KR101266768B1 - 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.

According to an exemplary embodiment of the present invention, a liquid crystal display device includes: a thin film transistor array substrate having a sensor thin film transistor for sensing light having image information; And a color filter array substrate bonded to the thin film transistor array substrate with a first pattern spacer interposed therebetween, wherein the color filter array substrate includes a pixel region corresponding to a pixel electrode of the thin film transistor array substrate and a sensor thin film transistor. A black matrix formed in a region other than a light receiving region exposing a light receiving unit for receiving light; And a second pattern spacer formed in an area overlapping with the black matrix around the light receiving area to block an optical path between the black matrix around the light receiving area in a backlight.

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 view showing a thin film transistor array substrate of a liquid crystal display 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 an 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.

FIG. 12 is a diagram which distinguishes an area which is covered by an illustrated black matrix from an area which is opened; FIG.

13A and 13B are schematic diagrams illustrating abnormal photo sensing according to normal photo sensing and internal reflection of a liquid crystal display, respectively.

14 is a sectional view schematically showing a liquid crystal display device according to a second embodiment of the present invention.

FIG. 15 is a plan view illustrating only a thin film transistor array substrate and a second pattern spacer in the liquid crystal display shown in FIG. 14;

FIG. 16 is a schematic diagram illustrating a light sensing process of a sensor thin film transistor of the liquid crystal display illustrated in FIGS. 14 and 15.

  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: 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 210: liquid crystal display panel

205: backlight

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 an image sensing function capable of document, image scanning, and touch input, and a manufacturing method thereof.

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, a liquid crystal display device includes a liquid crystal display panel in which liquid crystal cells are arranged in a matrix form, 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 pattern 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 a gate line and a data line, a thin film transistor formed of a switch element at each intersection of the gate lines and the data lines, a pixel electrode formed of a liquid crystal cell and connected to the thin film transistor, and the like. It consists of a coated 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 a pixel voltage signal supplied to the data line in response to a 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 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 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, it is an object of the present invention 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, and a manufacturing method thereof.

In order to achieve the above object, a liquid crystal display device according to the present invention includes a thin film transistor array substrate having a sensor thin film transistor for sensing light having image information; And a color filter array substrate bonded to the thin film transistor array substrate with a first pattern spacer interposed therebetween, wherein the color filter array substrate includes a pixel region corresponding to a pixel electrode of the thin film transistor array substrate and a sensor thin film transistor. A black matrix formed in a region other than a light receiving region exposing a light receiving unit for receiving light; And a second pattern spacer formed in an area overlapping with the black matrix around the light receiving area to block an optical path between the black matrix around the light receiving area in a backlight.

The first and second pattern spacers may be made of an opaque photoacrylic material.

The first and second pattern spacers may have the same height.

The second pattern spacer may surround the light receiving unit of the sensor thin film transistor.

The second pattern spacer may protrude from the color filter array substrate to be in contact with the thin film transistor array substrate.

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 for storing a signal sensed by the sensor thin film transistor; An integrated circuit for detecting the sensing signal stored in the second storage capacitor; A second thin film transistor connected to the second storage capacitor and a front gate line and selectively supplying the sensing signal to the integrated circuit; And a sensing signal transfer line positioned parallel to the data line with the pixel region therebetween and configured to transfer a sensing signal from the second thin film transistor to an integrated circuit.

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.

The light receiving part of the sensor thin film transistor is positioned between the first source electrode and the first drain electrode and is a channel region that is part of the first semiconductor pattern.

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; It is characterized by comprising a transparent electrode pattern.

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. It is done.

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 characterized in that it comprises 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.

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, comprising: preparing a thin film transistor array substrate on which a sensor thin film transistor is formed to sense light having image information; Providing a color filter array substrate facing the thin film transistor array substrate with a first pattern spacer interposed therebetween; And bonding the thin film transistor array substrate and the color filter array substrate to each other, wherein preparing the color filter array substrate includes light in the pixel region corresponding to the pixel electrode of the thin film transistor array substrate and the sensor thin film transistor. Forming a black matrix in a region other than a light receiving region exposing the light receiving unit for receiving light; Forming a color filter in the pixel region; Forming a common electrode on the color filter and the black matrix to form a vertical electric field with the pixel electrode; And forming a second pattern spacer positioned on the common electrode to overlap the first pattern spacer and the black matrix around the light receiving region.

The second pattern spacer may block the optical path between the black matrix around the light receiving area in the backlight.

The forming of the thin film transistor array substrate may include forming a gate pattern including a gate line, a first gate electrode of a 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; 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. A sensor thin film transistor formed by forming a source / drain pattern including a second source electrode and a second drain electrode positioned to be visible, and a third source electrode and a third drain electrode respectively connected to the third semiconductor pattern and facing 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.

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 parallel to the gate line and extending from the first driving voltage supply 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. Characterized in that.

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. And forming a first transparent electrode pattern in contact with the first source electrode through a fourth hole exposing the first source electrode of the transistor.

The forming of the source / drain pattern may include forming a sensing signal transmission line positioned parallel to the data line and connected to the third drain electrode of the second thin film transistor.

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, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 4 to 16.

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 an exemplary embodiment of the present invention, and FIG. 5 is a line II-II ', III-III', and IV- shown in FIG. 4. Sectional drawing which cut | disconnected 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 "first storage capacitor") formed at an overlapping portion of the () and the sensing signal storage storage capacitor located between the second TFT 170 and the sensor TFT 140. 180 (hereinafter referred to as a "second storage capacitor").

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 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 formed according to the sensed amount of light. do. The photocurrent 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 an image such as a document, an image scan, a touch input, or the like 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 shown in FIG. 7, a black matrix 194 that partitions a cell region on the upper substrate 193 and prevents light leakage, and a color filter formed in the cell region partitioned by the black matrix 194. 196, the color filter array substrate 192 on which the common electrode 199 and the pattern spacer 163 forming a vertical electric field with the pixel electrode of the thin film transistor array substrate 190 formed on the color filter and the black matrix are formed. After the formation, the liquid crystal display panel 210 having image sensing is formed by bonding the thin film transistor array substrate 190 and the liquid crystal 197 therebetween. Here, the pattern spacer 163 maintains the cell gap between the color filter array substrate 192 and the thin film transistor array substrate 190.

The liquid crystal display panel 210 having such a configuration receives light from the backlight 205.

In the liquid crystal display device capable of sensing an image as described above, a sensor, a scan, and the like can display both a document and an image, but the frequency of use of the display will be higher than that of the sensor. Accordingly, the backlight 205 for supplying light to the liquid crystal display panel 210 supplies different amounts of light in the display mode and the image sensor or the scanner mode. That is, the backlight 205 is controlled by the user to supply the amount of light required by the display device in the display mode to the liquid crystal display panel 210, and in the case of the image sensor or the scanner mode, relatively strong light is supplied. As a result, it is possible to supply light that is relatively stronger than the light required by the display element. Here, the amount of light of the backlight 205 can be controlled by any known backlight control method.

Hereinafter, a method of manufacturing a thin film transistor array substrate of 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. The gate electrode 108a of the first TFT 106, 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 Gate patterns including the gate electrode 108b and the first storage lower electrode 121 of the sensor TFT 140 extending from the line 171 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. 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 first driving voltage supply line 171 through the fifth contact hole 115e.

Thereafter, the cell region is partitioned on the upper substrate 193 by a separate process, and the color formed in the cell region partitioned by the black matrix 194 and the black matrix 194 prevents light leakage when the LCD is driven. A color filter array substrate 192 having a filter 196 or the like 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. Here, a common electrode, an alignment layer, a pattern spacer, an overcoat layer, etc. 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. 2, for example, a voltage of about -5V is applied to the gate electrode 108b of the sensor TFT 140 from the driving voltage supply line 171 and exits from the backlight 205 as shown in FIG. Etc.) 185, the sensor TFT 140 senses light (or external light) having image information by incident on the active layer 114b of the sensor TFT 140. At this time, a photo current path is formed which flows 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 amount of light sensed by the sensor TFT 140. . The photocurrent 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 lead-out 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.

Meanwhile, in the present invention, as shown in FIG. 12, the liquid crystal display includes a pixel region P1 in which the pixel electrode 118 is located and a light receiving region P2 for allowing light to enter the sensor TFT 140. The excluded region is covered by the black matrix 194 of the color filter array substrate 192.

Here, the black matrix 194 is made of an opaque metal, for example, chromium (Cr) or the like so that noise light due to internal reflection in the liquid crystal display panel 210 is sensed by the sensor TFT 140. Problems may arise. When such unwanted noise light is incident on the sensor TFT 140, the sensor TFT 140 may not accurately sense a document, a human finger, or the like, and there are many errors and errors in the implementation of the sensed image. Deviation occurs and a problem may occur in which reliability as a sensing element may be degraded.

For example, referring to FIG. 13A, light from the backlight 205 that passes through the pixel area P1 and is reflected on the printed matter, document, finger, etc. 185 corresponds to the sensor TFT 140 in the light receiving area P2. When irradiated to the channel region between the active layer 114b, that is, the source electrode 110b and the drain electrode 112b, the scanner function, input and touch functions can be normally performed.

In contrast, as shown in FIG. 13B, when the backlight light reflected by the black matrix 194 is irradiated onto the active layer 114b of the sensor TFT 140, the sensor TFT 140 reflects the printed matter 185 such as a document. As a result of sensing light that is not, abnormal sensing is performed.

Accordingly, another embodiment of the present invention proposes a structure of a liquid crystal display device for improving the reliability of the photo sensing function in the liquid crystal display device having a photo sensing function and for preventing the deterioration of display quality when implementing an image. .

14 is a cross-sectional view of a liquid crystal display according to a second exemplary embodiment of the present invention.

The liquid crystal display according to the second exemplary embodiment of the present invention is the same as the first exemplary embodiment of the present invention except that the second pattern spacer 165 is formed around the sensor TFT 140 in comparison with the first exemplary embodiment of the present invention. Since the second embodiment is the same as the first embodiment of the present invention, in the second embodiment of the present invention, the same components as those described in the first embodiment will be denoted by the same reference numerals and redundant description thereof will be omitted.

In the liquid crystal display panel 210 of the liquid crystal display illustrated in FIG. 14, the thin film transistor array substrate 190 including the sensor TFT 140 and the like and the color filter array substrate 192 including the color filter 196 are formed of a liquid crystal layer. Are interposed between them. The color filter array substrate 192 and the thin film transistor array substrate 190 of the liquid crystal display panel 210 are pattern spacers 163 formed on the color filter array substrate 192 (hereinafter referred to as “first pattern spacers”). The cell gap is maintained by.

Unlike the first embodiment of the present invention, the liquid crystal display panel 210 includes a second pattern spacer 165 positioned around the sensor TFT 140.

The first pattern spacer 163 is a spacer having a function for maintaining a normal cell gap and is positioned in a region other than the pixel region P1. That is, the first pattern spacer 163 is positioned in an area overlapping the first TFT 106, the gate line 102, the data line 104, and the like of the thin film transistor array substrate 190, thereby reducing the aperture ratio. These serve to secure the filling area. In FIG. 14, an example in which the first pattern spacer 163 is positioned in a region overlapping with the first TFT 106 is illustrated.

The second pattern spacer 165 is formed on the color filter array substrate 192 and is positioned around the sensor TFT 140. For example, the second pattern spacer 165 is positioned to surround the sensor TFT 140 and exposes a channel region for receiving light from the sensor TFT 140.

Looking at the position of the second pattern spacer 165 in a plan view as shown in FIG. That is, the second pattern spacer 165 exposes the channel region that receives the light from the sensor TFT 165 on the thin film transistor array substrate 190, that is, the active layer 145b exposed to the outside, and exposes the sensor TFT 140. It is formed to surround the active layer 145b.

The second pattern spacer 165 is made of an opaque photoacrylic material and absorbs the backlight light incident to the black matrix 194 positioned around the light receiving region P2 to prevent the light from being irradiated onto the black matrix 165. It serves to block.

Referring to FIG. 16, the light emitted from the backlight 205 is reflected by a printed matter (photo, document), a human hand, a touch pen 185, etc., positioned on the liquid crystal display panel 210. Irradiated to the channel region of the sensor TFT 140. Among the light emitted from the backlight 205, light incident to the black matrix 194 around the sensor TFT 140 is absorbed or blocked by the second pattern spacer 163. That is, the second pattern spacer 163 blocks the optical paths between the black matrix 194 positioned around the light receiving region P2 in the backlight 205. As a result, the light reflected from the black matrix 194 is not sensed by the sensor TFT 140. Accordingly, only the backlight light passing through the pixel region P1 and reflected by the printed matter, document, finger, etc. 185 corresponds to the active layer 114b of the sensor TFT 140, that is, the source electrode 110b. ) And the channel region between the drain electrode 112b.

This improves the reliability of the photo-sensing function of the liquid crystal display such as a scanner function of a printed matter such as a document or an input and a touch function such as a human finger can be performed normally, thereby preventing the deterioration of display quality when implementing an image. .

Meanwhile, since the second pattern spacer 165 is formed at the same time as the first pattern spacer 163, the first pattern spacer 163 and the second pattern spacer 165 have the same height. Accordingly, the second pattern spacer 165 may also be in contact with the thin film transistor array substrate 190 like the first pattern spacer 163. When contacted with the second pattern spacer 165 and the thin film transistor array substrate 190, the cell gap organic function may be performed in the same manner as the first pattern spacer 163.

The second pattern spacer 165 is formed by a patterning process such as a photolithography process after the photo acrylic material is coated on the common electrode 199 of the color filter array substrate 192.

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, the liquid crystal display of the present invention further includes a second pattern spacer which exposes the channel region of the sensor TFT and is positioned around the sensor TFT. The second pattern spacer absorbs or blocks the light incident from the backlight into the black matrix around the sensor TFT. As a result, the light reflected from the black matrix rather than the printed matter (photo, document), human hand, touch pen 185, etc. is not sensed by the sensor TFT. Input and touch functions such as can be performed. Accordingly, it is possible to improve the reliability of the photosensing function of the liquid crystal display device and to prevent the deterioration of the display quality when implementing the image.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the 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 (22)

A thin film transistor array substrate having a sensor thin film transistor for sensing light having image information; A color filter array substrate bonded to the thin film transistor array substrate with a first pattern spacer interposed therebetween, The color filter array substrate A black matrix formed in a region excluding a pixel region corresponding to a pixel electrode in the thin film transistor array substrate and a light receiving region exposing a light receiving unit for receiving light in the sensor thin film transistor; And a second pattern spacer formed in an area overlapping the black matrix around the light receiving area to block an optical path between the black matrix around the light receiving area in a backlight. The method of claim 1, And the first and second pattern spacers are made of an opaque photoacrylic material. The method of claim 1, And the first and second pattern spacers have the same height. The method of claim 1, And the second pattern spacer surrounds a light receiving portion of the sensor thin film transistor. The method of claim 1, And the second pattern spacer protrudes from the color filter array substrate to be in contact with the thin film transistor array substrate. The method of claim 1, The thin film transistor array substrate A gate line and a data line formed to cross each other on a substrate 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 in parallel with the first driving voltage supply line and supplying a second driving voltage to the sensor thin film transistor; A second storage capacitor for storing a signal sensed by the sensor thin film transistor; An integrated circuit for detecting the sensing signal stored in the second storage capacitor; A second thin film transistor connected to the second storage capacitor and a front gate line and selectively supplying the sensing signal to the integrated circuit; And a sensing signal transfer line positioned to be parallel to the data line with the pixel region therebetween and configured to transfer a sensing signal from the second thin film transistor to an integrated circuit. The method of claim 6, The sensor thin film transistor 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 7, wherein The light receiving portion of the sensor thin film transistor And a channel region positioned between the first source electrode and the first drain electrode and part of the first semiconductor pattern. The method of claim 7, 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. The method of claim 9, 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. The method of claim 9, 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. 9. The method of claim 8, 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. 9. The method of claim 8, 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. Providing a thin film transistor array substrate on which a sensor thin film transistor for sensing light having image information is formed; Providing a color filter array substrate facing the thin film transistor array substrate with a first pattern spacer interposed therebetween; Bonding the thin film transistor array substrate and the color filter array substrate to each other; Preparing the color filter array substrate Forming a black matrix in a region other than a pixel region corresponding to a pixel electrode in the thin film transistor array substrate and a light receiving region exposing a light receiving unit for receiving light in the sensor thin film transistor; Forming a color filter in the pixel region; Forming a common electrode on the color filter and the black matrix to form a vertical electric field with the pixel electrode; And forming a second pattern spacer disposed on the common electrode to overlap the first pattern spacer and the black matrix around the light-receiving region. 15. The method of claim 14, And the second pattern spacer blocks an optical path between the black matrices around the light receiving area in a backlight. 15. The method of claim 14, 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. A sensor thin film transistor formed by forming a source / drain pattern including a second source electrode and a second drain electrode positioned to be visible, and a third source electrode and a third drain electrode respectively connected to the third semiconductor pattern and facing 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. 17. The method of claim 16, The light receiving portion of the sensor thin film transistor And a channel region located between the first source electrode and the first drain electrode and being a part of the first semiconductor pattern. 17. The method of claim 16, 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. 17. The method of claim 16, 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. 20. The method of claim 19, 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. 17. The method of claim 16, Forming the pixel electrode Contacting the first driving voltage supply line through a third hole that exposes the first driving voltage supply line through the gate insulating layer and the protective layer, and exposes the first source electrode of the sensing thin film transistor through the protective layer. And forming a first transparent electrode pattern in contact with the first source electrode through the fourth hole. 17. The method of claim 16, Forming the source / drain pattern And forming a sensing signal transmission line positioned parallel to the data line and connected to a third drain electrode of the second thin film transistor.

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