KR101434983B1 - Apparatus and method for pre-attachment inspection of liquid crystal display - Google Patents

Abstract

An apparatus and method for inspecting a color filter substrate module and a TFT array substrate module before an LCD adhesion process, comprising: a liquid crystal sealed sheet disposed between the two substrate modules; A backlight unit for emitting light at the rear surface of the array substrate module, and a driving signal input unit for inputting driving signals to the two substrate modules or the TFT array substrate module; The two substrate modules can be inspected for defects of the two substrate modules while realizing almost the same condition as the state after the adhesion, so that defects such as pixels, lines, or unevenness are inspected in a non-adhered state, , The economic loss can be minimized and the productivity can be improved.

Adhesion, color filter, TFT, PDLC, defective, backlight, polarizing film

Description

TECHNICAL FIELD [0001] The present invention relates to a pre-assembly final inspection device for LCD,

1 is a sectional view showing the internal structure of a general liquid crystal display device,

FIG. 2 is a schematic view showing an inspection structure of a conventional liquid crystal display device before adherence,

FIG. 3 is a schematic cross-sectional view showing an inspection structure of a conventional liquid crystal display device after adhesion,

FIG. 4 is a diagram showing a pre-attachment inspection apparatus of a liquid crystal display according to the present invention,

5 is a configuration diagram of a test state using a pre-attachment inspection apparatus of a liquid crystal display device according to the present invention,

6 is a sectional view showing a liquid crystal sealed sheet used in the present invention,

7 is a flowchart showing a pre-adhesion inspection method of a liquid crystal display device according to the present invention.

Description of the Related Art

50: color filter substrate module 51: upper substrate

52: color filter 53: common electrode

60: TFT array substrate module 61: lower substrate

62: TFT array 63: pixel electrode

70: liquid crystal sealed sheet 80: backlight unit

90: drive signal input section

The present invention relates to an inspection apparatus and method for a liquid crystal display (hereinafter, referred to as 'LCD'), and more particularly, to an inspection apparatus and method for a liquid crystal display The present invention relates to an apparatus and method for pre-attachment inspection of a liquid crystal display device which can be inspected beforehand.

2. Description of the Related Art In general, an LCD displays an image corresponding to a video signal on a liquid crystal substrate on which liquid crystal cells are arranged in a matrix by adjusting a light transmittance of liquid crystal cells according to a video signal. TFTs are mainly used as switching elements in an active matrix type LCD.

1 is a sectional view showing the internal structure of a general LCD.

As shown, the LCD includes a color filter substrate module 10 patterned with R, G, and B colors, a TFT array substrate module 20 patterned with elements capable of controlling electric signals of respective pixels, A liquid crystal 35 capable of controlling the passage of light with optical anisotropy between the two substrate modules 10 and 20 and a backlight unit 40 for emitting light from the back surface of the TFT array substrate module 20, And the like.

The color filter substrate module 10 includes a color filter 12, a common electrode 13 and an alignment film 14 sequentially formed on an upper substrate 11. The TFT array substrate module 20 includes a lower substrate The TFT array 22, the pixel electrode 23, and the alignment film 24 are sequentially formed on the substrate 21.

A spacer or a sealing material 30 is provided between the color filter substrate module 10 and the TFT array substrate module 20 to maintain a gap therebetween and the liquid crystal 35 is injected into the space.

The LCD having such a structure has a very fine lattice shape with a pitch of 80 to 300 μm or the like of the basic structure pattern, which is manufactured by the same photolithography or photo process as the semiconductor process.

At this time, various defects such as color drop, protrusion, pinhole, unevenness, disconnection, and short can occur in the color filter 12 and the TFT array 22, and when they are leaked, the color filter 12 and the TFT array 22 have a considerable influence on the yield, The TFT array substrate module 20, the cell panel, and the like are inspected for defects by various inspection methods, and subjected to processes such as correction and disposal.

The LCD inspection method includes a method of inspecting two substrate modules 10 and 20 in an unattached state and a method of inspecting the two substrate modules 10 and 20 after they are attached to each other. do.

First, the inspection of the substrate prior to the laminating process may include a scan coater, a lens smear (see FIG. 2) generated in the color filter substrate module 10 or the TFT array substrate module 20 before the two substrate modules 10, (CS), a colum space (CS), and the like, and the inspection method is performed by a method such as light reflection and light transmission.

That is, in the state of the TFT array substrate module 20 in which the color filter substrate module 10 in which the color filter is constituted or the TFT film is constituted, as shown in Fig. 2, in the transmission light 1 or the reflection light 3, 20 are recognized by the image pickup element 5 and subjected to image processing. At this time, a manual inspection by the naked eye may be performed instead of the automatic inspection by the image pickup device 5. [

In particular, in the case of color spots, in the state of the color filter substrate module 10 and the TFT array substrate module 20, a special inspection is performed by examining the special illumination due to the characteristics that can not be seen with the naked eye.

However, in the case of inspecting the color filter substrate module 10 and the TFT array substrate module 20 individually, the pre-adhesion inspection method may be applied to the case where the defect of the stain etc. occurring after the two substrate modules 10, Which is difficult to accurately detect.

That is, in the conventional pre-bonding inspection method, it is possible to perform stain inspection by CD, film thickness or the like due to stain inspection, interference of reflected light, diffraction and scattering occurring in a specific process, but after bonding two substrate modules 10 and 20, It is difficult to check a pixel by pixel in the inspection. In particular, since the correlation between the two substrate modules after bonding is unknown, it is very difficult to detect the defect in advance.

3, the liquid crystal 35 is injected between the color filter substrate module 10 and the TFT array substrate module 20 and is sealed by the sealing agent 30 In this case, the inspection of the stain, liquid crystal driving state, etc. is performed. In the inspection method, the backlight unit is driven or the liquid crystal is driven to perform an auto-probe inspection. do.

That is, in a state where the two substrate modules 10 and 20 are joined together, an electric signal is applied to the TFT array substrate module 20 and the color filter substrate module 10 through the driving signal input unit 45 and the backlight unit 40, And the display state is checked in a state in which various patterns are displayed. At this time, the film thickness of the color filter substrate module 10 and the TFT array substrate module 20 affects the liquid crystal behavior and senses the difference in the final transmissivity, and distinguishes specific color spots by pixel-by-pixel liquid crystal driving .

Such an inspection method probes a probe for driving a TFT and uses a necessary inspection system such as a pattern generator for applying an appropriate pattern.

However, in the post-adhesion inspection method as described above, defects that are not seen in the state of the color filter substrate module 10 and the TFT array substrate module 20 before the two substrate modules 10 and 20 are bonded together are transferred to the liquid crystal 35 And is often detected in an auto probe inspection that is performed in a final state after being subjected to a cell process such as a polarizer 14 and a polarizer 25 attached to the TFT array substrate module 20 are viewed from the light scattered by the liquid crystal 35, errors in inspection may occur due to differences in optical characteristics between the substrate module and the substrate module before the adhesion.

The TFT array substrate module 20, the liquid crystal 35, and the like, even if only one of the substrate modules of the two substrate modules 10 and 20 is defective. It is necessary to discard the entire product, so that it is impossible to regenerate the product, resulting in an increase in economic loss and a significant decrease in productivity.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems described above, and it is an object of the present invention to provide a color filter substrate module in which a liquid crystal sealed sheet is inserted between an uncoated color filter substrate module and a TFT array substrate module, So as to improve the reliability of the inspection of the substrate, minimize the economic loss, and improve the productivity, by attaching the liquid crystal display device so as to inspect the defects of the pixels, lines, It is an object of the present invention to provide a pre-test apparatus and method.

In particular, it is an object of the present invention to provide an apparatus and method for pre-bonding a liquid crystal display device capable of simultaneously inspecting a colorless filter substrate module and a TFT array substrate module.

In order to accomplish the above object, there is provided an apparatus for inspecting a color filter substrate module and a TFT array substrate module before an LCD adhesion process, comprising: a liquid crystal enclosure disposed between the two substrate modules; A backlight unit for emitting light at the back surface of the TFT array substrate module, and a driving signal input unit for inputting driving signals to the two substrate modules or the TFT array substrate module; And to check whether at least one of the two substrate modules is defective.

Preferably, liquid crystal is injected between the upper protective film and the lower protective film, and the liquid crystal is injected with polymer dispersed liquid crystal (PDLC).

It is preferable that a polarizing film is provided on the backlight unit side surface of the TFT array substrate module.

And a polarizing film is provided on the color filter substrate module or the inspection equipment in front of the color filter substrate module.

A liquid crystal sealed sheet is disposed between the color filter substrate module and the TFT array substrate module before the LCD sticking process, and the TFT array substrate module The backlight unit is illuminated from the backside of the TFT array substrate module, and a drive signal is inputted to the two substrate modules or the TFT array substrate module to check whether at least one of the two substrate modules is defective.

According to another aspect of the present invention, there is provided a method of inspecting a liquid crystal display before inserting a liquid crystal sealed sheet between a color filter substrate module and a TFT array substrate module before an LCD sticking process so as to overlap each other; Performing alignment on each pixel of the color filter substrate module and the TFT array substrate module after the step; And inspecting whether the two substrates are defective by inputting a driving signal to the two substrate modules or the TFT array substrate module in a state in which the backlight unit is turned on after the step.

In the above two inspection methods, it is preferable that the liquid crystal sealed sheet is injected with polymer dispersed liquid crystal (PDLC).

Further, in the step of checking whether or not the defect is present, at least one of a visual inspection and an image inspection using an image pickup device can be used as the inspection method.

And separating at least one of the color filter substrate module and the TFT array substrate module from the liquid crystal injecting sheet after the step of inspecting the defect.

In the step of separating the substrate module, the entire process of the substrate module may be performed in a vacuum chamber so as to facilitate separation of the substrate module.

Alternatively, the substrate may be separated while injecting air between the two substrate modules to facilitate separation of the substrate module in the step of detaching the substrate module.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 4 and FIG. 5 are a structural view and a state diagram at the time of inspection of the liquid crystal display apparatus according to the present invention, and FIG. 6 is a view showing the liquid crystal sealed sheet of the present invention.

The pre-adhesion inspection apparatus of the liquid crystal display according to the present invention can be applied to a liquid crystal display device in which a liquid crystal is injected in a sealed state and an inspection is performed, or in place of a conventional method in which only a color filter substrate module or a TFT array substrate module is inspected, In a state where the liquid crystal sealed sheet 70 is inserted between the filter substrate module 50 and the TFT array substrate module 60 and the two substrate modules 50 and 60 are not cemented together, State, and it is an apparatus for inspecting whether the two substrate modules 50 and 60 are defective.

The inspection apparatus of the present invention includes a color filter substrate module 50 and a TFT array substrate module 60 before the LCD sticking process and a liquid crystal encapsulation sheet 70 inserted between the two substrate modules 50, A backlight unit 80 for emitting light at the back surface of the TFT array substrate module 60 and a driving signal input unit 90 for inputting driving signals to the two substrate modules 50 and 60, To check whether the two substrate modules (50, 60) are defective.

The main constituent parts of the inspection apparatus of the present invention constituted as described above will be described in detail. For reference, the color filter substrate module 50 and the TFT array substrate module 60 shown in the drawing are schematically shown in a simplified form, and the present invention is not limited to the structure of the drawings. It is needless to say that the present invention can be applied to any substrate module in a state in which the substrate module is manufactured up to the state immediately before the coalescence of the substrate module. Thus, the basic configuration of the two substrate modules 50 and 60 will be briefly described with reference to the drawings.

First, the color filter substrate module 50 to be inspected is constituted of a set of the color filter 52, the common electrode 53, and the alignment film 54 sequentially formed on the upper substrate 51.

The color filter 52 may be formed by applying a material that transmits only light of a specific wavelength (R, G, B) by applying a white light source to the entire surface of the upper substrate 51, and then patterning the material.

The common electrode 53 is formed of a transparent conductive film to which a ground potential is supplied on an upper substrate 51 on which a color filter 52 is formed.

The alignment film 54 is formed by applying polyimide on the common electrode 53.

In FIG. 4, reference numeral 55 denotes a polarizing plate or a polarizing film attached to the upper substrate 51.

The color filter substrate module 50 having the color filter 52, the common electrode 53 and the alignment film 54 formed on the upper substrate 51 as described above is mounted on the TFT array substrate module 60 However, the present invention is not limited to the configuration in which all the components are completely installed in the upper substrate 51, and it is possible to use a structure in which some components such as the alignment film 54 and the polarizing plate 55 are not provided It is possible to check whether the substrate module is defective or not.

That is, in the color filter substrate module 50, the viewer or the camera polarizing film or the polarizing plate 55 for inspection are not installed, and as shown by the hidden line of FIG. 5, the front end of the camera lens 100, The small polarizing film 110 or the polarizing plate 110 may be placed on the small polarizing plate 110. If necessary, the small polarizing plate 110 may be rotated while the amount of polarized light is adjusted.

In addition, IPS of the LCD type, that is, IPS of the PVA, may be configured such that the common electrode is not formed on the color filter substrate module 50. At this time, electrodes are formed on the same side of the TFT array substrate module.

Next, the TFT array substrate module 60 to be inspected is formed into a single set of a TFT array 62, a pixel electrode 63, an orientation film 64, and a polarizing film 67 sequentially on a lower substrate 61 .

The TFT array 62 is composed of a gate electrode connected to the gate line, a source electrode connected to the data line, and a drain electrode connected to the pixel electrode through the contact hole, as a main constituent part of the LCD switching the driving of the liquid crystal cell. A gate insulating film for insulating the gate electrode from the source electrode and the drain electrode, and a semiconductor layer for forming a conduction channel between the source electrode and the drain electrode by a gate voltage supplied to the gate electrode. Since such a configuration is well-known, a detailed illustration is omitted in the drawings.

The pixel electrode 63 is formed on a protective film 65 applied to the entire surface of the lower substrate 61 and is electrically connected to the drain electrode of the TFT through a contact hole formed in the protective film 65.

The alignment layer 64 is formed on the lower substrate 61 on which the pixel electrode 63 is formed.

The TFT array substrate module 60 in which the TFT array 62, the pixel electrode 63 and the alignment film 64 are formed on the lower substrate 61 in the final state before being adhered to the color filter substrate module 50 The color filter substrate module is not necessarily limited to the configuration in which all the components are completely installed on the lower substrate 61. For example, some components such as the alignment layer 64 may be provided depending on the inspection conditions It is possible to check whether or not the substrate module is defective.

6, the liquid crystal encapsulating sheet 70 is an important component for inspecting the two substrate modules 50 and 60. The liquid crystal encapsulating sheet 70 includes an upper protective film 71 and a lower protective film 73, And a liquid crystal 75 is injected and sealed in the space. The liquid crystal 75 injected at this time is preferably a PDLC (Polymer Dispersed Liquid Crystal) After mixing, it is cured by UV or other methods.

The upper protective film 71 and the lower protective film 73 are preferably sheets that protect the PDLC and are formed of a transparent thin film and the overall size of the upper and lower protective films 71 and 72 is the same as that of the color filter substrate module 50 and the TFT array substrate module 60 ) Are preferably the same or similar in size.

The liquid crystal encapsulation sheet 70 is inserted between the color filter substrate module 50 and the TFT array substrate module 60 before being attached to each other so that liquid crystal is injected between the two substrate modules 50 and 60, So that the two substrate modules 50 and 60 can be inspected.

The backlight unit 80 is a means for emitting light from the back surface of the TFT array substrate module 60 when the LCD module is constructed after the two substrate modules 50 and 60 are assembled together. It is possible to inspect whether the two substrate modules 50 and 60 are defective by using a backlight unit 80 having the same condition as that of the backlight unit assembled after bonding.

Next, the driving signal input unit 90 is connected to the common electrode 53, the TFT array 62, the pixel electrode 63, etc. of the color filter substrate module 50 and the TFT array substrate module 60, Lines, and lines generated by the two substrate modules 50 and 60 by applying an electric signal substantially similar to an LCD driving signal to the modules 50 and 60 to adjust the light transmittance through the liquid crystal of the liquid crystal encapsulating sheet 70, Or defects such as dust and the like.

In the drawing, reference numerals 92 and 93 are connectors capable of inputting driving signals to the electrodes provided in the color filter substrate module 50 and the TFT array substrate module 60. 4 and 5, the electrodes are connected to both the color filter substrate module 50 and the TFT array substrate module 60. However, when the electrodes are provided only in the TFT array substrate module 60 depending on the LCD type, Only the TFT array substrate module 60 is provided with a connector.

The inspection apparatus of the present invention may further include an image pickup device such as the inspection camera 100 as shown in FIG. 5 to check whether or not any one or both of the two substrate modules 50 and 60 are defective Equipment may be further configured.

In the process of separating the color filter substrate module 50, the liquid crystal encapsulation sheet 70 and the TFT array substrate module 60 from each other after performing the defect inspection in the laminated state, the two substrate modules 50 and 60, Separation between the sheets 70 can be made difficult due to the influence of surface tension or the like, and it is possible to perform a vacuum chamber in which the inspection of the substrate module can be carried out in a vacuum atmosphere or a vacuum chamber in which two substrate modules 50, 60 and a liquid crystal sealing sheet 70 For separating the two substrate modules 50 and 60 by blowing air or gas between the substrate module 50 and the substrate module 50.

Hereinafter, the inspection method of the present invention using the inspection apparatus according to the present invention will be described.

7 is a flowchart showing a pre-adhesion inspection method of a liquid crystal display device according to the present invention.

The liquid crystal sealed sheet 70 is disposed between the color filter substrate module 50 and the TFT array substrate module 60 before the LCD sticking process, A driving signal is inputted to the two substrate modules 50 and 60 in a state in which the backlight unit 80 is emitted from the rear surface of the substrate module 60 so that the failure of at least one of the two substrate modules 50 and 60 Or by checking whether there is a problem.

This is explained step by step.

First, a color filter substrate module 50 and a TFT array substrate module 60 are fabricated (S ₁ ). The manufacturing method of the two substrate modules is generally well-known technology, and thus a detailed description thereof will be omitted.

Next, the liquid crystal encapsulation sheet 70 as described above is disposed between the color filter substrate module 50 and the TFT array substrate module 60 before the LCD adhesion process (S ₂ ). As shown in FIG. 5, the two substrate modules 50 and 60 and the liquid crystal encapsulating sheet 70 are laminated and disposed in a state of being completely in close contact with each other so as to be substantially the same condition as the state after the actual LCD laminating process.

Next, the color filter substrate module 50 and the TFT array substrate module 60 are aligned for each pixel (S ₃ ). The reason for aligning the two substrate modules 50 and 60 is to accurately check whether the two substrate modules 50 and 60 are defective in a state in which the two substrate modules 50 and 60 are in the same condition as the actual bonded state.

Next, the two substrate modules 50 and 60 (in the case of a PVA structure among LCD types) or the TFT array substrate module 60 (in the case of the LCD type) are turned on with the backlight unit 80 disposed on the back surface of the TFT array substrate module 60 lit. (In the case of an IPS structure among the LCD types), and checks whether the two substrates are defective (S ₄ ) (S ₅ ).

At this time, the inspection method uses a device such as a visual inspection or an image inspection using an image pickup device to inspect defects such as a pixel, a line, or a mura generated in the substrate module. 5, the small polarizing plate 110 may be placed in front of the lens of the inspection camera 100 or in front of the inspector. In this case, the small polarizing plate 110 may be inspected, While adjusting the amount of polarization.

As described above, since the two substrate modules 50 and 60 can be inspected at the size of the original board module, which is capable of manufacturing various cell panels, not in the state of being cut into unit cell panels, So that the efficiency and productivity of inspection can be improved.

Next, When the tests are completed as described above, a color filter substrate separated recall module 50 and the TFT array panel module 60 from the liquid crystal sealing sheet (70) (S _6).

At this time, separation can be difficult due to the influence of surface tension between the two substrate modules 50, 60 and the liquid crystal sealing sheet 70. In order to facilitate separation of the respective substrate modules from the liquid crystal sealing sheet 70, After the inspecting process is performed in the vacuum chamber and the inspection of each substrate module is completed, the vacuum atmosphere is released to separate the substrate module from the liquid crystal encapsulating sheet 70.

In addition to the method using a vacuum chamber, the substrate may be separated while air is injected between the liquid crystal sealing sheet 70 and each substrate module using an air jetting device for separation or an air supplying device.

The apparatus and method for pre-bonding a liquid crystal display according to the present invention configured and operated as described above have the following effects.

First, since the inspection is performed before the two substrates are bonded together, the present invention solves the problem of disposal due to defects occurring after the laminating process, thereby reducing material cost and yield, thereby reducing LCD production cost.

In other words, since each substrate is inspected before the laminating process, only the substrate on which the defect has occurred is corrected or discarded, so that the entire LCD module after the laminating process is not wasted, thereby reducing the failure cost. In addition, since the determination of whether or not the LCD is defective is performed before the cementation, problems in the manufacturing process can be detected early, and defective products produced over a long period of time can be prevented until a defect is found in the final state. .

Next, the present invention has the effect of improving the substrate inspection ability because the inspection is performed under the same condition as the final state. That is, by overcoming the difference between the pre-inspection and the final cell (CELL) inspection of the TFT array substrate module, the color filter substrate module, and the overkill or underkill smudge determination criteria, it is possible to detect only defects that are actually problematic without overkill or underkill problems and to detect defects that are not visible in a single substrate state as the final product state.

Next, the present invention is capable of inspecting the entire substrate with a large area using a PDLC, thereby reducing inspection cost. In other words, it is possible to inspect the driving performance of the TFT element in addition to the inspection of the stain, and the inspection can be performed before cutting in units of cells, so that a large-area inspection is possible, and the inspection time of the LCD product can be drastically reduced.

In addition, auto macro functions can be implemented, array tester functions can be included, and manual macro functions can be implemented. Thus, automatic optical inspection (AOI) inspection, it is possible to drastically reduce the number of various inspection equipments, thereby reducing the investment cost of the inspection equipment and the construction and operation cost by reducing the foot print.

Claims (12)

An apparatus for inspecting a color filter substrate module and a TFT array substrate module prior to an LCD adhesion process, Wherein the two substrate modules are overlapped with the two substrate modules and are in close contact with the two substrate modules to implement a state after the two substrate modules are bonded together, A seat; A backlight unit for emitting light at the back surface of the TFT array substrate module; And a drive signal input unit for inputting a drive signal to the two substrate modules or the TFT array substrate module, And a vacuum chamber for performing inspection of the two substrate modules in a vacuum atmosphere in order to easily separate the two substrate modules from the liquid crystal sealed sheet. The method according to claim 1, Wherein the liquid crystal sealed sheet has a liquid crystal injected between an upper protective film and a lower protective film. The method according to claim 1, Wherein a polymer dispersed liquid crystal (PDLC) is injected into the liquid crystal sealed sheet. The method according to claim 1 or 2, And a polarizing film is provided on the backlight unit side surface of the TFT array substrate module. The method according to claim 1 or 2, Wherein a polarizing film is provided on the color filter substrate module or the inspection equipment in front of the color filter substrate module. A liquid crystal sealed sheet is placed between the color filter substrate module and the TFT array substrate module before the LCD sticking process so as to overlap with the two substrate modules so that the two substrate modules and the liquid crystal sealed sheet are closely contacted to each other, and, A driving signal is inputted to the two substrate modules or the TFT array substrate module in a state in which the backlight unit is emitted from the back surface of the TFT array substrate module, Inspecting the two substrate modules, separating the two substrate modules from the liquid crystal encapsulated sheet, Wherein the entire process including inspection of the two substrate modules is performed inside the vacuum chamber so as to facilitate separation of the two substrate modules and the liquid crystal sealed sheet. A liquid crystal sealed sheet is placed between the color filter substrate module and the TFT array substrate module before the LCD sticking process so as to overlap with the two substrate modules so that the two substrate modules and the liquid crystal sealed sheet are closely contacted to each other, ; Performing alignment for each pixel of the color filter substrate module and the TFT array substrate module after the step; Inserting a driving signal into the two substrate modules or the TFT array substrate module in a state in which the backlight unit is illuminated after the step of inspecting whether the two substrate modules are defective; And separating the two substrate modules from the liquid crystal encapsulating sheet after the step of inspecting the defect, Wherein the step of separating the two substrate modules from the liquid crystal encapsulated sheet is performed in the inside of the vacuum chamber so as to facilitate separation of the two substrate modules and the liquid crystal encapsulated sheet. method of inspection. The method according to claim 6 or 7, Wherein the liquid crystal encapsulating sheet is one in which a polymer dispersed liquid crystal (PDLC) is injected. The method of claim 7, Wherein the inspection method includes at least one of a visual inspection and an image inspection using an image pickup device. delete delete delete

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