KR101432569B1 - Liquid crystal display device having touch screen and method for fabricating the same - Google Patents

Abstract

The present invention relates to a liquid crystal display device having a touch screen, which comprises a lower array substrate on which a thin film transistor and a pixel electrode electrically connected to the thin film transistor are formed on a first transparent substrate, An upper array substrate on which a black matrix and a color filter layer are formed, and a liquid crystal layer formed between these substrates; A touch screen including a transparent conductive film formed on a rear surface of a second transparent substrate of the upper array substrate constituting the liquid crystal display panel, a position sensing film laminated on the transparent conductive film, and a transparent conductive film; And a backlight assembly disposed under the liquid crystal display panel and providing light to the liquid crystal display panel.

Touch screen, position sensing film, transparent conductive film, transparent conductive film

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal display device having a touch screen and a method of manufacturing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a touch screen capable of increasing a transmittance and slimming a panel thickness, and a method of manufacturing the same.

The touch screen is a state-of-the-art input device replacing a keyboard and a mouse. The touch screen is mounted on a monitor, and then the user touches the monitor using a hand or a touch pen to perform a desired operation.

Such a touch screen is an ideal device that can perform intuitive work under GUI (Graphic User Interface) environment (Windows operating system).

Accordingly, the touch screen can be widely used in computer board training, simulation application field, office automation application field, educational application field, and game application field.

Such a touch screen generates a photo current corresponding to a light reflected from a contacted object, for example, a finger or a touch pen, charges the generated electric charge, and outputs a voltage corresponding to the charged electric charge. The position of the object to be detected is detected.

Generally, since the touch screen is formed as a thin film, it is mounted on the upper part of the liquid crystal display panel.

A conventional liquid crystal display device having a touch screen will now be described with reference to FIGS. 1 and 2. FIG.

FIG. 1 is a schematic view of a conventional liquid crystal display device to which a touch screen is adhered.

2 is a schematic exploded view of a liquid crystal display device before a touch screen according to the related art is adhered.

As shown in FIG. 1, a liquid crystal display device provided with a touch screen according to the related art includes a liquid crystal display panel 10; A lower polarizer 15 and an upper polarizer 17 formed on the lower surface and the upper surface of the liquid crystal display panel 10; And a thin film-type touch screen 20 adhered on the upper polarizer 17.

 2, the liquid crystal display panel 10 includes a lower array substrate 11 formed of a transparent material and having a switching element formed thereon; An upper array substrate 13 on which images of various colors are realized; And a liquid crystal layer (not shown) formed between these substrates and whose alignment direction is adjusted by an electric field.

As shown in FIG. 2, the touch screen 20 of the thin film type includes a transparent ITO substrate (Indium Tin Oxide substrate) 21; A position sensor film 23 for recognizing X and Y position coordinates of an object adhered on the ITO substrate 21 and contacting the liquid crystal display panel; And an ITO film 25 adhered on the position sensor film 23.

A method of manufacturing a liquid crystal display device having a touch screen according to the related art having the above structure will be described with reference to FIG.

 Although not shown in the figure, a TFT forming process, which is a switching device, is performed on the lower array substrate (see 11 in FIG. 2), and a pixel electrode (not shown) electrically connected to the TFT (not shown) (Not shown).

Although not shown in the drawing, a black matrix (not shown) defining an image display region on the upper array substrate (see 13 in FIG. 2), a color filter layer (not shown) implementing a plurality of colors, (Not shown) and an alignment film (not shown) are formed.

2, a seal pattern (not shown) for defining a pixel display region of the lower array substrate 11 or the upper array substrate 13 is formed, and then a seal pattern (not shown) A liquid crystal layer (not shown) is formed in the upper array substrate 11 and the upper array substrate 13.

Subsequently, the lower polarizer plate 15 and the upper polarizer plate 17 are formed on the outer surfaces of the lower array substrate and the upper array substrate to complete the manufacturing process of the liquid crystal display panel.

Next, as shown in FIG. 2, the process of bonding the touch screen 20 to the upper surface of the upper polarizer 17 is performed to complete the process of manufacturing a liquid crystal display device having a touch screen.

The touch screen 20 includes an ITO substrate 21 adhered to the upper surface of the liquid crystal display panel 10 and a position sensor 21 attached to the ITO substrate 21 for recognizing X, Y position coordinates of the object. Film 23 and an ITO film 25 as shown in Fig.

As described above, the liquid crystal display device having the touch screen according to the related art and the manufacturing method thereof have the following problems.

According to the conventional liquid crystal display device having a touch screen and the method of manufacturing the same, the transmittance of the touch screen is reduced by the ITO substrate because the touch screen is bonded to a separate ITO substrate before being mounted on the liquid crystal display panel.

In addition, according to the conventional liquid crystal display having a touch screen and the method of manufacturing the same, the color reproduction ratio of the color filter itself may be lowered due to the ITO substrate being on the liquid crystal display panel.

According to a conventional liquid crystal display device having a touch screen and a method of manufacturing the same, the touch screen is composed of a separate ITO substrate, a position sensor film, and an ITO film, so that a liquid crystal display Thereby increasing the thickness and weight of the entire device.

Further, according to the liquid crystal display device having a touch screen and the method of manufacturing the same according to the related art, a liquid crystal display panel and a touch screen are manufactured separately, and the liquid crystal display panel and the touch screen are bonded to each other, The cost of parts is increased.

Accordingly, it is an object of the present invention to provide a liquid crystal display device having a touch screen capable of increasing the transmittance and improving the color reproduction rate while reducing the thickness of the liquid crystal display device. And a method of manufacturing the same.

According to an aspect of the present invention, there is provided a liquid crystal display device having a touch screen, including a thin film transistor on a first transparent substrate, a lower array substrate on which pixel electrodes electrically connected to the thin film transistor are formed, A liquid crystal display panel comprising an upper array substrate on which a black matrix and a color filter layer are formed, and a liquid crystal layer formed between these substrates; A touch screen including a transparent conductive film formed on a rear surface of a second transparent substrate of the upper array substrate constituting the liquid crystal display panel, a position sensing film laminated on the transparent conductive film, and a transparent conductive film; And a backlight assembly disposed under the liquid crystal display panel and providing light to the liquid crystal display panel.

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device having a touch screen, including: forming a thin film transistor on a first transparent substrate and a pixel electrode electrically connected to the thin film transistor; Forming a black matrix and a color filter layer on a second transparent substrate; Forming a transparent conductive film on a back surface of the second transparent substrate; Forming a liquid crystal layer between the first transparent substrate and the second transparent substrate; And sequentially forming a position sensing film and a transparent conductive film on the transparent conductive film.

The liquid crystal display device having a touch screen and the method of manufacturing the same according to the present invention have the following effects.

According to the liquid crystal display device having a touch screen and the method of manufacturing the same according to the present invention, the touch screen is not adhered to a separate transparent substrate before being mounted on the liquid crystal display panel, (That is, on the upper array substrate), a separate transparent substrate is not required, and the transmittance is improved.

In addition, according to the liquid crystal display device having a touch screen and the method of manufacturing the same according to the present invention, it is possible to reduce the color reproducibility reduction of the color filter itself, which is caused by the fact that a separate ITO substrate is present on the liquid crystal display panel .

According to the liquid crystal display device having a touch screen and the method of manufacturing the same according to the present invention, since the touch screen is not formed on a separate ITO substrate but is formed on a color filter substrate (i.e., an upper array substrate) The total thickness of the liquid crystal display device combined with the liquid crystal display panel and the touch screen is reduced and the weight is reduced.

Therefore, according to the liquid crystal display device having the touch screen and the method of manufacturing the same according to the present invention, since the touch screen is formed on the color filter substrate of the liquid crystal display panel without separately manufacturing, a separate transparent substrate is not needed, .

Hereinafter, a liquid crystal display device having a touch screen according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic block diagram of a liquid crystal display device having a touch screen according to the present invention.

4 is a schematic exploded view of a liquid crystal display device having a touch screen according to the present invention.

As shown in FIG. 3, a liquid crystal display device provided with a touch screen according to the present invention includes a liquid crystal display panel 100; A touch screen 160 adhered to the upper surface of the liquid crystal display panel 100; A lower polarizer plate 171 and an upper polarizer plate 173 formed on the lower surface of the liquid crystal display panel 100 and the upper surface of the touch screen 160; And a backlight assembly (not shown) provided under the liquid crystal display panel 100 to transmit light to the liquid crystal display panel.

 4, the liquid crystal display panel 100 includes a switching element (not shown) and a pixel electrode (not shown) electrically connected to the element on a lower substrate (not shown) made of a transparent material A lower array substrate 110 on which a plurality of pixel electrodes are formed; An upper array substrate 130 on which an image is formed by forming a black matrix (not shown) blocking light and a color filter layer (not shown) of various colors in a pixel region defined by the black matrix (not shown); And a liquid crystal layer (not shown) formed between these substrates and whose alignment direction is adjusted by an electric field. A common electrode (not shown) for generating an electric field with the pixel electrode (not shown) is formed on the upper array substrate 130 or the lower array substrate 110. In this case, the common electrode (not shown) is formed on the upper array substrate 130 in the case of the TN mode and on the lower array substrate 110 in the case of the IPS mode.

4, the touch screen 160 in the form of a thin film is formed on the upper surface of the upper array substrate 130 and includes a transparent conductive film made of a transparent material such as ITO (Indium Tin Oxide) (141); A position detection sensor film 161 for recognizing the position of an object which is adhered to the surface of the transparent conductive film 141 and is in contact with the liquid crystal display panel, that is, X, Y position coordinates; And an ITO film 163 bonded on the position sensing film 161.

A method of manufacturing a liquid crystal display device having a built-in touch screen according to the present invention will be described with reference to FIGS. 5A to 5F.

5A to 5F are cross-sectional views illustrating a method of manufacturing a liquid crystal display device incorporating a touch screen according to the present invention.

Although the method of manufacturing a TN (Twist nemetic) mode liquid crystal display device is described here, the present invention is applicable not only to the TN mode but also to an IPS (In-Plane Switching) mode, VA (Vertical Alignment) Do.

As shown in FIG. 5A, a metal material is deposited on a lower substrate 111 made of transparent glass or the like by a sputtering method and selectively patterned by a mask process to form a gate line (not shown) (Not shown) to form the protruding gate electrode 113. [

At this time, the metal material for forming the gate line may be selected from Al-based metals such as Al and Al alloys, Ag-based metals such as Ag and Ag alloys, Mo-based metals such as Mo and Mo alloys, Cr, Ti and Ta do.

In addition, they may comprise two membranes of different material properties, namely a bottom membrane and a top membrane thereon. Here, the upper film is made of a metal having a low resistivity, for example, an Al-based metal or an Ag-based metal so as to reduce signal delay and voltage drop of the gate line.

Alternatively, the lower film may be made of a material having excellent physical, chemical and electrical contact properties with other materials, particularly indium tin oxide (ITO) or indium zinc oxide (IZO), such as Ti, Ta, Cr, , Or an example of a combination of the lower film and the upper film is Cr / Al-Nd alloy.

Next, a gate insulating film 115 made of an inorganic insulating material such as silicon nitride (SiNx) is formed on the lower substrate 111 including the gate line (not shown) and the gate electrode 113.

Next, a semiconductor layer (not shown) made of a hydrogenated amorphous silicon layer is formed on the gate insulating layer 115.

Next, an ohmic contact layer (not shown) made of a material such as silicide or n + hydrogenated amorphous silicon with high concentration of n-type impurity is formed on the semiconductor layer (not shown).

Then, the ohmic contact layer and the semiconductor layer are selectively patterned by a mask process using a photolithography process technique to form the active pattern 117 and the ohmic contact pattern 118.

Next, a metal material for forming a data line is deposited on the lower substrate 111 including the active pattern 117 and the ohmic contact pattern 118 by a sputtering method, and then a metal material for forming a data line is selectively deposited by a mask process using a photolithography process technique. A source electrode 119 protruding from the data line (not shown), and a drain electrode 121 spaced apart from the source electrode 119 by a predetermined distance are formed.

Although not shown in the figure, the data line (not shown) is formed so as to intersect with the gate line (not shown), and the source electrode 119 and the drain electrode 121 are formed in the gate electrode 113 constitute a thin film transistor (not shown) as a switching element.

A channel of the thin film transistor (not shown) is formed in the active pattern 117 between the source electrode 119 and the drain electrode 121.

As the metal material for forming the data line (not shown), a material such as an Al-based metal, an Ag-based metal, a Mo-based metal, Cr, Ti, or Ta may be used.

Next, an organic material having excellent planarization characteristics and having a photosensitive property, an insulating material having a low dielectric constant property, or a material having a low dielectric constant is formed on the entire surface of the lower substrate 111 including the data line (not shown) and the source / drain electrodes 119 and 121 A protective film 123 made of silicon nitride is formed.

The protective film 123 is selectively patterned by a mask process using a photolithography process technique to form a contact hole (not shown) exposing a part of the drain electrode 121 in the protective film 123.

5B, a metal material layer (not shown) made of a transparent conductive material such as ITO (indium tin oxide) or IZO (indium tin oxide) is formed on the protective film 123 including the contact hole Is formed by a sputtering method and then selectively removed by a mask process using a photolithography process technique to form a pixel electrode 125. [

When the data voltage is applied to the pixel electrode 113, a common electrode (not shown in FIG. 5C, not shown) of the upper array substrate (not shown in FIG. 5C) The liquid crystal molecules of the liquid crystal layer (not shown in FIG. 5E, 150) between the pixel electrode 125 and the common electrode 127 are arranged.

 Although not shown in the drawing, a process of forming an alignment film (not shown) for aligning liquid crystal molecules in a predetermined direction is performed on the protective film 123 including the pixel electrode 125.

On the other hand, as shown in FIG. 5C, a black matrix 133 is formed on the upper substrate 131 to define a plurality of unit cell regions using an opaque metal material such as Cr.

At this time, the black matrix 133 absorbs light incident from adjacent cells, thereby preventing the contrast from lowering.

A color filter layer 135 of red (R), green (G), and blue (B) is formed on the surface of the upper substrate 131 between the black matrices 133.

At this time, the color filter layer 135 includes color filters of red (R), green (G), and blue (B) to transmit light in a specific wavelength band, thereby enabling color display.

Next, a common electrode 137 made of a transparent conductive material is formed on the upper substrate 131 including the color filter layer 135 and the black matrix 133. Although the common electrode 137 is formed on the upper substrate 131, the common electrode 137 may be formed on the lower substrate 111 according to the driving mode of the liquid crystal display panel. That is, when the driving mode of the liquid crystal display panel is the IPS mode (In-Plane Switching mode), the common electrode 137 is formed on the lower substrate 111.

Although not shown in the drawing, a process of forming an alignment film (not shown) for arranging liquid crystal molecules in a predetermined direction is performed on the common electrode 137.

Next, as shown in FIG. 5D, a transparent conductive film 141 is formed on the rear surface of the upper substrate 131 by depositing a conductive material made of a transparent material by a sputtering method. At this time, the transparent conductive film 141 may be formed of ITO (indium tin oxide), IZO (indium tin oxide), or a transparent conductive material.

Next, a seal pattern (not shown) defining each pixel region is formed on the upper surface of the lower array substrate 110, which has been subjected to the array forming process, around each pixel region.

Then, a liquid crystal layer 150 is formed by dropping liquid crystal in a pixel region in the seal pattern.

Subsequently, the liquid crystal display panel 100 is formed by attaching the upper array substrate 130 on the lower array substrate 110 on which the liquid crystal layer 15 is formed while being spaced apart from each other by a predetermined distance. At this time, a spacer (not shown) is formed between the lower array substrate 110 and the upper array substrate 130 so that a uniform gap therebetween can be maintained.

The position of an object in contact with the liquid crystal display panel 100, that is, the position of the object contacting the liquid crystal display panel 100, that is, the XY coordinate (Y coordinate) of the liquid crystal display panel 100, And then the ITO film 163 is adhered to the position detection sensor film 161 again. At this time, as the material of the ITO film 163, IZO or a transparent conductive material may be used in addition to ITO.

Subsequently, a lower polarizer plate 171 and an upper polarizer plate 173 are formed on the lower surface of the lower array substrate 110 and the upper surface of the ITO film 163, respectively.

A backlight assembly (not shown) for transmitting light to the liquid crystal display panel 100 is mounted below the lower polarizer plate 171 of the lower array substrate 110.

After the array process of the lower array substrate 110 and the upper array substrate 130 is performed, a liquid crystal layer 150 is formed between the lower array substrate 110 and the upper array substrate 130 In addition, the process of forming the touch screen 160 directly on the back surface of the upper array substrate 130 completes the process of manufacturing the liquid crystal display device with the touch screen 160 embedded therein.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

Therefore, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also within the scope of the present invention.

FIG. 1 is a schematic view of a conventional liquid crystal display device to which a touch screen is adhered.

2 is a schematic exploded view of a liquid crystal display device before a touch screen according to the related art is adhered.

3 is a schematic block diagram of a liquid crystal display device having a touch screen according to the present invention.

4 is a schematic exploded view of a liquid crystal display device having a touch screen according to the present invention.

5A to 5F are cross-sectional views illustrating a method of manufacturing a liquid crystal display device incorporating a touch screen according to the present invention.

DESCRIPTION OF THE REFERENCE SYMBOLS

100: liquid crystal display panel 110: lower array substrate

111: lower substrate 113: gate electrode

115: gate insulating film 117: active pattern

118: Ohmic contact pattern 119: Source electrode

121: drain electrode 123: protective film

125: pixel electrode 130: upper array substrate

131; Upper substrate 133: black matrix

135: color filter layer 137: common electrode

141: transparent conductive film 161; Position sensor film

163: Transparent conductive film 171: Lower polarizer plate

173: Upper polarizer

Claims (13)

A lower array substrate on which a thin film transistor and pixel electrodes electrically connected to the thin film transistor are formed on a first transparent substrate; an upper array substrate on which a black matrix and a color filter layer are formed on a second transparent substrate; A liquid crystal display panel comprising a plurality of layers; A touch screen including a transparent conductive film formed on a rear surface of a second transparent substrate of the upper array substrate constituting the liquid crystal display panel, a position sensing film laminated on the transparent conductive film, and a transparent conductive film; And And a backlight assembly disposed under the liquid crystal display panel and providing light to the liquid crystal display panel, A lower polarizer is formed on a back surface of the first transparent substrate of the lower array substrate, Wherein an upper polarizer is formed on an upper surface of the transparent conductive film of the touch screen. delete The liquid crystal display of claim 1, wherein the transparent conductive film is formed of a metal material such as ITO, IZO, or a transparent material. The liquid crystal display of claim 1, wherein the transparent conductive film is formed of a metal material such as ITO, IZO, or a transparent material. The liquid crystal display of claim 1, further comprising a common electrode formed on the lower array substrate or the upper array substrate. Forming a thin film transistor on the lower array substrate and a pixel electrode electrically connected to the thin film transistor; Forming a black matrix and a color filter layer on an upper array substrate bonded to the lower array substrate; Forming a transparent conductive film on a rear surface of the upper array substrate; Forming a liquid crystal layer between the lower array substrate and the upper array substrate; Sequentially forming a position sensing film and a transparent conductive film on the transparent conductive film to form a touch screen including the transparent conductive film, the position sensing film, and the transparent conductive film; And Forming a lower polarizer on a rear surface of the lower array substrate and forming an upper polarizer on an upper surface of the transparent conductive film of the touch screen; . delete The method of claim 6, wherein the transparent conductive film is formed of a metal material such as ITO, IZO, or a transparent material. 7. The method of claim 6, wherein the transparent conductive film is formed of a metal material such as ITO, IZO, or a transparent material. delete 7. The method of claim 6, further comprising forming a backlight assembly below the lower polarizer plate to provide light to the lower array substrate and the upper array substrate. The method of claim 6, further comprising: forming a first alignment layer on the lower array substrate after forming the pixel electrode; and forming a second alignment layer on the upper array substrate A method for manufacturing a liquid crystal display device having a screen. 7. The method of claim 6, further comprising forming a common electrode on the lower array substrate or the upper array substrate.

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