KR101201041B1 - Liquid Crystal Display Device And Method For Fabricating Thereof - Google Patents

Abstract

The present invention relates to a liquid crystal display device having an image sensing function capable of realizing a document, an image scan, a touch input, and an input image to an image, and a manufacturing method thereof.

In the present invention, a liquid crystal display device includes a sensor thin film transistor for sensing light having image information, an integrated circuit for detecting a signal sensed by the sensor thin film transistor, and a signal sensed by the sensor thin film transistor to transfer the signal to the integrated circuit. A thin film transistor array substrate having a sensing signal transmission line therein; And a color filter array substrate facing the thin film transistor array substrate with a liquid crystal interposed therebetween, wherein the color filter array substrate is positioned to overlap the pixel electrode of the thin film transistor array substrate to form a vertical electric field with the pixel electrode. The common electrode is not overlapped with the sensing signal transmission line.

Description

Liquid crystal display device and method for manufacturing the same {Liquid Crystal Display Device And Method For Fabricating Thereof}

1 is a plan view showing a portion of a conventional TFT array substrate.

FIG. 2 is a cross-sectional view of the TFT array substrate illustrated in FIG. 1 taken along the line II ′. FIG.

3 is a cross-sectional view showing a conventional photo sensing device.

4 is a diagram illustrating a thin film transistor array substrate of a liquid crystal display device having an image sensing function according to a first embodiment of the present invention.

FIG. 5 is a cross-sectional view taken along lines II-II ', III-III', and IV-IV 'of FIG. 4;

FIG. 6 is a circuit diagram schematically illustrating one pixel illustrated in FIG. 4.

7 is a cross-sectional view showing a liquid crystal display device according to the present invention.

8A to 8E are flowcharts illustrating a method of manufacturing a thin film transistor array substrate having an image sensing function according to a first embodiment of the present invention.

9 is a schematic diagram illustrating a process of sensing light by a sensor thin film transistor of a liquid crystal display according to the present invention.

10 and 11 are circuit diagrams for explaining in detail the photo-sensing process according to the present invention.

12 is a cross-sectional view of a portion of a liquid crystal display having an image sensing function according to a second exemplary embodiment of the present invention.

13 illustrates the principle that the sensed voltage is delivered by the readout integrated circuit.

FIG. 14 is a cross-sectional view of a liquid crystal display according to a first exemplary embodiment of the present invention, showing the same cutting surface as that of FIG.

15A to 15C are process diagrams illustrating a manufacturing process of the color filter array substrate of FIG. 12.

  Description of the Related Art

102: gate line 104: data line

106: first thin film transistors 108a, 108b, 108c: gate electrode

110a, 110b, 110c: source electrode 112a, 112b, 112c: drain electrode

14, 114a, 114b, 114c: active layer 115a, 115b, 115c, 115d, 115e: contact hole

18, 118: pixel electrode 120: first storage capacitor

180,280: second storage capacitor 44,144: gate insulating film

50,150: protective film 140: sensor thin film transistor

170: second thin film transistor 152: first driving voltage supply line

171: second driving voltage supply line 155: first transparent electrode pattern

156: second transparent electrode pattern 199: common electrode

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having an image sensing function capable of document, image scanning, and touch input, a manufacturing method thereof, and an image sensing method using the same.

A conventional liquid crystal display device displays an image by adjusting the light transmittance of a liquid crystal using an electric field. To this end, the liquid crystal display includes a liquid crystal display panel in which liquid crystal cells are arranged in a matrix, and a driving circuit for driving the liquid crystal display panel.

The liquid crystal display panel includes a thin film transistor array substrate and a color filter array substrate facing each other, a spacer positioned to maintain a constant cell gap between the two substrates, and a liquid crystal filled in the cell gap.

The thin film transistor array substrate includes gate lines and data lines, a thin film transistor formed as a switching element for each intersection of the gate lines and the data lines, a pixel electrode formed in a unit of a liquid crystal cell and connected to the thin film transistor, And an applied alignment film. The gate lines and the data lines are supplied with signals from the driving circuits through respective pad portions. The thin film transistor supplies the pixel voltage signal supplied to the data line to the pixel electrode in response to the scan signal supplied to the gate line.

The color filter array substrate includes color filters formed in units of liquid crystal cells, a black matrix for separating the color filters and reflecting external light, a common electrode for supplying a reference voltage commonly to the liquid crystal cells, .

The liquid crystal display panel is completed by separately manufacturing a thin film transistor array substrate and a color filter array substrate, and then injecting and encapsulating a liquid crystal.

1 is a plan view illustrating a thin film transistor array substrate of a conventional liquid crystal display, and FIG. 2 is a cross-sectional view of the thin film transistor array substrate illustrated in FIG. 1 taken along the line II ′.

The thin film transistor array substrate shown in FIGS. 1 and 2 includes a gate line 2 and a data line 4 intersecting each other with a gate insulating film 44 interposed on the lower substrate 42, and a thin film formed at each intersection thereof. A transistor (Thin Film Transistor, hereinafter referred to as " TFT ") 6 and a pixel electrode 18 formed in a cell region provided in a cross structure thereof are provided. The TFT array substrate includes a storage capacitor 20 formed at an overlapping portion of the pixel electrode 18 and the previous gate line 2.

The TFT 6 includes a gate electrode 8 connected to the gate line 2, a source electrode 10 connected to the data line 4, a drain electrode 12 connected to the pixel electrode 18, The active layer 14 overlaps the gate electrode 8 and forms a channel between the source electrode 10 and the drain electrode 12. The active layer 14 is formed to overlap the data line 4, the source electrode 10, and the drain electrode 12, and further includes a channel portion between the source electrode 10 and the drain electrode 12. An ohmic contact layer 48 for ohmic contact with the data line 4, the source electrode 10, and the drain electrode 12 is further formed on the active layer 14. Here, the active layer 14 and the ohmic contact layer 48 are commonly referred to as a semiconductor pattern 45.

The TFT 6 causes the pixel voltage signal supplied to the data line 4 to be charged and held in the pixel electrode 18 in response to the gate signal supplied to the gate line 2.

The pixel electrode 18 is connected to the drain electrode 12 of the TFT 6 through the contact hole 16 penetrating the protective film 50. The pixel electrode 18 generates a potential difference with the common electrode formed on the upper substrate (not shown) by the charged pixel voltage. Due to this potential difference, the liquid crystal positioned between the TFT array substrate and the color filter array substrate is rotated by dielectric anisotropy and transmits the light incident through the pixel electrode 18 from the light source (not shown) toward the upper substrate.

The storage capacitor 20 is formed by the front gate line 2 and the pixel electrode 18. The gate insulating layer 44 and the passivation layer 50 are positioned between the gate line 2 and the pixel electrode 18. The storage capacitor 20 helps the pixel voltage charged in the pixel electrode 18 to be maintained until the next pixel voltage is charged.

Such a conventional liquid crystal display device has only a display function and does not have a function of sensing and displaying an external image such as an external document or a content image such as an image.

FIG. 3 is a diagram illustrating a conventional image sensing device. (The elements included in a conventional TFT among the components in the image sensing device shown in FIG. 3 are the same as those of the TFTs shown in FIGS. 1 and 2. Reference numerals will be given.)

The image sensing device shown in FIG. 3 is a switch located opposite to the photo TFT 40 with the photo TFT 40, the storage capacitor 80 connected to the photo TFT 40, and the storage capacitor 80 interposed therebetween. TFT 6 is provided.

The photo TFT 40 is electrically connected to the active layer 14 and the active layer 14 overlapping the gate electrode 8 with the gate electrode 8 formed on the substrate 42 and the gate insulating film 44 interposed therebetween. The driving source electrode 60 and the driving drain electrode 62 facing the driving source electrode 60 are provided. The active layer 14 is formed to overlap the driving source electrode 60 and the driving drain electrode 62, and further includes a channel portion between the driving source electrode 60 and the driving drain electrode 62. An ohmic contact layer 48 for ohmic contact with the driving source electrode 60 and the driving drain electrode 62 is further formed on the active layer 14. The photo TFT 40 serves to sense incident light by a predetermined image such as a document or a fingerprint of a person.

The storage capacitor 80 overlaps the storage lower electrode 72 with the storage lower electrode 72 and the insulating layer 44 connected to the gate electrode 8 of the photo TFT 40 interposed therebetween, and the photo TFT 40 overlaps with the photo TFT 40. The storage upper electrode 74 is connected to the driving drain electrode 62. The storage capacitor 80 stores a charge due to the photocurrent generated in the photo TFT 40.

The switching TFT 6 includes a gate electrode 8 formed on the substrate 42, a source electrode 10 connected to the storage upper electrode 74, a drain electrode 12 facing the source electrode 10, and An active layer 14 overlapping the gate electrode 8 and forming a channel between the source electrode 10 and the drain electrode 12 is provided. The active layer 14 is formed to overlap the source electrode 10 and the drain electrode 12, and further includes a channel portion between the source electrode 10 and the drain electrode 12. An ohmic contact layer 48 for ohmic contact with the source electrode 10 and the drain electrode 12 is further formed on the active layer 14.

The driving of the image sensing device having the structure will be briefly described. For example, a driving voltage of about 10 V is applied to the driving source electrode 60 of the photo TFT 40 and the gate electrode 8 is applied to the driving source electrode 60. For example, when a reverse bias voltage of about -5V is applied and light is sensed in the active layer 14, the photocurrent flowing from the driving source electrode 60 to the driving drain electrode 62 through the channel according to the sensed light amount (Photo) Current) pass is generated. Since the photocurrent path flows from the driving drain electrode 62 to the storage upper electrode 74, the storage lower electrode 72 is connected to the gate electrode 8 of the photo TFT 40, and thus the storage capacitor 80 receives a photocurrent. Charge is caused to be charged. As such, the charges charged in the storage capacitor 80 are transferred to the switch TFT 6 so that the image sensed by the photo TFT 40 can be read.

As such, the conventional liquid crystal display device has only a function for display, and a conventional image sensing device has only a function of sensing an image.

Accordingly, an object of the present invention is to provide a liquid crystal display device having an image sensing function capable of inputting an image such as a document, a fingerprint of a person, etc. and displaying the input image on the image, a manufacturing method thereof, and an image sensing method using the same.

In order to achieve the above object, the liquid crystal display according to the present invention is a sensor thin film transistor for sensing light having image information, an integrated circuit for detecting a signal sensed by the sensor thin film transistor, the sensor thin film transistor A thin film transistor array substrate having a sensing signal transfer line for transferring the signal to the integrated circuit; And a color filter array substrate facing the thin film transistor array substrate with a liquid crystal interposed therebetween, wherein the color filter array substrate is positioned to overlap the pixel electrode of the thin film transistor array substrate to form a vertical electric field with the pixel electrode. The common electrode is not overlapped with the sensing signal transmission line.

A gate line and a data line formed on the substrate so as to cross each other to define a formation region of the pixel electrode; A first thin film transistor positioned at an intersection of the gate line and the data line; A first storage capacitor storing a pixel voltage charged in the pixel electrode; A first driving voltage supply line positioned parallel to the gate line and supplying a first driving voltage to the sensor thin film transistor; A second driving voltage supply line positioned parallel to the first driving voltage supply line and supplying a second driving voltage to the sensor thin film transistor; A second storage capacitor configured to store a signal sensed by the sensor thin film transistor; And a second thin film transistor connected to the second storage capacitor and the front gate line and selectively supplying the sensing signal to the integrated circuit through the sensing signal transmission line.

The sensor thin film transistor may include a first gate electrode extending from the second driving voltage supply line; A gate insulating film formed to cover the first gate electrode; A first semiconductor pattern overlapping the first gate electrode with the gate insulating layer interposed therebetween; A first source electrode in contact with the first semiconductor pattern and electrically connected to the first driving voltage supply line; And a first drain electrode facing the first source electrode.

A protective film formed to cover the sensor thin film transistor; A first hole penetrating the passivation layer and the gate insulating layer to expose the first driving voltage supply line; A second hole penetrating the protective film to expose the first source electrode; Contacting the first driving voltage supply line through the first hole and contacting the first source electrode through the second contact hole to electrically connect the first source electrode and the first driving voltage supply line; 1 transparent electrode pattern is provided.

The first storage capacitor includes: a first storage lower electrode extending from the second driving voltage supply line; And a first storage upper electrode overlapping the first storage lower electrode with the gate insulating layer interposed therebetween, wherein the first storage upper electrode penetrates through the passivation layer and contacts the pixel electrode through a third hole.

The second storage capacitor supplies the second driving voltage overlapping the second storage electrode with the first drain electrode, the second storage electrode in contact with the second thin film transistor, and the gate insulating layer interposed therebetween. A 2-1 storage capacitor comprising a line; A second-2 storage capacitor comprising the first driving voltage supply line overlapping the second storage electrode with the gate insulating layer interposed therebetween; A second transparent electrode pattern overlapping the second storage electrode with the passivation layer interposed therebetween and contacting the second driving voltage supply line through a fourth hole exposing the second driving voltage supply line; It includes a storage capacitor.

The second thin film transistor may include a second gate electrode in contact with the front gate line; A second semiconductor pattern overlapping the second gate electrode with the gate insulating layer interposed therebetween; A second source electrode electrically connected to the second semiconductor pattern and extending from the second storage electrode; And a second drain electrode facing the second source electrode and connected to the sensing signal transmission line.

The first thin film transistor may include a third gate electrode extending from the gate line; A third semiconductor pattern formed to overlap the third gate electrode with the gate insulating layer interposed therebetween; A third source electrode electrically connected to the third semiconductor pattern and extending from the data line; And a third drain electrode facing the third source electrode and connected to the pixel electrode.

The color filter array substrate may include a black matrix formed in a region excluding the pixel region where the pixel electrode is located and a region corresponding to the sensor thin film transistor; The apparatus further includes a color filter formed in an area corresponding to the pixel area.

The common electrode is formed in a region other than the region overlapping the sensing signal transmission line.

A method of manufacturing a liquid crystal display according to the present invention includes a sensor thin film transistor for sensing light having image information, an integrated circuit for detecting a signal sensed by the sensor thin film transistor, and a signal sensed by the sensor thin film transistor. Forming a thin film transistor array substrate having a sensing signal transfer line for transferring to an integrated circuit; And forming a color filter array substrate facing the thin film transistor array substrate with a liquid crystal interposed therebetween, wherein forming the color filter array substrate overlaps the pixel electrode of the thin film transistor array substrate and transmits the sensing signal. Forming a common electrode which is not overlapped with the line.

The forming of the thin film transistor array substrate may include a gate pattern including a gate line, a first gate electrode of the sensor thin film transistor, a second gate electrode of a first thin film transistor, and a third gate electrode of a second thin film transistor on the substrate. Forming a; Forming a gate insulating film on the substrate on which the gate pattern is formed; Forming a first semiconductor pattern overlapping the first gate electrode, a second semiconductor pattern overlapping the second gate electrode, and a third semiconductor pattern overlapping the third gate electrode on the gate insulating layer; A data line intersecting the gate line with the gate insulating layer interposed therebetween, and a first source electrode, a first drain electrode, and a second semiconductor pattern, which are respectively connected to and face each other and face each other. The sensor thin film transistor is formed by forming a source / drain pattern including a second source electrode, a second drain electrode, and a third source electrode and a third drain electrode, which are respectively connected to the third semiconductor pattern and face each other. Forming first and second thin film transistors; Forming a passivation layer having a first hole exposing a second drain electrode of the first thin film transistor; Forming a pixel electrode connected to the second drain electrode through the first hole.

The forming of the gate pattern may include a first driving voltage supply line which is formed in parallel with the gate line to supply a first driving voltage to the sensor thin film transistor, and is connected to the first gate electrode and is connected to the first driving voltage. And forming a second driving voltage supply line parallel to a supply line, and a first storage lower electrode extending from the first driving voltage supply line and parallel to the gate line.

The forming of the source / drain pattern may include forming a first storage upper electrode formed to overlap the first storage lower electrode with the gate insulating layer interposed therebetween to form the first storage lower electrode and the first storage capacitor. do.

The method may further include forming a second storage capacitor for resisting the signal sensed by the sensor thin film transistor, wherein the forming of the second storage capacitor comprises: a first drain electrode and the second drain capacitor of the sensor thin film transistor; A second storage capacitor including a second storage electrode interposed between the second source electrode of the thin film transistor, and the second driving voltage supply line overlapping the second storage electrode with the gate insulating layer interposed therebetween; Forming; Forming a second-second storage capacitor including the second storage electrode and the first driving voltage supply line overlapping the second storage electrode with the gate insulating layer interposed therebetween; A second transparent electrode pattern contacting the second driving voltage supply line through a second hole overlapping the second storage electrode with the second storage electrode and a passivation layer interposed therebetween and exposing the second driving voltage supply line; Forming a 2-3 storage capacitor comprising a.

The forming of the pixel electrode may contact the first driving voltage supply line through a third hole through the gate insulating layer and the passivation layer to expose the first driving voltage supply line, and penetrate the passivation layer. The method may further include forming a first transparent electrode pattern contacting the first source electrode through a fourth hole exposing the first source electrode of the transistor.

The common electrode is formed in a region other than the region overlapping the sensing signal transmission line.

Forming the color filter array substrate; Forming a black matrix in a region excluding the pixel region where the pixel electrode is located and a region corresponding to the sensor thin film transistor; The method may further include forming a color filter in an area corresponding to the pixel area.

Other objects and advantages of the present invention in addition to the above object will be apparent from the description of the preferred embodiments of the present invention with reference to the accompanying drawings.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 4 to 15C.

4 is a plan view illustrating a thin film transistor array substrate of a liquid crystal display device having an image sensing function according to a first exemplary embodiment of the present invention, and FIG. 5 is a line II-II ', III-III', shown in FIG. Sectional drawing which cut | disconnected IV-IV ', respectively.

4 and 5, the thin film transistor array substrate includes a gate line 102 and a data line 104 formed to intersect on the lower substrate 142 with a gate insulating layer 144 interposed therebetween, and pixels formed at each intersection thereof. (Pixel) switching TFT (hereinafter referred to as " first TFT ") 106, and the data line 104 with the pixel electrode 118 and the pixel electrode 118 formed in the cell region provided in the intersection structure interposed therebetween. A read-out line 204 formed in parallel with each other, first and second driving voltage supply lines 152 and 171 formed in parallel with the gate line 102, and first and second driving voltage supply lines Between the first and second driving voltages 152 and 171 and the first and second driving voltages supplied from the first and second driving voltage supply lines 152 and 171, the front gate line 102 and the lead-out line 204. The switching TFT (hereinafter referred to as "second TFT") 170 formed in the cross region, the second driving voltage supply line 171 and the pixel electrode 118 The storage capacitor for storing pixel data (hereinafter, referred to as a "first storage capacitor") formed at an overlapping portion of the first and the second TFT 170 and the sensor TFT 140 is a storage capacitor for storing the sensing signal ( Hereinafter referred to as a “second storage capacitor” 180.

The first TFT 106 includes a gate electrode 108a connected to the gate line 102, a source electrode 110a connected to the data line 104, and a drain electrode 112a connected to the pixel electrode 118. And an active layer 114a overlapping the gate electrode 108a and forming a channel between the source electrode 110a and the drain electrode 112a. The active layer 114a is formed to partially overlap the source electrode 110a and the drain electrode 112a and further includes a channel portion between the source electrode 110a and the drain electrode 112a. An ohmic contact layer 148a for ohmic contact with the source electrode 110a and the drain electrode 112a is further formed on the active layer 114a. Here, the active layer 114a and the ohmic contact layer 148a are commonly referred to as a semiconductor pattern 145a.

The first TFT 106 allows the pixel voltage signal supplied to the data line 104 to be charged and held in the pixel electrode 118 in response to the gate signal supplied to the gate line 102.

The pixel electrode 118 is connected to the drain electrode 112a of the first TFT 106 through the first contact hole 115a penetrating the protective film 150. The pixel electrode 118 generates a potential difference with a common electrode formed on an upper substrate (eg, a color filter array substrate) not shown by the charged pixel voltage. Due to this potential difference, the liquid crystal positioned between the TFT array substrate and the color filter array substrate is rotated by dielectric anisotropy and transmits the light incident through the pixel electrode 118 from the light source (not shown) toward the upper substrate.

The first storage capacitor 120 overlaps the first storage lower electrode 121 with the first storage lower electrode 121 extended from the second driving voltage supply line 171 and the gate insulating layer 144 interposed therebetween. One storage upper electrode 123 is formed. The first storage upper electrode 123 penetrates through the passivation layer 150 to be in contact with the pixel electrode 118 through the second contact hole 115b.

The first storage capacitor 120 maintains the pixel voltage charged in the pixel electrode 118 until the next pixel voltage is charged.

The sensor TFT 140 includes an active layer 114b and an active layer 114b overlapping the gate electrode 108b with the gate electrode 108b extending from the second driving voltage supply line 171 and the gate insulating layer 144 therebetween. And a source electrode 110b electrically connected to the first driving voltage supply line 152 and a drain electrode 112b facing the source electrode 110b. The drain electrode 112b of the sensor TFT 140 is formed in a “U” shape so that a channel region for receiving light can be formed wide.

In addition, the sensor TFT 140 passes through the passivation layer 150 and the gate insulating layer 144 to pass through the third contact hole 115c and the passivation layer 150 that partially expose the first driving voltage supply line 152. And a fourth contact hole 115d exposing the electrode 110b, and contacting the source electrode 110b through the third contact hole 115c and the first driving voltage supply line through the fourth contact hole 115d. A first transparent electrode pattern 155 is in contact with 152. The first transparent electrode pattern 155 serves to electrically connect the source electrode 110b and the first driving voltage supply line 152. The active layer 114b is formed to partially overlap the source electrode 110b and the drain electrode 112b and further includes a channel portion between the source electrode 110b and the drain electrode 112b. An ohmic contact layer 148b for ohmic contact with the source electrode 110b and the drain electrode 112b is further formed on the active layer 114b. The sensor TFT 140 senses incident light by a predetermined image such as a document or a fingerprint of a person.

The second storage capacitor 180 is composed of at least three storage capacitors. In FIG. 5, the 2-1 storage capacitor 180a and the gate insulating layer 144 including the second storage electrode 182 and the second driving voltage supply line 171 overlapping each other with the gate insulating layer 144 interposed therebetween. The second storage electrode 182 and the second storage electrode 180b formed of the first driving voltage supply line 152 and the second storage electrode overlapping each other with the passivation layer 150 interposed therebetween. A second-3 storage capacitor 180c including 182 and a second transparent electrode pattern 156 is illustrated. Here, the second storage electrode 182 is connected to the source electrode 110c of the second TFT 170 and the drain electrode 112b of the sensor TFT 140, respectively, and the second transparent electrode pattern 156 is a gate insulating film. The second driving voltage supply line 171 is contacted through the fifth contact hole 115e penetrating the 144 and the passivation layer 150.

The second storage capacitor 180 stores the charge due to the photocurrent generated in the photo TFT 140.

The second TFT 170 may include a gate electrode 108c which is a part of the front gate line 102, a source electrode 110c connected to the second storage electrode 182, and a drain electrode facing the source electrode 110c. 112c and an active layer 114c overlapping the gate electrode 108c and forming a channel between the source electrode 110c and the drain electrode 112c. The gate electrode 108c in the second TFT 170 is distinct from the gate electrode 108a in the first TFT 106. That is, the gate electrode 108a in the first TFT 106 has a shape protruding from the gate line 102, whereas the gate electrode 108c in the second TFT 170 is substantially the gate line 102. ) Shows one area. The active layer 114c is formed to partially overlap the source electrode 110c and the drain electrode 112c and further includes a channel portion between the source electrode 110c and the drain electrode 112c. An ohmic contact layer 148c for ohmic contact with the source electrode 110c and the drain electrode 112c is further formed on the active layer 114c.

The light sensing process of the liquid crystal display according to the present invention having the structure will be described with reference to the circuit diagram shown in FIG.

First, the first driving voltage Vdrv is applied to the source electrode 110b of the sensor TFT 140, and the second driving voltage Vbias is applied to the gate electrode 108b of the sensor TFT 140. When a predetermined light is sensed on the active layer 114b of the 140, a photo current path that flows from the source electrode 110b of the sensor TFT 140 to the drain electrode 112b via a channel is generated according to the sensed amount of light. do. The photocurrent path flows from the drain electrode 112b of the sensor TFT 140 to the second storage electrode 182. Accordingly, the second driving voltage supply line 172 and the second storage capacitor 180a by the second storage electrode 182 are connected to the second storage electrode 182 and the first driving voltage supply line 152. Photocurrent to the second storage capacitor 180 including the second-2 storage capacitor 180b by the second storage capacitor 180b, the second storage electrode 182, and the second-3rd storage capacitor 180c by the second transparent electrode pattern 156. The charge by is charged. In this way, the charge charged in the second storage capacitor 180 is read by the readout IC through the second TFT 170 and the readout line 204.

In other words, the signal detected by the read-out integrated circuit according to the amount of light sensed by the sensor TFT 140 is changed, so that images such as documents, image scans, and touch inputs can be sensed. The sensed image may be transferred to a controller or the like or may be embodied in an image of the liquid crystal display panel according to a user's adjustment.

Meanwhile, the liquid crystal display device having the image sensing function according to the present invention is formed by bonding the color filter array substrate facing the thin film transistor array substrate shown in FIGS. 4 and 5.

That is, as illustrated in FIG. 7, the cell matrix (or the pixel region P1) is partitioned on the upper substrate 193 and partitioned by the black matrix 194 and the black matrix 194 which prevent light leakage. The color filter 196, the color filter 194, and the common electrode 199 formed on the entire surface of the black matrix 194 and forming a vertical electric field with the pixel electrode 118 formed on the thin film transistor array substrate may be formed. After the color filter array substrate 192 is formed separately, the thin film transistor array substrate 190 and the liquid crystal 197 are bonded together to form a liquid crystal display having image sensing.

Hereinafter, a method of manufacturing a liquid crystal display device having an image sensing function according to the present invention will be described in detail with reference to FIGS. 8A to 8E.

First, as the gate metal layer is formed on the lower substrate 142 through a deposition method such as a sputtering method, and then the gate metal layer is patterned by a photolithography process and an etching process, as shown in FIG. 8A, the first TFT 106 is formed. The gate electrode 108a extends from the gate electrode 108c of the second TFT 170, the first driving voltage supply line 152, the second driving voltage supply line 171, and the second driving voltage supply line 171. Gate patterns including the gate electrode 108b, the first storage lower electrode 121, and a gate line (not shown) of the sensor TFT 140 are formed. Here, the second driving voltage supply line 171 is integrated with the first storage lower electrode 121 of the first storage capacitor 180 and the gate electrode 108b of the sensor TFT 140.

The gate insulating layer 144 is formed on the lower substrate 142 on which the gate patterns are formed through a deposition method such as PECVD or sputtering. An amorphous silicon layer and an n + amorphous silicon layer are sequentially formed on the lower substrate 142 on which the gate insulating layer 144 is formed.

Subsequently, the amorphous silicon layer and the n + amorphous silicon layer are patterned by a photolithography process and an etching process using a mask to correspond to the first and second TFTs 106 and 170 and the sensor TFTs 140, respectively, as shown in FIG. 8B. The semiconductor patterns 145a, 145b, and 145c are formed. The semiconductor patterns 145a, 145b, and 145c may be formed of a double layer of the active layers 114a, 114b and 114c and the ohmic contact layers 148a, 148b and 148c.

After the source / drain metal layer is sequentially formed on the lower substrate 142 on which the semiconductor patterns 145a, 145b, and 145c are formed, the data line as shown in FIG. 8C using a photolithography process and an etching process using a mask. (104), source electrode 110a and drain electrode 112a of first TFT 106, source electrode 110c and drain electrode 112c of second TFT 170, and source electrode of sensor TFT 140 The first storage upper electrode 123 overlapping the first storage lower electrode 121 with the drain electrode 112b and the drain electrode 112b and the gate insulating layer 144 interposed therebetween, and the drain electrode 112b of the sensor TFT 140. Source / drain patterns including the second storage electrode 182 connected to the substrate are formed.

Thereafter, the passivation layer 150 is entirely formed on the gate insulating layer 144 on which the source / drain patterns are formed, and then patterned by a photolithography process and an etching process, as shown in FIG. 8D. The first contact hole 115a exposing the drain electrode 112a of the 106, the second contact hole 115b exposing the first storage upper electrode 123, and the first driving voltage supply line 152 are exposed. The third contact hole 115c, the fourth contact hole 115d exposing the source electrode 110b of the sensor TFT 140, and the second driving voltage supply line 171 in the second storage capacitor 180. A fifth contact hole 115e is formed to expose.

After the transparent electrode material is completely deposited on the passivation layer 150 by a deposition method such as sputtering, the transparent electrode material is patterned through a photolithography process and an etching process, thereby as shown in FIG. 8E. The transparent electrode pattern 155 and the second transparent electrode pattern 156 are formed.

The pixel electrode 118 contacts the drain electrode 112a of the first TFT 106 through the first contact hole 115a and the first storage upper electrode 123 through the second contact hole 115b. do.

The first transparent electrode pattern 155 is in contact with the first driving voltage supply line 152 through the third contact hole 115c and at the same time, the source electrode 110b of the sensor TFT 140 through the fourth contact hole 115d. ).

The second transparent electrode pattern 156 partially overlaps the second storage electrode 182 and is in contact with the second driving voltage supply line 171 through the fifth contact hole 115e.

Thereafter, the cell region (or the pixel region P1) is partitioned on the upper substrate 193 by a separate process, and the black matrix 194 and the black matrix 194 prevent light leakage when the liquid crystal display is driven. The color filter array substrate 192 including the color filter 196, the common electrode 199, and the like formed in the cell region partitioned by the cell region is formed. The black matrix 194 masks the second TFT 170 and the like, opens the light receiving area P2 corresponding to the pixel area P1 and the sensor TFT 140, and the color filter 196 stores the pixel electrode 118. Corresponds to this pixel area. The common electrode 118 is entirely formed on the color filter 196 and the black matrix 194 to form a vertical electric field with the thin film transistor array substrate pixel electrode 118 when the liquid crystal display implements a display mode, that is, an image. .

In this case, an alignment layer, a spacer, and the like may be selectively formed on the color filter array substrate 192.

Thereafter, the thin film transistor array substrate 190 and the color filter array substrate 192 are bonded to each other with the liquid crystal 197 interposed therebetween to form a liquid crystal display as shown in FIG. 7.

9 is a cross-sectional view illustrating a process of sensing an image by the above-described liquid crystal display, and FIG. 10 is a circuit diagram illustrating a process of sensing external light incident on a sensor TFT, and FIG. 11 is a readout integrated circuit ( It is a circuit diagram which shows the process detected by IC).

First, the liquid crystal display of FIG. 9 includes a color filter array substrate facing the TFT array substrate on which the sensor TFT 140 is formed with the liquid crystal layer on which the liquid crystal is located. A printed matter (document, photo, etc.) 185 is positioned on the color filter array substrate. In the drawing, for convenience, the sensor TFT 140 is configured to sense light.

In the liquid crystal display, as shown in FIG. 10, a driving voltage of, for example, about 10V is applied from the first driving voltage supply line 152 to the source electrode 110b of the sensor TFT 140. For example, a reverse bias voltage of about -5V is applied to the gate electrode 108b of the sensor TFT 140 from the driving voltage supply line 171, and the active layer 114b of the sensor TFT 140 is shown in FIG. When light (eg, external light) is sensed, a photocurrent flowing from the source electrode 110b of the sensor TFT 140 to the drain electrode 112b via the channel of the active layer 114b according to the sensed amount of light (Photo Current) A pass is generated. The photocurrent path flows from the drain electrode 112b of the sensor TFT 140 to the second storage electrode 182. Accordingly, the charge by the photocurrent is charged in the 2-1st storage capacitor 180a, the 2-2nd storage capacitor 180b, and the 2-3th storage capacitor 180c constituting the second storage capacitor 180. . Here, the maximum charging amount of the second storage capacitor 180 may be charged by a voltage difference of about 15V between the source electrode 110b of the sensor TFT 140 and the second driving voltage supply line 171.

As such, while the sensor TFT 140 senses light and charge is charged in the second storage capacitor 180, a gate low voltage, for example, -5V is applied to the gate electrode 108c of the second TFT 170. The second TFT 170 maintains a turn-off state.

Subsequently, as shown in FIG. 11, the second TFT 170, which is supplied with a high voltage, for example, about 20 to 25 V, is supplied to the gate electrode 108c of the second TFT 170 while being turned on. The current path due to the charge charged in the storage capacitor 180 is read through the source electrode 110c of the second TFT 170, the channel of the active layer 114c, the drain electrode 112c and the leadout line 204. Supplied to an out integrated circuit (IC). The sensing signal by the current path supplied in this way is read by the readout integrated circuit IC.

As described above, the liquid crystal display having the image sensing function according to the present invention has an image sensing capability as well as a display function for realizing an image, thereby inputting an external document, a touch, and the like, and outputting the input image according to a user's request. You have everything you can.

FIG. 12 is a cross-sectional view illustrating a liquid crystal display device having an image sensing function according to a second exemplary embodiment of the present invention, and the thin film transistor array substrate 170 when the VV ′ line is cut from the thin film transistor array substrate illustrated in FIG. 4. ) And a cross section of the color filter array substrate 192 are shown.

The liquid crystal display according to the second exemplary embodiment of the present invention has the same structure as the thin film transistor array substrate 170 as compared with the first exemplary embodiment of the present invention, except that the common electrode (not shown) in the color filter array substrate 192 is formed. 199 may not be located in an area corresponding to the leadout line 204. Except for this difference, since the second embodiment of the present invention is the same as the first embodiment of the present invention, the same components as those described in the first embodiment are given the same numbers in the second embodiment of the present invention. Duplicate description will be omitted.

Referring to FIG. 12, in the second embodiment of the present invention, a region in which the common electrode 199 formed on the color filter array substrate 192 corresponds to the lead-out line 204 formed on the thin film transistor array substrate 170 is provided. Is formed to be removed. As a result, the common electrode 199 and the lead-out line 204 are not overlapped with each other. That is, the region removed from the common electrode 199 has a line shape like the lead-out line 204.

In the liquid crystal display according to the second exemplary embodiment of the present invention having the above structure, the parasitic capacitor between the lead-out line 204 and the common electrode 199 is formed by overlapping the common electrode 199 with the lead-out line 204. Since it is not formed, the reliability of the sensor capability may be improved, such as the ability of detecting a signal sensed by the sensor TFT 140 is improved.

This will be described in detail with reference to FIG. 13 as follows.

FIG. 13 is a diagram illustrating a principle in which a sensed voltage is transmitted by a readout integrated circuit IC.

First, light having a predetermined image is sensed by the sensor TFT 140, and a charge by photocurrent is charged in the second storage capacitor 180. Here, Rs represents the total resistance between the second storage capacitor 280 in the first drive voltage source. For example, it means the sum total of the sensor TFT 140 and the resistance in an electrode. Vs represents the voltage across the second storage capacitor 280, that is, the storage voltage Vs.

Subsequently, when the second TFT 170 is turned on, the current path due to the charge charged in the second storage capacitor 280 is transmitted through the source electrode 110c of the second TFT 170, the channel of the active layer 114c, and the drain electrode ( 112c) and via the readout line 204 to the readout integrated circuit (IC). Here, Rro represents the total resistance from the second storage capacitor 280 to the readout integrated circuit (IC).

Here, the sensing voltage Vro substantially sensed by the readout integrated circuit IC may be represented by Equation 1 below.

Vro ≒ Cst2 / (Cst2 + Cro) * Vs

Here, Cro represents the sum of the parasitic capacitors generated between the lead-out line 204 and the adjacent metal materials (electrodes, lines, etc.).

As shown in Equation 1, the voltage Vro sensed by the readout integrated circuit IC and the second storage voltage Vs stored in the second storage capacitor 280 are substantially parasitic capacitors Cro. The difference is due to.

Therefore, in the second embodiment of the present invention, a method of reducing the deviation between the second storage voltage Vs and the voltage Vro sensed by the readout integrated circuit IC by reducing the Cro value as compared with the first embodiment. As a structure, a parasitic capacitor formed by the common electrode 199 and the lead-out line 204 line is removed.

FIG. 13 is a cross-sectional view taken along the line VV ′ of the liquid crystal display according to the first exemplary embodiment of the present invention. That is, FIG. 13 is a cross section of the liquid crystal display according to the first embodiment of the present invention, and the common electrode 199 is formed on the color filter 196 and the black matrix 194 as compared with FIG. 12 showing the second embodiment. Since the entire surface is formed, the common electrode 199 is positioned in the region overlapping the lead-out line 204.

The total parasitic capacitor Cro formed by the lead-out line 204 in the first embodiment of the present invention having such a structure includes a first parasitic capacitor Cro1 between the lead-out line 204 and the data line 104. And a second parasitic capacitor Cro2 between the readout line 204 and the common electrode 199.

In contrast, in the second embodiment of the present invention, the second parasitic capacitor Cro2 between the leadout line 204 and the common electrode 199 among the parasitic capacitors Cro formed by the leadout line 204 as shown in FIG. 12. ) Is not formed, it is possible to significantly reduce the capacity of the entire parasitic capacitor (Cro).

The applicant of the present application was able to confirm this through experimental data shown in Table 1 and Table 2.

In case of the first embodiment Parasitic Capacitor Capacity (F) Time constant (sec) Total Cro except Cro2 9.84E-12 1.00E-7 Cro1 6.38E-12 Sum 1.62E-11 1.65E-7

In case of the second embodiment Parasitic Capacitor Capacity (F) Time constant (sec) Total Cro except Cro2 3.89E-12 Cro1 6.38E-12 Sum 1.03E-11 1.05E-7

Table 1 shows time constants (sec) indicating the amount of delay caused by the capacitance F of the parasitic capacitor and the amount of deflection generated in the lead-out line 204 according to the first embodiment of the present invention. Denotes a time constant (sec) indicating the degree of delay by the capacitance F of the parasitic capacitor in the second embodiment of the present invention and thus the amount of load generated in the lead-out line 204.

Referring to Table 1 and Table 2, it can be seen that in the second embodiment of the present invention, the total Cro except for Cro2 is 3.89E-12, and the total Cro except for Cro2 in the first embodiment is 9.84E-12. Accordingly, in the second embodiment of the present invention, the value of Cro2 is not included, so that the capacitance of the parasitic capacitor is smaller than that of the first embodiment (1.62E-11 in Table 1 and 1.03E-11 in Table 2). Such a difference in capacity of the parasitic capacitor will eventually lead to a difference in time constant (1.65E-7 in Table 1 and 1.05E-7 in Table 2). Accordingly, the first and second embodiments have a difference of about 38% in the capacity and time constant of the parasitic capacitor.

From this result, as in the second embodiment of the present invention, by removing the parasitic capacitor capacitance between the common electrode 199 and the lead-out line 204, the load on the lead-out line 204 is reduced, so that the first embodiment of the present invention is reduced. Compared to the embodiment, it is possible to sense the image more precisely and accurately. In addition, since the value of the time constant is smaller in the second embodiment than in the first embodiment, the sensed signal can be supplied to the readout integrated circuit IC in a faster response time. As a result, the reliability of image sensing is further improved.

In the manufacturing method of the liquid crystal display panel according to the second embodiment of the present invention which exhibits such an operation and effect, the common electrode 199 formed on the color filter array substrate 192 is compared with the first embodiment of the present invention. It is formed in the same manner as in the first embodiment of the present invention except that it is not formed in the region corresponding to the lead-out line 204.

First, since the thin film transistor array substrate 170 is formed by the same method as the manufacturing process described with reference to FIGS. 8A to 8E, the manufacturing method of the thin film transistor array substrate 170 will be omitted.

15A to 15C are process charts showing the manufacturing process of the color filter array substrate.

First, an opaque metal or resin is deposited on the upper substrate 193, and then the opaque material is patterned by a photolithography process using a mask to form a black matrix 194 as illustrated in FIG. 15A. The black matrix 194 is formed in a region other than the region corresponding to the pixel region P1 and the sensor TFT 140 of the thin film transistor array substrate 170. Accordingly, the black matrix 194 partitions the cell region (or the pixel region P1) in which the color filter 196 is to be positioned and prevents light leakage during the liquid crystal driving of the liquid crystal display. Here, as the opaque metal, chromium (Cr), CrOx / Cr / CrOx, CrOx / Cr / CrSix and the like are formed of a material.

After the red resin is deposited on the upper substrate 193 on which the black matrix 194 is formed, the red resin is patterned by a photolithography process using a mask to form a red color filter R. After the green resin is deposited on the upper substrate 193 on which the red color filter R is formed, the green resin G is patterned by a photolithography process using a mask to form the green color filter G. After the blue resin is deposited on the upper substrate 193 on which the green color filter G is formed, the blue resin is patterned by a photolithography process and an etching process using a mask to form a blue color filter B. By this process, as shown in FIG. 15B, the RGB color filter 196 is formed. Since only one sub-pixel is shown in FIG. 15B, only one of the RGB color filters is illustrated.

The transparent conductive material is deposited on the upper substrate 193 on which the color filter 196 is formed through a deposition method such as sputtering. Thereafter, the transparent conductive material is patterned by a photolithography process and an etching process using a mask to form a common electrode 199 as shown in FIG. 15C. Here, the common electrode 199 has a structure removed in a region corresponding to the lead-out line 204 of the thin film transistor array substrate 170.

As described above, the color filter array substrate 193 and the thin film transistor array substrate 190 are formed by separate processes, and the bonding process is performed to complete the liquid crystal display as shown in FIG. 12.

As described above, the liquid crystal display device having an image sensing function according to the present invention, a manufacturing method thereof, and an image sensing method using the same include a sensing element capable of sensing a document, an image, etc. in a liquid crystal display device capable of realizing only an image. By doing so, not only an image or the like can be input using a single liquid crystal display device, but also the input image can be embodied in the image as needed. In particular, by adding an image sensing function to the liquid crystal display device, the input and output of the image into the liquid crystal display device are possible, which has a great advantage in terms of cost and volume.

In addition, since the parasitic capacitor between the common electrode and the lead-out line positioned on the color filter array substrate is not formed, the total capacity of the parasitic capacitor formed by the lead-out line may be minimized. As a result, the reliability of the image sensor is further improved.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (18)

A thin film transistor array substrate and a color filter array substrate formed to face each other with a liquid crystal interposed therebetween, The thin film transistor array substrate, A gate line and a data line formed on the substrate to cross each other and defining a pixel area; A pixel electrode positioned in the pixel region; A sensor thin film transistor for sensing light having image information; A sensing signal transfer line formed in parallel with a data line with the pixel electrode interposed therebetween and transferring a signal sensed by the sensor thin film transistor; And an integrated circuit connected to the sensing signal transmission line and configured to sense an image by receiving and detecting a signal sensed by the sensor thin film transistor from the sensing signal transmission line. The color filter array substrate A black matrix formed in a region excluding the pixel region where the pixel electrode is located and a region corresponding to the sensor thin film transistor; A color filter formed in a region corresponding to the pixel region; A common electrode formed on an entire surface of the color filter and the black matrix and positioned to overlap the pixel electrode of the thin film transistor array substrate to form a vertical electric field with the pixel electrode; The common electrode And a non-overlapping with the sensing signal transmission line. The method of claim 1, The thin film transistor array substrate A first thin film transistor positioned at an intersection of the gate line and the data line; A first storage capacitor storing a pixel voltage charged in the pixel electrode; A first driving voltage supply line positioned parallel to the gate line and supplying a first driving voltage to the sensor thin film transistor; A second driving voltage supply line positioned parallel to the first driving voltage supply line and supplying a second driving voltage to the sensor thin film transistor; A second storage capacitor configured to store a signal sensed by the sensor thin film transistor; And a second thin film transistor connected to the second storage capacitor and the front gate line and selectively supplying the sensing signal to the integrated circuit through the sensing signal transmission line. The method of claim 2, The sensor thin film transistor is A first gate electrode extending from the second driving voltage supply line; A gate insulating film formed to cover the first gate electrode; A first semiconductor pattern overlapping the first gate electrode with the gate insulating layer interposed therebetween; A first source electrode in contact with the first semiconductor pattern and electrically connected to the first driving voltage supply line; And a first drain electrode facing the first source electrode. The method of claim 3, wherein A protective film formed to cover the sensor thin film transistor; A first hole penetrating the passivation layer and the gate insulating layer to expose the first driving voltage supply line; A second hole penetrating the protective film to expose the first source electrode; Contacting the first driving voltage supply line through the first hole and contacting the first source electrode through the second contact hole to electrically connect the first source electrode and the first driving voltage supply line; 1. A liquid crystal display device comprising a transparent electrode pattern. 5. The method of claim 4, The first storage capacitor A first storage lower electrode extending from the second driving voltage supply line; A first storage upper electrode overlapping the first storage lower electrode with the gate insulating layer interposed therebetween; And the first storage upper electrode penetrates through the passivation layer and contacts the pixel electrode through a third hole. 5. The method of claim 4, The second storage capacitor A second driving electrode including a first drain electrode of the sensor thin film transistor, a second storage electrode in contact with the second thin film transistor, and the second driving voltage supply line overlapping the second storage electrode with the gate insulating layer interposed therebetween; 1 storage capacitor; A second-2 storage capacitor comprising the first driving voltage supply line overlapping the second storage electrode with the gate insulating layer interposed therebetween; A second transparent electrode pattern overlapping the second storage electrode with the passivation layer interposed therebetween and contacting the second driving voltage supply line through a fourth hole exposing the second driving voltage supply line; Liquid crystal display comprising a storage capacitor. The method of claim 2, The second thin film transistor is A second gate electrode in contact with the front gate line; A second semiconductor pattern overlapping the second gate electrode with the gate insulating layer interposed therebetween; A second source electrode electrically connected to the second semiconductor pattern and extending from the second storage electrode; And a second drain electrode facing the second source electrode and connected to the sensing signal transmission line. The method of claim 2, The first thin film transistor is A third gate electrode extending from the gate line; A third semiconductor pattern formed to overlap the third gate electrode with the gate insulating layer interposed therebetween; A third source electrode electrically connected to the third semiconductor pattern and extending from the data line; And a third drain electrode facing the third source electrode and connected to the pixel electrode. delete The method of claim 1, And the common electrode is formed in an area except for an area overlapping the sensing signal transmission line. A pixel region defined by crossing a gate line and a data line, a pixel electrode formed in the pixel region, a sensor thin film transistor for sensing light having image information, and a sensing formed parallel to the data line with the pixel electrode interposed therebetween A thin film transistor array substrate having an integrated circuit connected to a signal transmission line and the sensing signal transmission line and receiving a signal sensed by the sensor thin film transistor from the sensing signal transmission line, and detecting and sensing an image; Steps; Forming a color filter array substrate facing the thin film transistor array substrate with a liquid crystal interposed therebetween; Bonding the thin film transistor array substrate and the color filter array substrate to each other; Forming the color filter array substrate, Forming a black matrix in a region excluding the pixel region where the pixel electrode is located and a region corresponding to the sensor thin film transistor; Forming a color filter in a region corresponding to the pixel region; And forming a common electrode formed on an entire surface of the color filter and the black matrix and overlapping a pixel electrode of the thin film transistor array substrate and non-overlapping the sensing signal transmission line. . The method of claim 11, Forming the thin film transistor array substrate Forming a gate pattern on the substrate, the gate pattern including a gate line, a first gate electrode of the sensor thin film transistor, a second gate electrode of the first thin film transistor, and a third gate electrode of the second thin film transistor; Forming a gate insulating film on the substrate on which the gate pattern is formed; Forming a first semiconductor pattern overlapping the first gate electrode, a second semiconductor pattern overlapping the second gate electrode, and a third semiconductor pattern overlapping the third gate electrode on the gate insulating layer; A data line intersecting the gate line with the gate insulating layer interposed therebetween, and a first source electrode, a first drain electrode, and a second semiconductor pattern, which are respectively connected to and face each other and face each other. The sensor thin film transistor is formed by forming a source / drain pattern including a second source electrode, a second drain electrode, and a third source electrode and a third drain electrode, which are respectively connected to the third semiconductor pattern and face each other. Forming first and second thin film transistors; Forming a passivation layer having a first hole exposing a second drain electrode of the first thin film transistor; And forming a pixel electrode connected to the second drain electrode through the first hole. 13. The method of claim 12, Forming the gate pattern A first driving voltage supply line formed in parallel with the gate line to supply a first driving voltage to the sensor thin film transistor; A second driving voltage supply line connected to the first gate electrode and parallel to the first driving voltage supply line; And forming a first storage lower electrode parallel to the gate line and extending from the first driving voltage supply line. 13. The method of claim 12, Forming the source / drain pattern And forming a first storage upper electrode formed to overlap the first storage lower electrode with the gate insulating layer interposed therebetween to form the first storage lower electrode and the first storage capacitor. Way. 13. The method of claim 12, Forming a second storage capacitor for resisting the signal sensed by the sensor thin film transistor, Forming the second storage capacitor is A second storage electrode disposed between the first drain electrode of the sensor thin film transistor and the second source electrode of the second thin film transistor, and the second driving overlapping the second storage electrode with the gate insulating layer interposed therebetween; Forming a 2-1 storage capacitor including a voltage supply line; Forming a second-second storage capacitor including the second storage electrode and the first driving voltage supply line overlapping the second storage electrode with the gate insulating layer interposed therebetween; A second transparent electrode pattern contacting the second driving voltage supply line through a second hole overlapping the second storage electrode with the second storage electrode and a passivation layer interposed therebetween and exposing the second driving voltage supply line; Forming a 2-3 storage capacitor comprising a liquid crystal display device comprising the step of forming. 13. The method of claim 12, Forming the pixel electrode Contacting the first driving voltage supply line through a third hole through the gate insulating layer and the passivation layer to expose the first driving voltage supply line, and exposing the first source electrode of the sensing thin film transistor through the protection layer. And forming a first transparent electrode pattern in contact with the first source electrode through the fourth hole. The method of claim 11, And the common electrode is formed in a region other than the region overlapping the sensing signal transmission line. delete

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