KR20170079927A - Organic light emitting display device - Google Patents

Abstract

INDUSTRIAL APPLICABILITY The present invention can prevent degradation of the image quality of an organic light emitting display device due to external light, prevent external light from being reflected again, and prevent degradation of image quality. The organic light emitting diode display of the present invention includes a first electrode connected to a thin film transistor and a thin film transistor, an organic light emitting layer disposed on the first electrode, a second electrode disposed on the organic light emitting layer, and a light shielding layer overlapping the organic light emitting layer .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light-

The present invention relates to an organic light emitting display.

In recent years, the importance of display devices has been increasing with the development of multimedia. In response to this, flat panel display devices such as liquid crystal display devices, plasma display devices, and organic light emitting display devices have been commercialized. Among such flat panel display devices, liquid crystal display devices and organic light emitting display devices are widely used in a variety of fields such as a notebook computer, a television, a tablet computer, a monitor, a smart phone, a portable display device, a portable information device, and the like due to their excellent characteristics such as thinness, light weight, And is widely used as a display device of a display device.

The OLED display has a structure in which a light emitting layer is provided between a cathode for injecting electrons and an anode for injecting holes, and electrons generated from the cathode and holes generated from the anode When the injected electrons and holes are injected into the light emitting layer, an exciton is generated by the excited electrons and holes, and the generated excitons are emitted from the excited state to the ground state, to be.

The organic light emitting display device is divided into a top emission type and a bottom emission type according to the transmission direction of light emitted through the organic light emitting device. At this time, the conventional organic light emitting display uses a polarizing plate to prevent external light from entering in order to prevent the image quality from being deteriorated by the light incident from the outside. However, in the conventional organic light emitting diode display, external light is reflected by the polarizer, and the image is visually outdoors in the outdoor, such as a mirror image, and the image quality is deteriorated. In addition, a conventional OLED display has a disadvantage in that a manufacturing cost is increased by applying a polarizing plate.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an organic light emitting display device with improved image quality.

According to an aspect of the present invention, there is provided an organic light emitting display comprising a thin film transistor, a first electrode connected to the thin film transistor, an organic light emitting layer disposed on the first electrode, a second electrode disposed on the organic light emitting layer, And an organic light emitting display device.

The OLED display according to an exemplary embodiment of the present invention can prevent the light incident from the outside from entering the OLED display device and prevent the light from being reflected back to the OLED display. Therefore, the organic light emitting diode display according to an exemplary embodiment of the present invention prevents deterioration of the image quality of the organic light emitting diode display device due to external light, prevents external light from being reflected again, Can be prevented from being lowered.

In addition, the organic light emitting diode display according to an exemplary embodiment of the present invention can prevent the luminance from being greatly reduced even if the light shielding layer is disposed so as to overlap the light shielding layer.

In addition, since the light-shielding layer and the light shield can be formed through the same process using the same material, an additional process for forming the light-shielding layer may not be added, It is possible to prevent the manufacturing cost from being increased by using the same material as the shield.

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

1 is a schematic plan view of an OLED display according to an exemplary embodiment of the present invention.
2 is a cross-sectional view of the organic light emitting diode display according to the first example of the present invention, taken along the line II in Fig.
3 is an enlarged view of the area A in Fig.
4A is a plan view of an OLED display according to a second example of the present invention.
4B is a plan view of an OLED display according to a third example of the present invention.
5 is a cross-sectional view of the OLED display according to a fourth example of the present invention, taken along line II of Fig.
6 is an enlarged view of a region B in Fig.

The meaning of the terms described herein should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms. It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof. It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one. The term "on" means not only when a configuration is formed directly on top of another configuration, but also when a third configuration is interposed between these configurations.

Hereinafter, preferred embodiments of the organic light emitting display according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, 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.

1 is a schematic plan view of an OLED display according to an exemplary embodiment of the present invention.

1, an OLED display includes a display panel 11, a gate driver 12, an integrated circuit (IC) 13, A film 14, a circuit board 15, and a timing controller 16. [

The display panel 11 includes a first substrate 100 and a second substrate 270. At this time, the second substrate 270 may be a sealing substrate. The first substrate 100 may be larger than the second substrate 270 so that a portion of the first substrate 100 may be exposed without being covered by the second substrate 270.

In the display area DA of the display panel 11, pixels arranged in the intersecting regions of the gate lines, the data lines, the gate lines and the data lines are formed. The pixels of the display area DA can display an image.

The gate driver 12 supplies gate signals to the gate lines in response to a gate control signal input from the timing controller 16.

The source driver IC 13 receives the digital video data and the source control signal from the timing controller 16. [ The source drive IC 13 converts the digital video data into analog data voltages according to the source control signal and supplies the analog data voltages to the data lines. When the source drive IC 13 is fabricated from a drive chip, it can be mounted on the flexible film 14 by a COF (chip on film) or a COP (chip on plastic) method.

Since the size of the first substrate 100 is larger than that of the second substrate 270, a part of the first substrate 100 may be exposed without being covered by the second substrate 270. In this manner, pads such as data pads are provided on a portion of the first substrate 100 exposed by the second substrate 270.

Wires connecting the pads to the source drive IC 13 and wirings connecting the pads to the wirings of the circuit board 15 may be formed on the flexible film 14. [ The flexible film 14 is adhered to the pads using an anisotropic conducting film, whereby the pads and the wirings of the flexible film 14 can be connected.

The circuit board 15 may be attached to the flexible films 14. Such a circuit board 15 can be mounted with a plurality of circuits implemented with driving chips. For example, the timing control section 16 may be mounted on the circuit board 15. [ At this time, the circuit board 15 may be a printed circuit board or a flexible printed circuit board.

The timing controller 16 receives digital video data and a timing signal from an external system board (not shown). At this time, the timing control unit 60 generates a gate control signal for controlling the operation timing of the gate driving unit 12 and a source control signal for controlling the source drive ICs 13 based on the timing signal. The timing controller 60 supplies a gate control signal to the gate driver 12 and a source control signal to the source driver ICs 30.

FIG. 2 is a cross-sectional view of the organic light emitting diode display according to the first example of the present invention, taken along line I - I of FIG. 1, and FIG. 3 is an enlarged view of region A of FIG.

2 and 3, the OLED display according to the first exemplary embodiment of the present invention includes a first substrate 100, a light shield 110, a light shield layer LS, a buffer layer 120, a thin film transistor T A reflective layer RE, a passivation layer 180, a black matrix 190, a color filter 200, a planarization layer 210, a first electrode 220, a bank 230, an organic emission layer 240, Two electrodes 250, an encapsulation layer 260, and a second substrate 270.

Although glass is mainly used for the first substrate 100, transparent plastic such as polyimide which can be bent or rolled can be used. When the polyimide is used as the material of the first substrate 100, a polyimide excellent in heat resistance that can withstand high temperatures can be used, considering that a high temperature deposition process is performed on the first substrate 100 .

The light shield 110 is disposed between the first substrate 100 and an active layer 130 described below. The light shield 110 prevents the electron movement in the channel region of the active layer 130 from being adversely affected by the components contained in the first substrate 100. Thus, the light shield 110 is disposed to overlap the active layer 130. [ At this time, the light shield 110 is made of a low reflection material, and it is possible to prevent the light introduced from the outside from being reflected back to the outside.

The light shielding layer LS may be disposed on the same layer as the light shield 110 and may be disposed in a pixel region overlapping the organic light emitting layer 240. The light blocking layer LS is disposed on the first substrate 100 to prevent light incident from the outside from entering the OLED display. Further, the light-shielding layer LS is made of a low-reflection material, and can prevent light that is introduced from the outside from being reflected back to the outside. Accordingly, the OLED display according to the first exemplary embodiment of the present invention includes a light-shielding layer LS on the first substrate 100 to prevent light incident from the outside from flowing into the organic light emitting display device , It is possible to prevent the light from being reflected back to the outside. Therefore, the organic light emitting diode display according to the first example of the present invention can prevent deterioration of the image quality of the organic light emitting diode display device due to external light, It is possible to prevent degradation of quality.

Further, the light-shielding layer LS may be formed through the same process with the same material as the light shield 110. Accordingly, the organic light emitting diode display according to the first embodiment of the present invention may not include a separate process for forming the light shielding layer LS, and the manufacturing cost may be increased by using the same material as the light shield 110 Can be prevented.

Although not shown in the figure, the light shielding layer LS may be disposed at a position overlapping the color filter 200, and may be disposed at least one of the light shielding layers LS May be disposed. In this case, in the case of a bottom emission type organic light emitting display in which light emitted from the organic light emitting layer 240 is emitted downward, since the light shielding layer LS overlaps with the light emitting region, The brightness of the device can be reduced. However, since the OLED display according to the first embodiment of the present invention includes the reflective layer RE so as to overlap with the light-shielding layer LS, the brightness of the OLED display can be prevented from being greatly reduced. A detailed description of the reflective layer RE will be given later.

The buffer layer 120 is disposed on the first substrate 100. The buffer layer 120 prevents external moisture or moisture from penetrating into the inside of the transparent display device. At this time, the buffer layer 120 may be formed of silicon oxide or silicon nitride.

The thin film transistor T is disposed on the buffer layer 120. The thin film transistor T includes an active layer 130, a gate insulating layer 140, a gate electrode 150, an interlayer insulating layer 160, a source electrode 170 and a drain electrode 171.

The active layer 130 is disposed on the buffer layer 120 so as to overlap with the gate electrode 150. The active layer 130 includes a first end region 132 located on the side of the source electrode 170 and a second end region 132 located on the side of the drain electrode 171 and a second end region 132 located between the first end region 131 and the second end region 132 As shown in FIG. The center region 133 may be a semiconductor material that is not doped with a dopant, and the one end region 131 and the other end region 132 may be a semiconductor material doped with a dopant.

The gate insulating layer 140 is disposed on the active layer 130. The gate insulating layer 140 insulates the active layer 130 from the gate electrode 150. At this time, the gate insulating layer 140 may be formed of an inorganic insulating material such as a silicon oxide film (SiOX), a silicon nitride film (SiNX), or a multilayer thereof, but is not limited thereto.

The gate electrode 150 is disposed on the gate insulating layer 140. At this time, the gate electrode 150 is arranged to overlap with the active layer 130 with the gate insulating layer 140 therebetween. More specifically, the gate electrode 150 may overlap the central region 133 of the active layer 130 with the gate insulating layer 140 therebetween. The gate electrode 150 may be formed of any one selected from the group consisting of Mo, Al, Cr, Au, Ti, Ni, Ne, Or an alloy thereof. However, the present invention is not limited thereto.

The interlayer insulating layer 160 is disposed on the gate electrode 150. The interlayer insulating layer 160 isolates the gate electrode 150 from the source electrode 170 and the drain electrode 171. At this time, the interlayer insulating layer 160 may be formed of the same inorganic insulating material as the gate insulating layer 140, for example, a silicon oxide film (SiOx), a silicon nitride film (SiNX), or a multilayer thereof. However, It is not.

The source electrode 170 and the drain electrode 171 are spaced apart from each other on the interlayer insulating layer 160. Each of the source electrode 170 and the drain electrode 171 is connected to the active layer 130 through a contact hole formed in the interlayer insulating layer 160. The source electrode 170 is connected to the one end region 131 of the active layer 130 through the contact hole and the drain electrode 171 is connected to the other end region 132 of the active layer 130 through the contact hole. do. The source electrode 170 and the drain electrode 171 may be formed of one selected from the group consisting of Mo, Al, Cr, Au, Ti, Ni, Copper (Cu), or an alloy thereof, and may be composed of a single layer of the metal or alloy, or multiple layers of two or more layers, but is not limited thereto.

The thin film transistor T configured as described above may be formed in each pixel region on the first substrate 100. [ Further, the structure of the thin film transistor T is not limited to the above-described example, and can be variously modified to a known structure that can be easily practiced by those skilled in the art.

The reflective layer RE is disposed on the same layer as the source electrode 170 and the drain electrode 171 and is overlapped with the light-shielding layer LS. The reflective layer RE is disposed to overlap with the light-shielding layer LS to prevent light emitted from the organic light-emitting layer 240 from being incident on the light-shielding layer LS. In addition, the reflective layer RE reflects the light emitted from the organic light emitting layer 240 to the lower portion. More specifically, the reflective layer RE intercepts light emitted from the organic light emitting layer 240 in the direction of the light blocking layer LS and reflects the light back to the upper portion of the reflective layer RE, And is reflected back to the bottom by the two-electrode 250. Accordingly, in the organic light emitting diode display according to the first example of the present invention, by arranging the reflective layer RE so as to overlap with the light-shielding layer LS, even if the light-shielding layer LS is disposed in the pixel area, have.

The reflective layer RE may be formed through the same process with the same material as the source electrode 170 and the drain electrode 171. [ Therefore, the OLED display according to the first embodiment of the present invention may not include a separate process for forming the reflective layer RE.

Although not shown in the drawing, the reflective layer RE may be disposed only at a place where the reflective layer RE does not overlap with the color filter 200, but may be disposed at a position overlapping the color filter 200, And may be disposed so as to overlap with the light-shielding layer LS.

The passivation layer 180 is entirely disposed on the interlayer insulating layer 160, the source electrode 170, and the drain electrode 171. The protective layer 180 may be made of an inorganic insulating material such as silicon oxide or silicon nitride, but is not necessarily limited to, but may be made of an organic insulating material such as photo acryl or benzocyclobutene (BCB) It is possible.

The black matrix 190 is disposed between the red (R), green (G), and blue (B) patterns of the color filter 200, ) Of light from the light source. With the provision of the black matrix 190, the contrast of the first substrate 100 is improved and the leakage current of the thin film transistor T can be reduced.

The color filter 200 is disposed on the passivation layer 180 and the black matrix 190 and overlaps with the organic light emitting layer 240 to be described later. The color filter 200 converts the color of light emitted downward from the organic light emitting layer 240. At this time, the color filter 200 may be composed of a red color filter R, a green color filter G, and a blue color filter B.

The planarization layer 210 is disposed on the protection layer 180. The planarization layer 210 flattens the upper portion of the protection layer 180. The planarization layer 210 may be formed of an acryl resin, an epoxy resin, a phenolic resin, a polyamide resin, a polyimide resin, or the like. have.

The first electrode 220 is disposed on the planarization layer 200. The first electrode 220 is electrically connected to the drain electrode 171 through the contact hole. In this case, the first electrode 220 may be a transparent conductive material having a relatively large work function value, for example, indium-tin-oxide (ITO) or indium-zinc-oxide (IZO). The first electrode 220 may be formed of at least two layers including a metal material having excellent reflection efficiency, for example, aluminum (Al), silver (Ag), APC .

The banks 230 are disposed on the planarization layer 200. At this time, the bank 230 may be overlapped with one side and the other side of the first electrode 220. The bank 230 may be formed of an organic film such as polyimide resin, acryl resin, benzocyclobutene (BCB), or the like.

The organic light emitting layer 240 is disposed on the first electrode 220. The organic light emitting layer 240 may be formed using a combination of a hole injection layer, a hole transporting layer, an emission layer, an electron transporting layer, and an electron injection layer But it is not limited thereto and can be changed into various structures known in the art.

The second electrode 250 is disposed on the organic light emitting layer 240. At this time, the second electrode 250 may extend from the organic light emitting layer 240 and be disposed on the bank 200, and may be provided entirely on the first substrate 100. When the voltage is applied to the second electrode 250 together with the first electrode 220, holes and electrons are transferred to the organic light emitting layer 240 through the hole transporting layer and the electron transporting layer, respectively. And are combined to emit light. As the second electrode 250, a very thin metallic material having a low work function may be used. For example, the second electrode 250 may be formed of a metallic material such as silver (Ag), titanium (Ti), aluminum (Al), molybdenum (Mo), or an alloy of silver (Ag) and magnesium .

The encapsulation layer 260 is disposed entirely on the second electrode 250. The sealing layer 260 can prevent moisture from penetrating into the OLED display. In addition, the sealing layer 260 may include an adhesive material to bond the first substrate 100 and the second substrate 270 together. As the sealing layer 260, various materials known in the art may be used.

The second substrate 270 is disposed on the second electrode 250 to face the first substrate 100. The second substrate 270 may be replaced with an inorganic film, an organic film or the like having a multilayer structure, or may be omitted by attaching the film through the face seal.

The OLED display according to the first exemplary embodiment of the present invention includes a light shielding layer LS on the first substrate 100 to prevent light incident from the outside from flowing into the organic light emitting display At the same time, it is possible to prevent the light from being reflected back to the outside. Therefore, the organic light emitting diode display according to the first example of the present invention can prevent deterioration of the image quality of the organic light emitting diode display device due to external light, It is possible to prevent degradation of quality. The organic light emitting diode display according to the first embodiment of the present invention can prevent the luminance from being greatly reduced even if the light shielding layer LS is disposed in the pixel region by disposing the reflective layer RE so as to overlap the light shielding layer LS have.

FIG. 4A is a plan view of an OLED display according to a second example of the present invention, and FIG. 4B is a plan view of an OLED display according to a third example of the present invention. 2 and 3, the areas of the light-shielding layer LS and the reflective layer RE are changed and shown briefly. Table 1 below compares the reflectance and the luminance according to the area of the light-shielding layer LS and the reflective layer RE of the organic light emitting display shown in Figs. 4A and 4B.

[Table 1]

Referring to FIG. 4A, the light-shielding layer LS of the organic light emitting diode display according to the second embodiment of the present invention is composed of at least one or more. Further, the plurality of light-shielding layers LS according to the second example of the present invention may be arranged in a spaced apart manner in one direction. At this time, the reflective layer RE is disposed so as to overlap the light-shielding layer LS.

Referring to FIG. 4B, the light-shielding layer LS of the OLED display according to the third embodiment of the present invention is composed of at least one or more. In addition, the plurality of light-shielding layers LS according to the third embodiment of the present invention may include a light-shielding layer LS spaced apart in one direction and a light-shielding layer LS spaced apart in a direction perpendicular to the one direction, . At this time, the reflective layer RE is disposed so as to overlap the light-shielding layer LS.

As described above, the organic light emitting display according to the second and third embodiments of the present invention can be applied variously by changing the area of the light-shielding layer LS and the reflective layer RE.

In Table 1, the aperture ratio is a ratio of a region not overlapped with the light-shielding layer LS and the reflective layer RE among the entire region of the pixel region, and the aperture ratio is reduced as the area of the light-shielding layer LS and the reflective layer RE increases do. The reflectance is a ratio of light that is reflected back to the outside among the light that enters the OLED display from the outside. As the reflectivity increases, the image visibility deteriorates. Referring to Table 1, the reflectance of the organic light emitting display device using the light-shielding layer LS of the present invention is 8.5% when the aperture ratio is 5%. As described above, since the reflectance of the organic light emitting diode display of the present invention can be lowered to 8.5% by applying the light shielding layer LS, the image quality can be prevented from being lowered at a low cost. Further, in the organic light emitting display device using the reflective layer RE of the present invention, the luminance must be decreased sharply as the aperture ratio is reduced, but the luminance is not greatly reduced to 68% as compared with the rate at which the aperture ratio is decreased. Therefore, the organic light emitting display device to which the light-shielding layer (LS) and the reflective layer (RE) of the present invention are applied can prevent the image quality from being lowered at a low cost.

FIG. 5 is a cross-sectional view of the OLED display according to a fourth example of the present invention, taken along the line I-I in FIG. 1, and FIG. 6 is an enlarged view of the region B in FIG. This is the same with the exception of the reflective layer RE in the views shown in Figs. Accordingly, only the reflective layer RE will be described in the following description, and redundant description of the same constitution will be omitted.

5 and 6, the reflective layer RE of the OLED display according to the fourth aspect of the present invention is disposed on the same layer as the gate electrode 150 and overlaps with the light-shielding layer LS. The reflective layer RE is disposed to overlap with the light-shielding layer LS to prevent light emitted from the organic light-emitting layer 240 from being incident on the light-shielding layer LS. In addition, the reflective layer RE reflects the light emitted from the organic light emitting layer 240 to the lower portion. More specifically, the reflective layer RE intercepts light emitted from the organic light emitting layer 240 in the direction of the light blocking layer LS and reflects the light back to the upper portion of the reflective layer RE, And is reflected back to the bottom by the two-electrode 250. Therefore, in the OLED display according to the fourth example of the present invention, even if the light-shielding layer LS is disposed in the pixel region by arranging the reflective layer RE so as to overlap with the light-shielding layer LS, have.

In addition, the reflective layer RE may be formed using the same material as the gate electrode 150 through the same process. Therefore, the OLED display according to the fourth exemplary embodiment of the present invention may not include a separate process for forming the reflective layer RE.

Although not shown in the drawing, the reflective layer RE may be disposed only at a place where the reflective layer RE does not overlap with the color filter 200, but may be disposed at a position overlapping the color filter 200, And may be disposed so as to overlap with the light-shielding layer LS.

The OLED display according to the fourth exemplary embodiment of the present invention includes a light blocking layer LS on the first substrate 100 to prevent light incident from the outside from entering the organic light emitting display At the same time, it is possible to prevent the light from being reflected back to the outside. Therefore, the organic light emitting diode display according to the fourth example of the present invention prevents deterioration of the image quality of the organic light emitting diode display device due to external light, It is possible to prevent degradation of quality. Further, the OLED display according to the fourth example of the present invention can arrange the light-shielding layer LS so that the light-shielding layer LS overlaps the light-shielding layer LS, have.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those embodiments and various changes and modifications may be made without departing from the scope of the present invention. . Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of protection of the present invention should be construed according to the claims, and all technical ideas within the scope of equivalents should be interpreted as being included in the scope of the present invention.

100: first substrate 110: light shield
115: shielding layer 120: buffer layer
130: active layer 140: gate insulating layer
150: gate electrode 160: interlayer insulating layer
170, 171 Source and drain electrodes T: Thin film transistor
175: reflective layer 180: protective layer
190: Black Matrix 200: Color filter
210: planarization layer 220: first electrode
230: bank 240: organic light emitting layer
250: second electrode 260: sealing layer
270: second substrate

Claims (9)

Thin film transistor;
A first electrode connected to the thin film transistor;
An organic light emitting layer disposed on the first electrode;
A second electrode disposed on the organic light emitting layer; And
And a light-shielding layer overlapping the organic light-emitting layer. The method according to claim 1,
Wherein the light-shielding layer comprises a low reflection material. The method according to claim 1,
Further comprising a reflective layer between the organic light-emitting layer and the light-blocking layer to overlap the light-blocking layer. The method of claim 3,
Wherein the thin film transistor comprises an active layer,
And a light shield disposed under the thin film transistor so as to overlap with the active layer,
Wherein the light shielding layer is disposed on the same layer as the light shield. The method of claim 3,
Wherein the thin film transistor includes a drain electrode,
Wherein the reflective layer is disposed on the same layer as the drain electrode. 6. The method of claim 5,
Wherein the reflective layer is made of the same material as the drain electrode. The method of claim 3,
Wherein the light-shielding layer comprises at least one or more light-shielding layers, and the plurality of light-shielding layers are spaced apart in one direction. 8. The method of claim 7,
Wherein the plurality of light-shielding layers further include light-shielding layers arranged perpendicularly to one direction. The method of claim 3,
Wherein the thin film transistor includes a gate electrode,
Wherein the reflective layer is disposed on the same layer as the gate electrode.

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