KR102230843B1 - In Cell Touch Liquid Crystal Display Device - Google Patents

Abstract

The present invention relates to an in-cell touch liquid crystal display capable of improving electrostatic discharge (ESD) performance.
In the in-cell touch liquid crystal display according to an embodiment of the present invention, a TFT (thin film transistor) array substrate on which a pixel array including a touch driving electrode and a touch sensing electrode is disposed, and a color bonded to the TFT array substrate with a liquid crystal layer interposed therebetween. A first discharge structure including a filter array substrate and discharging static electricity formed on the color filter array substrate and a second discharging structure for removing noise flowing into the TFT array substrate are disposed on the liquid crystal panel.

Description

In-cell touch liquid crystal display device

The present invention relates to an in-cell touch liquid crystal display capable of improving electrostatic discharge (ESD) performance.

As various portable electronic devices such as mobile communication terminals and notebook computers develop, there is an increasing demand for a flat panel display device that can be applied thereto.

As flat panel displays, a liquid crystal display device, a plasma display panel, and an organic light emitting diode display device have been developed.

Among these flat panel displays, the liquid crystal display is expanding its application fields due to the advancement of mass production technology, ease of driving means, low power consumption, high quality and large screen realization.

A typical liquid crystal display device includes a display panel in which a lower substrate and an upper substrate are bonded to face each other with a liquid crystal layer therebetween. In addition, a driving circuit for applying a driving voltage and a signal to the display panel is included.

In such a liquid crystal display, an image according to an image signal is displayed by adjusting transmittance of light passing through the liquid crystal layer of each of a plurality of pixels according to a data voltage.

In recent years, a touch screen has been applied in which a user can directly input information on the screen using a finger or a pen, replacing conventional input means such as a mouse, a keyboard, and a keypad.

Such touch screens include monitors such as navigation, industrial terminals, notebook computers, financial automation devices, and game machines; Portable terminals such as mobile phones, MP3s, PDAs, PMPs, PSPs, portable game consoles, DMB receivers, and tablet PCs; And home appliances such as refrigerators, microwave ovens, washing machines, and the like; And so on. The application of the touch screen is expanding due to the advantage that anyone can easily operate it.

Conventionally, in the application of a touch screen to a liquid crystal display device, a separately provided touch screen (touch panel) is additionally disposed on the liquid crystal panel in an add-on method. Recently, in order to reduce the thickness of a liquid crystal display to which a touch screen is applied, an in-cell touch liquid crystal display having a touch screen mounted in a cell of a liquid crystal panel has been developed.

1 is a diagram schematically illustrating an in-cell touch liquid crystal display according to the prior art.

Referring to FIG. 1, an in-cell touch liquid crystal display 10 according to the related art displays an image according to an image signal by adjusting a transmittance of light passing through a liquid crystal layer (not shown) of each pixel according to a data voltage. In addition, the touch position TS is detected by detecting the change in capacitance Ctc according to the user's touch. To this end, the in-cell touch liquid crystal display 10 includes a TFT (thin film transistor) array substrate 50 and a color filter array substrate 60 bonded with a liquid crystal layer therebetween.

The color filter array substrate 60 includes a black matrix 62 defining a pixel area to correspond to each of a plurality of pixels, and red, green, and blue color filters 64R formed in each pixel area defined by the black matrix 62. , 64G, 64B), and an overcoat layer 66 formed to cover the color filters 64R, 64G, 64B and the black matrix 62 to planarize the color filter array substrate 60. An upper polarizing film (not shown) is disposed on the upper surface of the color filter array substrate 60.

The TFT array substrate 50 includes a pixel array 40 including a plurality of pixels for driving a liquid crystal layer and detecting a touch of a user's finger or a touch of a pen. A lower polarizing film (not shown) is disposed on the rear surface of the TFT array substrate 50.

Each of the plurality of pixels is defined by a data line (not shown) and a gate line (not shown) crossing each other. In each pixel, a common electrode (not shown) to which a common voltage is applied and a pixel electrode (not shown) to supply a data voltage to the pixel are formed.

In each of the plurality of pixels, a thin film transistor (TFT) is switched according to a gate signal applied through a gate line. In addition, an electric field is formed according to the data voltage applied to the data line to drive the liquid crystal layer.

Each of the plurality of pixels displays an image according to an applied video signal in a display section in which an image is displayed. In a non-display section where an image is not displayed, the common electrode formed in the pixel array 40 is driven as a sensing/driving electrode for detecting a touch to detect a touch of a user's finger or a touch of a pen.

Here, a touch capacitance Ctc is formed between the color filter array substrate 60 and the common electrode according to the user's finger touch. The touch position TS is detected by comparing the touch capacitance Ctc according to the touch and the reference capacitance. Then, the detected touch position is output to the outside.

In the in-cell touch liquid crystal display device 10 according to the prior art, since a user's touch frequently occurs, static electricity is generated by a touch on the color filter array substrate 60. There is a problem in that touch sensing performance is deteriorated due to static electricity.

In addition, noise due to driving of a backlight unit and an external system supplying light of the liquid crystal panel may be introduced into the TFT array substrate 50. There is a problem in that touch sensing performance is deteriorated due to noise introduced into the TFT array substrate 50 from the backlight unit and the external system.

The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a discharge structure capable of improving the touch performance of an in-cell touch liquid crystal display.

An object of the present invention is to provide an in-cell touch liquid crystal display device capable of improving the discharge performance of static electricity generated by a touch as to solve the above-described problem.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an in-cell touch liquid crystal display device capable of removing noise by passing noise introduced from a backlight unit and an external system to the ground.

In addition to the technical problems of the present invention mentioned above, other features and advantages of the present invention will be described below or will be clearly understood by those of ordinary skill in the art from such technology and description.

In the in-cell touch liquid crystal display according to an embodiment of the present invention, a TFT (thin film transistor) array substrate on which a pixel array including a touch driving electrode and a touch sensing electrode is disposed, and a color bonded to the TFT array substrate with a liquid crystal layer interposed therebetween. A first discharge structure including a filter array substrate and discharging static electricity formed on the color filter array substrate and a second discharging structure for removing noise flowing into the TFT array substrate are disposed on the liquid crystal panel.

The in-cell touch liquid crystal display according to an embodiment of the present invention provides a discharge structure capable of improving touch performance.

The in-cell touch liquid crystal display according to an exemplary embodiment of the present invention may improve discharge performance of static electricity generated by a touch.

The in-cell touch liquid crystal display according to an exemplary embodiment of the present invention may remove noise by passing noise introduced from a backlight unit and an external system to the ground (GND pass).

1 is a diagram schematically illustrating an in-cell touch liquid crystal display according to the prior art.
2 is a plan view of an in-cell touch liquid crystal display according to an exemplary embodiment of the present invention, as viewed from the top of a color filter array substrate.
3 is a plan view of an in-cell touch liquid crystal display device according to an exemplary embodiment of the present invention, as viewed from a rear surface of a TFT array substrate.
4 is a diagram showing a touch electrode disposed on a TFT array substrate.
5 is a cross-sectional view illustrating an in-cell touch liquid crystal display according to an exemplary embodiment of the present invention, cut along line A1-A2 of FIGS. 2 and 3.

The same reference numbers throughout the specification mean substantially the same elements. In the following description, when not related to the core configuration of the present invention and detailed descriptions of configurations and functions known in the technical field of the present invention may be omitted.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only the present embodiments are intended to complete the disclosure of the present invention, and those with ordinary knowledge in the technical field to which the present invention pertains. It is provided to fully inform the person of the scope of the invention, and the invention is only defined by the scope of the claims.

In the present specification, in adding reference numerals to elements of each drawing, it should be noted that, even though they are indicated on different drawings, the same elements are to have the same number as much as possible.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for describing the embodiments of the present invention are exemplary, and the present invention is not limited to the illustrated matters. The same reference numerals refer to the same elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. When'include','have','consists of','formed' and the like mentioned in the present specification are used, other parts may be added unless'only' is used. Even when the constituent elements are expressed in the singular, the case including the plural is included unless specifically stated otherwise.

In interpreting the constituent elements, it is interpreted as including an error range even if there is no explicit description.

In the case of a description of the positional relationship, for example, if the positional relationship of the two parts is described as'upper','upper of','lower of','next to', etc.,'right' Alternatively, one or more other parts may be located between the two parts unless'direct' is used.

First, second, etc. are used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one component from another component. Accordingly, the first component mentioned below may be a second component within the technical idea of the present invention.

Each of the features of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments can be implemented independently of each other or can be implemented together in a related relationship. May be.

Hereinafter, an in-cell touch liquid crystal display according to an embodiment of the present invention will be described with reference to the accompanying drawings.

Prior to the description with reference to the drawings, the in-cell touch liquid crystal display according to an embodiment of the present invention includes a liquid crystal panel, a back light unit that supplies light to the liquid crystal panel, and a drive for driving the liquid crystal panel and a light source. It consists of a circuit part.

The driving circuit unit includes a timing controller, a data driver, a gate driver, a backlight driver, a touch driver, and a power supply unit. Some or all of the driving circuit units may be disposed on the liquid crystal panel in a COG (Chip On Glass) method, or may be connected to the liquid crystal panel in a Chip On Flexible Printed Circuit (COF) method.

In the present invention, since a discharge structure for removing static electricity and noise is disposed in a liquid crystal display device, a detailed description of the backlight unit and the driving circuit unit not related to the discharge structure will be omitted.

2 is a plan view of an in-cell touch liquid crystal display device according to an embodiment of the present invention, as viewed from the top of a color filter array substrate, and FIG. 3 is a plan view of the in-cell touch liquid crystal display device according to an embodiment of the present invention. It is a view as seen from the rear surface of the array substrate.

2 and 3, a liquid crystal display device 100 according to an exemplary embodiment of the present invention includes a liquid crystal panel, a first anti-static polarizing film 132 disposed on the liquid crystal panel, and a first anti-static polarizing film 132 disposed on the liquid crystal panel. 2 Discharge polarizing film 134 (second anti-static polarizing film), first discharge pad 140, first conductive pattern 150, second discharge pad 160, shield layer 170, second conductive pattern ( 180) and a third conductive pattern 190. Although not shown in the drawings, the backlight unit may be disposed on the back or side of the liquid crystal panel.

The liquid crystal panel includes a TFT array substrate 110 and a color filter array substrate 120 bonded with a liquid crystal layer (not shown) therebetween. The TFT array substrate 110 is disposed below, and the color filter array substrate 120 is disposed on the TFT array substrate 110.

The color filter array substrate 120 covers a black matrix defining a pixel area to correspond to each of a plurality of pixels, red, green, and blue color filters formed in each pixel area defined by the black matrix, and the color filter and the black matrix. The overcoat layer is formed so as to planarize the color filter array substrate. The first discharge polarizing film 132 is disposed on the upper surface of the color filter array substrate 120 to correspond to the display area. Since the first discharge polarizing film 132 includes a conductive material, it polarizes light and conducts electric charges.

A plurality of pixels are defined on the TFT array substrate 110, and a pixel electrode for supplying a data voltage to the plurality of pixels and a common electrode for supplying a common voltage are disposed.

Here, the common electrode serves not only for supplying a common voltage to the pixels in the display period, but also functions as a touch electrode in the non-display period. A second discharge polarizing film 134 is disposed under the TFT array substrate 110 so as to correspond to the display area. Since the second discharge polarizing film 134 contains a conductive material, it polarizes light and conducts electric charges.

4 is a diagram showing a touch electrode disposed on a TFT array substrate.

Referring to FIG. 4, an in-cell touch liquid crystal display according to an exemplary embodiment of the present invention displays an image according to an image signal by adjusting a transmittance of light passing through a liquid crystal layer according to a data voltage applied to each pixel. In addition, a change in capacitance according to a user's touch is sensed through a touch electrode disposed on the pixel array to detect a user's touch position. To this end, the touch driving electrode 112b and the touch sensing electrode 112a are formed of the common electrode 112.

The plurality of touch driving electrodes 112b are patterned to have a predetermined area, and a plurality of touch driving electrodes 112b disposed on the same horizontal line are connected. The plurality of touch drive electrodes 112b are connected to the touch drive signal line 116. Touch driving signals from the touch driver are supplied to the plurality of touch driving electrodes 112b.

The plurality of touch sensing electrodes 112a are patterned in the form of a long bar from the upper side to the lower side of the liquid crystal panel to form a tubular wire shape. The plurality of touch sensing electrodes 112a are connected to the touch sensing signal line 114 so that the touch driver can sense the formed capacitance of the touch sensing electrode 112a.

In the in-cell touch liquid crystal display according to an embodiment of the present invention, an image display and touch sensing are time-divided and driven. In the display period, a common voltage is supplied from the data driver to the common electrode 112 to display an image. In the non-display period, the touch driver supplies a touch driving signal to the plurality of touch driving electrodes 112b, and the touch driver senses the capacitance formed on the plurality of touch sensing electrodes 112a to detect the presence or absence of a touch. I can.

5 is a cross-sectional view illustrating an in-cell touch liquid crystal display according to an exemplary embodiment of the present invention, cut along line A1-A2 of FIGS. 2 and 3.

2, 3, and 5 will be described in conjunction with the in-cell touch liquid crystal display according to an embodiment of the present invention, a first discharge structure for discharging static electricity formed on the upper surface of the color filter array substrate 120 by a touch. And a second discharge structure for removing noise introduced into the TFT array substrate 110 from the backlight unit and the external system.

Here, the first discharge structure includes a first discharge polarizing film 132, a first discharge pad 140, and a first conductive pattern 150. In addition, the second discharge structure includes a second discharge polarizing film 134, a second discharge pad 160, a shield layer 170, a second conductive pattern 180, and a third conductive pattern 190.

First discharge pads 140 are disposed on left and right edges of the upper surface of the pad area of the TFT array substrate 110. Further, second discharge pads 160 are disposed at left and right ends of the upper surface of the pad region of the TFT array substrate 110. A portion of the second discharge pad 160 is disposed on the TFT array substrate 110 and the remaining portion protrudes out of the TFT array substrate 110.

When viewed from the top of the color filter array substrate 120, the first discharge pad 140 is disposed at the edge of the pad area, and the second discharge pad 160 is disposed above the first discharge pad 140. It is placed.

When viewed from the lower side of the TFT array substrate 110, a portion of the second discharge pad 160 protruding out of the TFT array substrate 110 is exposed.

The first discharge pad 140 is connected to a ground terminal disposed on the TFT array substrate 110. In addition, the second discharge pad 160 is connected to the ground terminal of the system driver through the FPC.

The first conductive pattern 150 electrically connects the first discharge polarizing film 132 and the first discharge pad 140. The first side of the first conductive pattern 150 is overlapped with an edge portion of the first discharge polarizing film 132 disposed on the color filter array substrate 120. That is, it is disposed so that the first side of the first conductive pattern 150 and the edge portion of the first discharge polarizing film 132 contact each other. In addition, the second side of the first conductive pattern 150 overlaps the first discharge pad 140 disposed on the TFT array substrate. That is, the second side of the first conductive pattern 150 and the first discharge pad 140 are disposed to contact each other. The first conductive pattern 150 is formed of a metal material having excellent electrical conductivity, for example, silver (Ag). The first conductive pattern 150 may be arranged in a bar shape.

Static electricity formed on the color filter array substrate 120 may be passed to the first discharge pad 140 through the first discharge structure. That is, in the in-cell touch liquid crystal display 100 according to the embodiment of the present invention including the above-described first discharge structure, charges formed on the liquid crystal panel due to static electricity are transferred to the ground GND through the first discharge pad 140. You will get out. Through this, it is possible to prevent deterioration of touch sensing performance due to static electricity generated by the touch.

As described above, in the second discharge pad 160 constituting the second discharge structure, the pad region of the TFT array substrate 110 is disposed at the upper end of the upper surface.

A shield layer 170 is disposed on the lower surface of the TFT array substrate 110. The shield layer 170 is formed of a transparent conductive material such as ITO, and is disposed to correspond to a pad area as well as a display area.

In the above description, it has been described that the shield layer 170 may be formed of ITO, but is not limited thereto. The shield layer 170 is IZO (Indium Zinc Oxide), ZnO, ZnO:B, ZnO:Al, SnO2, SnO2:F, ITZO (Indium Tin Zinc Oxide), ZTO (Zinc Tin Oxide), or ATO (Antimony Tin Oxide). ) May be formed of any one of transparent conductive materials.

A second discharge polarizing film 134 is disposed under the shield layer 170. The second discharge polarizing film 134 is disposed to correspond to the display area.

The first side of the second conductive pattern 180 overlaps the edge of the shield layer 170 and the edge of the second discharge polarizing film 134. That is, the first side of the second conductive pattern 180 and the edge of the shield layer 170 and the edge of the second discharge polarizing film 134 are arranged to contact each other. The second side of the second conductive pattern 180 overlaps the third conductive pattern 190. That is, the second side of the second conductive pattern 180 and the third conductive pattern 190 are disposed to contact each other.

The shield layer 170, the second discharge polarizing film 134, and the third conductive pattern 190 are electrically connected by the second conductive pattern 180. The second conductive pattern 180 is formed of a metal material having excellent conductivity, for example, silver (Ag). The second conductive pattern 180 may be arranged in a bar shape.

In this way, the second discharge pad 160 is disposed on the upper surface of the TFT array substrate 110. In addition, the shield layer 170, the second discharge polarizing film 134, and the second conductive pattern 180 are disposed on the lower surface of the TFT array substrate 110.

To directly connect the second discharge pad 160 disposed on the upper surface of the TFT array substrate 110 and the shield layer 170 and the second conductive pattern 180 disposed on the lower surface of the TFT array substrate 110 The third conductive pattern 190 is disposed.

The first side of the third conductive pattern 190 is disposed to be in contact with the lower surface of the second discharge pad 160, and the second side of the third conductive pattern 190 is the shield layer 170 and the second conductive pattern 180. It is arranged to be in contact with. The third conductive pattern 190 is formed of a metal material having excellent conductivity, for example, silver (Ag). The third conductive pattern 190 may be arranged in a dot shape.

That is, the second conductive pattern 180 and the third conductive pattern 190 serve as a bridge connecting the shield layer 170 and the second discharge polarizing film 134 to the second discharge pad 160.

Through the second discharge structure, noise flowing into the TFT array substrate 110 from the backlight unit and an external system may be passed to the ground. That is, in the in-cell touch liquid crystal display device according to the embodiment of the present invention including the above-described second discharge structure, noise introduced from the backlight unit and the external system escapes to the ground (GND) through the second discharge pad 160. do. Through this, it is possible to prevent deterioration of touch performance due to noise introduced from the backlight unit and an external system.

The first discharge structure of the in-cell touch liquid crystal display according to an embodiment of the present invention includes a first discharge polarizing film disposed on an upper surface of the color filter array substrate, and a first discharge pad disposed in a pad area of the TFT array substrate. And a first conductive pattern electrically connecting the first discharge polarizing film and the first discharge pad.

The second discharge structure of the in-cell touch liquid crystal display according to an embodiment of the present invention includes a second discharge pad disposed in a pad area of the TFT array substrate, a shield layer disposed on a lower surface of the TFT array substrate, and the shield layer. A second discharge polarizing film disposed on a lower surface, a second conductive pattern electrically connected to the shield layer and the second discharge polarizing film, and a third conductive pattern electrically connecting the second conductive pattern and the second discharge pad Includes.

The first conductive pattern of the in-cell touch liquid crystal display according to an embodiment of the present invention is arranged in a bar shape, a first side of the first conductive pattern is in contact with the first discharge polarizing film, and a second side is It is in contact with the first discharge pad.

The first discharge pad and the second discharge pad of the in-cell touch liquid crystal display according to an exemplary embodiment of the present invention are disposed at the edge of the upper pad area of the TFT array substrate.

A portion of the second discharge pad of the in-cell touch liquid crystal display according to an exemplary embodiment of the present invention is disposed on the upper surface of the TFT array substrate, and the remaining portion protrudes out of the TFT array substrate.

The third conductive pattern of the in-cell touch liquid crystal display according to an exemplary embodiment of the present invention is arranged in a dot shape, the first side of the third conductive pattern is in contact with the lower surface of the second discharge pad, and the second side is the second side. The second side is in contact with the second conductive pattern.

The second conductive pattern of the in-cell touch liquid crystal display according to an embodiment of the present invention is arranged in a bar shape, and a first side of the second conductive pattern is in contact with the shield layer and the second discharge polarizing film. , The second side is in contact with the third conductive pattern.

The first discharge pad of the in-cell touch liquid crystal display according to an embodiment of the present invention is connected to a ground terminal disposed on the TFT array substrate, and the second discharge pad is a system ground terminal disposed on a set PCB of the liquid crystal display. Is connected with. The ground terminal disposed on the TFT array substrate may also be connected to the system ground terminal disposed on the set PCB of the liquid crystal display.

The in-cell touch liquid crystal display 100 according to the embodiment of the present invention including the above-described configurations can remove static electricity formed on the color filter array substrate without a shield electrode applied to the upper surface of the color filter array substrate in the prior art.

Those skilled in the art to which the present invention pertains will be able to understand that the above-described present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting.

The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

100: liquid crystal display
110: TFT array substrate
112: common electrode
112a: touch receiving electrode
112b: touch drive electrode
114: touch sensing signal line
116: touch drive signal line
120: color filter array substrate
132: first discharge polarizing film
134: second discharge polarizing film
140: first discharge pad
150: first conductive pattern
160: second discharge pad
170: shield layer
180: second conductive pattern
190: third conductive pattern

Claims (9)

A thin film transistor (TFT) array substrate on which a pixel array including a touch driving electrode and a touch sensing electrode is disposed;
A color filter array substrate bonded to the TFT array substrate with a liquid crystal layer therebetween;
A first discharge structure for discharging static electricity formed on the color filter array substrate; And
Including a second discharge structure for removing noise introduced into the TFT array substrate,
The first discharge structure,
A first discharge polarizing film disposed on an upper surface of the color filter array substrate;
A first discharge pad disposed in a pad area of the TFT array substrate; And
And a first conductive pattern electrically connecting the first discharge polarizing film and the first discharge pad,
The second discharge structure,
A second discharge pad disposed in a pad area of the TFT array substrate;
A shield layer disposed on a lower surface of the TFT array substrate;
A second discharge polarizing film disposed on a lower surface of the shield layer;
A second conductive pattern electrically connected to the shield layer and the second discharge polarizing film; And
A third conductive pattern electrically connecting the second conductive pattern and the second discharge pad,
The first discharge pad and the second discharge pad are disposed to be spaced apart from each other at the edge of the upper pad area of the TFT array substrate,
Part of the second discharge pad is disposed on the upper surface of the TFT array substrate, and the remaining part protrudes out of the TFT array substrate,
The first side of the third conductive pattern is in contact with the lower surface of the second discharge pad,
The second side of the third conductive pattern is in contact with the second conductive pattern on the lower surface of the TFT array substrate,
A portion of the third conductive pattern connecting the first side and the second side is provided along a side surface of the TFT array substrate. delete delete The method of claim 1,
The first conductive pattern is arranged in a bar shape,
A first side of the first conductive pattern is in contact with the first discharge polarizing film, and a second side of the first conductive pattern is in contact with the first discharge pad. delete delete The method of claim 1,
The third conductive pattern is an in-cell touch liquid crystal display that is arranged in a dot shape. The method of claim 7,
The second conductive pattern is arranged in a bar shape,
A first side of the second conductive pattern is in contact with the shield layer and the second discharge polarizing film, and a second side of the second conductive pattern is in contact with the third conductive pattern.
The method of claim 1,
The first discharge pad is connected to a ground terminal disposed on the TFT array substrate,
The second discharge pad is an in-cell touch liquid crystal display connected to a system ground terminal.

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