KR102746370B1 - Flexible display device - Google Patents

Abstract

The present specification discloses a display device. The display device includes a foldable region and a non-foldable region, and the foldable region may include a durability-enhancing structure. In one embodiment, the display device may include a base layer having at least one first region that can be folded along a predetermined axis and a second region adjacent to the first region; a thin film transistor, an organic light-emitting element, and functional layers laminated on the second region of the base layer; the first region does not include the thin film transistor, the organic light-emitting element, and the functional layers laminated on the second region, and instead includes a filling layer filling the corresponding space.

Description

FLEXIBLE DISPLAY DEVICE

This specification relates to a flexible display device.

The video display device that implements various information on the screen is a core technology of the information and communication era and is developing in the direction of thinner, lighter, more portable, and more high-performance. Accordingly, organic light-emitting display devices that control the light emission of organic light-emitting elements to display images are in the spotlight.

Organic light-emitting elements are self-luminous elements that utilize a thin light-emitting layer between electrodes, and have the advantage of being able to be made thin. A typical organic light-emitting display device has a structure in which a pixel driver circuit and an organic light-emitting element are formed on a substrate, and the light emitted from the organic light-emitting element displays an image by passing through the substrate or barrier layer.

Since organic light-emitting displays are implemented without a separate light source device, they are easy to implement as flexible, bendable, and foldable displays. At this time, flexible materials such as plastic and metal foil are used as substrates for organic light-emitting displays.

Recently, the demand for display devices that can be transformed into various forms is increasing, and accordingly, research on implementing organic light-emitting display devices as foldable or rollable display devices is also actively being conducted. However, conventional foldable or rollable display devices still have many areas for improvement due to structural/material characteristics and limitations.

The purpose of this specification is to propose a folding structure of a flexible display device and a durability-enhancing structure used therein.

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

According to one embodiment of the present disclosure, a display device is provided. The display device includes a foldable region and a non-foldable region, and the foldable region may include a durability-enhancing structure. In one embodiment, the display device may include a base layer having at least one first region that can be folded along a predetermined axis and a second region adjacent to the first region; a thin film transistor, an organic light-emitting element, and functional layers stacked on the second region of the base layer; The first region does not include the thin film transistor, the organic light-emitting element, and the functional layers stacked on the second region, and instead includes a filling layer filling the corresponding space.

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

The embodiments of the present specification can provide a stable structure that minimizes defects occurring at the folding portion of a foldable display device. Furthermore, the embodiments of the present specification can provide a durability-enhanced structure that enhances the structural rigidity of a foldable/rollable display device. The effects according to the embodiments of the present specification are not limited to the contents exemplified above, and more diverse effects are included in the present specification.

Figure 1 illustrates an exemplary flexible display device that may be included in an electronic device.
FIGS. 2A to 2C are plan views of a flexible display device according to one embodiment of the present specification.
Figure 3 is a cross-sectional view along line 1-1' of Figure 2c.
Figure 4 is a cross-sectional view along line 2-2' of Figure 2c.
FIGS. 5A and 5B are plan and cross-sectional views of a flexible display device according to another embodiment of the present specification.

The advantages and features of the present specification and the methods for achieving them will become clearer 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 the present embodiments are provided only to make the disclosure of the present invention complete and to fully inform those skilled in the art 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 the embodiments of the present specification are illustrative and therefore the present specification 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 the singular, it includes a case where the plural is included unless there is a specifically explicit description. When interpreting a component, it is interpreted to include a range of errors even if there is no separate explicit description.

When describing a positional relationship, for example, when 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 "directly" or "directly" is used. When an element or layer is referred to as "on" another element or layer, it includes both cases where it is directly on the other element or where another layer or other element is interposed. When it is described that a component is "connected", "coupled", or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but it should also be understood that other components may be "interposed" between each component, or each component may be "connected", "coupled", or "connected" through the other component.

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 referred to below may also be a second component within the technical concept of the present invention.

The size and thickness of each component shown in the drawings are shown for convenience of explanation, and the present invention is not necessarily limited to the size and thickness of the components shown. Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings.

Figure 1 illustrates an exemplary flexible display device that may be included in an electronic device.

The flexible display device above refers to a display device with flexibility, and can be used with the same meaning as a foldable display device, a bendable display device, a rollable display device, etc. Referring to FIG. 1, the display device (100) can include at least one display area (active area). For example, the foldable display device can have a plurality of display areas divided left and right (or up and down) based on a bending line. An array of pixels is formed in the display area. One or more inactive areas can be arranged around the display area. That is, the inactive areas can be adjacent to one or more side surfaces of the display area. In FIG. 1, the inactive areas surround a rectangular display area. However, the shape of the display area and the shape/arrangement of the inactive areas adjacent to the display area are not limited to the example illustrated in FIG. 1. The above display area and the non-display area may have shapes suitable for the design of an electronic device equipped with the display device (100). Exemplary shapes of the display area include a pentagon, a hexagon, a circle, an oval, etc.

Each pixel within the display area may be associated with a pixel circuit. The pixel circuit may include one or more switching transistors and one or more driving transistors on a backplane. Each pixel circuit may be electrically connected to a gate line and a data line to communicate with one or more control circuits, such as a gate driver and a data driver, located in the non-display area.

The above control circuit may be implemented as a TFT (thin film transistor) in the non-display area, as illustrated in FIG. 1. Such a control circuit may be referred to as a GIP (gate-in-panel). In addition, several components, such as a data driver IC, may be mounted on a separate printed circuit board and coupled to a connection interface (pad/bump, pin, etc.) placed in the non-display area using a circuit film, such as an FPCB (flexible printed circuit board), a COF (chip-on-film), a TCP (tape-carrier-package), etc.

The flexible display device (100) may include various additional elements for generating various signals or driving pixels within a display area. Additional elements for driving the pixels may include an inverter circuit, a multiplexer, an electro static discharge circuit, etc. The display device (100) may also include additional elements associated with functions other than pixel driving. For example, the display device (100) may include additional elements that provide a touch detection function, a user authentication function (e.g., fingerprint recognition), a multi-level pressure detection function, a tactile feedback function, etc. The above-mentioned additional elements may be located in the non-display area and/or an external circuit connected to the connection interface.

Various parts of the display device (100) can be bent along a bend line (BL). The bend line (BL) can extend horizontally (e.g., in the X direction of FIG. 1), vertically (e.g., in the Y direction of FIG. 1), or diagonally. Accordingly, the display device (100) can be bent in a combination of horizontal, vertical, and diagonal directions based on a required design.

As mentioned, one or more edges of the display device (100) may be bent away from the central portion along the curved line (BL). The curved line (BL) may extend across the central portion, or may extend diagonally from one or more corners of the display device (100). This structure may enable the display device (100) to be a foldable display device, or a display device in which displays are formed on both sides when folded. Furthermore, since a plurality of curved lines (BL) are densely present, the display device may be rollable at least at one portion.

In some embodiments, the curved portion of the flexible display device (100) may include a display area capable of displaying an image. This display area is referred to as an auxiliary display area. That is, a curved line (BL) may be placed within the display area so that at least some pixels of the display area are included in the curved portion.

FIGS. 2A to 2C are plan views of a flexible display device according to one embodiment of the present specification.

Hereinafter, a flexible display device and its display area according to an embodiment of the present specification will be described using an Organic Light Emitting Display as an example. The flexible display device (100) has a durability-enhancing structure arranged along a bending line (BL). The organic light emitting display device exemplified by the durability-enhancing structure can be more suitably used in a foldable or rollable display device.

Conventional foldable or rollable displays have many areas for improvement due to structural/material characteristics and limitations. For example, as the thickness of a foldable or rollable display device becomes thinner, the bending curvature increases, but it has been discovered that damage (cracks, etc.) occurs and propagates in the inorganic film or metallic elements in the bending portion. In addition, when the bending portion is patterned as a countermeasure, there is a problem that the rigidity of the display device is weakened. Therefore, it has been very difficult to secure maximum flexibility by implementing a display device below a certain thickness.

Accordingly, the inventors of the present specification have devised a durability-enhancing structure that can reduce the folding radius of a foldable or rollable display device and at the same time prevent a decrease in rigidity due to the reduction. The durability-enhancing structure may include an etched portion provided along a folding area (B) and a filling layer filling the etched portion.

First, referring to Fig. 2a, a plan view of a display device according to one embodiment of the present specification can be seen. Fig. 2a is the same as the drawing of the flexible display device of Fig. 1 with some of the upper and lower portions omitted.

In the display area (A/A) of the display device (100), a base layer, and thin film transistors, organic light-emitting elements, and functional layers (insulating layers, planarizing layers, etc.) provided thereon may be arranged. Thin film transistors (102, 104, 106, 108), organic light-emitting elements (112, 114, 116), and various functional layers are positioned on the display area (A/A). The thin film transistor is arranged on one side (the first side) of the base layer (101). When the base layer (101) is made of plastic, it may be referred to as a plastic film or a plastic substrate. An organic light-emitting diode is arranged on the thin film transistor. The organic light-emitting diode is controlled by a pixel circuit and a control circuit implemented on the base layer (101), and another external driving circuit connected to a connection interface on the base layer (101). The above organic light-emitting diode includes an organic light-emitting material layer that emits light of a specific color (e.g., red, green, blue). In some embodiments, the organic light-emitting material layer may have a laminated structure that can emit white light (essentially a combination of light of various colors).

In addition, a control circuit block (e.g., GIP, etc.) provided on the base layer, related components, various signal wiring, etc. can be placed in the non-display area (I/A) of the display device (100).

The base layer of the display device (100) can be divided into a first region (B) and a second region (C). The first region (B) is a region provided to be foldable along a predetermined axis (BL). One or more first regions (B) can be provided in the display device. In addition, the second region (C) is a region adjacent to the first region (B) and is a part that is less bent than the first region (B). In the case of a foldable display device, the second region (C) is a part that is substantially not bent. That is, the second region (C) is a region formed to correspond to a display device of the same type, and the first region (B) is a foldable region between the second regions (C). Here, the first region (B) and the second region (C) can be defined not only over the display region (A/A) but also over the non-display region (I/A), as shown in the drawing. Therefore, the first region (B) and the second region (C) may include the display region (A/A) and the non-display region (I/A) on both sides thereof.

The first region (B) is a portion that is actually bent when the display device is deformed (folded, rolled), and thus receives a large amount of stress. Therefore, various stress-reducing structures are applied to the first region (B). To this end, at least some of the components laminated in the second region (C) do not exist in the first region (B). For example, thin film transistors, organic light-emitting diodes, and/or related functional layers (e.g., buffer layers, insulating layers, planarization layers, etc.) may not be arranged in the first region (B). That is, only a minimum number of layers may be arranged in the first region (B) to facilitate bending. For example, in the folded region (B), all functional layers associated with the thin film transistor, the organic light-emitting diode, and/or the control circuit may be removed, leaving only the base layer. The functional layers may be removed through a series of etching processes. Additionally, the empty space from which the functional layers are removed may be filled with a filling layer. The above-mentioned filling layer may have sufficient elasticity to withstand the stress applied to the first region (B). In this way, by forming a kind of slit on one side of the display device and filling the space between them with an elastic material, deformation stress is concentrated on the slit, minimizing damage to other parts. At the same time, since the patterned and thinned part is reinforced by the filling layer, the rigidity of the entire display device can be increased. Through this structure for reinforcing the durability of the folding part, a display device capable of being folded in both directions (inward/outward) can also be more easily implemented.

The first region (B) may be in the form of a stripe parallel to the folding axis (BL), as shown in Fig. 2a. Alternatively, the first region (B) may be in the form of a mesh parallel to two different folding axes (BL1, BL2), as shown in Fig. 2b. That is, the first region (B) may extend in two or more different directions. In this case, the second region may be divided into a greater number of pieces.

The number and pitch of the first regions (B) can be designed in consideration of the folding characteristics of the flexible display device. For example, a rollable display device can have a larger number of first regions (B) than a foldable display device that folds only one part. Also, even for the same rollable display device, if the required radius of curvature is smaller, the first regions can be arranged at a narrower interval.

The width of the first region (B) above is related to the folding radius, and thus can be determined based on this. In addition, since visibility may be impaired if the width of the first region (B) is too large, the width of the first region (B) can be determined at a level that does not affect the user's visibility.

Fig. 2c is a drawing showing an enlarged portion of X2 of Fig. 2a. As described above, the second region (C) may include pixels (R, G, B) of the display region and a control circuit (e.g., GIP) of the non-display region.

The first region (B) above includes an electrical conductor (108) that connects pixels (R, G, B) arranged in the second region (C) with the first region (B) in between. The conductor (108) may have a shape that reduces stress applied when the display device is bent or folded. For example, the conductor may be implemented in a shape suitable for stress distribution, such as a wave shape, a square wave shape, or a sawtooth wave shape, in addition to the shape illustrated in FIG. 2C.

Figures 3 and 4 are cross-sectional views showing specific portions of Figure 2c.

Fig. 3 is a cross-sectional view taken along line 1-1' of Fig. 2c. The illustrated organic light-emitting display device (100) includes a durability-enhanced structure.

The above organic light-emitting display device (100) has thin film transistors (102, 104, 106, 108), organic light-emitting elements (112, 114, 116) and various functional layers positioned on a base layer (101).

The above base layer (101) supports various components of the organic light-emitting display device (100). The base layer (101) may be formed of a transparent insulating material, for example, an insulating material such as glass or plastic. The substrate (array substrate) is also referred to as a concept including elements and functional layers formed thereon, for example, a switching TFT, a driving TFT connected to the switching TFT, an organic light-emitting element connected to the driving TFT, a protective film, etc.

A buffer layer may be positioned on the base layer (101). The buffer layer (MB, AB) is a functional layer for protecting a thin film transistor (TFT) from impurities such as alkali ions leaking from the base layer (101) or lower layers. The buffer layer may be formed of silicon oxide (SiOx), silicon nitride (SiNx), or a multilayer thereof.

A thin film transistor is placed on the base layer (101) or buffer layer. The thin film transistor may have a form in which a semiconductor layer (102), a gate insulating film (103), a gate electrode (104), an interlayer insulating film (105), and source and drain electrodes (106, 108) are sequentially arranged. The semiconductor layer (102) is positioned on the base layer (101) or buffer layer. The semiconductor layer (102) may be made of polysilicon (p-Si), in which case a predetermined region may be doped with an impurity. In addition, the semiconductor layer (102) may be made of amorphous silicon (a-Si) or may be made of various organic semiconductor materials such as pentacene. Furthermore, the semiconductor layer (102) may be made of an oxide. The gate insulating film (103) may be formed of an insulating inorganic material such as silicon oxide (SiOx) or silicon nitride (SiNx), and may also be formed of an insulating organic material. The gate electrode (104) may be formed of various conductive materials such as magnesium (Mg), aluminum (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), tungsten (W), gold (Au), or alloys thereof.

The interlayer insulating film (105) may be formed of an insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx), and may also be formed of an insulating organic material. By selectively removing the interlayer insulating film (105) and the gate insulating film (103), a contact hole exposing the source and drain regions may be formed.

The source and drain electrodes (106, 108) are formed in a single layer or multilayer shape using electrode materials on an interlayer insulating film (105).

A planarization layer (107) may be positioned on the thin film transistor. The planarization layer (107) protects the thin film transistor and planarizes its upper portion. The planarization layer (107) may be configured in various forms, and may be formed of an organic insulating film such as BCB (Benzocyclobutene) or Acryl, or an inorganic insulating film such as a silicon nitride film (SiNx) or a silicon oxide film (SiOx), and may be formed in a single layer or configured in a double or multi-layer, and various modifications are possible.

The organic light-emitting device may be in a form in which a first electrode (112), an organic light-emitting layer (114), and a second electrode (116) are sequentially arranged. That is, the organic light-emitting device may be composed of a first electrode (112) formed on a planarization layer (107), an organic light-emitting layer (114) positioned on the first electrode (112), and a second electrode (116) positioned on the organic light-emitting layer (114).

The first electrode (112) is electrically connected to the drain electrode (108) of the driving thin film transistor through a contact hole. If the organic light-emitting display device (100) is of a top emission type, the first electrode (112) may be made of an opaque conductive material having high reflectivity. For example, the first electrode (112) may be formed of silver (Ag), aluminum (Al), gold (Au), molybdenum (Mo), tungsten (W), chromium (Cr), or an alloy thereof.

The bank (110) is formed in the remaining area except for the light-emitting area. Accordingly, the bank (110) has a bank hole that exposes the first electrode (112) corresponding to the light-emitting area. The bank (110) can be made of an inorganic insulating material such as a silicon nitride film (SiNx) or a silicon oxide film (SiOx), or an organic insulating material such as BCB, an acrylic resin, or an imide resin.

An organic light-emitting layer (114) is positioned on the first electrode (112) exposed by the bank (110). The organic light-emitting layer (114) may include a light-emitting layer, an electron injection layer, an electron transport layer, a hole transport layer, a hole injection layer, etc. The organic light-emitting layer may be configured as a single light-emitting layer structure that emits one light, or may be configured as a structure that emits white light by being configured as a plurality of light-emitting layers.

The second electrode (116) is positioned on the organic light-emitting layer (114). When the organic light-emitting display device (100) is of the top emission type, the second electrode (116) is formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO), thereby emitting light generated in the organic light-emitting layer (114) to the upper portion of the second electrode (116).

A passivation layer (120) is positioned on the second electrode (116). The passivation layer (120) prevents the oxidation of the light-emitting material and the electrode material, thereby preventing the penetration of oxygen and moisture from the outside. When the organic light-emitting element is exposed to moisture or oxygen, a pixel shrinkage phenomenon in which the light-emitting area is reduced may occur, or dark spots may occur within the light-emitting area. The passivation layer and/or the encapsulation layer may be composed of an inorganic film made of glass, metal, aluminum oxide (AlOx), or silicon (Si) series materials, or may have a structure in which organic films and inorganic films are alternately laminated. The inorganic film serves to block the penetration of moisture or oxygen, and the organic film serves to flatten the surface of the inorganic film. The reason for forming the encapsulation layer as multiple thin film layers is to make the movement path of moisture or oxygen longer and more complicated compared to a single layer, thereby making it difficult for moisture/oxygen to penetrate to the organic light-emitting element. The above-described encapsulating layer (120) can be broken in the first region. Since the encapsulating layer (120) includes an inorganic film to prevent moisture penetration, it is preferable that the encapsulating layer (120) is present at a minimum in the first region (B), which is a bent portion. Accordingly, the encapsulating layer does not cover at least a portion of the first region (B).

A touch layer for detecting a user's touch input may be provided on an upper surface of the encapsulation layer (120). If necessary, an independent layer equipped with a touch detection electrode and/or other components related to touch input detection may be provided inside the display device (100). The touch detection electrode (e.g., touch drive/detection electrode) may be formed of a transparent conductive material, such as indium tin oxide, a carbon-based material such as graphene, carbon nanotubes, a conductive polymer, a hybrid material made of a mixture of various conductive/non-conductive materials, etc. In addition, a metal mesh, such as an aluminum mesh, a silver mesh, etc., may be used as the touch detection electrode.

A cover layer (140) may be provided on the sealing layer (120). The cover layer (140) may be used to protect the display device (100) and may be, for example, a cover glass. Meanwhile, a polarizing layer may be integrated into the cover layer (140) to control display characteristics (e.g., external light reflection, color accuracy, brightness, etc.). (e.g., coated-pol)

In order to increase strength and/or rigidity in a specific portion of the foldable display device (100), one or more support layers (180) may be provided under the base layer (101). The support layers (180) are attached to a side (second side) of the base layer (101) opposite to a side (first side) having an organic light-emitting element among both surfaces of the base layer (101). The support layers (180) may be made of a thin plastic film composed of a combination of polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethylene ether phthalate, polycarbonate, polyarylate, polyether imide, polyether sulfonate, polyimide, polyacrylate, and other suitable polymers. Other suitable materials that can be used to form the support layer (180) may be thin glass, a metal foil shielded with a dielectric, a multilayer polymer, a polymer film containing a polymer material combined with nano-particles or micro-particles, etc. An adhesive layer may be placed between the sealing layer (120) and the cover layer (140), and between the base layer (101) and the support layer (180). The adhesive layer may be a heat-curable or natural-curable adhesive. For example, the adhesive layer may be composed of a material such as OCA, B-PSA (Barrier pressure sensitive adhesive).

As an example, the organic light-emitting display device (100) includes a base layer (101) having at least one first region (B) that can be folded along a predetermined axis and a second region (C) adjacent to the first region (B); thin film transistors, organic light-emitting elements, and functional layers laminated on the second region (C) of the base layer; wherein the first region (B) does not have the thin film transistors, organic light-emitting elements, and functional layers laminated on the second region (C), and instead includes a filling layer (130) that fills the corresponding space.

The first region (B) may be a region where functional layers associated with the thin film transistor and the organic light-emitting element of the second region (C) are etched. That is, the first region (B) is a region whose thickness is minimized so that it can be bent better, and is a region where materials that cause crack occurrence/propagation are removed in advance. In addition, the first region (B) is a region where the space where the removed layers (materials) were is filled with an elastic material, thereby compensating for the weakening of rigidity due to patterning.

The second region (C) may include a display region and non-display regions at both ends thereof. For example, the second region (C) may include a control circuit (e.g., GIP) block at at least one of the two end portions thereof. The sealing layer (120) may be disconnected from the second region (C) as shown in FIG. 3. That is, the sealing layer (120) may be provided so as not to cover all or part of the second region.

The above filling layer (130) is a material having sufficient elasticity to withstand the stress applied to the first region (B), and may be a polymer compound such as polyimide, resin, etc. In this case, the filling layer (130) may have an elastic modulus of 2 to 15 MPa.

In addition, the filling layer (130) may be a material in a liquid, sol, or gel state. In this case, the filling layer (130) may be made of a chemically stable inert material. For example, the filling layer (130) may be made of a material such as polydimethylsiloxane (PDMS), a liquid getter, etc. The filling layer (130) made of PDMS may have an elastic modulus of about 13 to 14 MPa and a viscosity of 50 to 1000 cps. Meanwhile, the filling layer (130) may be provided so that the light transmittance is 90% or higher to minimize the reduction in visibility. Furthermore, the filling layer (130) may also function as a polarizer by including a liquid crystal. In this case, the overall thickness of the display device may be made thinner, thereby improving the foldable/rollable characteristics.

When the above-described filling layer (130) is a liquid, sol, or gel, the auxiliary structure (190) illustrated in FIGS. 5a and 5b may be further provided. The auxiliary structure (190) is provided to maintain the shape (height, distribution, etc.) of the filling layer constant when the display device is folded or rolled. That is, the auxiliary structure (190) is positioned in a portion excluding the opening area (EA) where the bank is open to control excessive flow of the filling layer. The auxiliary structure (190) may be formed of a material such as low-temperature photoacrylic (PAC) on the upper portion of the bank (110).

Meanwhile, the filling layer (130) can cover not only the first region (B) but also the upper part of the second region (C), as shown in FIG. 3.

Fig. 4 is a cross-sectional view taken along line 2-2' of Fig. 2c. Although a thin film transistor is not illustrated in Fig. 4, a thin film transistor may be positioned in that portion depending on a specific embodiment. The various functional layers illustrated in Fig. 4 are the same as those described in Fig. 3.

The part illustrated in FIG. 4 includes an electrical conductor (108) that connects pixels (R, G, B) arranged in a second region (C) with a first region (B) in between. The conductor (108) may have a shape that reduces stress applied when the display device is bent or folded. For example, the conductor may be implemented in a shape suitable for stress distribution, such as a wave shape, a triangular wave shape, a square wave shape, in addition to the diamond shape illustrated in FIG. 2c.

The above conductor (108) may be made of the same material as the source or drain electrode of the thin film transistor. In this case, the conductor (108) may be made simultaneously in the formation process of the source or drain electrode.

The above display device (100) can further improve folding reliability by including a durability-enhancing structure formed in the folding area.

Although the embodiments of the present specification have been described in detail with reference to the attached drawings, the present specification is not necessarily limited to these embodiments, and various modifications may be made without departing from the technical idea thereof. Accordingly, the embodiments disclosed in this specification 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. The respective 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 operated in various ways by those skilled in the art, and the respective embodiments may be implemented independently of each other or implemented together in a related relationship. The protection scope of the present invention should be interpreted by the following 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.

Claims (17)

A base layer having at least one first region foldable along a predetermined axis and a second region adjacent to the first region;
A thin film transistor, an organic light-emitting element and a plurality of insulating layers laminated in a second region of the base layer; and
Including a bag layer laminated on the first region and the second region,
The first region does not have a thin film transistor, an organic light-emitting element, and a plurality of insulating layers stacked on the second region, and instead includes a filling layer filling the space.
A display device characterized in that the encapsulating layer is disposed on top of the organic light-emitting element in the second region and extends to the first region so as to be in contact with the base layer, but does not exist in a portion of the entire area of the first region, but instead is filled by the filling layer. In the first paragraph,
A display device wherein the above filling layer comprises polyimide. In the second paragraph,
A display device wherein the above filling layer is a material having an elastic modulus of 2 to 15 MPa. In the first paragraph,
The above filling layer is a display device also located on the upper part of the second region. In the first paragraph,
A display device, wherein the first region is a region in which a thin film transistor, an organic light-emitting element, and a plurality of insulating layers of the second region are etched. In the first paragraph,
The above second region is a display device including a display region and a non-display region on both sides thereof. In Article 6,
The above second region is a display device including control circuit blocks on both sides thereof. In the first paragraph,
A display device including a first region and a second region that are spaced apart from the first region. In Article 8,
The above conductor is a display device having a diamond, wave shape, square wave shape or sawtooth wave shape. In the first paragraph,
The above first region is a display device extending in two different directions. In the first paragraph,
A display device in which the above-mentioned filling layer is a material in a liquid sol or gel state. In Article 11,
The above filling layer is a display device composed of polydimethylsiloxane. In Article 12,
The above-mentioned filling layer is a display device having an elastic modulus of 13 to 14 MPa and a viscosity of 50 to 1000 cps. In Article 11,
A display device wherein the above filling layer further includes a liquid crystal. In Article 11,
Further comprising a cover layer disposed on the above filling layer,
The uppermost layer of the plurality of insulating layers of the second region is a bank,
A display device having an auxiliary structure in contact with the cover layer between the cover layer and the filling layer on the upper part of the bank. A base layer having at least one first region foldable along a predetermined axis and a second region adjacent to the first region;
It comprises a thin film transistor, an organic light-emitting element and a plurality of insulating layers laminated in the second region of the base layer,
The first region does not have a thin film transistor, an organic light-emitting element, and a plurality of insulating layers stacked on the second region, and instead includes a filling layer filling the space.
The above first region is arranged in a mesh pattern parallel to the folding axes in two different directions,
A display device wherein the above-mentioned filling layer is a material in a liquid sol or gel state. A base layer having at least one first region foldable along a predetermined axis and a second region adjacent to the first region;
A thin film transistor, an organic light-emitting element and a plurality of insulating layers laminated in a second region of the base layer; and
Including a bag layer laminated on the first region and the second region,
The first region does not have a thin film transistor, an organic light-emitting element, and a plurality of insulating layers stacked on the second region, and instead includes a filling layer filling the space.
Further comprising a cover layer disposed on the above filling layer,
The uppermost layer of the plurality of insulating layers of the second region is a bank,
Between the cover layer and the bag layer on the upper part of the bank, an auxiliary structure in contact with the cover layer is provided.
A display device wherein the above-mentioned filling layer is a material in a liquid sol or gel state.

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