KR102445774B1 - Flexible Display Device - Google Patents

Abstract

The present invention relates to a flexible display device capable of relieving stress due to a folding operation by changing the shape of an inorganic insulating film, wherein the active region on a flexible substrate has a light emitting region at the same position of each pixel, and the lower or upper side thereof The effect of folding stress is prevented by providing a separation space in the provided inorganic insulating film of the provided thin film transistor array.

Description

Flexible Display Device {Flexible Display Device}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly, to a flexible display device capable of reducing stress due to a folding operation by changing the shape of an inorganic insulating layer.

Specific examples of the flat panel display device include a liquid crystal display device (LCD), an organic light emitting display device (OLED), a plasma display panel device (PDP), and a quantum dot display device (Quantum Dot Display). device), a field emission display device (FED), an electrophoretic display device (EPD), and the like. , a flat panel display panel has a structure in which a pair of transparent insulating substrates are bonded to each other with a unique light emitting or polarized light or other optical material layer interposed therebetween.

Recently, as the size of the display device increases, there is an increasing demand for a flat display device that occupies less space. This demand has been increased, and there is a demand for using the flat display device in a flexible form that can be folded or bent. In addition, such a display device is referred to as a flexible display device.

A flexible display device is being developed into a form that can be folded as the thickness is gradually reduced. However, in the flexible display device up to now, as the folding operation is repeated and the number of times of the folding operation is increased, damage occurs in the folding area, which is presented as various problems. For example, there is a problem in that the folding part is not lit at all because the pixels of the folding part are damaged due to a large amount of physical stress during folding. Alternatively, even if non-lighting due to repeated folding does not occur, stress accumulates over time due to repeated folding, so a solution is needed.

SUMMARY OF THE INVENTION The present invention has been devised to solve the above-described problems, and an object of the present invention is to provide a flexible display device capable of relieving stress due to a folding operation by changing the shape of an inorganic insulating layer.

A flexible display device of the present invention for achieving the above object has a light emitting region at the same position of each pixel in the active region on a flexible substrate, and spaced apart in an inorganic insulating film of a thin film transistor array provided below or above the active region to prevent the effect of folding stress.

The flexible display device of the present invention includes: a flexible substrate having an active region including a plurality of pixels of the same size in a matrix and a non-display region surrounding the active region, and having at least one uniaxial folding region defined; A bank having a light emitting region at the same position of each pixel in the active region of an image and a bank having a light emitting region at the same position of each pixel are located in different layers in the active region on the flexible substrate, respectively, arranged along an axis of the folding region and a direction crossing it A first separation space is provided along the axis of the folding area for every n (n is a natural number) number of first wirings between the plurality of first and second wirings and the layers between the first and second wirings in the folding area. A first inorganic insulating layer may be included.

In addition, a pitch of the pixels and a pitch of the first wiring may be different from each other in the folding area in the direction of the second wiring.

)(p는 제 2 배선 방향에서의 픽셀 피치, gp는 제 1 이격 공간의 폭)일 수 있다. In this case, the pitch of the n first wirings is a value obtained by dividing a value obtained by subtracting the width of the first separation space from the length of the n pixels in the direction of the second wiring by n (

) (p is the pixel pitch in the second wiring direction, gp is the width of the first separation space).

The organic light emitting diode may further include an organic light emitting diode provided in the light emitting region, and first and second electrodes positioned below and above the organic light emitting layer. The bank and the organic light emitting diode may be located above the second wiring or below the first wiring.

The second inorganic insulating layer may further include a second inorganic insulating layer having a second spacing having the same width corresponding to the first spacing between the layers of the flexible substrate and the first wiring. In this case, the second inorganic insulating layer has a plurality of layers, and insulating materials of the same type or different types are laminated.

In addition, a third inorganic insulating layer may be further included between the layers between the second wiring and the organic light emitting diode and having a third spacing having the same width corresponding to the first spacing.

)(p는 제 2 배선 방향에서의 픽셀 피치, gp는 제 1 이격 공간의 폭)일 수 있다. Meanwhile, in each of the pixels, a gate electrode protruding from the first wiring, a source electrode protruding from the second wiring, and a drain electrode of the same layer spaced apart from the source electrode, and both sides of the source electrode and the drain electrode, respectively A thin film transistor including a connected active layer may be further included. In this case, the pitch of the thin film transistor in the second wiring direction is a value obtained by subtracting the width of the first separation space from the length of the n pixels in the second wiring direction divided by n (

) (p is the pixel pitch in the second wiring direction, gp is the width of the first separation space).

In addition, a barrier laminate may further include an alternating pair of organic and inorganic layers covering an upper portion of the organic light emitting diode and an upper portion of the non-display area.

A scan driver may further include a scan driver in the non-display area on one side or both sides of the first wire, and a driver IC in the non-display area on one side of the second wire.

The first separation area may extend past the scan driver. In this case, the scan driver may include a plurality of scan circuit blocks respectively corresponding to the first wiring on a line, and a voltage signal and a clock signal wiring connected to the drive IC. Here, it is preferable that the first inorganic insulating layer covers the outside of the voltage signal and clock signal wiring in the non-display area.

The flexible display device of the present invention has the following effects.

First, in a high-resolution flexible display device, a space may be formed in the inorganic insulating layer that is vulnerable to impact to disperse stress, thereby reducing stress and reducing cracking in a region where folding stress is repeated. Accordingly, it is possible to implement a flexible display device that is resistant to folding stress and has flexibility.

Second, an inorganic insulating film having a spaced space is provided in the thin film transistor array, and with respect to an upper or lower organic light emitting diode, an organic light emitting layer is arranged in the same area of a pixel, so that uniform light emission is possible. Accordingly, even if the pitch is adjusted by the spaced space arrangement in the thin film transistor array, it is possible to display evenly without deterioration of display quality due to the spaced space of the inorganic insulating film.

1A and 1B are a plan view and a cross-sectional view illustrating a flexible display device of the present invention and a folding area thereof;
2 is an enlarged view of area A of FIG. 1A;
3 is an enlarged view of area B of FIG. 1A;
4 is a cross-sectional view taken along line I to I' of FIG.
5A to 5C are plan views illustrating a scan line, a space between an inorganic insulating layer, and a light emitting area of the flexible display device of the present invention;
6 is a plan view illustrating a flexible display device according to another exemplary embodiment;
7 is a cross-sectional view illustrating a flexible display device according to another exemplary embodiment;
8 is a cross-sectional view illustrating a modified example of the flexible display device of the present invention;
9 is a plan view illustrating a correspondence relationship between a light emitting region and a pixel region of a thin film transistor array according to a comparative example;
10 is a cross-sectional view taken along line II to II' of FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Like reference numerals refer to substantially identical elements throughout. In the following description, if it is determined that a detailed description of a known technology or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, the component names used in the following description are selected in consideration of the ease of writing the specification, and may be different from the part names of the actual product.

1A and 1B are plan and cross-sectional views illustrating a flexible display device of the present invention and a folding area thereof, FIG. 2 is an enlarged view of area A of FIG. 1A, and FIG. 3 is an enlarged view of area B of FIG. 1A. Also, FIG. 4 is a cross-sectional view taken along line I to I' of FIG. 2 .

The flexible display device of the present invention includes a foldable display device including a bendable display device in which the device can be partially bent or a rollable display device in which the device can be completely rolled, as shown in FIG. 1B . For a display device capable of being foldable), the folding area may be any of the center, the edge area, or the entire area, and not only one but also several folding areas may be provided to be spaced apart from each other. In some cases, when the flexible display device has a plurality of folding areas, it may be folded in different directions several times to have display surfaces in different directions.

In addition, the folding region can be set by giving flexibility to a specific portion of a set or frame disposed on the edge of the thin film transistor array and the organic light emitting diode array formed on the flexible substrate and on the lower surface of the flexible substrate.

In addition, as shown in FIGS. 1A, 2 and 3 , the folding area includes not only the folding line corresponding to the actual folding axis according to the tension of the flexible substrate on which the array of the flexible display device is formed but also the area in which the bending occurs. , a plurality of pixel lines are disposed in the folding area. In addition, the separation space GP of the inorganic insulating layer 150 configured to relieve the stress of the present invention is regularly provided in pixel lines along a folding axis (direction of the folding line) included in the folding region. As an essential configuration, the separation space GP of the inorganic insulating layer 150 is provided in the folding area, and the separation space GP of the inorganic insulating layer 150 may be further provided in an area other than the folding area. In addition, the inorganic insulating layer 150 may be separated from the active area AA with the separation space GP as a boundary.

Meanwhile, as shown in FIGS. 1A and 4 , the flexible display device of the present invention has an active area AA including a plurality of pixels of the same size in a matrix and a non-display area around the active area AA, and includes at least one uniaxial folding In the flexible substrate 10 in which the area is defined, and in the active area AA on the flexible substrate 10, for pixels in a direction crossing the axis of the folding area, a space ( On the provided thin film transistor array 1100 and the thin film transistor array 1100 having an inorganic insulating film 150 having a and an organic light emitting diode array 1200 having a light emitting layer. A barrier laminate 1300 in which one or more pairs of organic and inorganic layers are stacked is provided on the organic light emitting diode array 1200 to protect the inner organic light emitting diode from external moisture or external air.

The reason why the flexible substrate 10 is used as a substrate on which the arrays 1100 and 1200 is formed is to give the device flexibility, and the flexible substrate 10 has a thickness of 2 μm to 150 μm and has both insulation and flexibility. It is a plastic film. The flexible substrate 10 is a flexible plastic film, polyester or a copolymer containing polyester, a copolymer containing polyimide or polyimide, an olefin-based copolymer, polyacrylic acid ( Polyacrylic acid) or a copolymer containing polyacrylic acid, a copolymer containing polystyrene or polyesterin, a copolymer containing polysulfate or polysulfate, a polycarbonate containing polycarbonate or polycarbonate Copolymer, polyamic acid or a copolymer containing polyamic acid, a copolymer containing polyamine and polyamic acid, polyvinylalcohol, polyallylamine selected from the group consisting of One or more polymer compounds may be included.

In addition, the flexible substrate 10 is formed on a glass substrate (not shown) on a glass substrate (not shown) in order to prevent the problem that the flexible substrate 10 is dried or damaged by heat or pressure when the array process is directly performed thereon. 10) and, in turn, further providing a plurality of buffer layers 11 on the surface of the flexible substrate 10, an array may be formed. In this case, the glass substrate used during the process is removed after the array forming process is applied, and the flexible substrate 10 remains as a substrate of the entire flexible display device.

Here, the plurality of buffer layers 11 are formed by stacking a plurality of layers of the same or different inorganic insulating films, and have electrical insulation and an array protection function inside the flexible substrate 10 . For example, the buffer layer included in the plurality of buffer layers 11 may be an inorganic insulating film such as SiNx or SiOx, and as a component that does not impair flexibility, the plurality of buffer layers 11 are several times greater than the flexible substrate 10 . It is several tens of times thinner and is provided with a thickness of less than 1 μm.

Meanwhile, the thin film transistor array 1100 and the organic light emitting diode array 1200 may be formed by transposing the order of each other (refer to FIG. 7 ). In this case, the organic light emitting diode array 1200 may be in contact with the buffer layer 11 , and the thin film transistor array 1100 is formed on the organic light emitting diode array 1200 .

In either case, the thin film transistor array 1100 and the organic light emitting diode array 1200 each have a thin film transistor (TFT) and an organic light emitting diode (OLED) corresponding to a pixel, and the flexible display device of the present invention In the folding region of , the pitch of the thin film transistors (TFTs) of the thin film transistor array 1100 in a direction crossing the folding axis is different from the pitch of the organic light emitting diodes of the organic light emitting diode array 1200 . In particular, with respect to the folding region, a separation space GP is provided in the inorganic insulating film 150 positioned between the layers of the wirings of the thin film transistor array 1100 and above and below the wirings, and the organic light emitting diodes (OLEDs) are located at the same position for each pixel. , the pitch Pl of the thin film transistors TFT positioned between the separation spaces GP is smaller than the pitch P of the organic light emitting diode (P, equal to the pixel pitch). On the other hand, in the flexible display device of the present invention, since the organic light emitting diode is positioned at the same position of each pixel, the area of the light emitting region does not decrease regardless of the spacing of the inorganic insulating layer, so the luminous efficiency is reduced in a structure to relieve folding stress. This does not degrade.

The flexible display device of the present invention will be described in more detail as follows.

1A and 2 to 4 , a flexible substrate having an active area AA including a plurality of pixels of the same size in a matrix and a non-display area surrounding the active area, and having at least one uniaxial folding area defined. (10), a bank 162 having a light emitting area OR at the same position of each pixel in the active area AA on the flexible substrate 10, and the active area on the flexible substrate 10 ( AA), the plurality of first and second wirings 111 and 112 and the first wirings 111 located on different layers, respectively, arranged along the axis of the folding area and a direction crossing the axis of the folding area. An inorganic insulating layer 150 having a spaced apart space along the axis of the folding region is included on a lower side and an upper side of the second wiring 112 , for every n (n is a natural number) number of first wirings 111 .

The first wiring 111 is formed along the axis of the folding area, that is, the direction of the folding line, and the second wiring 112 is formed in a direction crossing the folding line. The first wiring 111 and the second wiring 112 are provided on different layers. For example, the first wiring 111 is a scan wiring, and the second wiring 112 is a data wiring and a power supply voltage ( Vdd) wiring and ground voltage (Vss) wiring.

1A and 2 to 4 illustrate a bar in which the direction of the folding line is set to the direction of the X-axis, but is not limited thereto. If the direction of the folding line is the Y-axis direction, the first wiring may be in the Y-axis direction, and the second wiring may be in the X-axis direction. When the direction of the folding line is the Y-axis direction, the general pixel arrangement method (X-axis direction scan wiring, Y-axis direction is data wiring) is rotated 90 degrees using the first wiring arranged in the Y-axis direction as the scan wiring. It could also be placed. Of course, even in this case, the first wiring may be maintained as the scan wiring, and the second wiring may be maintained as the data wiring, the power supply voltage (Vdd) wiring, and the ground voltage (Vss) wiring.

In the illustrated drawings, the first wiring 111 is located at the lower side and the second wiring 112 is located at the upper side, but the present invention is not limited thereto. In some cases, the first wiring 111 may be located above the second wiring 112 . At least the first wiring 111 and the second wiring 112 include one or more thin film transistors (TFTs) at their intersections, and in particular, as shown in FIGS. 2 to 4 , the first wiring ( 111) has a reduced shape compared to a structure in which there is no separation space GP between the separation spaces GP. In this case, referring to FIG. 3 , the y pitch (pitch in the second wiring direction) of the first wiring 111 between the separation spaces GP is reduced than the y pitch (pitch in the second wiring direction) of the pixels, When n pixel lines (n is a natural number) divided by the separation space GP are referred to as one block, in adjacent blocks, the first wiring 111 of the last pixel line of the previous block and the next block The spacing Hb between the first wirings 111 of the first pixel line of , is larger than the interval Ha between the first wirings 111 in the block due to the arrangement of the separation space GP.

Accordingly, the regular pitch P of the pixels in the direction of the second wiring 112 in the folding area and the pitch Pl of the first wiring 111 are different from each other.

In this case, the first wirings 111 are arranged in the same shape in a block period.

In addition, in the drawings of FIGS. 2 to 4 , three pixels correspond to the block in the direction of the second wiring 112 , but the present invention is not limited thereto. The block may be one or more pixel lines as a minimum unit, and in distributing the separation space GP at a level capable of dispersing the stress of the folding area, one or more divided pixel lines as a unit do. For the stress distribution effect, a plurality of pixel lines included in the folding area are divided smaller than that of the plurality of pixel lines. In addition, the width gp of the separation space GP is, for example, 3 μm to 10 μm, and when the stress is transmitted in the direction of the folding line, the stress is set to a width sufficient to stop or bypass the path. .

In addition, the second wiring 112 crossing the folding line has the same x pitch in every pixel.

)(P는 제 2 배선 방향에서의 픽셀 피치, gp는 이격 공간의 폭)에 해당한다.Here, the pitch Pl of the n first wirings 111 between the separation spaces is a value obtained by subtracting the width of the separation space from the length of the n pixels in the second wiring direction divided by n. (

) (P is the pixel pitch in the second wiring direction, gp is the width of the separation space).

Corresponding to each pixel, the organic light emitting layer 163 provided in the light emitting region OR defined by the bank 162 , the first electrode 161 and the first electrode 161 located below and above the organic light emitting layer 163 , An organic light emitting diode (OLED) including two electrodes 164 is provided. In this case, the organic material layer of the first and second common layers may be included between the organic light emitting layer 163 and the respective first and second electrodes 161 and 164, and the first and second common layers are respectively It functions as a hole transport layer and as an electron transport layer.

Here, the light emitting region OR is provided at the same position and with the same width corresponding to each pixel, and is not affected by the arrangement according to the setting of the spacing GP of the lower thin film transistor array 1100, so that sufficient light emission is achieved. efficiency can be ensured.

In addition, the first electrode 161 may be located on the thin film transistor array 1100 including the first and second wirings 111 and 112 , and may be located below the bank 162 .

Meanwhile, as shown in FIG. 4 , the thin film transistor array 1100 has a gate electrode 121 on the same layer as the first wiring 111 and the same as the second wiring 112 in each of the pixels. A thin film transistor (TFT) including a source electrode 122 and a drain electrode 123 spaced apart from each other, and an active layer 126 connected at both sides of the source electrode 122 and the drain electrode 123, respectively. .

The gate electrode 121 may have a shape extending from the first wiring 111 , or may extend from the storage electrode and be formed on the same layer as the first wiring 111 but spaced apart from each other.

Here, the drain electrode 123 of the thin film transistor (TFT) is electrically connected to the first electrode 161 of the organic light emitting diode (OLED) to selectively drive each pixel, thereby forming the flexible display device as an active matrix. can be driven by

As shown in the drawing, the active layer 126 may be formed below the first wiring 111 and the gate electrode 121 , or a layer of the gate electrode 121 and the source/drain electrodes 122 and 123 . ) may be located between the layers, or may be located above the source/drain electrodes 122 and 123 . In either case, both sides of the source/drain electrodes 122 and 123 and the active layer 126 are respectively connected.

The active layer 126 may be a polysilicon layer, amorphous silicon layer, or an oxide semiconductor layer. Since the active layer 126 is positioned on a different layer from the gate electrode 121 and the source/drain electrodes 122 and 123 , an inorganic insulating layer is also provided between the active layer 126 and other adjacent electrodes or wires.

Meanwhile, although not shown, in addition to the illustrated first and second wirings 111 and 122 or thin film transistors (TFTs), additional wirings and other thin film transistors or storage capacitors may be added in the pixel. Preferably, the additional wiring is also located on the same layer as any one of the first and second wirings 111 and 112, so that it is possible to exclude the addition of a separate mask.

The inorganic insulating film 150 includes a first interlayer insulating film 151 between the plurality of buffer layers 11 and the active layer 126 (when the active layer 126 is configured below the wirings); A second interlayer insulating layer 152 is formed between the active layer 126 and the first wiring 111/gate electrode 121, and the first wiring 111/gate electrode 121 and the second wiring 112 ) / a third interlayer insulating film 153 between the layers between the source electrode 122 / the drain electrode 123 and the second wiring 112 / the source electrode 122 / the drain electrode 123 and the organic light emitting diode and a fourth interlayer insulating film 154 provided between the layers of the OLED.

In addition, the first to fourth interlayer insulating layers 151 , 152 , 153 , and 154 have a separation space GP at the same position, and thus, when a stress is transferred through the inorganic layer, the separation space GP It can be dispersed through the The first to fourth interlayer insulating films 151 , 152 , 153 , and 154 are inorganic insulating films such as oxide films and nitride films, and have relatively low elasticity compared to organic films and are easily broken. However, in the flexible display device of the present invention, the separation space GP is provided in such an inorganic insulating layer having low elasticity, so that the stress of an external force applied during folding is dispersed without being concentrated in a specific region, and the stress is transmitted. By blocking each region, the insulating function of the inorganic insulating layer 150 of the entire thin film transistor array 1100 may be maintained. Accordingly, it is possible to solve problems such as non-lighting caused by stress concentration during folding.

)(P는 제 2 배선 방향에서의 픽셀 피치, gp는 이격 공간의 폭)에 해당한다. 만일 각 픽셀에 대응하여, 복수개의 박막 트랜지스터가 위치할 경우, 예를 들어, 스위칭 박막 트랜지스터와 구동 박막 트랜지스터가 하나의 픽셀에 구비된 경우, 동종의 박막 트랜지스터끼리 피치를 비교한다.In this case, the pitch in the second wiring direction of the thin film transistor in the separation space within the block is obtained by dividing a value obtained by subtracting the width of the separation space from the length of the n pixels in the second wiring direction by n. value (

) (P is the pixel pitch in the second wiring direction, gp is the width of the separation space). If a plurality of thin film transistors are positioned corresponding to each pixel, for example, when a switching thin film transistor and a driving thin film transistor are provided in one pixel, the pitches of thin film transistors of the same type are compared.

On the other hand, in the flexible display device of the present invention of the above-described embodiment, the organic light emitting diode is a top light emitting method, and the organic light emitting diode emits light according to the light emitting area of each pixel without being affected by the arrangement or pitch of the lower thin film transistor. High-resolution arrangement is possible because it is not affected by light blocking properties or reflections such as the lower wiring.

In addition, the flexible display device of the present invention further includes a barrier laminate 1300 in which at least one pair of alternating organic and inorganic layers covering the top of the organic light emitting diode array 1200 and the top of the non-display area is provided. . The barrier laminate 1300 sufficiently covers the organic light emitting diode 1200 as well as the upper side thereof, and the layered organic layer is formed enough to planarize the lower component or the inorganic layer.

In addition, scan drivers 130a and 130b are provided in the non-display area on one side or both sides of the first wiring 111 , and a driver IC 20 is further installed in the non-display area on one side of the second wiring 112 . may include

Here, the scan drivers 130a and 130b are disposed corresponding to the case where the first wiring 111 is a scan wiring, and are manufactured together in the same process of forming the thin film transistor array 1100, so that a separate pad configuration is required. It is embedded on the flexible substrate 10 without an attachment process.

Although not shown, the driver IC 20 is connected to a pad electrode provided on the flexible substrate 10 . The pad electrode extends from the second wiring 112 , and an image signal may be supplied from the driver IC 120 to the second wiring 112 through the pad electrode. Also, the driver IC 20 supplies a voltage signal and a clock signal to the scan drivers 130a and 130b through a voltage application line and a clock signal line 132 .

Functionally, the driver IC 20 includes a data driver that transmits an image signal to the second wiring 112 , and a timing controller that generates and transmits clock signals of a scan driver and a data driver.

On the other hand, the scan drivers 130a and 130b are connected to a plurality of scan circuit blocks GIP1 , GIP2 , ..., GIP9 corresponding to the first wiring 111 on a line, respectively, and the drive IC 20 . The voltage application line and the clock signal line 132 include the extended voltage signal and clock signal transmission line 135 .

Although the scan drivers 130a and 130b are shown in blocks, they have scan circuit blocks GIP1, GIP2, GIP3, ..., GIP9 on lines of the same Y pitch as the Y pitch between the gate lines. The circuit blocks GIP1, GIP2, GIP3, ..., GIP9 include a shift register, a level shifter, and a buffer. In this case, the output terminal of each buffer is directly connected to one end of the first wiring 111 , and the scan drivers 130a and 130b are electrically connected to the first wiring 111 in the active area AA. do.

When the scan drivers 130a and 130b are disposed at both ends of the first wiring 111 in the non-display area, as shown in FIG. 2 , the separation space GP is also provided to the scan drivers 130a and 130b. can be provided. In this case, each of the scan circuit blocks GIP of the scan drivers 130a and 130b is formed in the form of a plurality of thin film transistors, and is provided together when the thin film transistor array 1100 is formed, and an inorganic insulating film is formed on the same portion. It is possible to have a separation space (GP) of (150) together.

Even in this case, the inorganic insulating layer 150 is left outside of the voltage signal and clock signal transmission line 135 in the non-display area, rather than the space GP being provided up to the edge of the flexible substrate 10 . to prevent external air or moisture from entering from the edge, and to be primarily blocked by the inorganic insulating film 150 .

Since the inorganic insulating layer 150 is removed in the separation space GP, the bank 162 of the upper organic light emitting diode array 1200 may be filled in this region.

Hereinafter, the y pitch Pl of the first wiring of the thin film transistor array, the spacing GP of the inorganic insulating film provided one per block, and the light emitting region OR corresponding to the pixel will be described.

5A to 5C are plan views illustrating a scan line, a space between an inorganic insulating layer, and a light emitting area of the flexible display device of the present invention.

As shown in FIG. 5A, in contrast to pixels having the same y-pitch P in each region of the active region, the first wiring 111 is formed in a block to provide the separation space GP of FIG. 5B. When n pixel lines are arranged, n number of first wirings 111 should be distributed in an area adjusted by a value obtained by subtracting the width of the spaced space from the y-pitch of the block between adjacent spaced spaces GP. , has a pitch (Pl) that is relatively smaller than the y-pitch (P) of the pixel.

However, as shown in FIG. 5C , the light emitting region OR is disposed at a fixed position for every pixel regardless of the pitch adjustment of the lower thin film transistor array, so there is no loss of display area of the flexible display device of the present invention and uniform efficiency can emit light.

Meanwhile, in the above description, only the arrangement of the organic light emitting diode 1200 on the thin film transistor array 1100 has been described, but the flexible display device of the present invention is not limited thereto. For example, although the bank 162 having the same light emitting region OR is used, a quantum dot light emitting device or an electrophoretic device may be provided as a light emitting device instead of an organic light emitting diode, so that effective display may be possible.

Hereinafter, a flexible display device according to another exemplary embodiment of the present invention will be described.

6 is a plan view illustrating a flexible display device according to another exemplary embodiment.

As shown in FIG. 6 , in the flexible display device according to another embodiment of the present invention, the separation space GP is not limited to the folding area and may be provided throughout the flexible substrate 10 . In this case, the flexible display device may have uniform flexibility and stress dissipation over the entire flexible substrate 10 , and may have resistance to an unintentional folding operation.

Practically, the flexible display device has a risk of cracking in handling or in various environments due to the characteristics of the flexible panel during processing. In this case, as shown in FIG. 6 , when the inorganic insulating layer 150 having the separation space GP is provided over the entire area, physical stress that may be received in a process or a poor environment can be alleviated, and when stress occurs, a strain margin (strain margin) is provided. margin) can be secured.

7 is a cross-sectional view illustrating a flexible display device according to another exemplary embodiment of the present invention.

7 illustrates a flexible display device according to another embodiment of the present invention, in which an organic light emitting diode array 1200 is directly formed on the plurality of buffer layers 11 and then a thin film transistor array 1100 is disposed. will be. In this case, the thin film transistor array 1100 has an inorganic insulating film having the same separation space GP as described above. In this case, the upper barrier stack 1300 may fill the separation space GP. . The barrier laminate 1300 has a form in which one or more pairs of an organic film and an inorganic film are stacked, of which the organic film is formed to a sufficient thickness to fill the separation space GP, and thus the barrier laminate 1300 ) functions to prevent moisture permeation into the separation space (GP).

Meanwhile, in the same manner as described above, the thin film transistor array 1100 is formed with a pitch Pl smaller than the pitch P of the pixels between the separation spaces GP, but an organic light emitting diode (OLED) of each pixel. Since the light emitting area of ' is not affected by the reduced pitch Pl of the thin film transistor array 1100 , the light emitting efficiency is not reduced. In addition, in this structure, the organic light emitting diode is a bottom light emitting method, and the flexible substrate 10 may be used as a display surface. In addition, the organic light emitting diode on the lower side emits light regardless of the arrangement of the thin film transistor array 1100 on the upper side, which is advantageous for high resolution.

8 is a cross-sectional view illustrating a modified example of the flexible display device of the present invention.

FIG. 8 shows a shape in which the folding axis is along the Y-axis, and a modification of the flexible display device of the present invention including the inorganic insulating layer 150 having a plurality of spacing GPs in the Y-axis direction in the folding area along the direction of the folding axis example is shown.

About the same number, it has the same function, and the description is abbreviate|omitted.

The above-described modified example indicates that the folding axis is not limited to only one direction, but is also set in another direction, and indicates that stress and strain relief is performed in the folding axis direction.

Meanwhile, when there are a plurality of folding axes, a space between the inorganic insulating layers may be disposed in a direction along the folding axis.

9 is a plan view illustrating a correspondence relationship between a light emitting region and a pixel region of a thin film transistor array according to a comparative example, and FIG. 10 is a cross-sectional view taken along line II to II′ of FIG. 9 .

9 and 10 are comparative examples to compare with the flexible display device of the present invention of FIGS. 3 and 4 described above. In this case, the bank 62 for defining the light emitting region OR of the comparative example is the same as the present invention. Although the same, in the comparative example, the arrangement of the thin film transistors becomes the same for each pixel, and the inorganic insulating films 51 , 52 , 53 , and 54 are continuously formed in the active area AA without interruption, so that the path when the stress is transmitted It is connected as a whole without being cut off, and there is a problem in that line lighting failure may occur. The flexible display device of the present invention can solve such a linear lighting defect.

In addition, forming a hole or line removal region of the inorganic insulating film for each pixel is advantageous in terms of stress dissipation, but the size of the pixel gradually becomes smaller and the degree of integration goes to a high resolution, and in the current resolution, the stress It may be difficult to provide an inorganic insulating film removal region for every pixel to the extent that dispersion is possible. In the flexible display device of the present invention, an organic light emitting diode is provided with a line spacing for each of a plurality of pixel lines, so that, in a high-resolution model, the inorganic insulating layer can be sufficiently patterned to allow stress dissipation, and the organic light emitting diode is not affected by the patterning of the inorganic insulating layer. By arranging the light emitting area of , it is possible to display evenly in both the folding area and the non-folding area without loss of the light emitting area.

On the other hand, the present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications and changes are possible without departing from the technical spirit of the present invention. It will be clear to those of ordinary skill in the art.

10: flexible substrate 11: multiple buffer layers
111: first wiring 112: second wiring
121: gate electrode 122: source electrode
123: drain electrode 126: active layer
150: inorganic insulating film GP: separation region
151: first interlayer insulating film 152: second interlayer insulating film
153: third interlayer insulating film 154: fourth interlayer insulating film
161: first electrode 162: bank
163: organic light emitting layer 164: second electrode
OLED: organic light emitting diode 1100: thin film transistor array
1200: organic light emitting diode array 1300: barrier laminate

Claims (17)

a flexible substrate having an active region including a plurality of pixels of the same size in a matrix and a non-display region surrounding the flexible substrate, wherein at least one uniaxial folding region is defined;
a bank having a light emitting region at the same position of each pixel in the active region on the flexible substrate;
a plurality of first wirings and second wirings located in different layers in the active area on the flexible substrate and respectively disposed along an axis of the folding area and a direction crossing the same; and
Spaces apart along the axis of the folding area for every n (n is a natural number) number of first wirings in an interlayer between the first wiring and the second wiring in the folding area and below the first wiring and above the second wiring Including an inorganic insulating film having,
The pitch of the n first wirings is a value obtained by dividing a value obtained by subtracting the width of the separation space from the length of the n pixels in the second wiring direction by n (

) (P is the pixel pitch in the second wiring direction, gp is the width of the separation space). The method of claim 1,
A flexible display device in which a pitch of the pixels and a pitch of the first wiring are different from each other in the folding area in a direction of the second wiring. delete 3. The method of claim 2,
The flexible display device further comprising: an organic light emitting diode including an organic light emitting layer provided in the light emitting area, and first and second electrodes positioned below and above the organic light emitting layer. 5. The method of claim 4,
The bank and the organic light emitting diode are positioned above the second wiring. 5. The method of claim 4,
The bank and the organic light emitting diode are positioned below the first wiring. 6. The method of claim 5,
The inorganic insulating film,
A third interlayer insulating film provided between the flexible substrate and the layers of the first wiring, a second interlayer insulating film between the layers between the first wiring and the second wiring, and between the layers of the second wiring and the organic light emitting diode comprising an interlayer insulating film,
The first to third insulating interlayers have spaced apart spaces at the same location. 8. The method of claim 7,
The flexible display device further comprising a plurality of buffer layers on the entire surface of the flexible substrate and between the flexible substrate and the first interlayer insulating layer. 5. The method of claim 4,
A thin film transistor including, in each of the pixels, a gate electrode on the same layer as the first wiring, source and drain electrodes on the same layer as the second wiring, and active layers connected to both sides of the source electrode and the drain electrode, respectively A flexible display device further comprising a. a flexible substrate having an active region including a plurality of pixels of the same size in a matrix and a non-display region surrounding the flexible substrate, wherein at least one uniaxial folding region is defined;
a bank having a light emitting region at the same position of each pixel in the active region on the flexible substrate;
a plurality of first wirings and second wirings located in different layers in the active area on the flexible substrate and respectively disposed along an axis of the folding area and a direction crossing the same;
Spaces apart along the axis of the folding area for every n (n is a natural number) number of first wirings in an interlayer between the first wiring and the second wiring in the folding area and below the first wiring and above the second wiring an inorganic insulating film having; and
A thin film transistor including, in each of the pixels, a gate electrode on the same layer as the first wiring, source and drain electrodes on the same layer as the second wiring, and active layers connected to both sides of the source electrode and the drain electrode, respectively including,
The pitch of the thin film transistor in the second wiring direction is a value obtained by subtracting the width of the separation space from the length of the n pixels in the second wiring direction divided by n (

) (P is the pixel pitch in the second wiring direction, gp is the width of the separation space). 6. The method of claim 5,
The flexible display device further comprising a barrier laminate in which one or more pairs of an organic layer and an inorganic layer are alternated to cover an upper portion of the organic light emitting diode and an upper portion of the non-display area. 11. The method of claim 9 or 10,
The flexible display device further comprising: a scan driver in the non-display area at one side or both sides of the first line; and a driver IC in the non-display area at one side of the second line. 13. The method of claim 12,
wherein the scan driver includes a plurality of scan circuit blocks respectively corresponding to the first wiring on a line, and a voltage signal and a clock signal wiring connected to the driver IC. 14. The method of claim 13,
The separation space extends to pass through the scan driver. 14. The method of claim 13,
The inorganic insulating layer covers the outside of the voltage signal and clock signal lines in the non-display area. a flexible substrate having an active area including a plurality of pixels of the same size in a matrix and a non-display area around the flexible substrate, the flexible substrate having a folding area defined along a first axis;
A plurality of first and second wirings positioned in different layers in the active region on the flexible substrate and arranged along the first axis and a second axis crossing the first axis, respectively, and on the second axis a thin film transistor array provided with an inorganic insulating film having a spacing space for each of a plurality of pixels; and
an organic light emitting diode array having a bank having a light emitting area at the same position of each pixel and an organic light emitting layer in the light emitting area on the thin film transistor array,
The first wirings have a pitch smaller than a pitch of the pixels on the second axis between a plurality of spaced apart spaces in the inorganic insulating layer. 17. The method of claim 16,
The plurality of separation spaces do not overlap the first wiring.

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