KR20060056633A - Display device including sensing element - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device incorporating a sensing element, wherein the device is provided on a first substrate, a second substrate facing the first substrate, a plurality of pixel electrodes formed on the second substrate, and a second substrate The sensing signal line includes a common electrode formed on the first substrate and a sensing electrode formed on the second substrate, and is formed between two adjacent pixel electrodes and generates a touch sensing signal based on a common voltage according to a user's contact. The touch sensing unit may be provided to the sensing signal line according to the sensing scan signal. According to the present invention, it is possible to easily determine whether or not a contact by receiving a common voltage according to the user's contact and generate a detection signal according to the user's contact, and by placing the touch sensing unit in the area between the pixels, the transmittance is increased by increasing the transmission area. It can increase.

Display device, touch sensor, pixel electrode, sensor electrode, light sensor, sensing area, protrusion

Description

Display device with built-in sensing element {DISPLAY DEVICE INCLUDING SENSING ELEMENT}

1 is a block diagram of a liquid crystal display according to an exemplary embodiment of the present invention.

2 is an equivalent circuit diagram of one pixel of a liquid crystal display according to an exemplary embodiment of the present invention.

3 is an equivalent circuit diagram of an optical sensing unit of a liquid crystal display according to an exemplary embodiment of the present invention.

4 is an equivalent circuit diagram of a touch sensing unit of a liquid crystal display according to an exemplary embodiment of the present invention.

5 is an example of layout view of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 6 is a cross-sectional view of the liquid crystal display of FIG. 5 taken along the line VI-VI '. FIG.

FIG. 7 is a cross-sectional view of the liquid crystal display of FIG. 5 taken along lines VII-VII ′ and VII′-VII ″. FIG.

8A and 8B are schematic diagrams for describing an operation of a touch sensing unit of a liquid crystal display according to an exemplary embodiment of the present invention.

9 is an enlarged layout view of a touch sensing unit of a liquid crystal display according to another exemplary embodiment of the present invention.

FIG. 10 is an example of a schematic diagram of a pixel and a detector array of a liquid crystal display according to another exemplary embodiment of the present invention.

FIG. 11 is a cross-sectional view of a liquid crystal display according to another exemplary embodiment, taken along lines VII-VII ′ and VII′-VII ″ of the liquid crystal display of FIG. 5.

12A to 12C are equivalent circuit diagrams of a touch sensing unit of a liquid crystal display according to another exemplary embodiment of the present invention.

The present invention relates to a display device incorporating a sensing element.

Typical liquid crystal displays (LCDs) among display devices include two display panels provided with pixel electrodes and a common electrode, and a liquid crystal layer having dielectric anisotropy interposed therebetween. The pixel electrodes are arranged in a matrix and connected to switching elements such as thin film transistors (TFTs) to receive data voltages one by one in sequence. The common electrode is formed over the entire surface of the display panel and receives a common voltage. The pixel electrode, the common electrode, and the liquid crystal layer therebetween form a liquid crystal capacitor, and the liquid crystal capacitor becomes a basic unit that forms a pixel together with a switching element connected thereto.

In such a liquid crystal display, a voltage is applied to two electrodes to generate an electric field in the liquid crystal layer, and the intensity of the electric field is adjusted to adjust the transmittance of light passing through the liquid crystal layer to obtain a desired image. In this case, in order to prevent deterioration caused by the application of an electric field in one direction to the liquid crystal layer for a long time, the polarity of the data voltage with respect to the common voltage is inverted frame by frame, row by pixel, or pixel by pixel.

A touch screen panel refers to a device that touches a finger or a pen on the screen to write and draw a character or a picture, or executes an icon to perform a desired command on a machine such as a computer. The liquid crystal display with a touch screen panel may find out whether the user's finger or a touch pen touches the screen and the contact position information. However, such a liquid crystal display device has a higher cost due to a touch screen panel, a lower yield due to a process of adhering the touch screen panel to a liquid crystal display panel, a lower brightness of the liquid crystal panel, and an increase in product thickness.

Accordingly, a technology for embedding a sensing element made of a thin film transistor instead of a touch screen panel inside a pixel displaying an image in a liquid crystal display device has been developed. The sensing element detects a change in light applied to the screen by a user's finger or the like so that the liquid crystal display may determine location information where the user's finger or the like touches the screen.

However, when the contact location is determined only by the change of light, it is very difficult to distinguish the case where the user's finger or the like directly touches the liquid crystal display. This must be done in software, but the algorithm requires longer processing time and a faster processor speeds up power consumption.

In addition, due to the area occupied by the sensing element and the wiring therefor, the transmission window defining the transmission region cannot be enlarged, so that the transmittance of the liquid crystal display is lowered.

Accordingly, an aspect of the present invention is to provide a display device including a touch sensing unit which can easily determine whether a user touches and increases a transmittance by increasing a transmission area.

According to an embodiment of the present invention, a display device includes a first substrate, a second substrate facing the first substrate, a plurality of pixel electrodes formed on the second substrate, and the second substrate. A sensing signal line formed thereon, a common electrode formed on the first substrate, and a sensing electrode formed on the second substrate, and formed between two adjacent pixel electrodes, which are common according to a user's contact. And a touch sensing unit configured to generate a touch sensing signal based on a voltage and output the touch sensing signal to the sensing signal line according to a sensing scan signal.

The common voltage is applied to the common electrode, and the common electrode and the sensing electrode may be electrically connected by the contact.

The display device may further include a protrusion formed on the first substrate and protruding toward the sensing electrode, and the common electrode may be formed on the protrusion.

An interval between the common electrode and the sensing electrode may be 0.1 to 1.0 μm.

The common electrode may include a primary common electrode and a secondary common electrode, and the protrusion may be formed on the primary common electrode, and the secondary common electrode may be formed on the protrusion and the primary common electrode.

The thickness of the primary common electrode may be 0.05 to 0.1 μm, and the thickness of the secondary common electrode may be 0.05 to 0.2 μm.

The sensing electrode may further include an organic insulating layer formed under the sensing electrode and the pixel electrode, wherein the sensing electrode is formed on the depression, and the height of the sensing electrode may be lower than the height of the pixel electrode.

The organic insulating layer may have an uneven pattern, and the recessed portion and the uneven pattern may be formed in the same process.

And a column spacer formed on the first substrate and maintaining a distance between the first substrate and the second substrate, wherein the height of the column spacer and the protrusion may be substantially the same.

A light sensing unit formed on the second substrate and formed between two adjacent pixel electrodes on which the touch sensing unit is not disposed, and generating an optical sensing signal based on the amount of light by receiving external light and outputting the light sensing signal to the sensing signal line; It may include.

The display device may further include a data line connected to the pixel electrode to transfer a data voltage, wherein the data line adjacent to the touch sensing unit may be refracted along the touch sensing unit.

The data line may be symmetrical with respect to a boundary between two vertically adjacent pixel electrodes.                     

The touch sensing unit may further include a sensing element including a control terminal, an input terminal, and an output terminal, and the input terminal may be connected to the sensing electrode.

The touch sensing unit may further include a switching element connected to an output terminal of the sensing element and emitting the touch sensing signal.

DETAILED DESCRIPTION Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the other part being "right over" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

A display device incorporating a sensing element according to an exemplary embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

1 is a block diagram of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 2 is an equivalent circuit diagram of one pixel of the liquid crystal display according to an exemplary embodiment of the present invention. 3 is an equivalent circuit diagram of a light sensing unit of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 4 is an equivalent circuit diagram of a touch sensing unit of a liquid crystal display according to an exemplary embodiment of the present invention.                     

As shown in FIG. 1, a liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal panel assembly 300, an image scanning unit 400, a data driver 500, and a sensing scan connected thereto. The unit 700 includes a signal reader 800, a gray voltage generator 550 connected to the data driver 500, and a signal controller 600 for controlling the gray voltage generator 550.

The liquid crystal panel assembly 300 is connected to a plurality of signal lines G ₁ -G _n , D ₁ -D _m , S ₁ -S _N , P ₁ -P _M , P _SG , and P _SD in an equivalent circuit. It includes a plurality of pixels and the sensing unit arranged in a substantially matrix form.

The signal lines G ₁ -G _n and D ₁ -D _m include a plurality of image scanning lines G ₁ -G _n for transmitting an image scanning signal and data lines D ₁ -D _m for transmitting an image data signal. do. The image scanning lines G ₁ -G _n extend substantially in the row direction and are substantially parallel to each other, and the data lines D ₁ -D _m extend substantially in the column direction and are substantially parallel to each other.

The signal lines S ₁ -S _N and P ₁ -P _M include a plurality of sensing scan lines S ₁ -S _N for transmitting a sensing scan signal and sensing signal lines P ₁ -P _M for transmitting a sensing signal. . The sensing scan lines S ₁ -S _N extend approximately in the row direction and are substantially parallel to each other, and the sensing signal lines P ₁ -P _M extend substantially in the column direction and are substantially parallel to each other.

The signal lines P _SG and P _SD include a control voltage line P _SG for transmitting the control voltage V _SG and an input voltage line P _SD for transferring the input voltage V _SD , and extend in the row or column direction. have.

Each pixel includes a switching element Q connected to a signal line G ₁ -G _n , D ₁ -D _m , a liquid crystal capacitor C _LC , and a storage capacitor C _ST connected thereto. Include. The holding capacitor C _ST can be omitted as necessary.

A switching element Q, such as a thin film transistor, is provided in the lower panel 100. The three-terminal element has a control terminal and an input terminal of the image scanning line G ₁ -G _n and the data line D ₁ -D _m, respectively. The output terminal is connected to a liquid crystal capacitor (C _LC ) and a holding capacitor (C _ST ).

The liquid crystal capacitor C _LC has two terminals, the pixel electrode 190 of the lower panel 100 and the common electrode 270 of the upper panel 200, and the liquid crystal layer 3 between the two electrodes 190 and 270. It functions as a dielectric. The pixel electrode 190 is connected to the switching element Q, and the common electrode 270 is formed on the front surface of the upper panel 200 and receives a common voltage V _com . Unlike in FIG. 2, the common electrode 270 may be provided in the lower panel 100. In this case, at least one of the two electrodes 190 and 270 may be linear or rod-shaped.

The storage capacitor C _ST , which serves as an auxiliary part of the liquid crystal capacitor C _LC , is formed by overlapping a separate signal line (not shown) and the pixel electrode 190 provided on the lower panel 100 with an insulator interposed therebetween. A predetermined voltage such as the common voltage V _com is applied to this separate signal line. However, the storage capacitor C _ST may be formed such that the pixel electrode 190 overlaps the front end image scanning line directly above the insulator.

On the other hand, to implement color display, each pixel uniquely displays one of the three primary colors (spatial division) or each pixel alternately displays the three primary colors over time (time division) so that the desired color can be selected by the spatial and temporal sum of these three primary colors. To be recognized. 2 illustrates that each pixel includes a red, green, or blue color filter 230 in a region corresponding to the pixel electrode 190. Unlike FIG. 2, the color filter 230 may be formed above or below the pixel electrode 190 of the lower panel 100.

A polarizer (not shown) for polarizing light is attached to an outer surface of at least one of the two display panels 100 and 200 of the liquid crystal panel assembly 300.

The sensing unit includes a light sensing unit and a touch sensing unit.

As illustrated in FIG. 3, the light sensing unit includes a sensing element Q _P connected to the signal lines P _SG and P _SD and a switching element Q _S1 connected to a part of the signal lines S ₁ -S _N and P ₁ -P _M. ) And sense signal capacitor C _P connected thereto.

The sensing element Q _P is a three-terminal element whose control terminal and input terminal are connected to the control voltage line P _SG and the input voltage line P _SD, respectively, and the output terminal is a sensing signal capacitor C _P and a switching element. Is connected to (Q _S1 ). An opening is formed in the upper portion of the sensing element Q _P , and when light is irradiated to the channel semiconductor, a channel semiconductor made of amorphous silicon or polycrystalline silicon forms a photocurrent, and an input voltage applied to the input voltage line P _SD . The photocurrent flows in the direction of the sensing signal capacitor C _P and the switching element Q _S1 by V _SD .

The sensing signal capacitor C _{P is} connected between the sensing element Q _P and the control voltage line P _SG , and accumulates charges according to the photocurrent from the sensing element Q _P to maintain a predetermined voltage. The sensing signal capacitor C _P may be omitted as necessary.

The switching element Q _S1 is also a three-terminal element whose control terminals, output terminals and input terminals are part of the sensing scan lines S ₁ -S _N , the sensing signal lines P ₁ -P _M and the sensing elements Q _P, respectively. Is connected to. The switching element Q _S1 is a voltage stored in the sensing signal capacitor C _P or the sensing element Q _P when a voltage for turning on the switching element Q _S1 is applied to the sensing scan lines S ₁ -S _N. The photocurrent from is output as the detection signals V _P1 -V _PM to the corresponding detection signal lines P ₁ -P _M.

As illustrated in FIG. 4, the touch sensing unit includes a switch SWT connected to the common voltage V _com , a sensing element Q _T connected to the switch SWT, and a signal line P _SG , and a signal line S ₁ -S. _N , P ₁ -P _M ) includes a switching element (Q _S2 ) connected to a part of the signal line (S ₁ -S _N , P ₁ -P _M ) in the part where the light sensing unit is not connected Formed.

The switch SWT transfers the common voltage V _com to the sensing element Q _T according to the contact of the user.

The sensing element Q _T is a three-terminal element whose control terminal and input terminal are connected to the control voltage line P _SG and the switch SWT, respectively, and the output terminal is connected to the switching element Q _S2 . The sensing element Q _T outputs a sensing current according to the common voltage V _com transmitted from the switch SWT.

The switching element Q _S2 is also a three-terminal element, the control terminal, the output terminal and the input terminal of which are part of the sensing scan lines S ₁ -S _N , the sensing signal lines P ₁ -P _M and the sensing elements Q _T, respectively. Is connected to. A switching element (Q _S2) detects the scanning line (S ₁ -S _N) to the switching elements when a voltage for turning on the (Q _S2) applied to the sensing element detects a touch sensing current from the (Q _T) signal (V _P1 -V _PM ) is output to the corresponding sensing signal lines P ₁ -P _M.

The switching elements Q, Q _S1 and Q _S2 and the sensing elements Q _P and Q _T may be formed of amorphous silicon or poly crystalline silicon thin film transistors.

The sensing units are disposed one per dot in the liquid crystal panel assembly 300 and are disposed in an area between two adjacent pixels (hereinafter referred to as a sensing area). Here, one dot is formed of three R, G, and B pixels arranged horizontally, and becomes a unit displaying one color, and becomes a basic unit representing the resolution of the liquid crystal display.

The light sensing unit has a resolution of 1/4 of the resolution of the liquid crystal display. As an example, the light sensing unit may be disposed in an area where the odd-numbered sensing scan line and the odd-numbered sensing signal line cross each other. Then, a liquid crystal display device having such an optical sensing unit may be used even in a high precision application field such as character recognition. Of course, the resolution of the light sensing unit may have a higher or lower resolution as necessary.

The touch sensing unit has a resolution less than or equal to the resolution of the light sensing unit. As an example, the touch sensing unit may be disposed in an area where the odd-numbered sensing scan line and the even-numbered sensing signal line cross each other.

By placing the light sensing units in two vertically adjacent sensing regions, and connecting the two sensing scanning lines to each other, the sensing signals of the light sensing units can be superimposed on the same sensing signal line. The superimposed sensing signals not only reduce the characteristic variation of each optical sensing unit, but also double the signal to noise ratio to extract more accurate sensing signals. In this case, even though two light detectors are arranged vertically, one detection signal is actually output, so the resolution of the light detector is determined according to the detection signal. The contact sensing unit can also be arranged in this way.

Meanwhile, the gray voltage generator 550 generates two sets of gray voltages related to the transmittance of the pixel. One of the two sets has a positive value for the common voltage (V _com ) and the other set has a negative value.

The image scanning unit 400 is connected to the image scanning lines G ₁ -G _n of the liquid crystal panel assembly 300 to display an image scanning signal formed by a combination of a gate on voltage V _on and a gate off voltage V _off . It is applied to the scan line G ₁ -G _n .

The data driver 500 is connected to the data lines D ₁ -D _m of the liquid crystal panel assembly 300 to select the gray voltage from the gray voltage generator 550 and apply the gray voltage to the pixel as a data signal.

The sensing scan unit 700 is connected to the sensing scan lines S ₁ -S _N of the liquid crystal panel assembly 300 to sense a sensing scan signal formed by a combination of a gate on voltage V _on and a gate off voltage V _off . It is applied to the scanning lines S ₁ -S _N.

Signal reading unit 800 is input a sense signal (V _P1 -V _PM) output is connected to the detection signal of the liquid crystal panel assembly _{(300) (P 1 -P M} ) via the detected signal line (P ₁ -P _M) After receiving the signal processing such as amplification, filtering, etc., analog-to-digital conversion is performed to output a digital sensing signal (DSN).

The signal controller 600 controls the operations of the image scanner 400, the data driver 500, the sensing scanner 700, and the signal reader 800.                     

The image scanning unit 400, the data driving unit 500, the sensing scanning unit 700, or the signal reading unit 800 may be mounted directly on the liquid crystal panel assembly 300 in the form of a plurality of driving integrated circuit chips, or may be flexible printed. The LCD may be mounted on a flexible printed circuit film (not shown) and attached to the liquid crystal panel assembly 300 in the form of a tape carrier package (TCP). Alternatively, the image scanning unit 400, the data driver 500, the sensing scanning unit 700, or the signal reading unit 800 may be integrated in the liquid crystal panel assembly 300. Alternatively, the data driver 500, the signal reader 800, the signal controller 600, and the like may be integrated into one IC, also called a one-chip.

Next, the display operation and the detection operation of the liquid crystal display will be described in more detail.

The signal controller 600 may control the input image signals R, G, and B and their display from an external graphic controller (not shown), for example, a vertical sync signal V _sync and a horizontal sync signal. (H _sync ), a main clock (MCLK), a data enable signal (DE) is provided. The signal controller 600 properly processes the image signals R, G, and B according to operating conditions of the liquid crystal panel assembly 300 based on the input image signals R, G, and B and the input control signal, and controls image scanning. After generating the signal CONT1 and the data control signal CONT2, the image scan control signal CONT1 is sent to the image scanning unit 400, and the data control signal CONT2 and the processed image signal DAT are the data driver. Export to 500. In addition, the signal controller 600 generates the sensing scan control signal CONT3 and the read control signal CONT4 based on the input control signal, and then outputs the sensing scan control signal CONT3 to the sensing scan unit 700 and read control. The signal CONT4 is sent to the signal reading unit 800.

Image scan control signal (CONT1) includes at least one clock signal and the like to control the output of the start scan indicating the scanning start of a gate-on voltage (V _on) signal (STV) and the gate-on voltage (V _on).

The data control signal CONT2 is a horizontal synchronization start signal STH for transmitting data of one pixel row, a load signal LOAD for applying a corresponding data voltage to the data lines D ₁ -D _m , and a common voltage V _com. ), The inversion signal RVS, the data clock signal HCLK, and the like, which inverts the polarity of the data voltage (hereinafter, referred to as "polarity of the data voltage" by reducing the "polarity of the data voltage" with respect to the common voltage)).

The data driver 500 receives the image data DAT for one row of pixels according to the data control signal CONT2 from the signal controller 600, and displays each image among the gray voltages from the gray voltage generator 550. By selecting the gray scale voltage corresponding to the data DAT, the image data DAT is converted into the corresponding data voltage and then applied to the data lines D ₁ -D _m .

The image scanning unit 400 applies the gate-on voltage V _on to the image scanning line G ₁ -G _n in response to the image scanning control signal CONT1 from the signal controller 600, thereby applying the image scanning line G _1- . The switching element Q connected to G _n is turned on, and accordingly, a data voltage applied to the data lines D ₁ -D _m is applied to the corresponding pixel through the turned on switching element Q.

The difference between the data voltage applied to the pixel and the common voltage V _com is shown as the charging voltage of the liquid crystal capacitor C _LC , that is, the pixel voltage. The arrangement of the liquid crystal molecules varies according to the magnitude of the pixel voltage, thereby changing the polarization of light passing through the liquid crystal layer 3. The change in polarization is represented by a change in transmittance of light by a polarizer (not shown) attached to the display panels 100 and 200.

After one horizontal period (or "1H") (one period of the horizontal sync signal H _sync and the data enable signal DE) has passed, the data driver 500 and the image scanning unit 400 may perform the pixel processing on the next row of pixels. Repeat the same operation. In this manner, the gate-on voltage V _on is sequentially applied to all the image scanning lines G ₁ -G _n during one frame to apply the data voltage to all the pixels. At the end of one frame, the next frame starts and the state of the inversion signal RVS applied to the data driver 500 is controlled so that the polarity of the data voltage applied to each pixel is opposite to that of the previous frame ("frame inversion). "). In this case, the polarities of the data voltages flowing through one data line are changed according to the characteristics of the inversion signal RVS even in one frame (eg, inverted rows and inverted dots) or the polarities of the data voltages applied to one pixel row are also different from each other. (Eg: nirvana, point inversion).

Detecting the scanning unit 700 is applied to the scanning line is detected (S ₁ for detecting a gate-on voltage (V _on) the scan lines (S ₁ -S _N) according to the detected scan control signal (CONT3) from the signal controller 600, - S _N) switching elements (Q _S1, sensing signals from the turn-on sikimyeo, whereby the light sensor and / or the contact detection unit _{Q S2) (V P1 -V PM} ) that is turned on switching elements (Q _S1 connected to, Q _S2 ) is applied to the corresponding sensing signal lines P ₁ -P _M.

The signal reading unit 800 reads the sensing signals V _P1 -V _PM applied to the sensing signal lines P ₁ -P _M in accordance with the read control signal CONT4. The signal reader 800 converts the read sensing signals V _P1 -V _PM into a digital signal DSN after signal processing such as amplification and filtering, and then outputs them to an external device. The external device performs appropriate arithmetic processing on the digital signal DSN to find out whether or not it has been touched and the contact position, and transmits an image signal based thereon to the liquid crystal display.

The sensing operation is performed separately from the display operation described above, and is not affected by each other. The sensing operation for one row is performed every one horizontal period or a plurality of horizontal periods according to the formation density of the light sensing unit and the contact sensing unit. In addition, a sensing operation of one sensing unit does not necessarily need to be performed every frame, but may be performed once every plurality of frames as necessary.

Next, the structure of the liquid crystal display according to the exemplary embodiment of the present invention will be described in detail with reference to FIGS. 5 to 7.

FIG. 5 is an example of layout view of a liquid crystal display according to an exemplary embodiment of the present invention, and FIGS. 6 and 7 respectively illustrate lines VI-VI ', VII-VII', and VII'-VII of the liquid crystal display of FIG. "Is a cross-sectional view cut along the line.

The liquid crystal display according to the exemplary embodiment of the present invention includes a thin film transistor array panel 100 and a common electrode panel 200 facing each other, and a liquid crystal layer interposed between the thin film transistor array panel 100 and the common electrode panel 200. It consists of (3).

First, as illustrated in FIGS. 5 to 7, the thin film transistor array panel 100 includes a plurality of image scanning lines 121, a plurality of sustain electrode lines 131, a plurality of sensing scan lines 127, and the like on the insulating substrate 110. A plurality of control voltage lines 129 are formed.

The scan lines 121 and 127 and the control voltage line 129 mainly extend in the horizontal direction and are separated from each other, and transmit the image scan signal, the sense scan signal, and the control voltage V _SG , respectively, and each of the plurality of control terminal electrodes ( control electrodes 124, 128, 126.

The storage electrode line 131 mainly extends in the horizontal direction and includes a plurality of protrusions constituting the storage electrode 133. A predetermined voltage such as a common voltage applied to the common electrode 270 of the common electrode display panel 200 is applied to the sustain electrode line 131.

The scan lines 121 and 127, the sustain electrode line 131, and the control voltage line 129 are made of aluminum-based metals such as aluminum and aluminum alloys, silver-based metals such as silver and silver alloys, copper-based metals such as copper and copper alloys, and molybdenum And a molybdenum-based metal such as molybdenum alloy, chromium, titanium, and tantalum are preferable. The scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129 may include two layers having different physical properties, that is, a lower layer (not shown) and an upper layer (not shown) thereon. have. The upper layer is made of a low resistivity metal such as aluminum (Al) or aluminum alloy to reduce signal delay or voltage drop of the scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129. It is made of a series of metals. In contrast, the lower layer is made of a material having excellent contact properties with other materials, particularly indium tin oxide (ITO) and indium zinc oxide (IZO), such as molybdenum (Mo), molybdenum alloy, chromium (Cr), and the like. An example of the combination of the lower layer and the upper layer is chromium / aluminum-neodymium (Nd) alloy.

The scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129 may have a single layer structure or may include three or more layers.

In addition, the scanning lines 121 and 127, the sustain electrode line 131, and the control voltage line 129 are inclined with respect to the surface of the substrate 110, and the inclination angle thereof is about 30-80 ° with respect to the surface of the substrate 110. .

An insulating layer 140 made of silicon nitride (SiNx) is formed on the scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129.

A plurality of linear semiconductors 151 and a plurality of island-like semiconductors 156, 158, and 159 made of hydrogenated amorphous silicon (amorphous silicon is abbreviated a-Si) and the like are formed on the insulating layer 140. have. The linear semiconductor 151 extends mainly in the longitudinal direction, from which a plurality of projections 154 extend toward the control terminal electrode 124, from which the plurality of extensions 157 extend. In addition, the linear semiconductor 151 increases in width near the point where the scan lines 121 and 127, the sustain electrode line 131, and the control voltage line 129 meet, and thus the scan lines 121 and 127, the sustain electrode line 131, and the control voltage line 129. Covers a large area).

On top of the semiconductors 151, 156, 158, 159 a plurality of linear and island ohmic contacts 161 made of a material such as n + hydrogenated amorphous silicon doped with silicide or n-type impurities in high concentration. , 162, 164, 165, 166, and 168 are formed. The linear contact member 161 has a plurality of protrusions 163, and the protrusions 163 and the island contact members 165 are paired and positioned on the protrusions 154 of the semiconductor 151. In addition, the island contact members 162 and 164 and the island contact members 166 and 168 are also paired and positioned on the island semiconductors 156 and 158, respectively.

Side surfaces of the semiconductors 151, 156, 158, and 159 and the ohmic contacts 161, 162, 164, 165, 166, and 168 are also inclined with respect to the surface of the substrate 110, and the inclination angle is 30-80 °.

The plurality of data lines 171, the plurality of sensing signal lines 179, the plurality of output terminal electrodes 174, 175, and the plurality of resistive contact members 161, 162, 164, 165, 166, 168, and the insulating layer 140. Input terminal electrodes 172 and 176 are formed.

The data line 171 and the sensing signal line 179 mainly extend in the vertical direction to intersect the scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129, and transmit data voltage and sensing signals, respectively. do.                     

Each output terminal electrode 175 includes an extension 177 overlapping one storage electrode 133. Each of the data lines 171 includes a plurality of protrusions, and a vertical portion including the protrusions forms an input terminal electrode 173 partially surrounding one end of the output terminal electrode 175. One control terminal electrode 124, one input terminal electrode 173, and one output terminal electrode 175, together with the protrusion 154 of the semiconductor 151, form one thin film transistor (TFT). The channel of the thin film transistor is formed in the protrusion 154 between the input terminal electrode 173 and the output terminal electrode 175. This thin film transistor functions as the switching element Q.

The pair of input terminal electrodes 172 and output terminal electrodes 174 are separated from each other and are located opposite to each other with respect to the control terminal electrode 126. One control terminal electrode 126, one input terminal electrode 172, and one output terminal electrode 174 together with the semiconductor 156 constitute one thin film transistor (TFT), and the channel of the thin film transistor is an input terminal. Is formed in the semiconductor 156 between the electrode 172 and the output terminal electrode 174. This thin film transistor functions as a sensing element Q _T.

The output terminal electrode 174 and the input terminal electrode 176 are connected to each other. Each sensing signal line 179 includes a plurality of horizontal portions and a plurality of vertical portions, and some of the vertical portions of the sensing signal lines 179 form an output terminal electrode 178. The pair of input terminal electrodes 176 and output terminal electrodes 178 are separated from each other and are located opposite to each other with respect to the control terminal electrode 128. One control terminal electrode 128, one input terminal electrode 176 and one output terminal electrode 178 together with the semiconductor 158 constitute one thin film transistor (TFT), and the channel of the thin film transistor is an input terminal. Is formed in the semiconductor 158 between the electrode 176 and the output terminal electrode 178. This thin film transistor functions as a switching element Q _S2 .

The data line 171, the sensing signal line 179, the output terminal electrodes 174 and 175, and the input terminal electrodes 172 and 176 are preferably made of a refractory metal such as chromium or molybdenum-based metal, tantalum and titanium, and molybdenum (Mo), molybdenum alloy, chromium (Cr), such as a lower layer (not shown) and may be a multilayer film structure consisting of an upper layer (not shown), which is an aluminum-based metal located thereon.

The data line 171, the sensing signal line 179, the output terminal electrodes 174 and 175, and the input terminal electrodes 172 and 176 are similar to the scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129. The sides are inclined at an angle of about 30-80 ° respectively.

The ohmic contacts 161, 162, 164, 165, 166, and 168 may include semiconductors 151, 156, 158, and 159 at the lower portion thereof, data lines 171, sensing signal lines 179, and output terminal electrodes at upper portions thereof. It exists only between the 174 and 175 and the input terminal electrode (172, 176) serves to lower the contact resistance. The linear semiconductor 151 has an exposed portion between the input terminal electrode 173 and the output terminal electrode 175, and is not covered by the data line 171 and the output terminal electrode 175, and in most places, the linear semiconductor 151 is provided. Although the width of the 151 is smaller than the width of the data line 171, the width becomes larger at the portion where the scan lines 121 and 127, the storage electrode line 131, and the control voltage line 129 meet, and thus the scan lines 121 and 127 and the storage electrode line ( 131 and the insulation between the control voltage line 129 and the data line 171 is strengthened.

The data line 171, the sensing signal line 179, the output terminal electrodes 174 and 175, and the input terminal electrodes 172 and 176 and the exposed portion of the semiconductor 151 are made of an inorganic material such as silicon nitride or silicon oxide. A passivation layer 180 is formed, and an organic insulating layer 187 formed of an organic material having excellent planarization characteristics and photosensitivity is formed on the passivation layer 180. In this case, the surface of the organic insulating layer 187 has a concave-convex pattern, and the concave-convex pattern is induced to the reflective electrode 194 formed on the organic insulating layer 187 to maximize the reflection efficiency of the reflecting electrode 194.

In the passivation layer 180 and the organic insulating layer 187, contact holes 185 and 188 exposing the extension 177 of the output terminal electrode 175 and the input terminal electrode 172 are formed. The contact holes 185 and 188 may be made in various shapes such as polygons or circles. The side walls of the contact holes 185, 188 are inclined or stepped at an angle of 30-85 °.

In addition, a depression 199 lower than the peripheral height is formed in the organic insulating layer 187. The depressions 199 may be formed by exposing and developing the concave-convex pattern on the organic insulating layer 187 or may be formed using a separate mask.

A plurality of pixel electrodes 190 and a plurality of sensing electrodes 198 are formed on the organic insulating layer 187.

The pixel electrode 190 includes a transparent electrode 192 and a reflective electrode 194 formed on the transparent electrode 192. The transparent electrode 192 is made of ITO or IZO, which is a transparent conductive material, and the reflective electrode 194 may be made of aluminum or an aluminum alloy, silver or silver alloy, which are opaque and have reflectivity. The pixel electrode 190 may further include a contact auxiliary layer (not shown) made of molybdenum or molybdenum alloy, chromium, titanium, or tantalum. The contact auxiliary layer secures contact characteristics between the transparent electrode 192 and the reflective electrode 194 and prevents the transparent electrode 192 from oxidizing the reflective electrode 194.

One pixel is largely divided into a transmission area TA and a reflection area RA. The transmission area TA 195 is an area where the reflection electrode 194 is removed, and the reflection area RA is a reflection electrode ( 194) exists. The organic insulating layer 187 is removed from the transmission area TA 195 so that a cell gap of the transmission area TA 195 and a cell gap of the reflection area RA are different from each other.

The pixel electrode 190 is physically and electrically connected to the extension 177 of the output terminal electrode 175 through the contact hole 185 to receive a data voltage from the output terminal electrode 175. The pixel electrode 190 to which the data voltage is applied rearranges the liquid crystal molecules of the liquid crystal layer 3 between the two by generating an electric field together with the common electrode 270.

In addition, as described above, the pixel electrode 190 and the common electrode 270 form a liquid crystal capacitor C _LC to maintain an applied voltage even after the thin film transistor is turned off. _LC holding capacitor (C _ST ) in parallel. The storage capacitor C _ST is formed by overlapping the extension 177 of the output terminal electrode 175 and the storage electrode 133. The storage capacitor C _ST may be formed by overlapping the pixel electrode 190 and the adjacent image scanning line 121, and the storage electrode line 131 may be omitted.

The pixel electrode 190 overlaps the scan line 121 and the neighboring data line 171 to increase the aperture ratio, but may not overlap.

A transparent conductive polymer or the like may be used as the material of the pixel electrode 190, and in the case of a reflective liquid crystal display, an opaque reflective metal may be used.

The sensing electrode 198 includes a lower layer 196 and an upper layer 197 made of the same material as the transparent electrode 192 and the reflective electrode 194, respectively. Similar to the pixel electrode 190, the sensing electrode 198 may further include a contact auxiliary layer (not shown) or may be formed of a single layer.

A portion of the sensing electrode 198 is formed on the depression 199 of the organic insulating layer 187, has a lower height than the periphery, and switches together with the common electrode 270 disposed on the protrusion 240 of the common electrode display panel 200. (SWT).

The sensing electrode 198 is physically and electrically connected to the input terminal electrode 172 through the contact hole 188. When the switch SWT is turned on according to the user's contact, the common voltage V _com from the common electrode 270 is transmitted as the input voltage V _SD to the input terminal electrode 172 through the sensing electrode 198.

The green (G) and blue (B) pixel electrodes 190 are formed in a rectangular shape, but the red (R) pixel electrode 190 is formed in a shape in which one corner is cut according to the shape of the sensing electrode 198. However, the sizes of the transmission area TA and the reflection area RA of the red (R), green (G), and blue (B) pixels are substantially the same.

As described above, according to the exemplary embodiment of the present invention, the transmittance may be increased by increasing the transmissive area as compared with the conventional liquid crystal display in which the detector is formed inside the pixel. The total area of the red (R), green (G), and blue (B) pixels of the conventional liquid crystal display is the same as the total area of the red (R), green (G), and blue (B) pixels of the present embodiment and the sensing unit. In this case, the size of each pixel of this embodiment is reduced as compared with that of the conventional one. However, in the conventional liquid crystal display, the biggest reason why the transmissive area cannot be increased is that the space occupied by the sensing signal line and the input voltage line in the pixel is large. I can make it big.

The sensing area is shown as being between the blue (B) pixel and the red (R) pixel, but may be disposed between the green (G) and blue (B) pixels or between the red (R) and green (G) pixels. have.

On the common electrode panel 200 facing the thin film transistor array panel 100, a light blocking member 220 called a black matrix is formed on a substrate 210 made of an insulating material such as transparent glass. The light blocking member 220 prevents light leakage between the pixel electrodes 190 and defines an opening area facing the pixel electrode 190.

The plurality of color filters 230 are formed on the substrate 210 and the light blocking member 220, and are disposed to substantially enter the opening region defined by the light blocking member 220. The color filters 230 disposed between two neighboring data lines 171 and arranged in the vertical direction may be connected to each other to form a band. Each color filter 230 may represent one of three primary colors such as red, green, and blue.

An overcoat 250 made of an organic material is formed on the color filter 230 and the light blocking member 220 to protect the color filter 230 and to flatten the surface.

The primary common electrode 271 formed of a transparent conductive material such as ITO or IZO is formed on the overcoat 250. The thickness of the primary common electrode 271 is preferably in the range of 0.05 to 0.1 mu m.

A plurality of protrusions 240 and a plurality of column spacers 245 formed of an organic material are formed on the primary common electrode 271, and the primary common electrode 271, the protrusion 240, and the column spacer 245 are formed. On the upper side, a secondary common electrode 272 made of a transparent conductive material such as ITO or IZO is formed. The thickness of the secondary common electrode 272 is preferably in the range of 0.05 to 0.2 mu m.

The common electrode 270 includes primary and secondary common electrodes 271 and 272, and the primary common electrode 271 may be omitted as necessary.

The protrusion 240 is disposed corresponding to the position where the depression 199 of the thin film transistor array panel 100 is formed. When the protrusion 240 is pressed by the thin film transistor array panel 100 according to a user's contact, the secondary common electrode 272 on the protrusion 240 comes into contact with the sensing electrode 198 on the depression 199, thereby providing a common voltage. V _com is transmitted to the input terminal electrode 172.

Meanwhile, an alignment layer (not shown) is formed between the secondary common electrode 272 and the sensing electrode 198 to align the liquid crystal molecules of the liquid crystal material layer 3, but the common voltage V _com is substantially the same. (198) has little impact on delivery.

The column spacer 245 is disposed in the sensing region in which the sensing signal line 179 extends vertically, and is disposed in the region where the pixel electrode 190 of the thin film transistor array panel 100 is not formed. The column spacer 245 supports the thin film transistor array panel 100 and the common electrode panel 200 to maintain a gap therebetween.

The protrusion 240 and the column spacer 245 are formed at substantially the same height. The protrusion 240 and the column spacer 245 may be formed in a desired shape and height by applying and patterning an organic film or the like.

The thin film transistor array panel 100 and the common electrode panel 200 are formed around the edges and are coupled by a sealing material (not shown) to trap the liquid crystal material, and are supported by the column spacer 245. Separately, beads spacers 320 (see FIGS. 8A and 8B) may be provided to maintain their spacing together with the column spacer 245. At this time, the beads spacer 320 is spherical and irregularly distributed.

In the thin film transistor array panel 100 and the common electrode display panel 200, the distance t between the sensing electrode 198 on the depression 199 and the secondary common electrode 272 on the protrusion 240 is It is preferable that it is 0.1-1.0 micrometer. Since the height of the depression 199 is controlled relatively less than the exposure amount, the distance t can be controlled stably.

A polarizer (not shown) for polarizing light is attached to an outer surface of at least one of the two display panels 100 and 200 of the liquid crystal panel assembly 300.

Next, operations of the touch sensing unit of the liquid crystal display according to the exemplary embodiment of the present invention will be described in detail with reference to FIGS. 8A and 8B.

8A and 8B are schematic diagrams for describing an operation of a touch sensing unit of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 8A is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention without any contact. As illustrated in FIG. 8A, a pixel layer 115 is formed on the insulating substrate 110 in the thin film transistor array panel 100. A pixel, a sensing unit, and the like are formed in the pixel layer 115, and the sensing electrode 198 of the sensing element Q _T of the touch sensing unit is exposed on the pixel layer 115.

8B is a cross-sectional view of the liquid crystal display according to the exemplary embodiment of the present invention with the user's finger or the like being in contact. As shown in FIG. 8B, the common electrode panel 200 is pressed by the pressure according to the contact so that the common electrode 270 surrounding the protrusion 240 at the contact point portion is electrically connected to the sensing electrode 198 of the thin film transistor array panel 100. Is connected. Accordingly, the common voltage V _com is transmitted to the input terminal electrode 172 so that the sensing element Q _T flows a sensing current.

According to the touch sensing unit, the common electrode display panel 200 made of glass or the like is pressed over a large area by a user's contact (pressure), so that a plurality of switches SWT are connected, and thus it is difficult to accurately detect the contact position, Can be determined or an approximate contact area can be determined.

Next, a liquid crystal display according to another exemplary embodiment of the present invention will be described in detail with reference to FIGS. 9 and 10.

In the following, the same parts as in the previous embodiment will be omitted, and only differences will be described.

FIG. 9 is an enlarged layout view of a touch sensing unit of a liquid crystal display according to another exemplary embodiment, and FIG. 10 is an example of a schematic diagram of arrangement of pixels and sensing units of a liquid crystal display according to another exemplary embodiment.

As shown in Fig. 9, the data line 171 adjacent to the sensing unit is refracted without extending straight in the vertical direction as in the previous embodiment. The data line 171 has a first vertical portion passing through the left side of the switching element Q _S2 and the sensing element Q _T , a horizontal portion refracted therefrom and passing below the sensing element Q _T , and again refracted therefrom. And a second vertical portion extending side by side along the sensing signal line 179. If the data line 171 is formed in this way, the size of the pixel can be made larger, and the aperture ratio can be further increased.

As illustrated in FIG. 10, the pixel and the sensing unit disposed in the two pixel rows have a symmetrical structure with respect to the boundary between the two pixel rows. One sensing area S includes a narrow portion in which the sensing signal line 179 extends vertically and a wide portion in which the sensing element and the switching element are formed. The narrow part of one sensing area S is connected to the narrow part of the adjacent sensing area S, and the wide part of one sensing area S is connected to the wide part of the adjacent sensing area S. FIG. The first vertical portion of the data line 171 of one pixel is connected to the first vertical portion of the data line 171 of the pixel adjacent up or down, and the second vertical portion is the data line 171 of the pixel adjacent up or down. It is connected with the 2nd vertical part of. As described above, when the line symmetry is formed on the boundary between the two pixel rows, the number of refractions of the data line 171 may be reduced, thereby reducing the distortion of the data voltage.

Next, a liquid crystal display according to another exemplary embodiment of the present invention will be described with reference to FIG. 11.

FIG. 11 is a cross-sectional view of a liquid crystal display according to another exemplary embodiment, taken along lines VII-VII ′ and VII′-VII ″ of the liquid crystal display of FIG. 5.

As shown in FIG. 11, the depression 199 is not formed on the organic insulating layer 187 of the thin film transistor array panel 100, and instead, the sensing electrode 198 having the same height as the periphery is formed.

The protrusions 240 and the column spacers 245 of the common electrode panel 200 have different heights. The height of the protrusion 240 is lower than that of the column spacer 245, and the secondary common electrode 272 is formed on the protrusion 240 and the column spacer 245.

However, the distance t between the common electrode 270 and the sensing electrode 198 on the protrusion 240 is preferably formed to be in the range of 0.1 to 1.0 μm, the same as the distance t in the previous embodiment. .

Next, the touch sensing unit of the liquid crystal display according to another exemplary embodiment of the present invention will be described in detail with reference to FIGS. 12A to 12B.

12A to 12C are equivalent circuit diagrams of a touch sensing unit of a liquid crystal display according to another exemplary embodiment of the present invention.

Also it includes a switching element (Q _S2) is connected to a contact detection unit 12a shown in the common voltage is connected to the (V _com) switch (SWT) and the signal line (S _i, P _j) in.

The switch SWT transfers the common voltage V _com to the switching element Q _S2 according to a user's contact.

A switching element (Q _S2) is a three-terminal device a control terminal, an output terminal and an input terminal thereof is connected to a respective scan line detection (S _i), detection signal line (P _j) and a switch (SWT). A switching element (Q _S2) detects the scanning line when the (S _i) a voltage for turning on the switching element (Q _S2) applied to the common voltage (V _com) from the switch (SWT), depending on the user's contact with the touch sensing signal ( V _Pj ) is output directly to the corresponding sensing signal line P _j .

The contact sensing unit illustrated in FIG. 12B is a switch SWT connected to the common voltage V _com , a sensing element Q _T connected to the switch SWT and the signal line P _SD , and a signal line _Si and P _j . It includes a switching element Q _S2 connected to.

The sensing element Q _T is a three-terminal element whose input terminal and control terminal are connected to the input voltage line P _SD and the switch SWT, respectively, and the output terminal is connected to the switching element Q _S2 . The sensing element Q _T receives the common voltage V _com transmitted from the switch SWT to the control terminal and outputs a sensing current according thereto.

A switching element (Q _S2) is also a three-terminal device a control terminal, an output terminal and an input terminal thereof is connected to a respective scan line detection (S _i), detection signal line (P _j) and the sensing element (Q _T). A switching element (Q _S2) detects the scanning line corresponding as (S _i) the switching device (Q _S2) turns when on, the voltage applied to the sensing element detects contact the sensing current from the (Q _T) signal (V _Pj) to the sense signal line Output as (P _j ).

The touch sensing unit illustrated in FIG. 12C shows a switch SWT connected to the common voltage V _com , a sensing element Q _T connected to the switch SWT, and a switching element Q connected to the signal lines _Si and P _j . _S2 ).

The sensing element Q _T is a three-terminal element whose input terminal and control terminal are connected to each other and connected to the switch SWT, and the output terminal is connected to the switching element Q _S2 . The sensing element Q _T receives the common voltage V _com transmitted from the switch SWT and outputs a sensing current according thereto.

A switching element (Q _S2) and outputs a sense current from the sense elements (Q _T) similarly to the switching device (Q _S2) shown in Figure 12b.

The switch SWT of the touch sensing unit illustrated in FIGS. 12A to 12C includes a common electrode 270 and a sensing electrode 198 surrounding the protrusion 240 as in the previous embodiment.

Meanwhile, in the exemplary embodiment of the present invention, the liquid crystal display device has a built-in sensing unit in a region between pixels, but the present invention is not limited thereto, but the plasma display device and the organic light emitting diode display are not limited thereto. The same may be applied to a display device such as an emitting display.

According to the present invention, whether or not the touch can be easily determined by receiving the common voltage according to the user's touch and generating a detection signal according to the touch.

In addition, by disposing the touch sensing unit in the area between the pixels, the transmittance can be increased by increasing the transmission area.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (14)

First substrate, A second substrate facing the first substrate, A plurality of pixel electrodes formed on the second substrate, A sensing signal line formed on the second substrate, A common electrode formed on the first substrate and a sensing electrode formed on the second substrate, and formed between two adjacent pixel electrodes, and configured to generate a touch sensing signal based on a common voltage according to a user's contact. A touch sensing unit which is generated and output to the sensing signal line according to a sensing scan signal Display device comprising a. In claim 1, The common voltage is applied to the common electrode, and the common electrode and the sensing electrode are electrically connected by the contact. In claim 2, A protrusion formed on the first substrate and protruding toward the sensing electrode, The common electrode is formed on the protrusion Display device. In claim 3, The display device between the common electrode and the sensing electrode is 0.1 to 1.0㎛. In claim 3, The common electrode includes a primary common electrode and a secondary common electrode, The protrusion is formed on the primary common electrode, The secondary common electrode is formed on the protrusion and the primary common electrode. Display device. In claim 5, The thickness of the primary common electrode is 0.05 to 0.1㎛, the thickness of the secondary common electrode is 0.05 to 0.2㎛ display device. In claim 3, An organic insulating film having a depression and formed under the sensing electrode and the pixel electrode, The sensing electrode is formed on the depression, and the height of the sensing electrode is lower than the height of the pixel electrode. Display device. In claim 7, The organic insulating layer has an uneven pattern, and the depression and the uneven pattern are formed in the same process. In claim 3, A column spacer formed on the first substrate and maintaining a distance between the first substrate and the second substrate, The height of the column spacer and the protrusion is substantially the same Display device. In claim 3, A light sensing unit formed on the second substrate and formed between two adjacent pixel electrodes on which the touch sensing unit is not disposed, and generating an optical sensing signal based on the amount of light by receiving external light and outputting the light sensing signal to the sensing signal line; Display device including. In claim 3, A data line connected to the pixel electrode to transfer a data voltage; The data line adjacent to the touch sensing unit is refracted along the touch sensing unit. Display device. In claim 11, And the data line is symmetrical with respect to a boundary between two vertically adjacent pixel electrodes. In claim 3, The touch sensing unit may further include a sensing element including a control terminal, an input terminal, and an output terminal, and the input terminal is connected to the sensing electrode. In claim 13, The touch sensing unit further includes a switching element connected to an output terminal of the sensing element and emitting the touch sensing signal.

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