KR20120097762A - Touch sensor integrated liquid cryctal display device - Google Patents

Abstract

PURPOSE: A liquid crystal display device integrated with a touch sensor is provided to perform display and touch based on time-division to minimize signal interference during the display and touch, thereby increasing touch recognition quality. CONSTITUTION: A plurality of pixel electrodes(115) are formed on one side of a first substrate. The first substrate faces a second substrate. A common electrode(119) is overlapped with the pixel electrodes wherein an insulating layer is formed between the common electrode and the pixel electrodes. The common electrode is formed on one side of the first substrate. A touch detecting unit(TD) is arranged on one side of the second substrate. One side of the second substrate is a side opposite to a side that the first substrate faces.

Description

Touch sensor integrated liquid crystal display {TOUCH SENSOR INTEGRATED LIQUID CRYCTAL DISPLAY DEVICE}

The present invention relates to a display device, and more particularly to a touch sensor integrated liquid crystal display device.

Touch sensors include Liquid Crystal Display, Field Emission Display (FED), Plasma Display Panel (PDP), Electroluminescence Device (EL), Electrophoretic Display It is a type of input device installed in an image display device such as an input device for inputting predetermined information by pressing (touching or touching) the touch panel while the user views the image display device.

The touch sensor used in the above-described display device may be classified into an add-on type, an on-cell type, and an integrated type according to its structure. The top plate attaching type is a method of attaching the touch sensor to the top plate of the display device after separately manufacturing the display device and the touch sensor. The upper plate integrated type directly forms elements constituting the touch parser on the upper glass substrate surface of the display device. The built-in type has a built-in touch sensor inside the display device to achieve a thin display device and enhance durability.

However, the top-mounted touch sensor has a structure in which the completed touch sensor is mounted on the display device and is thick, and the brightness of the display device is dark. In addition, the upper panel integrated touch sensor has a structure in which a separate touch sensor is formed on the upper surface of the display device, and may have a thickness smaller than that of the upper panel attached type, but is still due to the driving electrode layer, the sensing electrode layer, and the insulating layer for insulating the touch sensor. There was a problem that the manufacturing thickness increases due to the increase in the overall thickness and the number of processes.

On the other hand, the built-in touch sensor has the advantage that can solve the problems caused by the top plate attached and the top plate integrated touch sensor in that durability and thickness can be reduced. These embedded touch sensors are classified into light type and pressure type.

The optical touch sensor is a method of forming a light sensing layer on a thin film transistor substrate array of a display device and recognizing light reflected through an object present in a touched portion by using light from an backlight unit or infrared light. However, the optical touch sensor shows relatively stable driving performance when the surroundings are dark, but light stronger than the reflected light acts as noise when the surroundings are bright. This is because the intensity of light reflected by the actual touch is so weak that even a little bright outside may cause an error in touch recognition. In particular, the optical touch sensor has a problem that may occur even when the surrounding environment is exposed to sunlight, the light intensity is so strong that the touch is not recognized in the child.

The pressure type touch sensor detects a touch by detecting a change in the gap between the upper glass substrate and the lower glass substrate according to the pressure to be touched. It is a way of recognizing.

The pressure touch sensor must press the upper glass substrate to change the gap between the upper glass substrate and the lower glass substrate, but there is a problem that the gap hardly changes by the soft touch. In addition, when the glass is thinned to solve such a problem, the touch characteristics are improved, but the durability is weakened, which may cause a serious problem that the device is easily broken or deformed.

Accordingly, there is a need for a touch sensor integrated liquid crystal display that can solve the problems caused by the prior art.

The present invention is to solve the above-mentioned conventional problems, an object of the present invention is to use a touch sensing element for recognizing the touch of the display device with the components of the display device to reduce the thickness and improve the durability of the touch sensor It is to provide an integrated liquid crystal display device.

Another object of the present invention is to provide a touch sensor-integrated liquid crystal display device which can improve display recognition quality by minimizing signal interference during display driving and touch driving by driving display driving and touch driving in time division.

In order to achieve the above object, a touch sensor integrated liquid crystal display device according to an embodiment of the present invention comprises: a first substrate and a second substrate facing each other with a liquid crystal layer interposed therebetween; A plurality of pixel electrodes formed on one surface of the first substrate facing the second substrate; A common electrode formed on one surface of the first substrate so as to overlap the plurality of pixel electrodes with an insulating layer interposed therebetween; And a touch detector disposed on one surface of the second substrate, the surface opposite to the surface facing the first substrate.

The touch detector includes a base film and a plurality of touch detection electrodes formed on one surface of the base film and arranged side by side in a first direction, wherein the plurality of touch detection electrodes are disposed to face the common electrode. And to form a capacitance between the common electrode and the common electrode.

The touch sensor integrated liquid crystal display may further include a first polarizing plate formed on the other surface of the first substrate and a second polarizing plate formed between the other surface of the base film and one surface of the second substrate.

The touch sensor integrated liquid crystal display may further include a second polarizing plate formed between the other surface of the base film and one surface of the second substrate.

The touch sensor integrated liquid crystal display may further include a first polarizing plate formed on the other surface of the first substrate, and a second polarizing plate formed between the other surface of the base film and one surface of the second substrate.

The touch sensor integrated liquid crystal display may further include a tempered glass layer attached to the plurality of detection electrodes.

The common electrode may include a plurality of first touch electrodes arranged side by side in at least the first direction and a plurality of second touch electrodes arranged side by side in a second direction crossing the first direction. Each of the first and second touch electrodes is configured to correspond to a plurality of sizes of the pixel electrodes.

In addition, the touch sensor integrated liquid crystal display further includes signal driving lines for connecting the first and second touch electrodes arranged in the first direction or the second direction in the first direction or the second direction. It is configured to include.

The touch sensor integrated liquid crystal display may be driven by a time division in which touch driving is turned off during display driving and display driving is turned off during touch driving, and a common voltage is supplied to the common electrode during the display driving. During touch driving, a touch driving voltage is supplied to the common electrode.

According to an embodiment of the present invention, by using a touch sensing element for recognizing a touch of a liquid crystal display with a display device component, it is possible to reduce the thickness, improve durability, and improve the visibility. Can be.

In addition, since the display drive and the touch drive of the touch sensor integrated liquid crystal display are driven by time division, the touch drive is turned off during display and the display drive is turned off during touch, so that the signal interference between the display drive and the touch drive is reduced. Minimized to achieve the effect of improving the touch recognition quality.

1 is a schematic block diagram of a touch sensor integrated liquid crystal display according to an embodiment of the present invention;
2 is a cross-sectional view of a touch sensor integrated liquid crystal display device according to an embodiment of the present invention;
3 is a cross-sectional view of a touch sensor integrated liquid crystal display device according to another embodiment of the present invention;
4 is a schematic view showing a touch electrode and a connection relationship of the common electrodes constituting the common electrode according to an embodiment of the present invention;
5 is a timing diagram of a touch sensor integrated liquid crystal display according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals throughout the specification denote substantially identical components.

1 is a schematic block diagram of a touch sensor integrated liquid crystal display according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a touch sensor integrated liquid crystal display according to an embodiment of the present invention, and FIG. 3 is another embodiment of the present invention. 4 is a cross-sectional view illustrating a touch sensor constituting a common electrode according to an embodiment of the present invention and a connection relationship thereof, and FIG. 5 is a touch sensor according to an embodiment of the present invention. A timing diagram of an integrated liquid crystal display device.

1 and 2, a touch sensor integrated liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal display panel including a color filter array (CFA) and a thin film transistor array (TFTA), a touch detector (TD), and a backlight. A unit BLU, a host controller 100, a timing controller 101, a data driver 102, a gate driver 103, a power supply 105, a touch recognition processor 107, and the like.

The liquid crystal display panel LCP includes a color filter array CFA and a thin film transistor array TFTA bonded by the sealant 133, and a liquid crystal layer 130 is formed therebetween.

The thin film transistor array TFTA includes a first substrate 110 as a circuit board, a plurality of pixel electrodes 115 arranged in a matrix form on one surface of the first substrate 110, and the plurality of pixel electrodes 115. ) An insulating layer 117 formed on the plurality of pixels, and a common electrode 119 formed on the insulating layer 117 and disposed to face the plurality of pixel electrodes 115. Here, the common electrode 119 constitutes a part of the touch sensor for performing a touch detection operation and is used as a driving electrode of the touch sensor.

The thin film transistor array TFTA also includes a thin film transistor for driving the plurality of pixel electrodes 115 and wirings for supplying a pixel signal to the plurality of pixel electrodes 115, but these components are liquid crystal displays. Since a general component of the device, a detailed description thereof will be omitted. The first polarizer 113 is adhered to the other surface of the first substrate 110 of the thin film transistor array TFTA.

The color filter array CFA includes a color filter and a black matrix formed on one surface of the second substrate 120. Since the color filter and the black matrix of the color filter array CFA are also general components of the liquid crystal display, detailed description thereof will be omitted. The second polarizing plate 123 is formed on the other surface of the second substrate 120.

The touch detector TD includes a base film 140 and a plurality of touch detection electrodes 143 arranged side by side in a first direction at predetermined intervals on one surface of the base film 140. The plurality of detection electrodes 143 may be disposed to face the common electrode 119 formed on the first substrate 110 of the thin film transistor array TFTA to form capacitance between the common electrodes 119. It is formed on the other surface of the second substrate 120 of the filter array (CFA). The second polarizer 123 is formed between the touch detector TD and the second substrate 120. The touch detection electrodes 143 constituting the touch detector TD constitute a part of a touch sensor that performs a touch detection operation and are used as sensing electrodes. The tempered glass layer 150 is attached to the other surface of the base film 140 constituting the touch detector TD by the adhesive layer 160 so that the touch detector TD is not damaged by an external environment.

The backlight unit BLU is disposed under the liquid crystal display panel LCP. The backlight unit BLU uniformly radiates light to the liquid crystal display panel LCP including a plurality of light sources. The backlight unit (BLU) may be implemented as a direct type backlight unit or an edge type backlight unit. The light source of the backlight unit may include at least one of a hot cathode fluorescent lamp (HCFL), a cold cathode fluorescent lamp (CCFL), an external electro fluorescent lamp (EEFL), and a light emitting diode (LED).

The data driver 102 samples and latches digital video data (RGB) under the control of the timing controller 101. The data driver 102 converts the digital video data RGB to positive / negative gamma compensation voltages GMA1 to GMAn to invert the polarity of the data voltage. The positive / negative polarity data voltage output from the data driver 102 is synchronized with the gate pulse output from the gate driver 103. Each of the source drive integrated circuits (ICs) of the data driver 102 is connected to the data lines DL of the liquid crystal display panel LCP using a chip on glass (COG) process or a tape automated bonding (TAB) process. Can be. The source drive IC may be integrated in the timing controller 101 and implemented as a one-chip IC together with the timing controller 101.

The gate driver 103 sequentially outputs a gate pulse (or scan pulse) under the control of the timing controller 101 and shifts the swing voltage of the output to the gate high voltage VGH and the gate low voltage VGL. The gate pulses output from the gate driver 103 are sequentially supplied to the gate lines GL in synchronization with the data voltages output from the data driver 102. The gate high voltage VGH is higher than or equal to the threshold voltage of the thin film transistor, and the gate low voltage VGH is lower than the threshold voltage of the thin film transistor. The gate drive ICs of the gate driver 103 are connected to the gate lines GL of the first substrate 110 of the liquid crystal display panel LCP through the TAP process, or are connected to the liquid crystal display panel together with the pixels in the GIP process. It may be directly formed on the first substrate 110 of the LCP.

The timing controller 101 generates timing control signals for controlling the operation timing of the data driver 102 and the gate driver 103 using the timing signal from the host controller 100. The timing control signals for controlling the operation timings of the data driver 102 and the gate driver 103 include a gate timing control signal for controlling the operation timing of the gate driver 103 and an operation timing of the data driver 102, And a data timing control signal for controlling the polarity of the voltage.

The gate timing control signal includes a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable signal (GOE), and the like. The gate start pulse GSP is applied from the gate driver 103 to the first gate drive IC that outputs the gate pulse first in every frame period to control the shift start timing of the gate drive IC. The gate shift clock GSC is a clock signal commonly input to the gate drive ICs of the gate driver 103 to shift the gate start pulse GSP. The gate output enable signal GOE controls the output timing of the gate drive ICs of the gate driver 103. [

The data timing control signal includes a source start pulse (SSP), a source sampling clock (SSC), a polarity control signal (POL), and a source output enable signal (SOE). It includes. The source start pulse SSP is applied to the first source drive IC which samples the data first in the data driver 102 to control the data sampling start timing. The source sampling clock SSC is a clock signal that controls sampling timing of data in the source drive ICs based on a rising or falling edge. The polarity control signal POL controls the polarity of the data voltages output from the source drive ICs. The source output enable signal SOE controls the output timing of the source drive ICs. the source start pulse SSP and the source sampling clock SSC may be omitted if digital video data RGB is input to the data driver 102 through the mini LVDS interface.

The power supply 105 includes a DC-DC converter including a pulse width modulation (PWM) modulation circuit, a boost converter, a regulator, a charge pump, a voltage divider circuit, an operation amplifier, and the like. Implemented as (DC-DC Convertor). The power supply 105 adjusts an input voltage from the host controller 100 to drive the liquid crystal display panel LCP, the data driver 102, the gate driver 103, the timing controller 101, and the backlight unit BLU. Generate the power required for

The power supplies applied from the power supply unit 105 include a high potential power voltage VDD, a gate high voltage VGH, a gate low voltage VGL, a common voltage Vcom, and positive / negative gamma reference voltages VGMA1? VGMAn), touch driving voltage Vtsp, and the like. Among these voltages, the common voltage Vcom and the touch driving voltage Vtsp are selectively supplied to the common electrode 119 under the control of the host controller 100.

The host controller 100 transmits digital video data (RGB) of the input image and timing signals (Vsync, Hsync, DE, MCLK) required for driving the display to LVDS interface (Low Voltage Difference Signaling) and TMDS (Transition Minimized Differential Signaling). It transmits to the timing controller 101 via an interface such as an interface. The host controller 100 also supplies a common voltage Vcom to the common electrode 119 when driving a display for displaying an image on a screen of the liquid crystal display, and the common electrode 119 when driving a touch for touch recognition. The control signal Vin for controlling the power supply 105 is supplied to the power supply 105 so that the touch driving voltage Vtsp can be supplied to the power supply 105.

The touch recognition processor 107 is connected to the plurality of touch detection electrodes 143 of the touch detection unit TD to differentially amplify the voltage of the initial capacitance of each of the touch detection electrodes and the voltage of the touch capacitance after touch. Convert the result to digital data. The touch recognition processor 107 determines a touch position where a touch is made based on the difference between the initial capacitance and the touch capacitance by using a touch recognition algorithm, and provides the touch coordinate data indicating the touch position to the host controller 100. Output to

3 is a cross-sectional view illustrating a touch sensor integrated liquid crystal display according to another exemplary embodiment of the present invention.

Since the touch detector TD is substantially the same as the embodiment of FIG. 2 except for the position where the touch detector TD is attached in FIG. 3, a description of overlapping portions will be omitted.

In FIG. 3, reference numeral 210 constituting the thin film transistor array TFTA is a first substrate, 215 is a plurality of pixel electrodes arranged in a matrix form on one surface of the first substrate 210, and 217 is the plurality of pixel electrodes. An insulating layer 219 formed on the insulating layers 215 is a common electrode formed on the insulating layer 217 and disposed to face the plurality of pixel electrodes 215. The first polarizer 213 is adhered to the other surface of the first substrate 210 of the thin film transistor array TFTA. In addition, similar to the embodiment of FIG. 2, the common electrode 219 constitutes a part of a touch sensor for performing a touch detection operation, and is used as a driving electrode of the touch sensor.

In addition, the color filter array CFA includes a color filter (not shown) and a black matrix (not shown) formed on one surface of the second substrate 220, and a second polarizing plate 223 formed on the other surface of the second substrate 220. ).

The touch detector TD includes a base film 240 and a plurality of touch detection electrodes 243 arranged side by side in a first direction at predetermined intervals on one surface of the base film 240. In addition, the tempered glass layer 250 is formed on the plurality of touch detection electrodes 243 constituting the touch detection unit TD such that the touch detection unit is not damaged by an external environment. When comparing the configurations of the touch sensor integrated liquid crystal display according to the embodiment of FIG. 2 and the touch sensor integrated liquid crystal display according to the embodiment of FIG. 3, the touch detection unit TD of FIG. The touch detection unit TD of FIG. 2 is attached to the second polarizer 223 by 260, but differs in that the plurality of detection electrodes 143 are directly attached to the second polarizer 123.

However, the plurality of detection electrodes 243 constituting the touch detection unit TD of the touch sensor integrated liquid crystal display according to the embodiment of FIG. 3 are formed on the first substrate 210 of the thin film transistor array TFTA. Electrostatic capacitances are formed between the common electrode 219 and the common electrode 219, and the touch detection electrodes 243 constituting the touch detector TD are formed of a touch sensor that performs a touch detection operation. It functions as the plurality of detection electrodes 143 constituting the touch detection unit TD of the touch sensor integrated liquid crystal display device according to the embodiment of FIG. 2 in that it is used as a sensing electrode.

Meanwhile, the common electrodes 119 and 219 according to the embodiment of the present invention are composed of a plurality of touch electrodes divided to have a size corresponding to the size of at least several or tens of pixel electrodes, and the touch electrodes are the detection electrodes. 143 and 243 are connected to each other by a plurality of drive signal lines arranged in a second direction crossing the arranged first direction.

FIG. 4 is a diagram illustrating an example in which three touch electrodes constituting the common electrodes 119 and 219 are formed in a horizontal direction and a vertical direction, respectively. The touch electrodes TE11, TE12, TE13, TE21, TE22, TE23, FIG. 3 shows an example in which TE31, TE32, and TE33 are connected by driving signal lines DSL1, DSL2, and DSL3 in a second direction crossing the first direction in which the detection electrodes 143 are arranged. Since the touch electrodes TE11, TE12, TE13, TE21, TE22, TE23, TE31, TE32, and TE33 illustrated in FIG. 4 are connected in the second direction by the driving signal lines DSL1, DSL2, and DSL3, the touch sensor. The driving signal lines DSL1, DSL2, and DSL3 have a common voltage Vcom and a touch driving voltage Vtsp. The touch electrodes TE11, TE12, TE13, TE21, TE22, TE23, It serves as a signal line for selectively supplying to TE31, TE32, and TE33).

Next, an operation of the touch sensor integrated liquid crystal display according to the exemplary embodiment will be described. In the following description, an example of 60 Hz time division driving will be described.

The touch sensor integrated liquid crystal display according to the embodiment of the present invention is driven by time division. In addition, one cycle of time division driving is composed of a display section and a touch section, as shown in FIG. have. For example, in 60Hz time division driving, 16.7ms is one cycle, and this is divided into a display driving section (about 10ms) and a touch driving section (about 6.7ms).

In the display period, the host controller 100 controls the power supply 105 to, for example, touch electrodes TE11, TE12, TE13, TE21, and TE22 through the driving signal lines DSL1, DSL2, and DSL3 (see FIG. 4). , The common voltage Vcom is supplied to the common electrodes 119 and 219 including the TE23, TE31, TE32, and TE33, and the data driver 102 is synchronized with the gate pulse Gate output from the gate driver 103. The pixel voltage Data corresponding to the digital video data is supplied to the pixel electrodes 115 and 215 through the data line DL. As such, an electric field is formed in the liquid crystal layers 130 and 230 by the common voltage Vcom and the pixel voltage Data applied to the pixel electrodes 115 and 215 and the common electrodes 119 and 219, respectively. As a result, the liquid crystal state is changed to perform a display operation. In this case, the touch recognition processor 107 connected to the plurality of touch detection electrodes 143 and 243 measures and stores voltage values of initial capacitances of the touch detection electrodes 143 and 243.

Next, in the touch driving period, the host controller 100 controls the power supply unit 105 to configure the common electrode 119 through the driving signal lines DSL1, DSL2, DSL3 (see FIG. 4), for example. The touch recognition processor supplies a touch driving voltage Vtsp to the touch electrodes TE11, TE12, TE13, TE21, TE22, TE23, TE31, TE32, TE33, and is connected to the plurality of touch detection electrodes 143 and 243. 107 differentially amplifies the voltage of each of the stored capacitances of the touch detection electrodes 143 and 243 and the voltage Vd of the capacitance measured in the touch driving section and converts the result into digital data. The touch recognition processor 107 determines a touch position where a touch is made based on the difference between the initial capacitance and the touch capacitance using a touch recognition algorithm, and outputs touch coordinate data indicating the touch position.

In the touch sensor integrated liquid crystal display, when the display is driven, the touch driving is turned off to stop the signal supply to the gate line GL and the data line DL, and when the touch driving is performed, the display driving is turned off and the common voltage Vcom It is driven by time division driving which is not supplied.

According to the above-described embodiments of the present invention, the touch sensing element for recognizing the touch of the liquid crystal display can be combined with the display element to reduce the thickness, improve durability, and improve visibility. Can be obtained.

In addition, since the display drive and the touch drive of the touch sensor integrated liquid crystal display are driven by time division, the touch drive is turned off during display and the display drive is turned off during touch, so that the signal interference between the display drive and the touch drive is reduced. Minimized to achieve the effect of improving the touch recognition quality.

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.

100: host controller 101: timing controller
102: data driver 103: gate driver
105: power supply unit 107: touch sensing processor
110, 210: first substrate 113, 213: first polarizing plate
115, 215: pixel electrodes 117, 217: insulating layer
119 and 219 common electrode 120 and 220 second substrate
123 and 223: second polarizing plates 130 and 230: liquid crystal layer
133, 233: sealant 140, 240: base film
143, 243: detection electrode 150, 250: tempered glass layer
160, 260: adhesive layer CFA: color filter array
TD: touch detector TFTA: thin film transistor array
Vcom: Common Voltage Vtsp: Touch Driving Voltage
TE11, TE12, TE13, TE21, TE22, TE23, TE31, TE32, TE33: touch electrode
DSL1, DSL2, DSL3: Drive Signal Line

Claims (10)

A first substrate and a second substrate facing each other with the liquid crystal layer interposed therebetween;
A plurality of pixel electrodes formed on one surface of the first substrate facing the second substrate;
A common electrode formed on one surface of the first substrate so as to overlap the plurality of pixel electrodes with an insulating layer interposed therebetween; And
And a touch detector disposed on one surface of the second substrate, the surface opposite to the surface facing the first substrate.
The method of claim 1,
The touch detection unit includes a base film and a plurality of touch detection electrodes formed on one surface of the base film and arranged side by side in a first direction.
And the plurality of touch detection electrodes are disposed to face the common electrode and form a capacitance between the common electrodes.
The method of claim 2,
And a second polarizing plate formed on the other surface of the first substrate, and a second polarizing plate formed between the plurality of touch detection electrodes and one surface of the second substrate. .
The method of claim 3, wherein
And a tempered glass layer attached to the other surface of the base film by an adhesive layer.
The method of claim 2,
And a second polarizing plate formed on the other surface of the first substrate, and a second polarizing plate formed between the other surface of the base film and one surface of the second substrate.
The method of claim 5, wherein
And a tempered glass layer attached to the plurality of detection electrodes.
7. The method according to any one of claims 1 to 6,
The common electrode includes a plurality of first touch electrodes arranged side by side in at least the first direction and a plurality of second touch electrodes arranged side by side in a second direction crossing the first direction. Each of the first and second touch electrodes corresponds to a plurality of sizes of the pixel electrodes.
The method of claim 7, wherein
And a signal driving line for connecting the first and second touch electrodes arranged side by side in the first direction or the second direction in the first direction or the second direction. Liquid crystal display.
7. The method according to any one of claims 1 to 6,
The touch sensor integrated liquid crystal display device is a touch sensor integrated liquid crystal display device, characterized in that the touch drive is turned off when driving the display, the display drive is driven by the time division when the display drive is turned off during the touch drive.
The method of claim 9,
And a touch driving voltage is supplied to the common electrode when the display is driven, and a touch driving voltage is supplied to the common electrode when the display is driven.

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