of the red sub-pixel region (R), the green sub-pixel region (G), and the blue sub-pixel region (B).

The electron transport layer (154) can play a role in transporting and injecting electrons, and the thickness of the electron transport layer (154) can be adjusted in consideration of the electron transport characteristics.

The electron transport layer (154) plays a role in facilitating electron transport and may be composed of one or more of Liq (8-hydroxyquinolinolato-lithium), Alq3 (tris (8-hydroxyquinolinato) aluminum), PBD (2-(4-biphenylyl)-5-(4-tert-butylpheny)-1,3,4oxadiazole), TAZ (3-(4-biphenyl)4-phenyl-5-tert-butylphenyl-1,2,4-triazole), spiro-PBD, and BAlq (bis (2-methyl-8-quinolinolate)-4-(phenylphenolato) aluminum), but is not limited thereto.

Additionally, it is possible to additionally form an electron injection layer (EIL) on the electron transport layer (154).

The electron injection layer (EIL) may be composed of metal-inorganic compounds such as, but not limited to, BaF2, LiF, NaCl, CsF, Li2O, and BaO.

Here, the structure is not limited according to the embodiment of the present invention, and at least one of the hole injection layer (151), the first hole transport layer (152a), the second hole transport layer (152b), the third hole transport layer (153c), and the electron transport layer (154) may be omitted. In addition, it is also possible to form one of the hole injection layer (151), the first hole transport layer (152a), the second hole transport layer (152b), the third hole transport layer (153c), and the electron transport layer (154) as two or more layers.

The second electrode (160) is placed on the electron transport layer (154) so as to correspond to all of the red sub-pixel region (R), the green sub-pixel region (G), and the blue sub-pixel region (B).

A capping layer may be disposed on the second electrode (160). The capping layer is intended to improve the light extraction effect of the organic light-emitting display device, and may be formed of any one of the host materials of the first hole transport layer (152a), the electron transport layer (154), the red light-emitting layer (153a), the green light-emitting layer (153b), and the blue light-emitting layer (153c). In addition, the capping layer may be omitted depending on the structure or characteristics of the organic light-emitting display device (100).

The organic light-emitting layer (153) of the organic light-emitting display device (100) according to an embodiment of the present invention may be configured to include at least one phosphorescent material. More specifically, the organic light-emitting layer (153) may be configured to include a red light-emitting layer (153a) for emitting red light located in a red sub-pixel (R), a green light-emitting layer (153b) for emitting green light located in a green sub-pixel (G), and a blue light-emitting layer (153c) for emitting blue light located in a blue sub-pixel (B). Here, the red light-emitting layer (153a) may include a phosphorescent material, the green light-emitting layer (153b) and the blue light-emitting layer (153c) may include a fluorescent material, or the red light-emitting layer (153a) and the green light-emitting layer (153b) may include a phosphorescent material, and the blue light-emitting layer (153c) may include a fluorescent material, or the red light-emitting layer (153a), the green light-emitting layer (153b) and the blue light-emitting layer (153c) may all include a phosphorescent material.

And, the organic light emitting display device (100) according to the embodiment of the present invention can be applied to display devices including TVs, mobiles, tablet PCs, monitors, laptop computers, vehicle display devices, and vehicle lighting devices. Or, it can be applied to wearable display devices, foldable display devices, and rollable display devices.

FIG. 3 is a drawing showing a method for measuring reflection luminance of an organic light-emitting display device according to an embodiment of the present invention.

Referring to FIG. 3, the reflection luminance refers to the luminance of the reflected light reflected at a reflection angle of 30 degrees among several reflected lights (Y) when 400 Knit light is incident at a 45 degree angle (in FIG. 3, the incident light is indicated as "X") on the organic light emitting display device (100). This reflection luminance is measured by the DMS803 equipment. Taking the reflection luminance of the organic light emitting display device (100) of FIG. 1 measured using this equipment as an example, the reflection luminance is 300 nit or more at a reflection angle of 30 degrees when 400 Knit is incident at an incident angle of 45 degrees. When the reflection luminance is 300 nit or more, the problem of the left and right visual characteristics of the organic light emitting display device (100) being deteriorated due to reflection by external light occurs. Therefore, in order to minimize reflection by external light of the organic light emitting display device (100), the bank layer must be composed of a material that does not reflect light transmitted from the outside. Accordingly, the inventor of this specification conducted several experiments to improve the material of the bank layer.

The inventor of the present invention, through several experiments, has formed the bank layer with a material containing black pigment so as to minimize reflection of external light.

That is, as described with reference to FIG. 1, in the case of the organic light emitting display device (100) according to the embodiment of the present invention, the planarization layer (134) on the thin film transistor is configured to include a first region (R1) having a first thickness (A) and a second region (R2) having a second thickness (B) greater than the first thickness (A), and a bank layer (145) made of a material including black pigment is configured on the second region (R2) of the planarization layer (134), so that when the incident angle of light incident on the organic light emitting display device (100) is 45 degrees, the reflection luminance at a reflection angle of 30 degrees can be configured to be 30 nits or less. Therefore, the organic light emitting display device (100) according to the embodiment of the present invention can improve the outdoor visibility of the organic light emitting display device by minimizing reflection by external light compared to a conventional structure and reducing the surface reflection luminance.

FIG. 4 is a drawing showing a cross-sectional structure of an organic light-emitting display device according to another embodiment of the present invention.

In describing an organic light emitting display device (200) according to another embodiment of the present invention, redundant detailed descriptions of components identical or corresponding to those in the previously described embodiments will be omitted or briefly described.

Referring to FIG. 4, an organic light emitting display device (200) according to another embodiment of the present invention is configured to include a substrate (210), a thin film transistor (220) positioned on the substrate (210), and a light emitting portion (250) positioned between a first electrode (240) and a second electrode (260) and including a plurality of organic layers and an organic light emitting layer.

A buffer layer (231) may be formed on the substrate (210) to block penetration of impure elements from the substrate (210) and the outside and to protect various components of the organic light-emitting display device (200).

A thin film transistor (220) including a semiconductor layer (222), a gate insulating layer (232), a gate electrode (221), an interlayer insulating layer (233), a source electrode (223), and a drain electrode (224) is formed on a buffer layer (231). A protective layer (270) is formed on the thin film transistor (220).

A planarization layer (234) is formed on the protective layer (270). The planarization layer (234) has a function of planarizing components such as a thin film transistor (220) on the substrate (210). For example, the planarization layer (234) may be made of polyimide, photo acryl, or benzocyclobutene (BCB), but is not limited thereto.

Referring to FIG. 4, a planarization layer (234) of an organic light-emitting display device (200) according to another embodiment of the present invention may include a first region (R1) having a first thickness (A) and a second region (R2) having a second thickness (B) greater than the first thickness (A).

That is, the organic light emitting display device (200) according to another embodiment of the present invention may include an emission area (EA) and a non-emission area (NEA), and the first area (R1) of the planarization layer (234) may be positioned to correspond to the emission area (EA), and the second area (R2) may be positioned to correspond to the non-emission area (NEA). More specifically, the planarization layer (234) is formed to have a first thickness (A) in the first area (R1) and a second thickness (B) in the second area (R2), so that the planarization layer (234) may be formed thicker in the non-emission area (NEA) than in the emission area (EA). Here, the second area (R2) of the planarization layer (234) may function as a first bank layer (234b) defining the emission area (EA) of the organic light emitting display device (200).

A first electrode (240) is formed on the planarization layer (234). The first electrode (240) may be an anode and is formed of a conductive material having a relatively large work function value to supply holes to the organic light-emitting layer of the light-emitting portion (150). The first electrode (240) may be electrically connected to the thin film transistor (220) through a contact hole (235) provided in the protective layer (270) and the planarization layer (234).

According to another embodiment of the present invention, the organic light-emitting display device (200) may be configured to include a second region (R2) having a second thickness (B) of the planarization layer (234), that is, a second bank layer (245) made of a material including black pigment on the first bank layer (234b). That is, a photoresist for forming the second bank layer (245) may be made of a material including black pigment. The black pigment may be made of an organic material or an inorganic material.

Referring to FIG. 4, in the case of an organic light emitting display device (200) according to another embodiment of the present invention, a spacer (246) may be further included on a portion of a second bank layer (245). The spacer (246) may be made of a transparent material, and the transparent material may be one of polyimide, photo acryl, and benzocyclobutene (BCB).

In addition, the spacer (246) may be formed by including black pigment, similarly to the second bank layer (245), in order to reduce reflection by external light. In this case, the second bank layer (245) and the spacer (246) may be simultaneously patterned and formed through a halftone process. That is, when the spacer (246) is formed of the same material as the second bank layer (245), the second bank layer (245) and the spacer (246) may be simultaneously formed through a halftone process, thereby simplifying the manufacturing process of the organic light-emitting display device.

A light-emitting portion (250) is formed on the first electrode (240), the first bank layer (234b), the second bank layer (245), and the spacer (246). The light-emitting portion (250) may include various organic layers as needed, and may also be configured to include a plurality of organic light-emitting layers.

A second electrode (260) is formed on the light-emitting portion (250). The second electrode (260) may be a cathode, and is formed of a conductive material with a low work function because it must supply electrons to the organic light-emitting layer of the light-emitting portion.

That is, an organic light-emitting display device (200) according to another embodiment of the present invention is configured such that a planarization layer (234) on a thin film transistor includes a first region (R1) having a first thickness (A) and a second region (R2) having a second thickness (B) greater than the first thickness (A), and includes a second bank layer (245) made of a material including a black pigment on the second region (R2) of the planarization layer (234) and a spacer (246) on the second bank layer (245), thereby minimizing reflection by external light compared to a conventional structure, thereby reducing surface reflection luminance, thereby improving outdoor visibility of the organic light-emitting display device.

And according to another embodiment of the present invention, the organic light emitting display device (200) can form the first bank layer (134b) while simultaneously forming the planarization layer (134) through a halftone process. In addition, when the spacer (246) on the second bank layer (245) is formed of the same material as the second bank layer (245), the second bank layer (245) and the spacer (246) can be formed simultaneously through a halftone process, thereby simplifying the manufacturing process of the organic light emitting display device.

FIGS. 5A to 5E are drawings for explaining a method for manufacturing an organic light-emitting display device according to an embodiment of the present invention.

Referring to FIG. 5a, a buffer layer (131) is formed on a substrate (110), and a thin film transistor (120) including a semiconductor layer (122), a gate insulating layer (132), a gate electrode (121), an interlayer insulating layer (133), a source electrode (123), and a drain electrode (124) is formed on the buffer layer (131). In addition, a protective layer (170) is formed on the thin film transistor (120).

Next, referring to FIG. 5b, a planarization layer (134) is formed on the protective layer (170). The planarization layer (134) can be formed to have a first region (R1) having a first thickness (A) and a second region (R2) having a second thickness (B) greater than the first thickness (A).

More specifically, the first region (R1) of the planarization layer (134) may be formed to have a first thickness (A) and correspond to the light-emitting area (EA), and the second region (R2) of the planarization layer (134) may be formed to have a second thickness (B) greater than the first thickness (A) and correspond to the non-light-emitting area (NEA). That is, the planarization layer (134) may be formed thicker in the non-light-emitting area (NEA) than in the light-emitting area (EA), and the second region (R2) of the planarization layer (134) may be the first bank layer (134b) of the organic light-emitting display device (100) according to an embodiment of the present invention.

The planarization layer (134) including the first region (R1) having the first thickness (A) and the second region (R2) having the second thickness (B) greater than the first thickness (A) can be formed through a halftone process using a halftone mask. That is, the first bank layer (134b) of the planarization layer (134) can be formed of the same material in the same layer as the planarization layer region (134a), and can be simultaneously patterned through the halftone process.

Next, referring to FIG. 5c, a first electrode (140) is formed on a portion of a planarization layer region (134a) of a planarization layer (134) and a portion of a first bank layer (134b). The first electrode (140) is electrically connected to a thin film transistor (120) of each sub-pixel through a contact hole (135) provided in a protective layer (170) and the planarization layer (134).

In addition, at least a part of the first electrode (140) may be positioned on the inclined surface of the first bank layer (134b). When at least a part of the first electrode (140) is positioned on the inclined surface of the first bank layer (134b), the width of the first electrode (140) may be expanded compared to the existing structure, and the width of the light-emitting area (EA) of the organic light-emitting display device may be increased, thereby improving the aperture ratio of the organic light-emitting display device.

Next, referring to FIG. 5d, a second bank layer (145) made of a material including black pigment is formed on a second region (R2) having a second thickness (B) of a flattening layer (134), that is, on the first bank layer (134b). Since the second bank layer (145) is made of a material including black pigment, when the incident angle of the incident light is 45 degrees, the reflection luminance at a reflection angle of 30 degrees can be configured to be 30 nits or less. Therefore, reflection due to external light can be improved, and the reflection luminance can be reduced.

In addition, so that the multi-layer bank layer can be stably formed, the width of the lower part of the second bank layer (145) can be formed smaller than the width of the upper part of the first bank layer (134b) of the flattening layer (134).

Next, referring to FIG. 5e, a light-emitting portion (150) is formed on the first electrode (140), the first bank layer (134b), and the second bank layer (145). The light-emitting portion (150) may include various organic layers as needed, and may also be configured to include a plurality of organic light-emitting layers. In addition, an organic light-emitting display device (100) according to an embodiment of the present invention is manufactured by forming a second electrode (160) on the light-emitting portion (150).

That is, the organic light emitting display device (100) according to the embodiment of the present invention is configured such that the planarization layer (134) on the thin film transistor includes a first region (R1) having a first thickness (A) and a second region (R2) having a second thickness (B) greater than the first thickness (A), and includes a bank layer (145) made of a material including black pigment on the second region (R2) of the planarization layer (134), thereby minimizing reflection by external light compared to a conventional structure, thereby reducing surface reflection luminance, thereby improving the outdoor visibility of the organic light emitting display device. In addition, the organic light emitting display device (100) according to the embodiment of the present invention is configured such that the bank layer includes a first bank layer made of the same material as the planarization layer on the thin film transistor and a second bank layer positioned on the first bank layer and including black pigment, thereby improving the optical density of the bank layer, thereby providing an organic light emitting display device capable of minimizing reflection by external light. In addition, the organic light emitting display device (100) according to the embodiment of the present invention can improve the aperture ratio of the organic light emitting display device by increasing the width of the light emitting area (EA) of the organic light emitting display device (100) by forming at least a portion of the first electrode (140) so as to be positioned on the inclined surface of the second region (R2). In addition, the organic light emitting display device (100) according to the embodiment of the present invention can form the first bank layer (134b) while simultaneously forming the planarization layer (134) through a halftone process, thereby simplifying the manufacturing process of the organic light emitting display device.

Therefore, the organic light-emitting display device according to the embodiment of the present invention can improve the outdoor visibility of the organic light-emitting display device by configuring the bank layer to include a first bank layer made of the same material as a planarization layer on a thin film transistor and a second bank layer including a black pigment on the first bank layer, thereby minimizing reflection by external light and reducing surface reflection luminance.

In addition, the organic light-emitting display device according to an embodiment of the present invention can provide an organic light-emitting display device capable of minimizing reflection by external light by configuring the bank layer to include a first bank layer made of the same material as a planarization layer on a thin film transistor and a second bank layer positioned on the first bank layer and including black pigment, thereby improving the optical density of the bank layer.

In addition, the organic light emitting display device according to the embodiment of the present invention can form at least a part of the first electrode on an inclined surface of the first bank layer, thereby improving the aperture ratio of the organic light emitting display device.

In addition, the organic light emitting display device according to the embodiment of the present invention can simplify the process of forming the organic light emitting display device by simultaneously patterning the first bank layer and the planarization layer through a halftone process.

An organic light emitting display device according to embodiments of the present invention can be described as follows.

An organic light-emitting display device according to an embodiment of the present invention includes a thin film transistor on a substrate, a planarization layer covering the thin film transistor, a first bank layer, a first electrode on the planarization layer and connected to the thin film transistor, a second bank layer on the first bank layer, an organic layer on the first electrode, and an organic light-emitting layer, and a light-emitting portion including a second electrode on the light-emitting portion, wherein the first bank layer is formed of the same material as the planarization layer in a same layer as the planarization layer, and the second bank layer includes black pigment, so that a bank layer defining a sub-pixel includes the first bank layer formed of the same material as the planarization layer on the thin film transistor in a same layer as the planarization layer, and the second bank layer including black pigment on the first bank layer, thereby minimizing reflection by external light and reducing surface reflection luminance, thereby improving outdoor visibility of the organic light-emitting display device. And in the organic light emitting display device according to an embodiment of the present invention, at least a part of the first electrode is formed so as to be positioned on an inclined surface of the first bank layer, so that the width of the light emitting area of the organic light emitting display device increases, thereby improving the aperture ratio of the organic light emitting display device. In addition, in the organic light emitting display device according to an embodiment of the present invention, the manufacturing process of the organic light emitting display device can be simplified by simultaneously patterning the first bank layer and the planarization layer using a halftone process.

According to another feature of the present invention, the first bank layer and the planarization layer can be formed simultaneously by a halftone process.

According to another feature of the present invention, the optical density of the second bank layer can be 4 or less.

According to another feature of the present invention, the first bank layer can be made of one of polyimide, photo acryl, and benzocyclobutene (BCB).

According to another feature of the present invention, when the incident angle of light incident on the organic light-emitting display device is 45 degrees, the reflection luminance of the organic light-emitting display device at a reflection angle of 30 degrees can be 30 nits or less.

According to another feature of the present invention, the width of the lower portion of the second bank layer may be smaller than the width of the upper portion of the first bank layer.

According to another feature of the present invention, at least a portion of the first electrode can be positioned on an inclined surface of the first bank layer.

According to another feature of the present invention, the device further comprises a spacer on a portion of the second bank layer, wherein the spacer may be made of a transparent material.

According to another feature of the present invention, the transparent material may be one of polyimide, photo acryl, and benzocyclobutene (BCB).

According to another feature of the present invention, the second bank layer may further include a spacer positioned on the second bank layer and made of the same material as the second bank layer.

In another aspect, an organic light emitting display device according to an embodiment of the present invention including an organic light emitting layer between a first electrode and a second electrode is configured such that a planarization layer on a thin film transistor includes a first region having a first thickness and a second region having a second thickness greater than the first thickness, and a bank layer made of a material including black pigment is included on the second region of the planarization layer, thereby minimizing reflection by external light compared to a conventional structure, thereby reducing surface reflection luminance, thereby improving outdoor visibility of the organic light emitting display device. In addition, in the organic light emitting display device according to an embodiment of the present invention, at least a portion of the first electrode is formed on an inclined surface of the second region of the planarization layer, thereby increasing the width of the light emitting region of the organic light emitting display device, thereby improving the aperture ratio of the organic light emitting display device. In addition, since the organic light emitting display device according to an embodiment of the present invention can form the first bank layer while simultaneously forming the planarization layer through a halftone process, the manufacturing process of the organic light emitting display device can be simplified.

According to another feature of the present invention, the organic light emitting display device includes a light emitting region and a non-light emitting region, and the first region can be positioned corresponding to the light emitting region, and the second region can be positioned corresponding to the non-light emitting region.

According to another feature of the present invention, the flattening layer can be made of one of polyimide, photo acryl, and benzocyclobutene (BCB).

According to another feature of the present invention, at least a portion of the first electrode is positioned on an inclined surface of the second region of the flattening layer, so that the aperture ratio can be improved compared to the existing structure.

According to another feature of the present invention, the present invention further comprises a spacer on a portion of the bank layer, wherein the spacer may be formed by including a black pigment.

According to another feature of the present invention, the bank layer and the spacer can be formed simultaneously by a halftone process.

According to another feature of the present invention, the optical density of the bank layer can be 4 or less.

According to another feature of the present invention, the dielectric constant of the flattening layer can be 7C/m2 or less.

Although the embodiments of the present invention have been described in more detail with reference to the attached drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made and implemented without departing from the technical idea of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to explain it, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are exemplary in all aspects and not restrictive. The protection scope of the present invention should be interpreted by the claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

100: Organic light emitting display device
110: Substrate
120: Thin film transistor
121: Gate electrode
122: Semiconductor layer
123: Source electrode
124: Drain electrode
131: Buffer layer
132: Gate insulation layer
133: Interlayer insulation layer
134: Flattening layer and first bank layer
135: Contact hole
140: 1st electrode
145: Second Bank Floor
150: Light source
151: Hole injection layer
152: Hole transport layer
152a: First hole transport layer
152b: Second hole transport layer
152c: 3rd hole transport layer
153: Organic light-emitting layer
153a: Red emitting layer
153b: Green luminescent layer
153c: Blue emitting layer
154: Electron transport layer
160: Second electrode
170: Protective layer
R: Red sub-pixel area
G: Green sub-pixel area
B: Blue sub-pixel area

Claims (20)

Thin film transistor on substrate;
A planarization layer and a first bank layer covering the above thin film transistor;
A first electrode on the above planarizing layer and connected to the thin film transistor;
A second bank layer on the first bank layer;
A light-emitting part including an organic layer and an organic light-emitting layer on the first electrode; and
Including a second electrode on the above light emitting portion,
The first bank layer is made of the same material as the flattening layer in the same layer, and the second bank layer includes black pigment.
Further comprising a spacer on a portion of the second bank layer,
The above spacer is made of a transparent material,
At least a portion of the first electrode is located on the inclined surface of the first bank layer,
An organic light emitting display device, wherein the light emitting portion has different thicknesses for each of a red sub-pixel area, a green sub-pixel area, and a blue sub-pixel area. In paragraph 1,
An organic light emitting display device in which the first bank layer and the planarization layer are formed simultaneously by a halftone process. In paragraph 1,
An organic light-emitting display device wherein the optical density of the second bank layer is 4 or less. In paragraph 1,
An organic light emitting display device wherein the first bank layer is made of one of polyimide, photo acryl, and benzocyclobutene (BCB). In paragraph 1,
An organic light-emitting display device, wherein when the incident angle of light incident on the organic light-emitting display device is 45 degrees, the reflection luminance of the organic light-emitting display device at a reflection angle of 30 degrees is 30 nits or less. In paragraph 1,
An organic light emitting display device, wherein the width of the lower portion of the second bank layer is smaller than the width of the upper portion of the first bank layer. delete delete In paragraph 1,
An organic light emitting display device wherein the above transparent material is one of polyimide, photo acryl and benzocyclobutene (BCB). delete In an organic light-emitting display device including an organic light-emitting layer between a first electrode and a second electrode on a substrate,
A thin film transistor disposed on the above substrate;
a planarization layer on the thin film transistor; and
Comprising a bank layer made of a material containing black pigment,
The flattening layer includes a first region having a first thickness and a second region having a second thickness greater than the first thickness,
The above bank layer is configured to be placed on the second area of the above flattening layer,
Further including a spacer on some area of the above bank layer,
The above spacer is made of a transparent material,
At least a portion of the first electrode is positioned on the inclined surface of the second region of the flattening layer,
An organic light-emitting display device, wherein the organic light-emitting layer has different thicknesses for each of a red sub-pixel area, a green sub-pixel area, and a blue sub-pixel area. In Article 11,
The above organic light emitting display device includes a light emitting region and a non-light emitting region,
An organic light-emitting display device, wherein the first region is positioned corresponding to the light-emitting region, and the second region is positioned corresponding to the non-light-emitting region. In Article 12,
An organic light emitting display device wherein the above-mentioned planarizing layer is made of one of polyimide, photo acryl, and benzocyclobutene (BCB). delete delete In Article 11,
An organic light-emitting display device in which the above bank layer and the above spacer are formed simultaneously by a halftone process. In Article 11,
An organic light-emitting display device wherein the optical density of the above bank layer is 4 or less. In Article 11,
An organic light-emitting display device wherein the dielectric constant of the above-mentioned flattening layer is 7 F/m or less. In paragraph 1,
An organic light emitting display device, wherein the second bank layer does not overlap with the first electrode. In paragraph 1,
The above light emitting part
A hole injection layer disposed on the first electrode so as to correspond to all of the red sub-pixel region (R), the green sub-pixel region (G), and the blue sub-pixel region (B);
A first hole transport layer disposed on the hole injection layer so as to correspond to all of the red sub-pixel region (R), the green sub-pixel region (G), and the blue sub-pixel region (B);
A second hole transport layer disposed on the first hole transport layer of the red sub-pixel region (R);
A third hole transport layer disposed on the first hole transport layer of the green sub-pixel region (G);
A red light-emitting layer disposed on the second hole transport layer;
A green light-emitting layer disposed on the third hole transport layer;
A blue light-emitting layer disposed on the first hole transport layer of the blue sub-pixel region (B); and
An organic light emitting display device comprising an electron transport layer disposed on the red light emitting layer, the green light emitting layer, and the blue light emitting layer so as to correspond to all of the red sub-pixel region (R), the green sub-pixel region (G), and the blue sub-pixel region (B).

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