KR20180036899A - Edge Bending Organic Light Emitting Diode Display - Google Patents

Abstract

The present invention relates to an organic light emitting diode display device having an edge unit/edge side bending structure. According to the present invention, the organic light emitting diode display device having an edge unit/edge side bending structure comprises: a back plate including a display region and a non-display region; a dam surrounding the display region; a barrier film surface-bonded to the back plate above the dam; a bending shaft defined at an edge bending position of the back plate; and a crack prevention pattern arranged to overlap with the bending shaft by separating from the outside in the display region by a certain distance.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light emitting diode (OLED)

The present invention relates to an organic light emitting diode display device having a side / side bent structure. More particularly, the present invention relates to an organic light emitting diode display device having a side edge bending structure including a flexible display panel having a pattern for preventing wiring cracking occurring at a bending portion.

2. Description of the Related Art Recently, various flat panel display devices capable of reducing weight and volume, which are disadvantages of cathode ray tubes (CRTs), have been developed. Such flat panel display devices include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an electroluminescence device (EL) have.

Since the flat panel display is thin and light in weight, it is widely used as a display means in a mobile communication terminal or a portable information processor. Particularly, there is a growing demand for display panels that are thinner, lighter, and have lower power consumption in portable or mobile devices.

Such an electroluminescent display device receives the spotlight as a display device most suitable for the demand. The electroluminescent device is divided into an inorganic electroluminescent device and an organic light emitting diode device depending on the material of the light emitting layer, and has a self-luminous self-luminous device, which has a high response speed and high luminous efficiency, luminance and viewing angle. The organic light emitting diode display device has an organic light emitting diode (OLED).

The organic light emitting diode includes an organic electroluminescent compound layer that emits light by an electric field, and a cathode electrode and an anode that face each other with the organic electroluminescent compound layer interposed therebetween. The organic electroluminescent compound layer includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer layer, EIL). The OLED emits electrons due to the energy generated from the excitons and excitons formed in the excitation process when the holes and electrons injected into the cathode and the cathode are recombined in the emission layer (EML).

2. Description of the Related Art An organic light emitting diode display (OLEDD) using an organic light emitting diode (OLED) as an electroluminescent device includes a passive matrix type organic light emitting diode display (PMOLED) Type organic light emitting diode display device (Active Matrix type Organic Light Emitting Diode Display (AMOLED)). In addition, depending on the direction in which the light is emitted, there are a top-emission type and a bottom-emission type.

Particularly, the liquid crystal display device and the plasma display device have limitations in developing a self-luminous element having high flexibility and elasticity, and thus there is a limit in application to a flexible display device. However, the organic light emitting diode display device is formed by using an organic thin film. Therefore, attention is focused on an optimum material that can be applied to a flexible display device by taking advantage of the flexibility and elasticity characteristic of the organic thin film. An active matrix type flexible organic light emitting diode display device (flexible AMOLED) displays an image by controlling a current flowing in an organic light emitting diode using a thin film transistor (TFT).

1, an organic light emitting diode display device (simply referred to as an organic light emitting display device) will be described. 1 is a cross-sectional view schematically showing a structure of an information processing organ employing an ultra-thin organic light emitting diode display device. Referring to FIG. 1, the OLED display includes an organic light emitting device layer FL, a back plate BP attached to the bottom of the organic light emitting device layer FL, A touch panel film TSP disposed on the film POL and the polarizing film POL and a cover substrate CV laminated on the touch panel film TSP in this order.

In order to make the organic light emitting display thinner, the thickness of the substrate supporting the display element must be thin. However, in order to satisfy the conditions for mass production in a production line for forming a display device to be used at present, the substrate used for the process must be at least 0.5 mm thick. In order to mass-produce an ultra-thin organic light emitting display device, a display device is completed on a production substrate having a thickness of 0.5 mm, a substrate is separated, and an ultra-thin back plate BP is again cemented.

The organic light emitting element layer FL includes a flexible base layer PI formed on a substrate for production (not shown), a display layer ACT formed on the flexible base layer PI, and an adhesive layer ADH for protecting the display layer ACT. And a protective layer BA adhered on the display layer ACT via the protective layer BA. After completing the organic light emitting element layer FL, the flexible base layer PI of the organic light emitting element layer FL is separated from the production substrate, and a back plate BP for protecting the organic light emitting element layer FL is attached do. Here, the back plate (BP) is also referred to as a protective film or a backing film.

The organic light emitting element layer FL includes a display area AA in which display elements including a thin film transistor and an organic light emitting layer are disposed for displaying image information, And a non-display area NA where driving elements for driving are arranged.

On the organic light emitting element layer FL, additional element films for user's convenience are further attached. For example, a polarizing film (POL) can be attached to prevent external light from being reflected and disturbing the viewing of the image represented by the display device. A touch film (TSP) can be attached to touch the screen to input user's information. The touch film TSP may include a first touch film TS1 having a wiring layer arranged in a lateral direction and a second touch film TS2 having a wiring layer arranged in a longitudinal direction. The touch film TSP is also divided into a display area AA in which an electrode part recognizing a user's touch signal is arranged and a non-display area NA in which a driving part for processing a signal in the electrode part is arranged.

A cover substrate (CV) for protecting all the display elements is attached to the uppermost layer of the ultra-thin organic light emitting display. Thereafter, the ultra-thin organic light emitting display device is attached to various information processing apparatuses and made into a final product. For example, the frame (FR) is used to couple the organic light emitting display device to the upper part of the information processing apparatus into one apparatus. At this time, a part of the frame FR covers the upper side of the side of the display device. This area is usually the bezel area (BZ). The bezel area BZ includes areas for disposing the driving circuit part and / or connecting areas for connecting the driving circuit part and the display panel, and includes the non-display area NA of the organic light emitting device layer FL.

There is an increasing need to use a larger display panel in the same area in order to provide precise and accurate screen information in a portable information device and to be able to input user information directly into the display panel. Efforts to reduce the bezel area (BZ) have been made for this purpose. However, even when a highly integrated technology is applied, there is a limit to minimizing the bezel area BZ due to the non-display area NA of the organic light emitting display.

An object of the present invention is to provide a display device having a lateral bending structure in which a bezel area is not recognized on the left side and the right side when viewed from the front. Another object of the present invention is to provide a flexible organic light emitting diode display panel which is applied to a display device having a side bending structure. Another object of the present invention is to provide a structure for distributing stress generated in a bending axis in a process of bending side surfaces of a flexible organic light emitting diode display panel and attaching the same to a cover glass.

In order to achieve the object of the present invention, an organic light emitting diode display device having a lateral side / side bending structure according to the present invention includes a back plate, a dam, a barrier film, a bending axis, and a crack prevention pattern. The back plate includes a display area and a non-display area. The dam surrounds the display area. The barrier film is surface-bonded to the back plate on the dam. The bending axis is defined in the side bending position of the back plate. The crack prevention pattern is disposed so as to overlap with the bending axis at a distance from the display area to the outside.

For example, the crack prevention pattern partially overlaps with the end of the barrier film.

In one example, the crack preventing pattern has an island shape spaced apart from the display area by at least 50 mu m and spaced apart from the adjacent edge of the back plate by at least 100 mu m.

In one example, the crack-preventing pattern has an island shape spaced apart by at least 50 mu m and at least 100 mu m from the adjacent rim of the back plate.

For example, the anti-crack pattern has island shapes each having a width of 100 mu m or more on the left and right sides with respect to the bending axis.

For example, it further includes a gate driving element, a base wiring, a thin film transistor and an organic light emitting diode, a planarizing film, a bank and a spacer. The gate driving element is disposed between at least one of the left side and the right side of the display area and the dam. The base wiring is disposed between the gate driving element and the dam and surrounds the display area. The thin film transistor and the organic light emitting diode are disposed in the display region. The flattening film covers the display area. The bank defines the light emitting region of the organic light emitting diode on the planarizing film. The spacer is disposed in a region where the thin film transistor is formed, and maintains a space between the barrier film and the back plate.

For example, the crack prevention pattern is formed by laminating a planarizing film and a bank.

For example, the crack prevention pattern is formed by laminating a planarizing film, a bank, and a spacer.

The present invention provides a flexible organic light emitting diode display panel that can be applied to a display device having a side bending structure. The flexible organic light emitting diode display panel according to the present invention includes a crack prevention pattern which overlaps with a bending axis at which a curved surface starts from a side. Therefore, a certain thickness is ensured across the bending axis so that the stress is uniformly dispersed when the flexible display panel is attached to the curved cover glass. The display device having the side bending structure according to the present invention does not cause cracks due to the stress difference. Further, the crack preventing pattern is spaced apart from the display area by a certain distance, thereby preventing external foreign matter from penetrating into the display area through the crack preventing pattern.

1 is a cross-sectional view schematically showing the structure of an information processing apparatus employing an ultra-thin organic light emitting diode display device.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light emitting diode (OLED) display device having a lateral side / side bending structure.
FIG. 3 is a cross-sectional view illustrating a bonding structure of a curved display panel used in an organic light emitting diode display device having a side bending structure according to the present invention.
4 is an enlarged sectional view showing a curved structure of a curved surface display panel according to the present invention shown in Fig.
5 is a plan view showing a structure of a flexible organic light emitting diode display panel according to a first embodiment of the present invention.
6 is a cross-sectional view showing a structure of a flexible organic light emitting diode display panel according to a first embodiment of the present invention, cut into a perforated line II-II 'in FIG. 5;
7 is a plan view showing a structure of a flexible organic light emitting diode display panel according to a second embodiment of the present invention.
FIG. 8 is a cross-sectional view showing the structure of a flexible organic light emitting diode display panel according to a second embodiment of the present invention, cut into a perforated line III-III 'in FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals throughout the specification denote substantially identical components. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, the component names used in the following description may be selected in consideration of easiness of specification, and may be different from the parts names of actual products.

Hereinafter, with reference to FIG. 2, an organic light emitting diode display device having a side / side bend structure according to the present invention will be described. 2 is a perspective view showing the structure of an organic light emitting diode display device having a side edge / side bending structure according to the present invention.

Referring to FIG. 2, the organic light emitting diode display device having a side bending structure includes a main panel MP and a curved display panel (CDP). The curved surface display panel (CDP) refers to a display panel in which a part of the display surface is curved or warped. For example, it refers to a display panel that does not affect the display element at all and performs a normal display function unless it is bent or bent to 90 degrees or more and 180 degrees or completely folded. Here, for the purpose of realizing a display device having a side bending structure, in the case of a display panel in which a curved surface portion is disposed on a side surface, it is also referred to as a curved display panel.

The main panel MP has a substantially rectangular thin plate-like structure. The main panel MP may include various devices for driving the curved display panel CDP. For example, in the case of a mobile communication terminal (mobile phone), various components having a communication function can be provided. In the case of a portable personal computer, various components for a computer function may be provided. A curved display panel (CDP) is attached to the front surface of the main panel (MP).

The curved surface display panel (CDP) has a side bending structure. For example, a flat display surface PS and a curved display surface CS. The flat display surface PS is a flat surface occupying most of the curved display panel CDP. The curved surface display surface CS is a curved surface extending from the left side and the right side of the flat display surface PS, respectively. In particular, the curved surface display surface CS may have a curved shape corresponding to 1/4 of the cylinder.

When a curved surface display panel (CDP) is applied to a portable telephone, the left side and the right side corresponding to the long side may have a structure bent 90 degrees toward the back side. Therefore, when viewed from the front, there are no non-display areas or bezel areas on the left side and the right side. On the other hand, it is possible to have a non-display area having a constant width at the upper side and the lower side corresponding to the shorter side. In the non-display area of the upper and lower sides, an external display device such as a product name or a manufacturer's logo, or an external input device such as a microphone, a speaker, a camera lens, or an optical sensor can be disposed.

Hereinafter, the curved surface display panel (CDP) will be described in detail with reference to FIGS. FIG. 3 is a cross-sectional view illustrating a structure of a curved display panel used in an organic light emitting diode display device having a side bending structure according to the present invention. 4 is an enlarged sectional view showing a curved structure of a curved surface display panel according to the present invention shown in Fig.

As shown in Fig. 3, the curved surface display panel CDP includes a flexible display panel FDP and a cover glass CG. The flexible display panel FDP is a display panel in which the entire display panel is excellent in elasticity and flexibility and is not held in a flat state but is free to bend or bend. In the present invention, for the sake of convenience, the flexible display panel (FDP) is referred to as a flexible display panel. On the other hand, a display panel bonded to a cover glass (CG) having a hard surface but having a curved surface is called a curved surface display panel (CDP). In the following description, the flexible display panel FDP will be described as a flexible organic light emitting diode display panel. However, the present invention is not necessarily limited to this, and the spirit of the present invention can be equally applied to other display panels that can secure flexibility.

The flexible display panel FDP includes a back plate BP, an organic light emitting element layer FL, a polarizing film POL, and a touch film TSP. It is preferable that the back plate BP is a film material which is easily bent while being flexible with a rigidity for protecting the organic light emitting element layer FL. The back plate BP is adhered to the organic light emitting element layer FL via a pressure sensitive adhesive (PSA) having a property of suppressing bubble formation applied on one side surface.

A polarizing film (POL) is attached on the organic light emitting element layer (FL) by a laminating method. A touch film (TSP) is attached on the polarizing film (POL) to directly input the user's information by touching the screen. The flexible display panel FDP is completed by stacking the organic light emitting element layer FL, the polarizing film POL and the touch film TSP on the back plate BP having a flexible property and a thin thickness.

Since the flexible display panel (FDP) is easily bent, it can be applied to various display devices. In the present invention, a flexible display panel (FDP) is attached to the inner side of a "U" -shaped cover glass (CG) whose sides are slightly curved to provide a curved display panel (CDP) which can use the upper surface and the curved side as a display area do.

For example, the cover glass CG has a flat display surface PS and a curved display surface CS. An optical adhesive OCA may be coated on the surface of the touch film TSP bonded to the upper layer of the flexible display panel FDP and attached to the inner side of the cover glass CG. As a result, it is possible to provide an organic light emitting diode display device having a lateral / side bending structure capable of providing video information on the surface from the flat display surface PS to the curved display surface CS.

As described above, in order to achieve a structure in which a part of the side surface is bent, a method of surface-bonding the flexible display panel (FDP) to the inner surface of the cover glass (CG) curved side is used. In this case, as shown in Fig. 4, a bending stress may occur in a bent portion of the flexible display panel FDP, that is, a curved portion that is a portion facing the curved display surface CS. Bending stresses can cause various defects. For example, cracks or sagging may occur in the thin films constituting the organic light emitting element layer FL.

The present invention provides a structure capable of preventing a crack generated in thin films by an assembling force. Particularly, the present invention provides an organic light emitting diode display device having a side edge bending structure with a crack prevention pattern for preventing cracks that may be caused by bending stress at a step formed in a curved portion.

≪ Embodiment 1 >

5 and 6, the structure of the flexible display panel FDP attached to the inner side of the cover glass CG having a side-side bending structure will be described in detail. 5 is a plan view showing the structure of a flexible display panel according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view showing the structure of a flexible display panel according to the first embodiment of the present invention, cut into a perforated line II-II 'in FIG.

Referring to Fig. 5, the flexible display panel FDP includes a rectangular flexible back plate BP. The back plate BP is divided into a display area AA and a non-display area NA. The display area AA is an area for directly displaying video information represented by the display device, and is disposed at the center of the back plate BP. The non-display area NA is an area disposed around the display area AA and in which driving elements necessary for driving the display elements arranged in the display area AA are disposed. In the display area AA, an organic light emitting diode and thin film transistors for driving the organic light emitting diode are formed. In the non-display area NA, gate driving elements (GIP) and data driving elements (DIC) necessary for performing a display function are disposed.

The gate driving element GIP can be formed simultaneously with the display elements formed in the display area AA. FIG. 5 shows a structure in which gate drive elements (GIP) are arranged on both sides. However, the gate driving element (GIP) may be disposed on either side. The data driving device (DIC), which is much more complicated than the gate driving device (GIP) and has a complicated structure, is not formed integrally with the display device but separately manufactured and mounted on the back plate (BP) And connects to the connection pads disposed on the back plate (BP). Here, the case of mounting on the back plate BP is shown.

And the planarizing film PL is coated so as to cover all of the display area AA. The planarizing film PL does not cover the gate driving element GIP. On the planarizing film PL, a bank BA is formed. The planarizing film PL and the bank BA are made of an organic material. Since the organic material is vulnerable to moisture and air introduced from outside, it is preferable to coat the planarizing film PL and the bank BA in a limited area so as to have a size slightly larger than the display area AA . That is, when the organic material is connected to the display area AA from the non-display area NA, water and air may flow through the organic material and damage the entire device. Therefore, it is preferable that the organic material is confined to the display area AA and is arranged so as to be disconnected from the outside.

Around the display area AA, a ground wiring GND is arranged so as to surround it. In particular, it is preferable to arrange to surround the outside of the gate driving element (GIP). The ground wiring GND is connected to the data driving element DIC. The data driving element DIC is connected to the outside, and the ground voltage applied from the outside is supplied to the ground wiring GND via the base pad of the data driving element DIC.

A dam DM is disposed outside the base wiring GND. The dam DM is disposed so as to completely enclose the display area AA and the gate driving elements GIP. The dam DM limits the particle prevention layer PCL for protecting the display elements formed on the back plate BP from particles (moisture or air) capable of penetrating from the outside in a stable manner in the inner region of the dam DM. . The particle barrier layer (PCL) is made of a thermosetting organic material.

A transparent adhesion layer (PSA) is applied on the particle prevention layer (PCL). The barrier film BF is bonded to the back plate BP via a transparent adhesive layer PSA. On the barrier film BF, a polarizing film POL is surface-bonded. Although not shown in the drawing, a touch film may be interposed between the barrier film BF and the polarizing film POL. Alternatively, the touch film may be laminated on the polarizing film POL.

The barrier film BF may have an area equal to or slightly larger than the area defined by the dam DM. It is preferable that the polarizing film POL has the same area as the barrier film BF and is cemented to each other.

The cross-sectional structure of the flexible display panel (FDP) according to the present invention will be further described with reference to Fig. Referring to Fig. 6, the flexible display panel FDP includes a backing plate BP and a barrier film BF bonded to the back plate BP. If necessary, a polarizing film (POL) may be adhered on the barrier film (BF). Further, it may further include a touch film. The touch film may be disposed above or below the polarizing film POL. Alternatively, a thin film having a touch function may be formed together with the organic light emitting diode. Since the touch film can be arranged in various ways, the description of the touch film is omitted here.

The thin film transistors ST and DT and the organic light emitting diode OLE are arranged in the display area AA of the back plate BP. The display region AA is provided with a plurality of pixel regions (data lines) DL, a driving current line VDD connected to the data driving device DIC and a scanning line SL connected to the gate driving portion GIP, PA are arranged in a matrix manner. In each pixel region PA, a switching thin film transistor ST and a driving thin film transistor DT connected to the switching drain electrode are formed. And an organic light emitting diode (OLE) connected to the driving drain electrode is formed in the pixel region PA.

In the non-display area NA, thin film transistors of a gate driving element (GIP) formed simultaneously with the switching and driving thin film transistors ST and DT are formed. A flattening film PL is applied on the thin film transistor of the gate driving element GIP and on the switching and driving thin film transistors ST and DT. An anode electrode ANO is formed in the pixel region PA on the planarizing film PL. The bank BA is coated on the back plate BP on which the anode electrode ANO is formed.

The bank BA defines an opening defining the light emitting region at the anode electrode ANO. On the bank BA, an organic light emitting layer OL and a cathode electrode CAT are successively laminated. An organic light emitting diode (OLED) is formed by stacking an anode electrode ANO, an organic light emitting layer OL and a cathode electrode CAT in an opening defined by the bank BA in the pixel region PA.

A ground wiring (GND) is disposed outside the gate driving element (GIP). The ground wiring GND may be formed of any one of the metal materials arranged in the display area AA. For example, it may be formed of the same material as the gate electrode or the source-drain material, or may be formed of a separate metal layer. A protective film PAS is formed on the surface of the back plate BP on which the base wiring GND, the gate driving element GIP and the thin film transistors ST and DT are formed. It is preferable that the planarizing film PL and the bank BA which are organic substances are disposed only in the display area AA.

The barrier film BF is surface-bonded to the back plate BP on which the display elements are formed. An anti-particle layer (PCL) is filled between the barrier film (BF) and the back plate (BP) to prevent moisture and air from penetrating into the display element from the outside. The particle barrier layer (PCL) is made of a thermosetting organic material.

A spacer SP for keeping the adhesion distance between the back plate BP and the barrier film BF constant can be disposed in the region where the thin film transistors ST and DT are arranged. A dam DM is formed on the back plate BP at a position slightly inward from the rim of the barrier film BF. The dam DM can be formed by laminating a planarizing film PL, a bank BA and / or a spacer SP.

Even if the dam DM is formed of an organic material such as the planarizing film PL and the bank BA, the dam DM is separated from the display area AA by a certain distance. That is, the organic material forming the dam DM is physically separated from the organic material covering the display area AA. Therefore, moisture or air that may exist outside the dam DM does not penetrate into the inside of the display area AA.

Referring back to FIG. 5, a bending axis BL is defined at the boundary between the flat display surface PS and the curved surface display surface CS. The bending axis BL is not a component that actually exists in the cover glass CG or the flexible display panel CDP. It can be defined that it corresponds to the center axis of the curved surface display surface CS as a part where the curved surface display surface CS starts. For example, when the curved surface display surface CS corresponds to 1/4 of the cylinder, the bending axis BL coincides with the boundary line between the flat display surface PS and the curved surface display surface CS, Lt; RTI ID = 0.0 > CS). ≪ / RTI >

When the flexible display panel CDP is attached to the inner surface of the cover glass CG, the combining force is evenly applied from the flat display surface PS to the curved display surface CS through the bending axis BL. Looking at the laminated structure in the vertical direction along the bending axis BL, the boundary between the dam DM and the back plate BP is very close to the lower side. However, in the case of the upper side, the boundary between the dam (DM) and the back plate (BP) is considerably far away. This is to secure a sufficient area for disposing the data driving element DIC because the data driving element DIC is attached to the top side.

Therefore, there is no stacking component between the cover glass CG and the back plate BP in view of the laminated structure of the upper part of the back plate BP. That is, in the display area, thick organic layers such as the planarizing film PL and the bank BA are laminated, and the barrier film BF and the polarizing film POL are laminated thereon. On the other hand, there is no laminated structure outside the barrier film (BF) and the polarizing film (POL). The bending assisting force is uniformly applied along the bending axis (BL). There is no stacked structure that can withstand the combining force at the upper side of the back plate (BP). In this case, the bonding force may be excessively concentrated on the wiring disposed on the upper side, particularly, the ground wiring (GND). As a result, cracks may occur in the base wiring (GND) after the flexible display panel (FDP) is attached to the cover glass (CG). This causes defective display devices.

The present invention further includes a crack prevention pattern (PAT) for preventing such cracks. Specifically, a crack prevention pattern PAT is further disposed in a predetermined region around the left and right bending axes BL.

In the organic light emitting diode display device having the side bending structure according to the first embodiment of the present invention, the crack preventing pattern PAT can be formed using the planarizing film PL and the bank BA. When the crack prevention film PAT is formed by laminating the planarizing film PL and the bank BA, it is preferable to arrange the crack preventing film PAT so as to overlap the bending axis BL in an island shape.

When the crack prevention pattern PAT is formed by the planarizing film PL including the organic material and the bank BA, moisture or air should not flow into the display area AA from the outside along the crack preventing pattern PAT do. Therefore, it is preferable that the flattening film PL formed in the display area AA and the island shape separated from the bank BA by at least 50 mu m or more. Further, it is preferable that the back plate BP has an island shape at least 100 mu m or more apart from the outside of the back plate BP. If the crack prevention pattern (PAT) is out of the region of the back plate (BP), it may cause a failure in the subsequent process or create a path for foreign foreign matter to penetrate.

The size of the crack prevention pattern (PAT) is the size of the back plate (BP). The size of the display area AA and / or the size of the curved surface display surface CS. Therefore, it can be defined in various sizes. However, it should have a width of at least 100 μm on the left and right sides around the bending axis BL. As described above, the minimum separation distance a from the planarizing film PL and / or the bank BA covering the display area AA, the minimum separation distance b from the side of the back plate BP, It is preferable that the minimum separation distance (c) from the upper side of the plate (BP) is secured.

The crack prevention pattern PAT and the dam DM can be formed by using the planarizing film PL, the bank BA and / or the spacer SP. For example, the planarizing film PL and the bank BA are laminated to form a crack prevention pattern PAT and a dam DM. Then, a spacer SP is further laminated on the portion where the dam DM is to be formed, thereby completing the dam DM. Then, the crack prevention pattern PAT extends inside the dam DM a certain distance and has a structure extending a certain distance outward beyond the dam DM. At this time, it is preferable that the inner boundary line of the crack preventing pattern PAT is separated by at least 50 mu m or more from the planarizing film PL and the bank BA covering the display area AA.

≪ Embodiment 2 >

In the second embodiment, the crack prevention pattern PAT may be formed to have an island shape disposed at a distance from the outside of the dam DM. Hereinafter, the second embodiment will be described with reference to FIGS. 7 is a plan view showing a structure of a flexible display panel according to a second embodiment of the present invention. FIG. 8 is a cross-sectional view showing the structure of a flexible display panel according to a second embodiment of the present invention, cut to a perforated line III-III 'in FIG.

The basic structure of the flexible display panel to be applied to the organic light emitting diode display device having the lateral bent structure according to the second embodiment is the same as that of the first embodiment. Therefore, redundant description is omitted. The structure of the crack prevention pattern (PAT) showing important features will be mainly described.

In the case of the second embodiment, the crack prevention pattern PAT can be formed to have the same structure as the dam DM. For example, the planarizing film PL, the bank BA and / or the spacer SP may be formed at the same time, and these three layers may have a laminated structure.

It is preferable that the crack prevention pattern PAT is disposed at a distance of about 50 mu m from the dam DM. Particularly, it is preferable that the size of the polarizing film POL is at least 50 mu m or more enlarged in size by the upper side so that a part of the anti-crack pattern PAT overlaps with the barrier film BF and / or the polarizing film POL .

When the crack prevention pattern (PAT) has the same lamination structure as the dam DM, there is an advantage that the bending stress can be more effectively dispersed. Further, when the barrier film BF and / or the polarizing film POL are partially overlapped with each other, they can be closely contacted with the crack preventing pattern PAT without any gap. Therefore, there is also an advantage that the change in stress that the barrier film (BF) and / or the polarizing film (POL) are bent at the bending axis (BL) portion can be absorbed.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the present invention should not be limited to the details described in the detailed description, but should be defined by the claims.

ST: switching thin film transistor DT: driving thin film transistor
GL: scan wiring DL: data wiring
VDD: driving current wiring IN: insulating film
PAS: protective film PL: planarization film
OL: organic light emitting layer OLE: organic light emitting diode
ANO: anode electrode CAT: cathode electrode
BF: Barrier film POL: Polarizing film
GIP: Gate driving device DIC: Data driving device
DM: Dam GND: Ground wiring
PAT: crack prevention pattern BL: bending axis

Claims (8)

A back plate on which a display area and a non-display area are defined;
A dam surrounding the display area;
A barrier film bonded to the back plate on the dam;
A bending axis defined in said back plate;
And a crack preventing pattern disposed at a predetermined distance from the display region and overlapping the bending axis.
The method according to claim 1,
The crack protection pattern
And a side-side bending structure partially overlapping with an end of the barrier film.
The method according to claim 1,
The crack protection pattern
At least 50 mu m apart from the display area,
And a side-side bending structure having an island shape spaced apart by at least 100 mu m from an adjacent rim of the back plate.
The method according to claim 1,
The crack protection pattern
At least 50 占 퐉 apart from the dam,
And a side-side bending structure having an island shape spaced apart by at least 100 mu m from an adjacent rim of the back plate.
The method according to claim 1,
The crack protection pattern
And a side-side bending structure having an island shape having a width of 100 mu m or more on the left and right sides with respect to the bending axis.
The method according to claim 1,
A gate driving element disposed between at least one of a left side and a right side of the display region and the dam;
A base wiring disposed between the gate driving element and the dam and surrounding the display region;
A thin film transistor and an organic light emitting diode disposed in the display region;
A planarizing film covering the display area;
A bank defining a light emitting region of the organic light emitting diode on the planarization layer;
And a spacer disposed in a region where the thin film transistor is formed and maintaining a gap between the barrier film and the back plate.
The method according to claim 6,
The crack protection pattern
Wherein the flattening film and the bank are laminated on a side surface of the organic light emitting diode.
The method according to claim 6,
The crack protection pattern
Wherein the planarizing film, the bank, and the spacer are laminated on the side surface of the organic light emitting diode.

Images