KR101819676B1 - Touch sensor integrated liquid cryctal display device - Google Patents

Abstract

The present invention relates to a touch sensor integrated liquid crystal display device capable of achieving a reduction in thickness and an improvement in touch recognition sensitivity, comprising: a first substrate and a second substrate opposing 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 detection unit disposed on one surface of the second substrate, which is a surface opposite to a surface facing the first substrate.

Description

TECHNICAL FIELD [0001] The present invention relates to a touch sensor integrated liquid crystal display (LCD)

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

The touch sensor includes a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an electroluminescence device (EL) And the like, and is a type of an input device that presses (presses or touches) the touch panel while the user views the image display device and inputs predetermined information.

The touch sensor used in the above-described display device can be divided into an add-on type, an on-cell type, and an integrated type according to its structure. In the top plate attaching type, a touch sensor is attached to an upper plate of a display device after separately manufacturing a display device and a touch sensor. The top plate integrated type is a method of directly forming the elements constituting the touch sensor on the surface of the upper glass substrate 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-plate-attached touch sensor has a structure in which the completed touch sensor is mounted on the display device and mounted thereon, resulting in a problem that the thickness of the touch sensor becomes thick and the brightness of the display device becomes dark. In addition, although the top plate integrated type touch sensor has a structure in which a separate touch sensor is formed on the top surface of the display device, the thickness of the touch sensor can be reduced compared to that of the top plate attachment type. However, the driving electrode layer and the sensing electrode layer, There is a problem that the total thickness is increased and the number of processes increases and the manufacturing cost increases.

Meanwhile, since the built-in touch sensor has improved durability and thinness, it has an advantage of solving the problems caused by the touch sensor of the top plate attachment type and the top plate integration type. These built-in touch sensors are classified into optical type and pressure type.

The optical touch sensor forms a light sensing layer on a thin film transistor substrate array of a display device and recognizes light reflected through an object existing in a touched portion by using light from a backlight unit or infrared light. However, the optical touch sensor exhibits relatively stable driving performance when the surroundings are dark, but stronger lights than the reflected light act as noise when the surroundings are bright. This is because the intensity of the light reflected by the actual touch is very weak, which may cause an error in touch recognition even if the outside is slightly bright. Particularly, the optical touch sensor has a problem that when the surrounding environment is exposed to sunlight, the light intensity is so strong that the touch recognition may not be performed.

The pressure type touch sensor senses the touch by sensing the change in the gap between the upper glass substrate and the lower glass substrate according to the pressure to be touched, .

The pressure type touch sensor must press the upper glass substrate to change the distance between the upper glass substrate and the lower glass substrate. However, there is a problem that the gap is hardly changed by the soft touch. In order to solve this problem, when the glass is thinned, the touch characteristics are improved, but the durability is weakened, and the device can easily break or deform.

Accordingly, a need has arisen for a touch sensor integrated liquid crystal display capable of solving the problems of the related art.

It is an object of the present invention to provide a touch sensing device for recognizing a touch of a display device as a component of a display device so as to reduce thickness and improve durability. And to provide an integrated liquid crystal display device.

Another object of the present invention is to provide a touch sensor integrated type liquid crystal display device capable of improving the quality of touch recognition by minimizing signal interference during display driving and touch driving by driving the display driving and the touch driving in a time division manner.

According to an aspect of the present invention, there is provided a touch sensor integrated liquid crystal display comprising: a first substrate and a second substrate opposing 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 detection unit disposed on one surface of the second substrate, which is a surface opposite to a surface facing the first substrate.

Wherein 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 in parallel in a first direction, the plurality of touch detection electrodes are disposed to face the common electrode, Thereby forming an electrostatic capacitance with the common electrode.

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

The touch sensor integrated liquid crystal display further includes a second polarizer formed between the other surface of the base film and one surface of the second substrate.

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

Further, the touch sensor-integrated liquid crystal display device is further configured to include a tempered glass layer attached to the plurality of detecting electrodes.

The common electrode may include a plurality of first touch electrodes arranged at least in parallel in the first direction and a plurality of second touch electrodes arranged in parallel 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 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 .

In the touch sensor integrated type liquid crystal display device, the touch driving is turned off at the time of the display driving and the display driving is turned off at the touch driving time. The common voltage is supplied to the common electrode during the display driving, A touch driving voltage is supplied to the common electrode at the time of touch operation.

According to the embodiment of the present invention, since the touch sensing element for recognizing the touch of the liquid crystal display device is also used as the display device component, the thickness can be reduced, durability can be improved, and visibility can be improved .

Further, since the display driving and the touch driving of the touch sensor integrated liquid crystal display device are driven in a time division manner, the touch driving is turned off at the time of display and the display driving is turned off at the time of touch, So that the effect of improving the quality of touch recognition can be obtained.

1 is a schematic block diagram of a touch-sensor-integrated liquid crystal display device 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,
FIG. 4 is a schematic view showing touch electrodes constituting a common electrode according to an embodiment of the present invention and their connection relationship,
5 is a timing diagram of a touch sensor integrated liquid crystal display device according to an embodiment of the present invention.

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

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

Referring to FIGS. 1 and 2, a touch sensor integrated type liquid crystal display device 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 detection unit TD, A host controller 100, a timing controller 101, a data driver 102, a gate driver 103, a power source 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 which are bonded by a 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 substrate, a plurality of pixel electrodes 115 arranged in a matrix on one surface of the first substrate 110, and a plurality of pixel electrodes 115 And a common electrode 119 formed on the insulating layer 117 and arranged to face the plurality of pixel electrodes 115. The common electrode 119 is formed on the insulating layer 117, Here, the common electrode 119 constitutes a part of a touch sensor for performing a touch detection operation and is used as a driving electrode of a touch sensor.

The thin film transistor array TFTA further includes thin film transistors for driving the plurality of pixel electrodes 115 and wirings for supplying pixel signals to the plurality of pixel electrodes 115, The detailed description thereof will be omitted. A first polarizing plate 113 is bonded 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. The color filter and the black matrix of the color filter array (CFA) are also general components of the liquid crystal display, so a detailed description thereof will be omitted. A second polarizing plate 123 is formed on the other surface of the second substrate 120.

The touch detection unit TD includes a base film 140 and a plurality of touch detection electrodes 143 arranged in parallel in a first direction at predetermined intervals on one surface of the base film 140. The plurality of detection electrodes 143 are disposed opposite to the common electrode 119 formed on the first substrate 110 of the thin film transistor array TFTA to form a capacitance between the common electrode 119 and the color Is formed on the other surface of the second substrate 120 of the filter array CFA. A second polarizing plate 123 is formed between the touch detection unit TD and the second substrate 120. The touch detection electrodes 143 constituting the touch detection unit TD constitute a part of a touch sensor for performing a touch detection operation and are used as sensing electrodes. The reinforced glass layer 150 is attached to the other surface of the base film 140 constituting the touch detection part TD by the adhesive layer 160 so that the touch detection part TD is not damaged by the external environment.

A backlight unit (BLU) is disposed under the liquid crystal display panel (LCP). The backlight unit (BLU) includes a plurality of light sources to uniformly irradiate the liquid crystal display panel (LCP) with light. 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 ICs (integrated circuits) of the data driver 102 is connected to the data lines DL of the liquid crystal display panel LCP by a COG (Chip On Glass) process or a TAB (Tape Automated Bonding) . 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 gate pulses (or scan pulses) 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 pulse output from the gate driver 103 is sequentially supplied to the gate lines GL in synchronism with the data voltage output from the data driver 102. The gate high voltage VGH is higher than 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 May be formed directly on the first substrate 110 of the LCP.

The timing controller 101 generates timing control signals for controlling the operation timings of the data driver 102 and the gate driver 103 using the timing signals 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 driver IC which outputs the first gate pulse every frame period to control the shift start timing of the gate driver 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) . 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 the sampling timing of data in the source drive ICs based on the rising or falling edge. The polarity control signal POL controls the polarity of the data voltage 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 unit 105 is a DC-DC converter including a PWM (Pulse Width Modulation) modulation circuit, a boost converter, a regulator, a charge pump, a voltage divider circuit, an operational amplifier, (DC-DC Converter). The power supply unit 105 adjusts an input voltage from the host controller 100 and drives the liquid crystal display panel LCP, the data driver 102, the gate driver 103, the timing controller 101, and the backlight unit BLU Thereby generating the necessary power for the power supply.

The power supplies supplied from the power supply unit 105 are connected to the high voltage source VDD and the gate high voltage VGH, the gate low voltage VGL, the common voltage Vcom, the positive / negative gamma reference voltages VGMA1- VGMAn, a touch driving voltage Vtsp, and the like. 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 converts the digital video data RGB of the input image and the timing signals Vsync, Hsync, DE and MCLK necessary for driving the display into an LVDS interface (Low Voltage Difference Signaling), a Transition Minimized Differential Signaling (TMDS) To the timing controller 101 through an interface such as an interface. The common voltage Vcom is supplied to the common electrode 119 at the time of the display driving to display an image on the screen of the liquid crystal display device and the common electrode 119 is supplied at the touch operation for touch recognition, To the power supply unit 105, a control signal Vin for controlling the power supply unit 105 so that the touch driving voltage Vtsp may be supplied to the power supply unit 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 touch detection electrode and the voltage of the touch capacitance after touch, And converts the result into digital data. The touch recognition processor 107 determines the touch position where the touch is made based on the difference between the initial capacitance and the touch capacitance using the touch recognition algorithm and transmits the touch coordinate data indicating the touch position to the host controller 100, .

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

3 except for the position where the touch detection part TD is attached, the description of the overlapping parts will be omitted.

Referring to FIG. 3, reference numeral 210 denotes a first substrate, reference numeral 215 denotes a plurality of pixel electrodes arranged in a matrix on one surface of the first substrate 210, reference numeral 217 denotes a plurality of pixel electrodes An insulating layer 219 formed on the insulating layer 217 and a common electrode 219 disposed on the insulating layer 217 so as to face the plurality of pixel electrodes 215. A first polarizing plate 213 is bonded to the other surface of the first substrate 210 of the thin film transistor array TFTA. 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 a touch sensor.

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 polarizer 223 (not shown) formed on the other surface of the second substrate 220 ).

The touch detection unit TD includes a base film 240 and a plurality of touch detection electrodes 243 arranged on the one surface of the base film 240 at regular intervals and in parallel in the first direction. The reinforced glass layer 250 is formed on the plurality of touch detection electrodes 243 constituting the touch detection unit TD so that the touch detection unit is not damaged by the external environment. 3, the touch detection unit TD shown in FIG. 3 has a structure in which the base film 240 is adhered to the adhesive layer 240, The touch detection part TD of FIG. 2 is different from the touch detection part TD of FIG. 2 in that a plurality of detection electrodes 143 are directly attached to the second polarizing plate 123. The touch detection part TD of FIG.

However, the plurality of detection electrodes 243 constituting the touch detection part TD of the touch sensor integrated type liquid crystal display device according to the embodiment of FIG. 3 are formed on the first substrate 210 of the thin film transistor array TFTA The touch sensing electrodes 243 are disposed opposite to the common electrode 219 so as to form an electrostatic capacitance between the common electrode 219 and the common electrode 219. The touch sensing electrodes 243 constituting the touch sensing unit And is used as a sensing electrode, it has the same function as the plurality of detection electrodes 143 constituting the touch detection part TD of the touch sensor integrated liquid crystal display device according to the embodiment of FIG.

The common electrodes 119 and 219 according to the exemplary embodiment of the present invention include a plurality of touch electrodes divided to have a size corresponding to a size of at least several or several tens of pixel electrodes, Are connected to each other by a plurality of driving signal lines arranged in a second direction intersecting the first direction in which the first and second driving signal lines (143, 243) are arranged.

The touch electrodes TE11, TE12, TE13, TE21, TE22, TE23, TE23, TE23, TE23, TE23, TE23, TE31, TE32, and TE33 are connected by the driving signal lines DSL1, DSL2, DSL3 in a second direction that intersects with 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 shown in FIG. 4 are connected in the second direction by the drive signal lines DSL1, DSL2, DSL3, And the driving signal lines DSL1, DSL2 and DSL3 function as the driving electrodes of the touch electrodes TE11, TE12, TE13, TE21, TE22, TE23, TE31, TE32, and TE33, respectively.

Next, the operation of the touch-sensor-integrated liquid crystal display device according to the embodiment of the present invention 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. As shown in FIG. 5, one cycle of the time division driving is constituted by a display period and a touch period, and the touch driving is turned off at the time of display and the display driving is turned off at the time of touch, have. For example, in 60 Hz time division driving, 16.7 ms is one cycle, which is divided into a display driving period (about 10 ms) and a touch driving period (about 6.7 ms).

In the display period, the host controller 100 controls the power supply unit 105 so that the touch electrodes TE11, TE12, TE13, TE21, and TE22 (see FIG. 4) are driven through the driving signal lines DSL1, DSL2, DSL3 The data driver 102 supplies the common voltage Vcom to the common electrodes 119 and 219 composed of the TE 23, TE 31, TE 32, and TE 33. The data driver 102 applies the common voltage Vcom to the common electrodes 119 and 219 synchronized with the gate pulse Gate output from the gate driver 103 And supplies the pixel voltage Data corresponding to the digital video data to the pixel electrodes 115 and 215 through the data line DL. Since 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 in this manner, The liquid crystal state is changed and the display operation is performed. At this time, the touch recognition processor 107 connected to the plurality of touch detection electrodes 143 and 243 measures and stores the voltage value of the initial capacitance of each of the touch detection electrodes 143 and 243.

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

In the touch-sensor-integrated liquid crystal display device, the touch driving is turned off at the time of driving the display, the supply of the signals to the gate line GL and the data line DL is stopped, Is driven by the time-divisional drive which is not supplied.

According to the embodiment of the present invention, a touch sensing element for recognizing a touch of a liquid crystal display device is also used as a component of a display device, thereby reducing thickness and improving durability as well as improving visibility Can be obtained.

Further, since the display driving and the touch driving of the touch sensor integrated liquid crystal display device are driven in a time division manner, the touch driving is turned off at the time of display and the display driving is turned off at the time of touch, So that the effect of improving the quality of touch recognition can be obtained.

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 polarizer
115, 215: pixel electrode 117, 217: insulating layer
119, 219: common electrode 120, 220: second substrate
123, 223: second polarizer 130, 230: liquid crystal layer
133, 233: sealant 140, 240: base film
143, 243: detecting electrode 150, 250: tempered glass layer
160, 260: Adhesive layer CFA: Color filter array
TD: Touch detection part TFTA: Thin film transistor array
Vcom: common voltage Vtsp: touch driving voltage
TE11, TE12, TE13, TE21, TE22, TE23, TE31, TE32, TE33:
DSL1, DSL2, DSL3: drive signal line

Claims (11)

A first substrate and a second substrate opposing each other with a liquid crystal layer therebetween;
A plurality of pixel electrodes formed on one surface of the first substrate facing the second substrate;
A plurality of first electrode patterns formed on one surface of the first substrate so as to overlap with the plurality of pixel electrodes with an insulating layer interposed therebetween and arranged in a first direction and a plurality of first electrode patterns arranged in a second direction crossing the first direction A plurality of second electrode patterns arranged in a first direction;
A touch detection unit disposed on one surface of the second substrate which is opposite to a surface facing the first substrate and having a plurality of touch detection electrodes extending in the first direction; And
And a driving signal line connecting the electrode patterns on the same line arranged in a second direction intersecting the extending direction of the touch detection electrode with each other.
The method according to claim 1,
Wherein the touch detection unit includes a base film and the plurality of touch detection electrodes formed on one surface of the base film,
Wherein the plurality of touch detection electrodes are disposed opposite to the common electrode and form an electrostatic capacitance between the touch electrode and the common electrode.
3. The method of claim 2,
A first polarizing plate formed on the other surface of the first substrate and a second polarizing plate formed between one surface of the plurality of touch detecting electrodes and the second substrate; .
The method of claim 3,
And a toughened glass layer adhered to the other surface of the base film by an adhesive layer.
3. The method of claim 2,
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.
6. The method of claim 5,
And a toughened glass layer attached to the plurality of touch detection electrodes.
7. The method according to any one of claims 1 to 6,
Wherein each of the first and second electrode patterns corresponds to a plurality of sizes of the pixel electrodes.
delete 7. The method according to any one of claims 1 to 6,
Wherein the touch sensor integrated type liquid crystal display device is driven in a time division manner in which the touch driving is turned off at the time of display driving and the display driving is turned off at the time of touch driving.
10. The method of claim 9,
Wherein a common voltage is supplied to the common electrode during the display driving and a touch driving voltage is supplied to the common electrode during the touch operation.
7. The method according to any one of claims 1 to 6,
Wherein the driving signal lines are arranged to overlap the electrode patterns on the same line.

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