KR101374312B1 - Capacitive type touch detecting means, method and touch screen panel using voltage changing phenomenon, and display device embedding said the capacitive type touch screen panel - Google Patents

Abstract

The present invention provides a new type of capacitive touch detection means, a detection method and a touch screen panel for detecting a touch signal by detecting a voltage change in a sensor pattern by a driving voltage applied through an auxiliary capacitor, and such a capacitive touch screen panel. It relates to a display device with a built-in.
According to an aspect of the present invention, there is provided a touch screen panel comprising: a sensor pattern in which island shapes isolated in an active region of a substrate are arranged in a matrix form; And a sensor signal line formed across the active area to connect the sensor pattern and the drive IC, wherein the drive IC comprises: an auxiliary capacitor having one side connected to the sensor pattern; Charging means for charging electric charges to the sensor pattern and the auxiliary capacitor; And detecting a touch based on a voltage change value in response to a driving voltage applied to the auxiliary capacitor in a state where the charged charge is isolated.
According to the present invention, a touch signal is detected by avoiding the state change of the common voltage, a drive voltage is applied through an auxiliary capacitor connected to the touch detection unit, a voltage variation is detected in the touch detection unit, The effect of parasitic capacitance caused by noise, coupling phenomenon or other factors is minimized and the touch signal can be stably obtained.

Description

Capacitive type touch detecting means, method and touch screen panel using voltage changing phenomenon, and display device embedding said the capacitive type touch screen panel}

The present invention relates to a means, a method, and an apparatus for detecting a capacitive touch input of a finger or a touch input tool having a similar conductive property. More specifically, a driving voltage is applied through an auxiliary capacitor connected to a touch detector. The present invention relates to capacitive touch detection means, a detection method and a touch screen panel for detecting a voltage change in a touch detector when a touch input occurs, and a display device incorporating the capacitive touch screen panel.

Generally, a touch screen panel is attached to a display device such as a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting diode (OLED), or an active matrix organic light emitting diode (AMOLED) And is an input device that generates a signal corresponding to a position when an object such as a finger or a pen is touched. The touch screen panel is used in a wide range of fields such as a small portable terminal, an industrial terminal, and a DID (Digital Information Device).

Conventionally, various types of touch screen panels have been disclosed, but resistance type touch screen panels having a simple manufacturing process and a low manufacturing cost have been widely used. However, since the resistance type touch screen panel has low transmittance and must be applied with pressure, it is inconvenient to use, and it is difficult to recognize multi-touch and gesture, and detection error occurs.

On the other hand, capacitive touch screen panels are increasingly penetrating the market because of their high transmittance, soft touch recognition, and good multi-touch and gesture recognition.

1 shows an example of a conventional capacitive touch screen panel. 1, a transparent conductive film is formed on the upper and lower surfaces of a transparent substrate 2 made of plastic or glass, and metal electrodes 4 for voltage application are formed on each of four corners of the transparent substrate 2. The transparent conductive film is formed of a transparent metal such as ITO (Indium Tin Oxide) or ATO (Antimony Tin Oxide). The metal electrodes 4 formed at the four corners of the transparent conductive film are formed by printing with a conductive metal having a low resistivity such as silver (Ag). A resistor network is formed around the metal electrodes 4. The resistance network is formed with a linearization pattern for uniformly transmitting a control signal to the entire surface of the transparent conductive film. A protective film is coated on the transparent conductive film including the metal electrode 4.

When a high frequency AC voltage is applied to the metal electrode 4, the electrostatic touch screen panel is spread over the front surface of the transparent substrate 2. At this time, when the transparent conductive film on the upper surface of the transparent substrate 2 is lightly touched with the finger 8 or the conductive touch input tool, a certain amount of current is absorbed into the body, and the current sensor incorporated in the controller 6 senses a change in current, The touch points are recognized by calculating the amount of current in each of the metal electrodes 4.

However, since the electrostatic touch screen panel as shown in FIG. 1 is a method of detecting the magnitude of the minute current, an expensive sensing device is required, so that the price rises and multi-touch which recognizes a plurality of touches is difficult.

In order to overcome such a problem, a capacitive touch screen panel as shown in FIG. 2 has been used in recent years. The touch screen panel of Fig. 2 comprises a horizontal linear sensor pattern 5a and a longitudinal linear sensor pattern 5b, and a touch drive IC 7 for analyzing the touch signal. This touch screen panel is a method of detecting the magnitude of the capacitance formed between the linear sensor pattern 5 and the finger 8 so as to scan the linear sensor pattern 5a in the lateral direction and the linear sensor pattern 5b in the longitudinal direction So that a plurality of touch points can be recognized.

However, when the touch screen panel is mounted on a display device such as an LCD, it is difficult to detect a signal due to noise. For example, the common electrode of the LCD is used, and the AC common voltage Vcom is applied to the common electrode in some cases. The common voltage Vcom of the common electrode acts as noise at the touch point detection.

Figure 3 shows an embodiment in which a conventional capacitive touch screen panel is mounted on an LCD. The display device 200 has a structure in which a liquid crystal is enclosed between the TFT substrate 205 on the lower side and the color filter 215 on the upper side to form the liquid crystal layer 210. The TFT substrate 205 and the color filter 215 are bonded to each other by the sealant 230 at the outer portion thereof. Although not shown, a polarizing plate is attached to the upper and lower sides of the liquid crystal panel, and a BLU (Back Light Unit) is installed thereon.

As shown in the figure, a touch screen panel is installed on the display device 200. The touch screen panel has a structure in which the linear sensor pattern 5 is mounted on the upper surface of the substrate 1. [ On the substrate 1, a protection panel 3 for protecting the linear sensor pattern 5 is attached. The touch screen panel is adhered to an edge portion of the display device 200 via an adhesive member 9 such as DAT (Double Adhesive Tape) or the like, and forms an air gap 9a with the display device 200.

In this configuration, when a touch as shown in FIG. 3 occurs, a capacitance equal to Ct is formed between the finger 8 and the linear sensor pattern 5. As shown in the drawing, a capacitance equal to Cvcom is formed between the linear sensor pattern 5 and the common electrode 220 formed on the lower surface of the color filter 215 of the display device 200, and the linear sensor pattern 5 Cp, which is an unknown parasitic capacitance due to electrostatic capacitive coupling between patterns or manufacturing process factors, also acts. Therefore, a circuit similar to that of the equivalent circuit of Fig. 4 is constructed.

Here, the conventional touch screen panel detects a touch by detecting a change amount of Ct, and a background component such as Cvcom and Cp acts as noise in detection of Ct. For example, since the common voltage Vcom of the common electrode 220 is used for one or a plurality of gate lines alternately in order to reduce current consumption in a small / medium-sized LCD for a portable device, It acts as a considerable noise in touch detection.

In order to remove such noise, an air gap 9a is placed between the touch screen panel and the display device 200 as shown in FIG. Although not shown, ITO or the like is coated on the lower surface of the substrate 1 of the touch screen panel to form a shielding layer, and this shielding layer is grounded to the ground signal.

However, the thickness of the product is increased by the air gap 9a, and quality deterioration occurs. Further, since a separate shielding layer and a manufacturing process are required to constitute a shielding layer, an increase in manufacturing cost is caused. In particular, when the touch screen panel is built in the LCD, it is impossible to manufacture the touch panel because the air gap 9a or the shielding layer can not be formed.

The present invention is proposed to solve the problems of the conventional capacitive touch screen panel as described above, connecting the auxiliary capacitor to the touch detection unit and applying a driving voltage through the auxiliary capacitor, formed between the sensor pattern and the touch input tool. When the touch capacitance is added, the touch signal is acquired by detecting a voltage change that causes a difference in the voltage detected by the touch detector according to the magnitude of the touch capacitance, thereby influencing and parasitic by noise of the common electrode of the display device. Capacitive touch detection means, detection method and touch screen panel using a new method of voltage fluctuation that makes it easy to embed the touch screen panel in a display device such as an LCD while minimizing the influence of capacitance and stably obtaining a touch signal. And, an object thereof is to provide a display device incorporating such a capacitive touch screen panel.

The capacitive touch detection means of the present invention for achieving the above object, the electrostatic capacities for detecting the generation of the touch capacitance (Ct) by the approach of a touch input tool, such as a finger of the body 25 or similar conductors A touch detection means comprising: a sensor pattern (10) for forming a touch capacitance (Ct) between the touch input tool; An auxiliary capacitor (Caux) having one side connected to the sensor pattern (10) and a driving voltage for touch detection being applied to the other side; Charging means (12) for supplying a precharge signal to the sensor pattern (10) and the auxiliary capacitor (Caux); And a sensor connected to the sensor pattern and detecting a voltage variation in the sensor pattern when the touch capacitance Ct is added to the auxiliary capacitor Caux according to whether or not the touch input tool is touched And a touch detection unit 14 for detecting a touch signal.

According to one embodiment, the charging means 12 is a three-terminal type switching device.

According to another embodiment, the other side of the auxiliary capacitor Caux is connected to the on / off control terminal of the charging means 12, and the driving voltage applied to the other side of the auxiliary capacitor Caux is connected to the charging / Is equal to the on / off control voltage.

According to another embodiment, the driving voltage applied to the other side of the auxiliary capacitor Caux is an alternating voltage alternating at a predetermined frequency.

According to another embodiment, the touch detection unit 14 may detect a voltage (voltage) in the sensor pattern 10 at a rising time and / or a falling time of a driving voltage applied to the auxiliary capacitor Caux, And detects a variation.

According to another embodiment, the sensor pattern 10 forms a common electrode capacitance Cvcom with the common electrode 220 of the display device 200, and the common voltage level of the common electrode 220 And a common voltage detecting unit 43 for detecting the voltage of the common voltage.

According to another embodiment, the common voltage detecting unit 43 detects a voltage variation in the sensor pattern 10 by the common electrode capacitance Cvcom and outputs a rising time and a falling time of the common voltage level, (falling time).

According to another embodiment, the sensor pattern 10 forms a common electrode capacitance Cvcom with the common electrode 220 of the display device 200 and the common electrode capacitance Cvcom from the display device 200 to the common electrode 220 And a common voltage receiving unit 45 for receiving common voltage information of the plurality of light emitting diodes 220.

According to another embodiment, the touch detection unit 14 detects a touch signal by avoiding a rising edge and a falling edge of the common voltage level.

According to another embodiment of the present invention, the touch sensing unit 14 may be configured such that the touch capacitance Ct is added by the touch generation in comparison with the voltage magnitude of the sensor pattern 10 by the auxiliary capacitor Caux Detects a voltage variation that is a difference in magnitude of a voltage in the sensor pattern 10 and detects a touch signal.

According to another embodiment, the voltage of the sensor pattern 10 by the auxiliary capacitor Caux during the non-touch occurrence is determined by the following equation 1, and when the touch capacitance Ct is added, The voltage in the pattern 10 is determined by the following Equation (2), and the voltage fluctuation is caused by the difference between Equation (1) and Equation (2).

≪ Formula 1 >

&Quot; (2) "

는 센서패턴에서의 전압변동분이며,

는 보조커패시터에 인가되는 하이 레벨 전압이며,

는 보조커패시터에 인가되는 로우 레벨 전압이며,

는 보조커패시터정전용량이며,

은 공통전극정전용량이며,

는 기생정전용량이며,

는 터치정전용량임.)
(here,

Is the voltage variation in the sensor pattern,

Is a high level voltage applied to the auxiliary capacitor,

Is a low level voltage applied to the auxiliary capacitor,

Is the capacitance of the auxiliary capacitor,

Is a common electrode electrostatic capacitance,

Is a parasitic capacitance,

Is the touch capacitance.)

According to another embodiment, the input terminal of the touch detection unit 14 is in a high impedance state of at least 1 Mohm when the touch signal is detected.

According to another embodiment, the touch detection unit 14 detects a touch occupation rate of the touch input tool with respect to the sensor pattern 10 corresponding to the magnitude of the voltage fluctuation.

According to another embodiment, the touch detection unit 14 includes an AD converter.

According to another embodiment, the touch detection unit 14 includes an amplifier 18 for amplifying a signal in the sensor pattern 10. [

According to another embodiment, the amplifier 18 is a differential amplifier 18a for differentially amplifying a signal in the sensor pattern 10. [

According to another embodiment of the present invention, there is further provided a memory unit 28 for storing the output of the amplifier 18 for each sensor pattern 10 when no touch occurs, ) To determine whether or not a touch is made.

In order to achieve the above object, the present invention provides an electrostatic touch detection method for detecting touch capacitance (Ct) by approaching a touch input tool such as a finger 25 of a body or a similar conductor, (A) a sensor pattern (10) forming a touch capacitance (Ct) with the touch input tool, and a sensor pattern (10) having one side connected to the sensor pattern (10) Supplying a precharge signal to an applied auxiliary capacitor Caux; (b) detecting a voltage variation in the sensor pattern (10); And (c) detecting whether a voltage variation occurs in the sensor pattern 10 and detecting a touch signal.

According to one embodiment, the charging means 12 is a three-terminal type switching device.

According to another embodiment, the other side of the auxiliary capacitor Caux is connected to the on / off control terminal of the charging means 12, and the driving voltage applied to the other side of the auxiliary capacitor Caux is connected to the charging / Is equal to the on / off control voltage.

According to another embodiment, the driving voltage applied to the other side of the auxiliary capacitor Caux is an alternating voltage alternating at a predetermined frequency.

According to another embodiment of the present invention, the step (b) may further include a step of detecting a voltage variation in the sensor pattern 10 at a rising time and / or a falling time of a driving voltage applied to the auxiliary capacitor Caux .

According to another embodiment, the sensor pattern 10 forms a common electrode capacitance Cvcom with the common electrode 220 of the display device 200, and the common voltage level of the common electrode 220 And a common voltage detecting step of detecting a common voltage.

According to still another embodiment, the common voltage detecting step detects a voltage variation in the sensor pattern 10 by the common electrode capacitance Cvcom and detects a rising time and a falling time of a common voltage level falling time.

According to another embodiment, the sensor pattern 10 forms a common electrode capacitance Cvcom with the common electrode 220 of the display device 200 and the common electrode capacitance Cvcom from the display device 200 to the common electrode 220 220) for receiving the common voltage information.

According to another embodiment, the step (c) detects a touch signal by avoiding a rising edge and a falling edge of the common voltage level.

According to another embodiment, in the step (c), when the touch capacitance Ct is added by the touch generation in comparison with the magnitude of the voltage in the sensor pattern 10 by the auxiliary capacitor Caux when the touch is not generated Detects a voltage fluctuation, which is a difference in magnitude of a voltage in the sensor pattern (10), and detects a touch signal.

According to another embodiment, the voltage of the sensor pattern 10 by the auxiliary capacitor Caux during the non-touch occurrence is determined by the following equation 1, and when the touch capacitance Ct is added, The voltage in the pattern 10 is determined by the following Equation (2), and the voltage fluctuation is caused by the difference between Equation (1) and Equation (2).

≪ Formula 1 >

&Quot; (2) "

는 센서패턴에서의 전압변동분이며,

는 보조커패시터에 인가되는 하이 레벨 전압이며,

는 보조커패시터에 인가되는 로우 레벨 전압이며,

는 보조커패시터정전용량이며,

은 공통전극정전용량이며,

는 기생정전용량이며,

는 터치정전용량임.)
(here,

Is the voltage variation in the sensor pattern,

Is a high level voltage applied to the auxiliary capacitor,

Is a low level voltage applied to the auxiliary capacitor,

Is the capacitance of the auxiliary capacitor,

Is a common electrode electrostatic capacitance,

Is a parasitic capacitance,

Is the touch capacitance.)

According to another embodiment, the input terminal of the part for detecting the touch signal in the step (c) is in a high impedance state of at least 1 Mohm or more.

According to another embodiment, the step (c) detects the touch occupation rate of the touch input tool with respect to the sensor pattern 10 corresponding to the magnitude of the voltage fluctuation.

According to another embodiment, the step (c) detects whether or not the voltage fluctuation in the sensor pattern 10 occurs using the AD converter.

According to another embodiment, the step (c) detects whether or not the voltage fluctuation in the sensor pattern 10 occurs by using an amplifier 18 for amplifying a signal in the sensor pattern 10.

According to another embodiment, the amplifier 18 is a differential amplifier 18a for differentially amplifying a signal in the sensor pattern 10. [

According to another embodiment of the present invention, the method further includes storing the output of the amplifier 18 for each sensor pattern 10 in the event of a touch failure, wherein the step (c) Detects whether or not the voltage fluctuation in the sensor pattern (10) occurs.

The electrostatic touch screen panel of the present invention for achieving the above object is an electrostatic touch screen panel which detects touch capacitance Ct generated by approaching a touch input tool such as a finger 25 of a body or the like, CLAIMS 1. A touch screen panel comprising: a substrate; A sensor pattern 10 formed on an upper surface of the substrate 50 and forming a touch capacitance Ct with the touch input tool; An auxiliary capacitor (Caux) having one side connected to the sensor pattern (10) and a driving voltage for touch detection being applied to the other side; Charging means (12) for supplying a precharge signal to the sensor pattern (10) and the auxiliary capacitor (Caux); A voltage variation in the sensor pattern 10 is detected when the touch capacitance Ct is added to the auxiliary capacitor Caux according to whether the touch input tool is touched or not, A touch detection unit 14 for detecting a touch signal; And a drive IC (30) for controlling the charging means (12) to supply a precharge signal to the touch capacitance (Ct) and to calculate touch coordinates from the output of the touch detection unit (14).

According to one embodiment, the charging means 12 is a three-terminal type switching device.

According to another embodiment, the other side of the auxiliary capacitor Caux is connected to the on / off control terminal of the charging means 12, and the driving voltage applied to the other side of the auxiliary capacitor Caux is connected to the charging / Is equal to the on / off control voltage.

According to another embodiment, the driving voltage applied to the other side of the auxiliary capacitor Caux is an alternating voltage alternating at a predetermined frequency.

According to another embodiment, the touch detection unit 14 may detect a voltage (voltage) in the sensor pattern 10 at a rising time and / or a falling time of a driving voltage applied to the auxiliary capacitor Caux, And detects a variation.

According to another embodiment, the sensor pattern 10 forms a common electrode capacitance Cvcom with the common electrode 220 of the display device 200, and the common voltage level of the common electrode 220 And a common voltage detecting unit 43 for detecting the voltage of the common voltage.

According to another embodiment, the common voltage detecting unit 43 detects a voltage variation in the sensor pattern 10 by the common electrode capacitance Cvcom and outputs a rising time and a falling time of the common voltage level, (falling time).

According to another embodiment, the sensor pattern 10 forms a common electrode capacitance Cvcom with the common electrode 220 of the display device 200 and the common electrode capacitance Cvcom from the display device 200 to the common electrode 220 And a common voltage receiving unit 45 for receiving common voltage information of the plurality of light emitting diodes 220.

According to another embodiment, the touch detection unit 14 detects a touch signal by avoiding a rising edge and a falling edge of the common voltage level.

According to another embodiment of the present invention, the touch sensing unit 14 may be configured such that the touch capacitance Ct is added by the touch generation in comparison with the voltage magnitude of the sensor pattern 10 by the auxiliary capacitor Caux Detects a voltage variation that is a difference in magnitude of a voltage in the sensor pattern 10 and detects a touch signal.

According to another embodiment, the voltage of the sensor pattern 10 by the auxiliary capacitor Caux during the non-touch occurrence is determined by the following equation 1, and when the touch capacitance Ct is added, The voltage in the pattern 10 is determined by the following Equation (2), and the voltage fluctuation is caused by the difference between Equation (1) and Equation (2).

≪ Formula 1 >

&Quot; (2) "

는 센서패턴에서의 전압변동분이며,

는 보조커패시터에 인가되는 하이 레벨 전압이며,

는 보조커패시터에 인가되는 로우 레벨 전압이며,

는 보조커패시터정전용량이며,

은 공통전극정전용량이며,

는 기생정전용량이며,

는 터치정전용량임.)
(here,

Is the voltage variation in the sensor pattern,

Is a high level voltage applied to the auxiliary capacitor,

Is a low level voltage applied to the auxiliary capacitor,

Is the capacitance of the auxiliary capacitor,

Is a common electrode electrostatic capacitance,

Is a parasitic capacitance,

Is the touch capacitance.)

According to another embodiment, the input terminal of the touch detection unit 14 is in a high impedance state of at least 1 Mohm when the touch signal is detected.

According to another embodiment, the touch detection unit 14 detects a touch occupation rate of the touch input tool with respect to the sensor pattern 10 corresponding to the magnitude of the voltage fluctuation.

According to another embodiment, the touch detection unit 14 includes an AD converter.

According to another embodiment, the touch detection unit 14 includes an amplifier 18 for amplifying a signal in the sensor pattern 10. [

According to another embodiment, the amplifier 18 is a differential amplifier 18a for differentially amplifying a signal in the sensor pattern 10. [

According to another embodiment of the present invention, there is further provided a memory unit 28 for storing the output of the amplifier 18 for each sensor pattern 10 when no touch occurs, ) To determine whether or not a touch is made.

According to another embodiment, the sensor pattern 10 is arranged in the form of a dot matrix in the active area 90 of the substrate 50, and the charging means 12 and the touch detection unit 14 are arranged in a matrix form, (10).

According to another embodiment, the sensor pattern 10 is arranged in a dot matrix form in the active area 90 of the substrate 50, and the charging means 12 and the touch detection unit 14 are arranged in a matrix form, (10) and multiplexes a plurality of sensor patterns (10).

According to another embodiment, the charging means 12 and the touch detection portion 14 are provided in the invisible region 92 of the substrate 50. [

According to another embodiment, the charging means 12 and the touch detection portion 14 are integrated in the drive IC 30. [

According to another embodiment, the sensor pattern 10 is linearly arranged in the active area 90 of the substrate 50, and at least two linear sensor patterns 10a and 10b intersect each other at intersections 42 Is formed.

According to another embodiment, the linear sensor patterns 10a and 10b include an opposing area 41a for forming a touch capacitance Ct with the touch input tool, And a connecting portion 41b for connecting.

According to another embodiment, the charging means 12 and the touch detecting portion 14 allocated to each of the linear sensor patterns 10a and 10b are installed in the invisible region 92 of the substrate 50. [

According to another embodiment, the charging means 12 and the touch detecting portion 14 allocated to each of the linear sensor patterns 10a and 10b are integrated into the drive IC 30.

According to another embodiment, the sensor signal line 22 drawn out from the sensor pattern 10 is wired as the transparent signal line 22a in the active region 90 of the substrate 50 at least.

The sensor signal line 22 is connected to the metal signal line 22b connected to the transparent signal line 22a via the connection part 59 in the nonvisible area 92 of the substrate 50, do.

According to another embodiment, the sensor signal line 22 is wired between the sensor pattern 10 and the sensor pattern 10 in the active region 90 of the substrate 50.

According to another embodiment, the line width of the sensor signal line 22 varies depending on the position of the sensor pattern 10 on the substrate 50.

According to another embodiment, the drive IC 30 is mounted on one side of the substrate 50 in the form of COG (Chip On Glass) or COF (Chip On Film).

According to another embodiment, a plurality of drive ICs 30 are mounted on one side of the substrate 50, one of which is a master drive IC 30a for transferring touch signals to the outside, And a slave drive IC 30b that communicates with the IC 30a.

According to another embodiment, the master drive IC 30a and the slave drive IC 30b refer to mutual touch detection information at the interface between the master drive IC 30a and the slave drive IC 30b.

According to another embodiment, a protection panel 52 is further attached to the upper surface of the substrate 50. [

According to yet another embodiment, the substrate 50 is either a substrate built in the display device 200 or a substrate constituting the display device 200.

In order to accomplish the above object, the present invention provides a display device having a built-in capacitive touch screen panel, wherein any one of the substrates including the touch screen panel or the basic structure described above can be used as the substrate 50 .

According to one embodiment, the display device 200 is a liquid crystal display device, and the substrate 50 is a color filter 215 of a liquid crystal display device.

According to another embodiment, the drive IC 60 for screen display and the drive IC 30 of the touch screen panel are integrated into a single IC.

According to another embodiment, the sensor pattern 10 is located at an interface separating pixels.

According to another embodiment, the sensor pattern 10 is formed so as not to invade the pixel region.

According to another embodiment, the sensor signal line 22 drawn out from the sensor pattern 10 is wired along a boundary surface for distinguishing pixels.

According to another embodiment, the sensor pattern 10 and the sensor signal line 22 are formed by the same mask.

According to another embodiment, the sensor pattern 10 and the sensor signal line 22 are made of metal.

According to another embodiment, the sensor pattern 10 is formed between the color resin of the color filter 215 and the glass.

According to the capacitive touch detection means, the detection method and the touch screen panel using the voltage variation of the present invention, and the display device incorporating the capacitive touch screen panel, the common voltage level of the common electrode of the display device is alternated at a predetermined frequency. In the case of having a common electrode of the display device or a DC level, or in the case where the common electrode of the display device alternates at an unspecified frequency, the state change of the common voltage is detected and the touch point is avoided. Applying the driving voltage through the auxiliary capacitor connected to the detector, and detecting the voltage change in the touch detector by the touch capacitance added by the touch input to obtain a touch signal, thereby preventing noise, coupling phenomenon or other factors Minimizes the effects of parasitic capacitance generated by the signal, and does not cause signal misrecognition By detecting the touch input at a relatively high voltage level, even if the cross section of the touch input tool is small, the signal can be easily captured and the stylus pen input is possible. By obtaining the touch share of the touch input tool according to the magnitude of voltage fluctuation, It is possible to make fine writing and drawing, and the active area can be formed as a single layer, which simplifies the manufacturing process and has a good yield.

1 is a perspective view showing an example of a conventional electrostatic touch screen panel.
2 is a plan view showing another example of a conventional capacitive touch screen panel
Fig. 3 is a sectional view showing an example in which the touch screen panel of Fig. 2 is installed on a display device
Fig. 4 is an equivalent circuit diagram for detecting the touch capacitance in Fig. 3
5 is a waveform diagram illustrating a common voltage waveform of the liquid crystal display device
Fig. 6 is a diagram conceptually illustrating a conventional three-terminal type switching device
7 is a diagram illustrating the principle of detecting a touch input
8 is a circuit diagram showing a basic structure of the touch detection means according to the present invention.
9 is a circuit diagram showing another embodiment of the touch detection means according to the present invention;
10 is a sectional view showing an example of the sensor pattern configuration according to the present invention
11 is a cross-sectional view showing another example of the sensor pattern configuration according to the present invention
12 is a circuit diagram showing another embodiment of the touch detection means according to the present invention;
13 is a waveform diagram illustrating a process of detecting a touch signal in the present invention
14 is a block diagram showing a configuration example of a memory unit
15 is a diagram showing an embodiment of a touch screen panel according to the present invention
16 is a diagram showing another embodiment of the touch screen panel according to the present invention
17 is a plan view showing an example in which a plurality of drive ICs are installed
18 is a view showing another embodiment of the touch screen panel according to the present invention
19 is a plan view illustrating a TFT substrate configuration of an LCD;
20 is a sectional view of a display device incorporating a touch screen panel according to the present invention
21 is an exploded perspective view of a display device incorporating a touch screen panel according to the present invention.
22 is a plan view showing still another example of the sensor pattern configuration

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings and embodiments.

Firstly, the present invention relates to a capacitive touch detection means using a voltage variation, a detection method and a touch screen panel, and a display device incorporating such a capacitive touch screen panel. Unlike the method of detecting a change in capacitance caused by the voltage difference, the voltage variation generated by the correlation of the touch capacitance due to the auxiliary capacitor and the sensor pattern when the alternating drive voltage is applied to the added auxiliary capacitor is detected. That's the way. The touch detection system according to the present invention compares the voltages due to the auxiliary capacitors and the common electrode electrostatic capacitances and the parasitic electrostatic capacitances and the voltages when the touch capacitances are added by touch generation, By detecting a voltage variation which is a difference, the influence of external noises, parasitic capacitance, and the like is minimized, and a touch signal can be acquired more stably.

The display device referred to in the present invention means any one of LCD, PDP, OLED, AMOLED, or any other means for displaying other images. Among the display devices listed above, the LCD requires a common voltage (Vcom) for driving the liquid crystal. For example, a small in-line LCD for a portable device uses a line inversion method in which a common voltage of a common electrode alternates one or a plurality of gate lines in order to reduce current consumption. As another example, the large LCD has a DC level at which the common voltage of the common electrode is constant. As another example, a display device forms a shielding electrode that works in common throughout the panel to shield the external ESD and grounds it to the ground signal. Alternatively, in a liquid crystal display (LCD) of a transverse electric field mode, the common electrode is located on the TFT substrate, and the common voltage detected on the upper surface of the color filter is alternately up and down at the unspecified frequency with reference to the DC level.

In the present invention, in addition to the electrode to which the common voltage Vcom is applied as described above, all the electrodes that commonly function in the display device are referred to as "common electrodes ", and alternate voltage, DC voltage, The voltage in the form of alternating in frequency will be referred to as "common voltage ".

The present invention detects a noncontact touch input of a finger or a touch input tool having similar electrical characteristics. Here, the term " noncontact touch input "means that a touch input tool such as a finger is touched by a substrate at a predetermined distance from the sensor pattern. The touch input tool can be brought into contact with the outer surface of the substrate. In this case, however, the touch input tool and the sensor pattern remain in a non-contact state. Thus, the touch behavior of a finger with respect to a sensor pattern can be expressed in terms of "approach ". On the other hand, since the finger may be in contact with the outer surface of the substrate, the touching action of the finger with respect to the substrate may be expressed by the term "contact ". As used herein, the terms "approach" and "contact"

In addition, the components such as "to" described below are components that perform certain roles, and refer to hardware components such as software or an FPGA (Field-Programmable Gate Array) or ASIC (Application Specific Integrated Circuit). Also, "part" may be included in a larger element or "part, " or may include smaller elements and" parts. &Quot; Also, "part" may have its own CPU.

In the following drawings, thicknesses and regions are enlarged to clearly show layers and regions. Like reference numerals are used for like parts throughout the specification. Whenever a portion of a layer, region, substrate, or the like is referred to as being "on" or "over" another portion, it includes not only the case where it is "directly on" another portion, but also the case where there is another portion in between. Conversely, when a part is "directly over" another part, it means that there is no other part in the middle. Also, the signals described herein are collectively referred to as voltage or current, unless otherwise specified.

Fig. 6 conceptually illustrates a three-terminal type switching element used as one example of the charging means in the present invention. Referring to FIG. 6, the three-terminal switching device has three terminals, typically an on / off control terminal (Cont), an input terminal (In), and an output terminal (Out). The on / off control terminal is a terminal for controlling on / off of the switching element. When a predetermined voltage or current is applied to the terminal, the voltage or current applied to the input terminal is outputted in the form of voltage or current to the output terminal.

The three-terminal switching device referred to as a charging means in the present invention may be, for example, a relay, a metal oxide semiconductor (MOS) switch, a bipolar junction transistor (BJT), a field effect transistor (FET) Field Effect Transistor (IGBT), Insulated Gate Bipolar Transistor (IGBT), Thin Film Transistor (TFT), and OP_AMP, or may be formed by a combination of the same species or different species.

The relay may be a 4-terminal type device in addition to the 3-terminal type device. As the charging means, any element having a control terminal capable of turning on / off the input / output regardless of the number of the input / output terminals and the input / output being turned on / off by the on / off control terminal can be used.

On the other hand, as an example of a three-terminal switching device, a CMOS switch is formed by mutual combination of a PMOS and an NMOS, and input / output terminals are mutually connected, but on / off control terminals exist separately, The ON / OFF state is determined by being separately connected to the control signal. Relay is a device in which the voltage or current applied to the input terminal is output without loss when a current is applied to the control terminal. The BJT is a device in which a voltage higher than the threshold voltage of the base is applied to the base , A certain amount of amplified current flows from the collector to the emitter. The TFT is a switching element used in a pixel portion constituting a display device such as an LCD or an AMOLED, and is constituted by a gate terminal serving as a control terminal, a source terminal serving as an input terminal, and a drain terminal serving as an output terminal When a voltage that is higher than the threshold voltage by a voltage applied to the drain terminal is applied to the gate terminal, a current that depends on the magnitude of the voltage applied to the gate terminal as it is conducted flows from the input terminal to the output terminal.

Before describing a specific embodiment of the present invention, the principle of detecting a touch input will be briefly described with reference to Fig. 7, the sensor pattern 10 and the finger 25 are spaced apart by an interval of "d" when the finger 25 or similar conductive touch means approaches the sensor pattern 10, . Then, a capacitance "C" is formed between the finger 25 and the sensor pattern 10 as shown in the right equivalent circuit and the equation of Fig. When a voltage or a current signal is supplied to the signal input line of the sensor pattern 10 having the capacitance "C" to accumulate the electric charge having the magnitude of the electric charge quantity "Q", a relational expression V = Q / C is formed, "C" can accumulate the charge. In the present invention, when a voltage variation having a correlation with the magnitude of capacitance "C" occurs in the sensed pattern 10 connected to the touch detection unit, the touch is detected using the voltage variation.

8 is a circuit diagram showing a basic structure of the touch detection means according to the present invention. Referring to this, the touch detection means specialized according to the present invention has a basic structure consisting of the charging means 12, the sensor pattern 10, the sensor signal line 22, the auxiliary capacitor (Caux), and the touch detection unit (14). .

The charging means 12 is a means for supplying a precharge to the sensor pattern 10. The precharging applies a constant DC voltage to all the capacitors connected to the touch detecting portion 14 before touch detection to charge the capacitors Voltage. Therefore, the charging means 12 is a switching element that performs a switching operation in accordance with a control signal supplied to an on / off control terminal, or a linear element such as an OP_AMP that supplies a signal in accordance with a control signal. When a three-terminal type switching device is applied to the charging means 12 as shown in the figure, a charging voltage suitable for a necessary point of time is supplied to the sensor pattern 10 (10) by using a control signal supplied to the on / off control terminal and a signal supplied to the input terminal, . The charging voltage can be DC voltage including zero voltage and alternating AC voltage such as square wave or triangle wave or sine wave.

The sensor pattern 10 is formed of the entire transparency or metal. In the case where the sensor pattern 10 is formed on the display device and is formed entirely of transparency, the entire transparency may be formed of indium tin oxide (ITO), antimony tin oxide (ATO), carbon nanotube (CNT), or indium zinc oxide A conductive transparent material or a transparent material having similar conductive properties. If the sensor pattern 10 is applied to a touch key such as a touch keyboard, a refrigerator, or a monitor other than a display device, the sensor pattern 10 may be formed of a non-transparent material such as a metal.

The sensor pattern 10 can be patterned in various forms. For example, it may be in the form of a dot matrix in which the isolated islands in the active region of the substrate 50 are arranged in a matrix, or the linear patterns may be arranged to be transverse to the substrate 50. The shape of the sensor pattern 10 will be described in detail in the following embodiments.

The sensor signal line 22 is a signal line for detecting the presence or absence of a touch input when the finger 25 or a touching means having a similar conductive property (for example, an electrostatic touch pen or the like) approaches the sensor pattern 10. The sensor signal line 22 is a signal line connecting the sensor pattern 10 and the touch detection unit 14 and may be formed of a conductive transparent material similar to the sensor pattern 10 and may be made of a non- . A specific embodiment of the sensor signal line 22 will also be described in the following embodiments.

The auxiliary capacitor Caux has a configuration for applying a driving voltage for touch detection in the present invention. One end of the auxiliary capacitor Caux is connected to the touch detection unit 14 and a driving voltage is applied to the other end. Here, "Caux" is a symbol that simultaneously expresses the name and size of a capacitor. For example, "Caux " means a capacitor named Caux while it means a capacitance of a size of Caux. Other capacitor symbols (such as Ct, Cvcom, Cp, etc.) described below have the same meaning.

As shown in the figure, the output terminal (out) of the charging means 12 is connected to the touch detecting section 14. [ One side of the auxiliary capacitor Caux is connected to the output terminal out of the charging means 12 and a driving signal is applied to the other side of the auxiliary capacitor Caux. The driving signal is a periodic or non-periodic waveform such as a square wave, a sine wave, or a triangular wave as an alternating voltage, and a voltage proportional to the magnitude of the alternating driving voltage is derived from the touch detection unit 14 or the sensor pattern 10 and detected. Since the detected voltage is detected at the intersection of the touch detection unit 14 or the sensor pattern 10, the meaning of detection in the sensor pattern 10 or the touch detection unit 14 throughout this specification is that any signal is detected at the same position .

FIG. 9 shows a case where a MOS (Metal Oxide Semiconductor) or FET is used as an embodiment of the switching element and an ADC (Analog to Digial Converter) is used as an embodiment of the touch detector 14. FIG. The ADC 14a has a function of converting the detected analog signal to digital and performs a function of converting the detected touch signal to digital in the present embodiment and delivering it to the signal processing unit 35 to be described later with reference to FIG. .

9, a touch capacitance "Ct" is formed between the finger 25 and the sensor pattern 10 when the finger 25 of the human body approaches the sensor pattern 10 at regular intervals. Ct is a value set by the relational expression in FIG. 7, and can be freely designed by adjusting the interval between the touching means and the sensor pattern 10, the facing area, and the like. For example, the area of the sensor pattern 10 is largely selected and Ct is also designed to be large based on the relational expression of FIG. Conversely, Ct is designed to be small because the area of the sensor pattern 10 is selected to be small (for example, by selecting 1 mm ² or less). In one embodiment, Ct can be designed from a few tens of fF to a few tens of microF.

Cp in FIG. 9 is a parasitic capacitor, which is a total sum of capacitor values other than the prescribed capacitors such as Ct and Caux, and can be modeled as a capacitor having one side connected to the touch detection unit 14 and the other side connected to an arbitrary ground . Therefore, although a plurality of parasitic capacitors Cp having different grounds may be formed, only one parasitic capacitor connected thereto is assumed in this specification assuming only one ground. The parasitic capacitor Cp is a parasitic capacitor generated between the sensor signal line 22 and the display device or a plurality of sensor patterns 10 arranged in the form of a dot matrix so that when the sensor signal lines 22 are wired in parallel to each other, A parasitic capacitor or the like may be generated between the source and drain electrodes 22 and the like.

9, when the precharge voltage Vpre is applied to the input terminal of the charging means 12 and the switching element is turned on by the control voltage Vg applied to the control terminal cont, The precharge voltage Vpre is output through the output terminal out. Therefore, all the capacitors connected to the output terminal of the charging means 12 are charged with the precharge voltage Vpre.

The auxiliary capacitor Caux, the touch capacitor Ct, and the parasitic capacitor Cp are set to 3 V when Vpre is 3 V and the switching element is turned on when Vg is changed from 0 V (zero voltage) to 10 V Is charged. After the charging, the control voltage Vg of the switching device is lowered from 10 V to 0 V to turn off the switching device, and the P point which is the touch detection part is set to the high impedance to isolate the charge at the P point. The magnitude of the voltage detected at the point P depends on the magnitude of the capacitors connected to the point P and the magnitude of the driving voltage.

Assuming that Caux and Cp are fixed values and the magnitude of the driving voltage is constant, the magnitude of the voltage detected at the point P is dependent on the touch capacitor Ct. Therefore, the voltage detected by the touch detecting unit 14 varies according to the size of the touch capacitor Ct. Therefore, when the voltage variation is detected, the presence or absence of touch and the facing area between the sensor pattern 10 and the touching unit 25 are also calculated Lt; / RTI >

In the present embodiment, the voltage drop due to the on-resistance (Rdson) of the switching device is ignored, and the size of the auxiliary capacitor (Caux) is determined once in the manufacturing process of the auxiliary capacitor (Caux) Cp is assumed to be a value without change in size.

On the other hand, when the sensor pattern 10 of Fig. 9 is mounted on the upper surface of the display device as a separate touch screen panel or is embedded in the display device, the common electrode capacitor (Cvcom) is formed. Alternatively, the common electrode 220 may be formed on the back surface of the substrate on which the sensor pattern 10 is formed to artificially form the common electrode capacitor Cvcom.

FIG. 10 is a sectional view showing an example of the sensor pattern configuration according to the present invention, and FIG. 11 is a sectional view showing another example of the sensor pattern configuration according to the present invention. Fig. 10 illustrates a case where the sensor pattern 10 is mounted on a substrate formed separately from the display device. Fig. 11 illustrates a case where the sensor pattern 10 is embedded in the display device, A case where the common electrode 220 is artificially formed on the back surface of the substrate 50 will be exemplified. The formation of the common electrode capacitor Cvcom will now be described with reference to FIGS. 10 and 11. FIG.

As shown in FIG. 10, the display device 200 has a common electrode 220. In the case of AMOLED, a virtual potential layer capable of forming the Cvcom shown in FIG. 9 is formed between the TFT substrate and the sensor pattern 10, It is called as an electrode. The display device 200 may be any of the above-described various types of display devices, and the common electrode 220 may be a Vcom electrode of an LCD or any other type of electrode. The embodiment of FIG. 10 exemplifies an LCD among display devices.

10 has a structure in which a liquid crystal is sealed between a TFT substrate 205 on the lower side and a color filter 215 on the upper side to form a liquid crystal layer 210. [ The TFT substrate 205 and the color filter 215 are bonded to each other by the sealant 230 at the outer portion thereof. Although not shown, a polarizing plate is attached to the upper and lower sides of the liquid crystal panel, and optical sheets constituting BLU (Back Light Unit) and BEF (Brightness Enhancement Film) can be installed together with the BLU.

As shown in the figure, a substrate 50 of a touch screen panel is provided on the display device 200. 10, the substrate 50 is attached to the upper portion of the display device 200 via an adhesive member 57 such as DAT (Double Adhesive Tape) or the like at its outer periphery. An air gap 58 is formed between the substrate 50 and the display device 200.

The common electrode 220 of the display device 200 is applied with a common voltage level which is alternated with a predetermined frequency and whose magnitude changes or is DC of a predetermined size. For example, in the case of a small LCD that performs line inversion, the common voltage of the common electrode 220 is alternated as shown in FIG. 5, and the common voltage of the DC level, which is a voltage of a certain magnitude, .

A common electrode capacitance Cvcom is formed between the sensor pattern 10 and the common electrode 220 of the display device 200. As shown in Fig. If a precharge signal is applied to the sensor pattern 10, the common electrode capacitance Cvcom has a predetermined voltage level depending on the charging voltage. Since the one end of the common electrode capacitance Cvcom is grounded to the common electrode 220, the common electrode capacitance Cvcom is grounded by the alternating voltage applied to the common electrode 220 when the common electrode 220 is an alternating voltage. The potential at the sensor pattern 10 which is the other end of the sensor pattern 10 will be alternated and the potential at the sensor pattern 10 will not be alternated when the common electrode is DC.

In the drawings, reference numeral 24 denotes a protective layer 24 for protecting the sensor pattern 10. [

11 shows an embodiment in which the sensor pattern 10 is embedded in the display device. Referring to FIG. 11, the substrate 50 constituting the touch screen panel may be a color filter 215, which is a part of the display device. As shown in the drawing, a common electrode 220 is formed below the color filter 215, and a sensor pattern 10 is patterned on the upper surface of the color filter. In the embodiment of Fig. 11, the protective layer 24 is replaced by a polarizing plate.

In this embodiment, the common electrode capacitance Cvcom is formed between the common electrode 220 and the sensor pattern 10. When the alternate voltage is applied to the common electrode, the potential of the sensor pattern 10 is induced to the alternating voltage, When the DC voltage is applied, the potential of the sensor pattern does not change by the common voltage.

11 may be an example in which the common electrode 220 is artificially formed on the bottom surface of the substrate 50 by patterning the sensor pattern 10 on the top surface thereof. In this case, the protective layer 24 is a layer for protecting the sensor pattern 10. For example, the protective layer 24 may be composed of glass, plastic, film, or the like. If a protective panel such as tempered glass is attached to the upper surface of the substrate 50, the flat layer 24 may be removed.

Also in this case, the common electrode capacitance Cvcom is formed between the sensor pattern 10 and the common electrode 220. [ The configuration in which the common electrode 220 is artificially formed on the back surface of the sensor pattern 10 is advantageous in that the touch screen panel is formed separately from the display device 200 while avoiding noise introduced from the display device 200 Can be selected for the purpose.

In the three embodiments described with reference to Figs. 10 and 11, when the voltages of the sensor pattern 10 are alternately synchronized by the alternation of the common voltages, the precharging through the charging means 12 causes the rising the edge and falling edge should be avoided to avoid the influence of the alternation of the common voltage. The detailed waveform will be described later.

Referring to the circuit diagram of Fig. 9, Caux, Ct, Cvcom, and Cp acting on the sensor pattern 10 are connected to the output terminal of the charging means 12. Therefore, when a precharge signal such as an arbitrary voltage or current is applied to the input terminal while the charging means 12 is turned on, Caux, Ct, Cvcom, and Cp are charged. Thereafter, if the charging means 12 is turned off, the charged signal is isolated unless the charged signal is separately discharged to the four capacitors.

In order to stably isolate the charged signal, the input terminal of the touch detection unit 14 is in a high impedance (Hi-impedance or Hi-z) state, and preferably has an impedance of at least 1 Mohm or more. If the input of the touch detection unit 14 is a Hi-Sense signal, if the signal charged in the four capacitors is discharged while observing the touch input or isolating the charged signal by other means, It does not have to be z.

The touch detection section 14 detects whether or not the signal level in the sensor pattern 10 fluctuates. Preferably, the touch detection unit 14 detects a touch when the touch is generated (i.e., when Ct is formed), in contrast to the magnitude of the voltage in the sensor pattern 10 when no touch occurs (i.e., when Ct is not formed) A touch signal is obtained by detecting whether a voltage difference in the sensor pattern 10, that is, a voltage variation occurs. The touch detection unit 14 may have various devices or circuit configurations. In the embodiment described below, an example in which the switching element and the amplifier are used as the touch detection unit 14 will be described, but the configuration of the touch detection unit 14 is not limited to such an embodiment.

The touch detection means of FIG. 12 is a case where one side of the auxiliary capacitor Caux is connected to the control terminal of the charging means 12, unlike the method of connecting the auxiliary capacitor Caux of FIG. 9. The embodiment of this case is disadvantageous in that the magnitude of the signal applied to the auxiliary capacitor Caux and the time point at which the signal is applied depend on the operation of the control terminal of the charging means 12. However, It is possible to integrate the auxiliary capacitor Caux in the auxiliary capacitor Caux and to form the driving voltage applied to the auxiliary capacitor Caux.

The voltage fluctuation in the sensor pattern 10 due to the driving voltage applied to one side of the auxiliary capacitor Caux and Caux in the absence of touch is determined by the following Equation 1.

≪ Formula 1 >

Since the touch capacitance Ct is added in parallel to the touch detection unit 14 when a touch is generated, the voltage variation in the sensor pattern 10 is determined by the following Equation (2).

&Quot; (2) "

는 센서패턴(10) 또는 터치검출부(14)에서의 전압변동분이며,

는 보조커패시터(Caux)에 인가되는 구동신호의 하이 레벨 전압 또는 충전수단(12)의 제어단자에 인가되는 턴 온 전압이며,

는 보조커패시터(Caux)에 인가되는 구동신호의 로우 레벨 전압 또는 충전수단(12)의 제어단자에 인가되는 턴 오프전압이며,

은 공통전극정전용량이며,

는 기생정전용량이며,

는 터치정전용량이다.In Equation 1 and Equation 2,

Is a voltage variation in the sensor pattern 10 or the touch detection section 14,

Level voltage of the driving signal applied to the auxiliary capacitor Caux or the turn-on voltage applied to the control terminal of the charging means 12,

Is the low level voltage of the driving signal applied to the auxiliary capacitor Caux or the turn-off voltage applied to the control terminal of the charging means 12,

Is a common electrode electrostatic capacitance,

Is a parasitic capacitance,

Is the touch capacitance.

The touch detection unit 14 detects the voltage fluctuation, which is a difference between Equation 1 and Equation 2, in the sensor pattern 10 using the above Equation 1 and Equation 2, Respectively.

및

는 쉽게 설정할 수 있는 값이다. 그리고 Cvcom은 다음의 <수식3>으로부터 얻을 수 있다.In the above formulas

And

Is a value that can be easily set. And Cvcom can be obtained from the following Equation (3).

&Quot; (3) &quot;

은 센서패턴(10)과 공통전극(220) 사이에 존재하는 매질들의 복합유전율이다. 예컨대, 글래스의 경우 비유전율이 3~5이므로, 여기에 진공의 유전율을 곱한 값으로부터 기판(50)의 유전율을 얻을 수 있다. 도 10의 경우 센서패턴(10)과 공통전극(220) 사이에는 유리, 공기층, 편광판 또한 편광판을 유리에 부착하기 위한 접착제가 존재하므로 이들의 복합유전율이 수식3의

이 된다.

은 센서패턴(10)과 공통전극(220)의 대향면적이므로 쉽게 구할 수 있다. 도 10의 예에서와 같이 공통전극(220)이 칼라필터(215)의 하면 전체에 걸쳐 형성된 경우, 대향면적

은 센서패턴(10)의 면적에 의해 결정된다. 또한,

은 센서패턴(10)과 공통전극(220)간 거리이므로, 매질의 두께에 해당된다.In Equation 3,

Is the complex permittivity of the mediums existing between the sensor pattern 10 and the common electrode 220. For example, in the case of glass, since the dielectric constant is 3 to 5, the dielectric constant of the substrate 50 can be obtained from the value obtained by multiplying the dielectric constant by the dielectric constant of vacuum. 10, since an adhesive for adhering a glass, an air layer, a polarizing plate and a polarizing plate to the glass is present between the sensor pattern 10 and the common electrode 220,

.

Can be easily obtained because it is the opposed area between the sensor pattern 10 and the common electrode 220. When the common electrode 220 is formed over the entire lower surface of the color filter 215 as in the example of FIG. 10,

Is determined by the area of the sensor pattern 10. Also,

Is the distance between the sensor pattern 10 and the common electrode 220, which corresponds to the thickness of the medium.

As you can see, Cvcom is a readily available value and a configurable value.

Ct can be obtained from the following Equation (4).

&Lt; Equation 4 &

는 센서패턴(10)과 손가락(25) 사이의 매질로부터 얻을 수 있다. 만약, 도 10에서 기판(50)의 상면에 강화 글래스를 부착한다면, 강화 글래스의 비유전율에 진공의 유전율을 곱한 값으로부터 유전율

를 얻을 수 있다.

는 센서패턴(10)과 손가락(25)의 대향면적에 해당한다. 만약 손가락(25)이 어떤 센서패턴(10)을 모두 덮고 있다면

는 센서패턴(10)의 면적에 해당한다. 만약 손가락(25)이 센서패턴(10)의 일부를 덮고 있다면

는 센서패턴(10)의 면적에서 손가락(25)과 대향하지 않은 면적만큼 줄어들 것이다. 또한,

는 센서패턴(10)과 손가락(25)간 거리이므로, 기판(50) 상면에 올려진 강화 글래스 또는 평탄층(24) 등의 두께에 해당할 것이다.In Equation 4,

Can be obtained from the medium between the sensor pattern 10 and the finger 25. If a tempered glass is attached to the upper surface of the substrate 50 in FIG. 10, the dielectric constant of the tempered glass multiplied by the dielectric constant of the vacuum,

Can be obtained.

Corresponds to the opposite area of the sensor pattern 10 and the finger 25. If the finger 25 covers all the sensor patterns 10

Corresponds to the area of the sensor pattern 10. If the finger 25 covers a part of the sensor pattern 10

The area of the sensor pattern 10 will be reduced by an area not opposed to the finger 25. Also,

Since the distance between the sensor pattern 10 and the finger 25 is equal to the thickness of the reinforcing glass or the flat layer 24 on the upper surface of the substrate 50,

As described above, Ct is a readily obtainable value and can be easily set by using the thickness of a material such as a protective layer 24 or a reinforcing glass which is placed on the substrate 50. In particular, according to Equation (4), Ct is proportional to the opposing area of the finger 25 and the sensor pattern 10, and thus the touch share of the finger 25 with respect to the sensor pattern 10 can be calculated.

The touch detection unit 14 detects whether a voltage variation in which the magnitude of the voltage according to Equation (2) is subtracted from the magnitude of the voltage according to Equation (1) as described above is detected. The touch detection unit 14 includes an amplifier for amplifying a signal in the sensor pattern 10, an analogue to digital converter (ADC), a voltage to frequency converter (VFC), a flip-flop, a latch, A buffer (TR), a transistor (TFT), a comparator, a digital to analog converter (DAC), an integrator, a differentiator, or the like.

9 illustrates a configuration in which the touch detection unit 14 includes the ADC 14a. Referring to Fig. 9, the sensor pattern 10 is connected to the input terminal of the ADC 14a. Therefore, the voltage variation in the sensor pattern 10 is detected through the input terminal of the ADC 14a. As shown in the drawing, when the connection point between the sensor pattern 10 and the input terminal of the ADC 14a is "P", the potential Vp at P is expressed by Equation 1 and Equation 2, and the touch capacitance Ct ). &Lt; / RTI >

On the other hand, the ADC 14a shown in FIG. 9 is an ADC having a buffer input of a high impedance state as described above, or a combination of the buffer and a buffer, as described above. When an amplifier or the like is used, it is considered to be combined with a buffer in a high impedance state.

As shown in the drawing, an alternating driving voltage having a constant height is applied to one end of the auxiliary capacitor Caux. Although not shown, in one embodiment, the driving voltage is an output of a device capable of outputting an alternating voltage, such as an inverter, a CMOS output such as an "AND gate, " Therefore, in the state where Caux is precharged (or charged) by the charging voltage Vpre, the potential of Vp is alternated in synchronization with the driving voltage applied to the auxiliary capacitor Caux. Thereafter, when the supply of the charging voltage and the alternation of the driving voltage are continued, when the non-touch occurs, Vp has the same voltage magnitude as Equation (1). If a touch input occurs, Equation (2) where Ct is added to the denominator of Equation (1) becomes Equation (2). Therefore, the voltage of Vp decreases, and a voltage variation is obtained by subtracting (Equation 2) from Equation (1).

13 is a waveform diagram showing a process of detecting a touch signal in the embodiment of FIG. A method of detecting the touch signal using the voltage variation will be described with reference to the following description.

In the embodiment of FIG. 13, the waveform is divided into three areas, and the section named "No Touch" as the first area in FIG. 13 is a section in which no touch occurs and is a section without Ct. The section labeled "Full Touch" in the second area of FIG. 13 is a section in which the finger 25 completely covers the sensor pattern 10, and Ct in Equation 4 is the maximum. On the other hand, the section labeled "1/2 Touch", which is the last area on the lower right end in FIG. 13, is a section in which the finger 25 covers only 50% of the sensor pattern 10, 50% &lt; / RTI &gt;

As described above, in the embodiment of the present invention, the common voltage may be an alternating voltage having a certain frequency, or alternatively may be a non-alternating DC voltage or an alternating AC voltage. In this embodiment, a common voltage having a DC voltage which is periodically alternated in the "No Touch" section and the "Full Touch" section and alternately 0 V (zero Volt) in the "1/2 Touch" section is exemplified, Can be performed irrespective of the form of the common voltage. On the other hand, the non-periodic Vcom can sense the rising edge and the falling edge and configure the embodiment in the same manner as the periodic Vcom of the present embodiment.

In order to proceed with this embodiment, a common voltage detection unit, not shown, must first detect the common voltage. If the common voltage has a certain magnitude and alternates, if a rising edge and a falling edge waveform of the common voltage are applied in a period in which the voltage variation is detected, the waveform detected by the touch detection unit 14 may be distorted due to the common voltage waveform . Therefore, the present invention avoids the point at which the rising and falling edges of the common voltage occur and detects the voltage variation of the precharge and the touch signal. However, in another embodiment of the present invention, the voltage variation occurring when the driving voltage is applied to one side of the auxiliary capacitor Caux and the voltage variation occurring at the rising edge and the falling edge of the common voltage are detected The touch input may be detected.

If the common voltage is a DC level that does not alternate, it is possible to detect voltage fluctuations that are not dependent on the waveform of the common voltage. In the drive IC 30 to be described later, when a common voltage is alternated, the drive IC 30 senses a rising edge and a falling edge of the common voltage and senses the mode. When the common voltage is not alternated, And may be provided with means for setting. This operation makes it possible to detect the voltage variation more easily than when the common voltage is not alternated.

The advantage of this method is that the common voltage is a display device that alternates or is not an alternate display device, or that in any case it is a touch Thereby enabling the detection of voltage fluctuation caused by the voltage drop.

* No Touch  In the region Example

First, after detecting a waveform of a common voltage to detect an edge, the on / off control unit of the charging means 12 is turned on to charge the capacitors after a certain period of time (in this embodiment, designated as 't1'). The capacitors charged in the non-touch region are Caux, Cvom, and Cp. The section in which the capacitors are charged is in section (2) and section (7) in FIG.

12, the interval 1 and the interval 6 are the intervals in which the voltage of Vp is dependent on the waveform of the common voltage due to the alternating common voltage. In the interval 1, it is assumed to be 0 V, but in the interval 6, the size is determined by a specific formula, .

If the charge means 12 is turned off after the capacitors are charged, the charge stored in the capacitors is kept isolated since the input terminal of the touch detector 14 is always in the Hi-z state. The potential of the sensor pattern 10 is also maintained. In this example, the ON voltage of the charging means 12 is 5V and the OFF voltage is 0V.

The precharge signal Vpre is applied, for example, at 5 V, and may be on-off synchronized with the gate signal Vg or may be kept in the on-state all the time. It is assumed that the common voltage of the common electrode 220 of the display device 200 is given as 5 V at the Hi level and -1 V at the Low level.

On the other hand, assuming that the Hi level of the driving voltage Vdrv applied to the auxiliary capacitor Caux is 9V and the Low level is 0V, as shown in the figure, after the charging operation is performed first, The detection operation is performed in the falling period, which is performed in the period ④ and the period ⑧.

In the example of FIG. 13, when precharging is performed in the section? And the section?, The potential Vp of P becomes 5V. In the waveform diagram of Fig. 13, the transient characteristics at the time of charging and discharging and the influence of noise are ignored.

는, <수식1>에 의하면 "{9-(-0)}*1/3"이므로 3V이다. 따라서 P의 전위 Vp은 5V에서 8V로 구동전압에 동기되어 크기가 변한다. 한편, 구간②에서 프리차지 후 구동전압의 변동이 발생하기까지의 대기시간인 t2는 일예로 수 us에서 수십 us정도이나 수 us가 바람직하다.Even if Vg is turned off, the electric charge stored in the capacitors remains in an isolated state, so that the potential of Vp is maintained at 5V. This section (section 4 and section 8) is the section during which the detection operation is performed, and since the touch has not yet occurred, the voltage according to Equation 1 is formed. If both Caux and Cvcom and Cp are assumed to be 1 according to their relative sizes, the driving voltage rises in the interval ③ and the voltage of Vp increases in synchronism with it.

Is equal to 3V since it is "{9 - (- 0)} * 1/3 &quot; according to Equation (1). Therefore, the potential Vp of P changes from 5V to 8V in synchronism with the driving voltage. On the other hand, the waiting time t2, which is the waiting time until the variation of the driving voltage after the precharge is generated in the section (2), is preferably about several tens of us to several tens of us, for example.

The voltage detected in the interval ④ is stored in the memory and used as comparison data with the detection voltage when the touch occurs. Therefore, the detected voltage in the interval ④ in the non-touch area is measured in a state in which the touch is not applied, such as "factory mode" (part of the manufacturing process) or "calibration mode" Can be used as reference data for detecting the voltage fluctuation in comparison with the "touch mode"

의 값은 "-{9-(-0)}*1/3"이므로 -3V이고, P의 전위 Vp은 8V에서 5V로 변동할 것이다. 이러, 연산과정을 통하여 측정된 데이터는 신뢰성을 높일 수 있게 된다.If the detection operation is performed in the falling period of the driving voltage Vdrv as opposed to the above in the section (5) after the section (4)

The potential Vp of P will fluctuate from 8V to 5V because the value of "- {9 - (- 0)} * 1/3" Thus, the data measured through the calculation process can be increased in reliability.

Referring to FIG. 13, the section 6 is a section where the common voltage alternates, and the voltage of Vp at this time is determined by the following equation.

&Lt; Eq. 5 &

는 센서패턴(10) 또는 터치검출부(14)에서의 전압변동분이며,

는 공통전극커패시터(Cvcom)에 인가되는 공통전압의 하이 레벨 전압이며,

는 공통전극커패시터(Cvcom)에 인가되는 공통전압의 로우 레벨 전압이며,

은 공통전극정전용량이며,

는 기생정전용량이다.In Equation (5) above,

Is a voltage variation in the sensor pattern 10 or the touch detection section 14,

Is a high level voltage of a common voltage applied to the common electrode capacitor Cvcom,

Is a low level voltage of a common voltage applied to the common electrode capacitor Cvcom,

Is a common electrode electrostatic capacitance,

Is the parasitic capacitance.

의 크기는 "-{5-(-1)}*1/3"이므로 -2V이고, 공통전압 변동 전 Vp의 전위가 5V이므로 구간⑥에서 Vp의 전위는 3V가 된다. According to Equation (5), in the region where the common voltage falls in the period (6)

Since the potential of Vp before the common voltage variation is 5 V, the potential of Vp becomes 3 V in the interval ⑥.

It is possible to detect the voltage variation due to the touch even in the section between the section 5 and the section 6 so that it is possible to detect the presence or absence of the touch and the occupation rate of the touch area in the sensor pattern 10. This is because when the touch is generated in the section from the section (5) to the section (6) and Ct is generated, the detection voltage detected by the touch detection section (14) becomes as follows.

&Quot; (6) &quot;

In Equation 6, Ct is the touch capacitance.

The difference between the equations (5) and (6) is that Ct is added to the denominator. The difference in the magnitude of the voltage detected by the touch detecting unit 14 according to the magnitude of Ct, i.e., Equation (5) It can be seen that a voltage fluctuation is a value indicating the degree of touch. However, this method requires a common voltage to be alternated, and thus has a disadvantage that touch detection is impossible when the common voltage is not alternated as in the &quot; 1/2 touch " However, this disadvantage can be solved by applying an alternating common voltage to the common electrode.

는 <수식 1>에 의해 "-{9-(-0)}*1/3"으로서 -3V이므로, P점에서 5V인 충전전압은 2V로 변경된다.
Since the section ⑦ in FIG. 13 is the charging section, the potential of Vp is charged to 5 V, and the driving voltage in the section ⑧ falls from high to low.

Is -3 V as "- {9 - (- 0)} 1/3" by Equation (1), so that the charging voltage of 5 V at the point P is changed to 2 V.

* Full Touch  In the region Example

는 <수식 6>에 의해 결정되며

는 "{5-(-1)}*1/6"로서 1V가 된다. 따라서 구간⑧에서의 검출전압이 2V이므로 구간⑨의 전압은 3V가 된다.Referring to FIG. 13, in the section (9), the area S of Equation (4) is completely occupied by the finger (25) and Ct represents the maximum value. Ct is a relative size of Cvcom or Caux having a relative size of 1 3, then in section ⑨

Is determined by Equation (6)

Quot; {5 - (- 1)} 1/6 " Therefore, since the detection voltage in section 8 is 2V, the voltage in section 9 is 3V.

에는 (2V-1V)인 1V의 전압변동이 발생하므로, 터치검출부(14)는 전압변동을 검출하여 터치여부 및 센서패턴(10)과 터치수단(25)이 대향하는 면적을 연산할 수 있다.As described above, according to Equation (6), depending on whether or not a touch occurs, when Ct exists and when Ct does not exist

A voltage variation of 1V of (2V-1V) is generated in the touch sensing section 14, so that the touch detection section 14 can detect the voltage variation and calculate the area where the touch pattern 25 and the sensor pattern 10 are opposed to each other.

는 <수식 2>에 의해서 결정되며 상승하는 구동전압에 의해 그 크기는 "{9-(-0)}*1/6"로서 1.5V가 된다. 구간⑩ 이전의 충전구간에서의 검출전압의 크기가 5V이므로 구간⑩에서 검출전압은 6.5V가 된다.In section ⑩

Is determined by Equation (2), and the magnitude of the driving voltage is increased to 1.5V as "{9 - (- 0)} 1/6 &quot;. Since the magnitude of the detection voltage in the charging section before the section ⑩ is 5V, the detection voltage in the section ⑩ is 6.5V.

In the "No Touch" area, the magnitude of the detection voltage in the interval ④, in which the magnitude of the detection voltage is defined by Equation 1, is 8 V, and in the interval ⑩ in which the magnitude of the detection voltage when "Full touch" The voltage obtained by subtracting the formula (2) from the formula (1), that is, the voltage fluctuation is 1.5V. The touch detection unit 14 can detect the magnitude of the voltage fluctuation and determine whether or not the touch is detected.

는 "-{9-(-0)}*1/6"로서 -1.5V이며, 직전의 충전전압이 5V이므로 3.5V가 검출된다. 이는 "No Touch" 영역의 구간⑧에서 <수식 1>에 의해 정의되는 전압변동에 의해 검출전압이 2V인 것에 비해, 구간⑪에서의 검출전압은 3.5V로서 그 전압의 차이, 즉, 전압변동이 1.5V이므로 앞서 설명한 전압변동의 크기와 동일하다. 따라서 전압변동의 크기는 구동전압인 Vdrv이 상승구간이건 하강구간이건 이에 무관하에 동일한 값을 가짐을 알 수 있으며, 이는 구동전압 Vdrv의 상승구간이나 하강구간에서의 전압변동을 모두 검출 가능하게 하는 장점이 있다.
In the interval 11, the detection voltage is defined by Equation 2,

Is -1.5 V as "- {9 - (- 0)} * 1/6", and 3.5 V is detected because the immediately preceding charging voltage is 5 V. This is because the detected voltage is 2 V in the section 8 of the "No Touch" area due to the voltage variation defined by Equation 1, whereas the detected voltage in the section 11 is 3.5 V, that is, the voltage variation 1.5 V, so it is equal to the magnitude of the voltage fluctuation described above. Therefore, it can be seen that the magnitude of the voltage fluctuation has the same value regardless of whether the driving voltage Vdrv is the rising period or the falling period. This is because it is possible to detect the voltage fluctuation in the rising period or the falling period of the driving voltage Vdrv .

* 1/2 Touch  In the region Example

가 작아지므로, Ct 역시 작아진다. 따라서 도 13의 파형도에서 전압변동의 크기 역시 작아질 것이다. 즉, 전압변동의 크기를 검출하면 센서패턴(10)에 대한 손가락(25)의 터치 점유율을 연산할 수 있다. 이러한 기능은 센서패턴(10)의 크기 및 해상도가 제한적임에도 불구하고, 터치 해상도를 증가시킬 수 있게 한다. 또한, 터치좌표의 미세한 변동을 감지하고, 손가락이나 기타 터치입력도구를 이용하여 고해상도의 그림을 그리는 것을 가능하게 한다. On the other hand, when the finger 25 partially covers the sensor pattern 10, the area of the opposing face between the finger 25 and the sensor pattern 10 in Equation (4)

Becomes smaller, Ct becomes smaller. Therefore, the magnitude of the voltage fluctuation will also become smaller in the waveform diagram of FIG. That is, when the magnitude of the voltage fluctuation is detected, the touch share of the finger 25 with respect to the sensor pattern 10 can be calculated. This function makes it possible to increase the touch resolution even though the size and resolution of the sensor pattern 10 is limited. It also allows for fine variations in touch coordinates and enables high resolution pictures to be drawn using a finger or other touch input tool.

Assuming that the finger 25 covers only 50% of the sensor pattern 10, Ct has a relative value of 1.5, which is half of that of the "Full touch &quot; Since the common voltage is not alternated in the "1/2 touch" region, the driving voltage Vdrv is advantageous in avoiding the moment when the common voltage is alternated, so that the detection time is not dependent on Vcom, do.

는 "{9-(-0)}*1/4.5"로서 2V가 된다. 구간⑫ 직전의 충전전압이 5V이므로 구간⑫에서의 검출전압은 7V가 되며, 구동전압 Vdrv가 하강구간인 구간⑬에서의 검출전압은 충전전압인 5V에서 2V가 차감된 3V가 된다. 따라서, 터치검출부(14)는 "No Touch" 영역에서의 구간④ 또는 구간⑧에서의 검출전압 값과 구간⑫ 또는 구간⑬의 검출전압 값의 차인 전압변동을 측정함으로써 센서패턴(10)과 손가락(25)의 대향면적을 계산하는 것이 가능하게 된다.
In section 12, Ct is 1.5

Quot; {9 - (- 0)} * 1 / 4.5 " Since the charging voltage immediately before ⑫ is 5V, the detection voltage in interval ⑫ becomes 7V, and the detection voltage in interval ⑬, in which the driving voltage Vdrv is in the falling interval, becomes 3V minus 2V at charging voltage of 5V. Therefore, the touch detection section 14 measures the voltage fluctuation, which is the difference between the detected voltage value in the section 4 or 8 in the "No Touch" area and the detected voltage value in the section 12 or 13, by detecting the sensor pattern 10 and the finger 25 can be calculated.

9 shows a case in which the auxiliary capacitor Caux does not depend on the operation of the on / off control terminal of the charging means 12, but FIG. 12 shows a case in which the driving voltage Vdrv applied to the auxiliary capacitor Caux is smaller than that of the charging element 12 And is dependent on the on / off control signal. This embodiment is advantageous in that the circuit is simple since there is no need to separately generate a driving voltage to be applied to the auxiliary capacitor Caux. However, since the driving voltage is dependent on the control voltage of the charging means 12, Since the output terminal of the charging means 12 is not Hi-z, the voltage fluctuation can not be detected and the voltage fluctuation can be detected at the time when the control voltage is lowered, so that the detection speed is lowered. However, such a problem can be overcome by advancing the charging operation and the detecting operation of the charging means quickly.

On the other hand, FIG. 12 shows a case where the amplifier 18 is used in the touch detection unit 14. FIG. An amplifier 18 coupled with a buffer whose input is in the Hi-z state or whose input is in the Hi-z state can also stably isolate the signal at the P point.

In the embodiment of FIG. 12, the voltage of the point P is changed by the voltage Ct, which is the same as the embodiment of FIG. However, the amplifier 18 is used as means for detecting the voltage fluctuation. The amplifier 18 amplifies the signal in the sensor pattern 10. Accordingly, since the voltage variation due to the generation of the touch is amplified and output, the touch signal can be stably obtained even when the value of the voltage variation is small.

Also, the amplifier 18 may be a differential amplifier 18a. 12, the potential of point P is input to the input terminal of the differential amplifier 18a instead of the amplifier 18, and the reference voltage Vdif for forming the differential voltage is input to another input terminal of the differential amplifier 18a. . If the reference voltage Vdif is input to the noninverting terminal of the differential amplifier, the output of the differential amplifier 18a is a value obtained by subtracting the reference voltage Vdif from the potential at the point P and multiplying the amplification factor of the differential amplifier And output as the output value of the differential amplifier 18a. An advantage of such a configuration is that the level of noise applied to the point P is reduced and the signal can be calculated more stably to improve the accuracy of the touch. In the embodiment of Fig. 12, the amplifier 18 and the differential amplifier 18a are not used at the same time, and only one of them is connected to point P.

13, the precharge voltage Vpre is exemplified as a single voltage of 5 V, but it may be varied in the rising period and the falling period of the driving voltage as needed, and a plurality of precharge voltages may be used. For example, when the control IC having the detection voltage of 8 V and the internal voltage of 5 V is used in the section 4 of FIG. 13, it may be out of the range of the breakdown voltage. In this case, the charging voltage Vpre can be applied to 1 V, so that the detection voltage in the interval ④ becomes 4 V so that it can be used in a range satisfying the internal pressure of the control IC.

On the other hand, Cp may be different for each sensor pattern 10. For example, it is very difficult to uniformly design the position of the sensor pattern 10, the wiring length, and other external factors for every sensor pattern 10. Cvcom may also be different for each sensor pattern 10. Such a deviation can be ignored if the magnitude of the voltage fluctuation is large. However, as the magnitude of the voltage fluctuation is small, the deviation for each sensor pattern 10 becomes a value that can not be ignored.

In order to solve the above problems, the drive IC 30 is provided with a touch detection section 14 and a signal processing section 35 described later, which are used when no touch is generated for each sensor pattern 10, And a memory unit 28 for storing the signal processing result. The signal stored in the memory unit 28 is a value based on the inherent Cp and inherent Cvcom of each sensor pattern 10 and may be different for each sensor pattern 10. [

For example, when the sensor pattern 10 is scanned immediately after the power is applied and the touch is not generated, the output of the touch detection unit 14 in the "factory mode " The processing result of the signal processing section 35 can be obtained. This factory initial value is stored in the memory unit 28. [

The memory unit 28 may also store a value when a touch occurs. In addition, a separate memory for storing a value at the time of occurrence of a touch may be further provided. Then, the drive IC 30 compares the values of the same cells and determines that a touch occurs when a voltage variation exceeding a preset reference value occurs, and calculates the touch share of the sensor pattern 10 through calculation.

In order to attenuate the influence of Cp, it is also possible to set the value of Caux or Ct relative to Cp in Equation (1) or (Equation (2)). Caux is embedded in a drive IC or installed outside of a drive IC. When incorporated into a drive IC, the size of the Caux is determined during the manufacture of the IC, and the size of the component is mounted even when mounted externally. Therefore, since a relatively small Cp can be implemented, the influence of Cp determined by an unknown factor can be minimized.

14, when the sensor patterns 10 are arranged in the form of a dot matrix and have resolution of m * n, the memory unit 28 is composed of a table having m rows and n columns. For example, the M1-1 address stores the output of the differential amplifier 18a when no touch is assigned to the upper left sensor pattern 10. The signal stored in the memory unit 28 is referred to when detecting the touch of the sensor pattern 10 at the upper left end.

The values stored in the respective addresses of the memory unit 28 may be periodically corrected. The periodic correction may be performed when the device is powered up as described above, or in a dormant state. As described above, the output of the differential amplifier 18a is stored in the memory unit 28 and periodically corrected at the time of occurrence of a non-touched state (or at the time of occurrence of the touched or non-touched state) The touch signal can be stably obtained even when the sensor pattern 10 has a unique Cp.

15 to 22 show embodiments of a touch screen panel according to the present invention. First, FIG. 15 and FIG. 16 show an example in which the touch detection means of FIG. 9 or FIG. 12 is applied, and the sensor pattern 10 is arranged in a dot matrix form.

The structure of the drive IC 30 is shown at the bottom of Fig. The drive IC 30 includes a drive unit 31, a touch detection unit 14, a timing control unit 33, a signal processing unit 35, and a memory unit 28. The drive IC 30 further includes a common voltage detection unit 43, A common voltage receiving unit 45, and an alternating voltage generating unit 37. [0044] FIG. 14, the drive IC 30 includes a common voltage detecting section 43, a common voltage receiving section 45 and an alternating voltage generating section 37. The selector 47 controls the common voltage detecting section 43, The common voltage receiver 43, the common voltage receiver 45, or the alternating voltage generator 37.

The drive signal acquired by the drive IC 30 is transmitted to the CPU 40. [ The CPU 40 may be a CPU of the display device, a main CPU of the computer device, or a CPU of the touch screen panel itself. For example, a microprocessor such as an 8-bit or 16-bit microprocessor may be embedded to process a touch signal. Although not shown, the system configuration further includes a power supply for generating a low or low voltage of signals for touch input detection.

The microprocessor built in the drive IC 30 calculates touch coordinates and recognizes gestures such as a touch point, zoom, rotation, and movement, and generates a reference coordinate (or a center point coordinate) And gesture data to the main CPU. Further, it is also possible to calculate the strength of the touch input, calculate only the GUI object that the user desires (for example, a large area is detected) when a plurality of GUI objects are touched at the same time The data can be processed and exported in various forms such as recognition as input.

The timing control unit 33 generates time division signals of several tens of ms or less and the signal processing unit 35 transmits and receives signals to and from the respective sensor patterns 10 through the driving unit 31. The driving unit 31 supplies the on / off control signal Vgn of the charging means 12 and the precharge signal Vpren. The ON / OFF control signal Vgn is time-divided by the timing control unit 33 and supplied sequentially or non-sequentially for each sensor pattern 10. As described with reference to FIG. 13, the memory unit 28 stores an initial value, which is a signal when a non-touch occurs in each sensor pattern 10, or stores a signal at the time of occurrence of a touch, Each pattern 10 has its own absolute address.

In this way, the memory unit 28 can store temporarily the acquired coordinate values with only one, or store the reference value when no touch occurs. Or a plurality of memory means, so that a reference value at the time of non-touch occurrence and a detection value at the time of occurrence of touch can be separately stored.

Although the illustrated embodiment exemplifies the case where the sensor pattern 10 has a resolution of 4 * 5, since the sensor pattern 10 actually has a higher resolution, the signal may be lost in the course of processing a large number of signals. For example, when the signal processing unit 35 is in the "Busy" state, the touch operation signal may not be recognized and the signal may be missed. The memory unit 28 may prevent the loss of such a signal. For example, the signal processing unit 35 temporarily stores the detected touch signal in the memory unit 28. [ After the entire sensor pattern 10 is scanned, it is determined whether there is a missing signal by referring to the memory unit 28. If there is touch coordinates stored in the memory unit 28 although they are missing in the signal processing process, the signal processing unit 35 recognizes the touch coordinates as normal input.

The common voltage receiving unit 45 directly receives the common voltage information of the common electrode 220 from the display device 200. In this case, information such as the start point, size, rising section and falling section of the common voltage can be obtained very easily, and it is easy for the signal processing section 35 to process the signal in conjunction with the rising section and the falling section of the common voltage. However, the burden of transmitting the common voltage information in the display device 200 occurs.

On the other hand, when the common electrode 220 of the display device 200 has a constant DC level, the alternating voltage generator 37 can forcibly apply the alternating voltage to the common electrode 220. The alternating voltage generator 37 applies an alternating voltage level to the common electrode 220 at a predetermined frequency in accordance with the time division signal of the timing controller 33. The frequency of the alternating voltage applied to the common electrode 220 can be adjusted by adjusting a resistor or the like. In this case also, the signal processing section 35 can easily process the signal in conjunction with the rising and falling sections of the common voltage. However, there is a burden of sending a common voltage to the display device 200 side.

However, the common voltage detector 43 automatically detects the common voltage information, so that it is not necessary to exchange information related to the common voltage with the display device. When the common voltage detected by the common voltage detecting unit 43 is an alternating signal, the signal processing unit 35 avoids a rising edge or a falling edge of the common voltage as shown in FIG. 12 and applies a driving voltage to be transmitted to the auxiliary capacitor . The common voltage detector 43 may have various circuit configurations.

15, the sensor signal line 22 is wired between the sensor patterns 10 in the active area in which the sensor pattern 10 is provided, and is connected to the drive IC 30. In the case where the touch screen panel is separately provided on the display device or embedded in the display device, the sensor signal line 22 should be formed of ITO or IZO which is a transparent signal line in at least visible region. The advantage of such a wiring is that the signal lines are not entirely gathered and transferred to the drive IC 30 through a single passageway, so that a separate area for wiring the signal lines is not necessary. However, since the signal line is disposed between the sensor pattern 10 and the sensor pattern 10, there is a burden of widening the interval between the sensor patterns 10.

On the other hand, in the wiring method of the sensor signal line 22 as shown in FIG. 15, since the length of the signal line connected to the sensor pattern 10 located at the top end and the signal line connected to the sensor pattern 10 located at the bottom end are different, The resistance varies depending on the sensor pattern 10. The width of the sensor signal line 22 to be wired to the upper end is wider than the width of the sensor signal line 22 to be wired to the lower end. As the distance from the drive IC 30 to the drive IC 30 increases, It becomes possible to match the wiring resistances of the signal lines with respect to all the sensor patterns 10. Therefore, the touch signal detection in the signal processing unit 35 becomes easier.

Meanwhile, in the conventional method as shown in FIG. 2, the linear sensor pattern is made of a transparent material, but a signal line connecting the linear sensor pattern to the touch drive IC must use opaque metal such as silver or copper to lower the resistance value , There is a problem that a plurality of masks must be used, which leads to an increase in process cost and a decrease in yield. However, referring to Equation 1 and Equation 2 showing the touch detection using the voltage variation of the present invention, since the resistance does not act as a variable, the resistance of the sensor signal line 22 can be set relatively high, ), ITO or IZO having a high resistance value can be used. 15, the sensor pattern 10 and the sensor signal line 22 may be formed of a transparent material such as ITO or IZO in the same manner, and the sensor pattern 10 and the sensor signal line 22 may be formed in a single mask It is possible to increase the production cost and yield.

Figure 16 shows another embodiment of a touch screen panel. Referring to FIG. 16, a sensor pattern 10 and a sensor signal line 22 are formed in an active region 90 of a substrate 50. The sensor signal line 22 may be wired as a metal in the active region 90 but is preferably wired as the transparent signal line 22a in the active region 90. The sensor signal line 22 may be wired to the transparent signal line 22a in the active region 90 and wired between the sensor patterns as in the embodiment of FIG. 15, but in the active region, the transparent signal line 22a And may be wired to the metal signal line 22b connected to the transparent signal line 22a via the connection portion 59 in the invisible region 92. [ A disadvantage of this wiring method is that it is difficult to make the touch device slim since the width of the non-visible region 92 must be widened.

The touch detection unit 14 may be an AD converter installed in the drive IC 30, a buffer or an amplifier, or a combination thereof. However, when the differential amplifier 18a is used as the touch detection unit 14 as shown in the figure, it is easy to acquire the signal because the noise signal is amplified and processed. In FIG. 16, the differential amplifier 18a and the ADC 14a are not used together but one of them detects the touch input. If the differential amplifier 18a detects the touch input, the ADC can be connected to the output of the differential amplifier and convert the analog signal output from the differential amplifier to a digital signal.

16, a comparator 19 is further connected to an output terminal of the differential amplifier 18a (or an output terminal of a buffer connected to the point P, not shown). The comparator 19 is used to automatically detect a rising edge and a falling edge when the common voltage of the display device 200 is alternated. In a state where the charging means 12 is turned off, the input terminal of the differential amplifier 18a is Hi-z, so that the sensor pattern 10 is electrically isolated and becomes a floating state. At this time, if the voltage level at the common electrode 220 of the display device 200 fluctuates, the potential at the sensor pattern 10 fluctuates accordingly. That is, the potential of P is alternated in synchronism with the alternation of the common voltage. The alternating voltage level is formed to be high or low based on the charging voltage. If the voltage of P is directly connected to the comparator 19 and compared with the comparison voltage of 5 V (such as the charging voltage in the waveform diagram of FIG. 13), the height of the common voltage can be read.

If the touch input occurs, the voltage fluctuation width of P will decrease. As shown in the figure, the voltage level of P is amplified by the differential amplifier 18a and then compared with the appropriate Vref in the comparator 19, It is possible to read the changing point. In this manner, the common voltage detecting unit 43 can be configured by a simple circuit configuration using the comparator 19. [

In the embodiment of Figs. 15 and 16, the sensor pattern 10 has its own positional coordinates. Since the unique position coordinates of each sensor pattern can be confirmed regardless of whether scanning is sequentially performed for each sensor pattern or scanning is performed for each group, multi-touch capable of recognizing occurrence of a touch in a plurality of sensor patterns 10 is possible .

In the embodiment of FIG. 16, the charging means 12 and the touch detecting portion 14 are separately formed for each unit element of the sensor pattern 10, but this is merely an embodiment, and a plurality of sensor patterns 10 may be connected to one charging means 12 and one touch detecting portion 14 through a group of muxes.

FIG. 17 shows a method of increasing the touch resolution. Referring to Fig. 17, a plurality of drive ICs 30a and 30b can be mounted on the substrate 50. Fig. Preferably, when the plurality of drive ICs 30a and 30b are mounted, the drive ICs 30a and 30b are mounted on the glass substrate 50 in a COG form as shown in the figure. The drive ICs 30a and 30b include a master drive IC 30a for transmitting a touch signal to the outside and a slave drive IC 30b connected to the master driver IC 30a and the substrate 50 via a communication channel 94. [ .

The master drive IC 30a is connected to an FPC 96a for sending and receiving signals to the outside. Since the slave drive IC 30b communicates with the master drive IC 30a through the communication channel 94, there is no need to connect a separate FPC. However, as shown in the figure, the power supply FPC 96b may be connected to the slave drive IC 30b.

In order to prevent a collision between the signal detected by the self drive IC 30a and the signal detected by the slave drive IC 30b, the master drive IC 30a gives a priority to each other, gives a scanning order, or has an independent memory space. Signals. Further, the master drive IC 30a and the slave drive IC 30b can refer to each other at the touch detection interface.

For example, in the case of the total resolution of 10 x 20 (width x height) in Fig. 17, assume that each IC is responsible for touch detection for an area of 10 x 10 (width x height). Then, the master drive IC 30a and the slave drive IC 30b at the tenth and eleventh contact points in the vertical direction do not know the touch information of the area out of the magnetic area, so that the tenth and eleventh The detection power in the region of &lt; RTI ID = 0.0 &gt; That is, the linearity of the touch detection is deteriorated.

To solve this problem, each drive IC refers to the information of the relative drive IC at the interface. For example, when the master drive IC 30a detects the touch with respect to the first to tenth areas in the vertical direction, the master drive IC 30a is in the eleventh position in the vertical direction and the slave drive IC 30b touches The touch of the sensor patterns 10 in the tenth position in the longitudinal direction is detected with reference to the signal of the area for detecting the signal. Also, when detecting the touch of the eleventh sensor patterns in the longitudinal direction by the slave drive IC 30b, information on the tenth sensor pattern 10 in the longitudinal direction governed by the master drive IC 30a is referred to.

To this end, the master drive IC 30a and the slave drive IC 30b add a memory, input a signal detected by the counterpart IC on the interface at the interface, through a communication line, write it into the memory, and use it for calculation in the signal processor 35 .

18 is a block diagram showing another embodiment of the touch screen panel. The embodiment of the prior art touch screen panel illustrates that the sensor pattern 10 is arranged in a dot matrix form, whereas the embodiment of FIG. 18 illustrates that the sensor pattern 10 is linearly arranged. 18, the x-axis linear sensor pattern 10a and the y-axis linear sensor pattern 10b are arranged in an alternating manner in the active area 90 of the substrate 50. [ Each of the linear sensor patterns 10a and 10b includes an opposing area 41a for forming the touch capacitance Ct with the touch input tool and a connecting part 41b for connecting the opposing area 41a . The x-axis linear sensor pattern 10a and the y-axis linear sensor pattern 10b intersect each other at the connection portion 41b to form the intersection portion 42. As shown in Fig.

The intersection portion 42 is configured to mutually insulate the linear sensor patterns 10a and 10b of different axes from each other. For example, after the connection portion 41b of the x-axis linear sensor pattern 10a is formed first, an insulation layer is formed on the connection portion 41b, and then the connection portion 41b of the y-axis linear sensor pattern 10b passes over the insulation layer do.

18 is that the number of sensor signal lines 22 wired to the active region 90 or the non-visible region 92 of the substrate 50 can be greatly reduced. If the size of the sensor pattern 10 is small, the number of the sensor signal lines 22 wired between the sensor pattern 10 in the non-visible region 92 and the active region 90 of the substrate 50 is increased The physical touch resolution can be increased compared with the above embodiments.

18, the x-axis linear sensor pattern 10a and the y-axis linear sensor pattern 10b can detect touch on the x-axis or the y-axis and perform touch detection on the remaining one axis Or it is possible to detect the x-axis or the y-axis at the same time. At the time of detection, there is a method of sequentially scanning the x-axis or the y-axis using the scanning method, and touch detection can be performed by making the entire x-axis active and touch detection or making the entire y-axis active. In the case of such a configuration, the detection technique using the voltage variation is applied in the same manner as the dot matrix method described above.

18, the resistance values of the linear pattern 10 and the sensor signal line 22 are not included in the variables. In the case of the linear array 10, A transparent material such as ITO or IZO having a relatively large resistance value can be used for both the linear pattern 10 and the sensor signal line 22 so that it is possible to manufacture the linear pattern 10 and the sensor signal line 22 with a single mask Do.

On the other hand, FIG. 19 illustrates the structure of a TFT substrate in a transverse electric field mode, which is an example of a TFT substrate structure of an LCD. In the LCD of the transverse electric field mode, the common electrode 220 is formed only on a part of the panel, unlike the above-mentioned embodiment. Referring to FIG. 19, the LCD in the transverse electric field mode will be briefly described as follows.

A gate line 242 and a data line 244 are vertically and horizontally arranged on the upper surface of the TFT substrate as shown in Fig. 19, and a region defined by the gate line 242 and the data line 244 forms a pixel . A TFT 250 for switching an image signal is provided in the pixel. The gate electrode 251 of the TFT 250 is connected to the gate line 242 to receive a scan signal and the source electrode 253 and the drain electrode 255 are connected to the data line 244 and the pixel electrode line 248, Respectively. A semiconductor layer 257 of the TFT 250 forms a channel between the source electrode 253 and the drain electrode 255 to apply an image signal to the liquid crystal layer. In the pixel, a common electrode line 246 is formed in parallel with the pixel electrode line 248 as shown in the figure.

When an image signal is applied to the pixel electrode line 248 by the operation of the TFT 250, a substantially parallel transverse electric field is generated between the common electrode line 246 and the pixel electrode line 248 And the liquid crystal molecules move in a plane.

However, as shown in the figure, the common electrode line 246 is formed only in a partial region. Therefore, Cvcom formed between the sensor pattern 10 and the common electrode line 246 is formed smaller than in the above example. Cvcom is proportional to the opposing area of the sensor pattern 10 and the common electrode line 246. Even if the sensor pattern 10 covers the entire pixel shown in Fig. 18, Area is generated. If the common electrode 220 of the display device 200 is formed as shown in FIG. 19 in the embodiment as shown in FIG. 18, the size of Cvcom with respect to Ct will be very small. Therefore, the magnitude of the voltage fluctuation depending on the presence or absence of the touch becomes larger.

19, the parasitic capacitance Cp by the gate line 242, the data line 244, the pixel electrode line 248, and the like may have a value that is close to or larger than Cvcom, It can act as a noise component in signal detection. Therefore, in the embodiment as shown in Fig. 19, it is preferable to detect the touch in consideration of the timing when there is no signal change in the gate line 242 and the data line 244 of the LCD in the drive IC 30. [

20 and 21 are a cross-sectional view and an exploded perspective view of a display device incorporating a touch screen panel. A touch screen panel according to the present invention and a display device including such a touch screen panel will now be described with reference to the drawings.

As shown in Fig. 20, the color filter 215 of the display device 200 may be replaced with a touch screen panel according to the present invention. The common electrode 220 is formed on the lower surface of the color filter 215 as in a typical LCD. As another example, in the transverse electric field mode as shown in FIG. 19, the common electrode 220 is formed on the upper surface of the TFT substrate 205. 19 or 20, the sensor pattern 10 is formed on the upper surface of the color filter 215 as shown in the figure. In order to protect the sensor pattern 10, a protective panel 52 such as a tempered glass or the like may be provided on the sensor pattern 10. In the embodiment of Fig. 20, the protective panel 52 is attached to the upper surface of the color filter 215 by transparent adhesion means such as an ultraviolet curing resin 98 or the like.

In this configuration, only the color filter 215 exists between the sensor pattern 10 and the common electrode 220 as a medium. Therefore, Cvcom becomes larger and Ct becomes smaller. The increase in Cvcom means that the influence of Cp can be minimized as shown in Equation 1, so that the influence of Cp due to an unknown factor can be minimized and the touch signal can be detected more stably.

In the illustrated example, a drive IC 60 for displaying a screen of an LCD is mounted on the TFT substrate 205 in a COG form. A drive IC 30 for controlling a touch signal is mounted on the color filter 215 in a COG or COF form. The FPCs 96 and 97 are drawn out from the drive ICs 30 and 60, respectively. 21, the touch drive IC 30 and the LCD drive IC 60 may be integrated into a single IC. The TFT substrate 205 and the color filter 215 are connected to each other by an FPC to transmit and receive signals.

On the other hand, if the sensor pattern 10 and the sensor signal line 22 of the present invention can be manufactured with a single mask, the yield can be increased and the manufacturing time can be shortened, which is a means of reducing the manufacturing cost of the product. Such a method will be described with reference to FIG.

When the sensor pattern 10 is formed on the upper surface of the color filter 215 as shown in Figs. 20 and 21, a resin for displaying color on the opposite side of the surface of the color filter 215 on which the sensor pattern 10 is patterned (Red), green (green), and blue (blue) are defined as pixels, and a combination of three pixels 270a, 270b, and 270c of R / ).

The example of FIG. 22 shows a color filter 215 composed of six dots 270 in the transverse direction and five dots 270 in the longitudinal direction. As shown in FIG. 22, the sensor pattern 10 may be located on a BM (Black Matrix) 275 which is a boundary between the pixels 270a, 270b and 270c.

The BM 275 covers a signal line connected to each of the pixels 270a, 270b and 270c of the LCD, or distinguishes the color of a pixel. The BM 275 is usually arranged in a width of several um to several tens of um. The BM 275 is composed of a black-based material that is not reflected and transmitted, and is located at the interface of the resin on the lower side of the collar filler. The occupancy rate of the BM 275 in one pixel 270a, 270b and 270c is usually about 20% to 50%. Therefore, even if the sensor pattern 10 is formed on the BM 275, sufficient sensor pattern area can be ensured.

Referring to FIG. 22, the sensor pattern 10 is located at a BM between pixels, and one sensor pattern 10 is formed to receive four dots 270. The sensor pattern 10 is connected to the pixels 270a, 270b and 270c in the BM 275 around the dots 270 in a lattice structure and the sensor signal line 22 is also wired to the BM, Lt; / RTI &gt;

The advantage of this structure is that the sensor pattern 10 and the sensor signal line 22 can be arranged in the non-visible region BM 275 so that the sensor pattern 10 and the sensor signal line 22 can be formed of metal. Therefore, not only the sensor pattern 10 and the signal line 22 can be constituted by a single mask but also the resistance value of the sensor signal line 22 can be lowered, so that the wiring resistance is not required to be considered. Even if the sensor pattern 10 and the sensor signal line 22 are made of metal, the aperture ratio of the pixel is not lowered and the electrical conductivity of the metal is excellent, so that it is possible to transmit the signal to the drive IC more stably.

22 requires a plurality of pixels that do not include a sensor pattern between the sensor pattern 10 and the sensor pattern 10 in order to wire the sensor signal line 22. Also, in the illustrated example, one pixel is divided into boundaries on the boundary of the sensor pattern 10 in the vertical direction, but the boundary may be formed by a plurality of pixels.

22, the sensor pattern 10 is provided on the upper surface of the color filter, that is, on the outer side of the color filter. However, the sensor pattern 10 may be formed on the inner side of the color filter, that is, the color resin (R / G / B) Or may be between the inside of the filter. When the sensor pattern is located on the upper side of the color filter, the manufacturing process of the color filter should be performed at the inner and outer sides of the glass. However, if the sensor pattern is located inside the color filter, the process is performed only inside the glass. Simplified and yield is increased.

When an impermeable material such as metal is used, a non-reflective metal may be used, or chromium oxide, silver oxide (Ag) or black based inorganic material or organic material may be applied to the upper surface of the metal. Although the embodiment using metal is used in the present embodiment, the material constituting the sensor pattern and the signal line is not limited to a non-transmissive material such as metal, and a material having conductivity such as a transparent conductive material is also applicable.

In this embodiment, since the occupancy rate of the BM is about several tens%, the area of the sensor pattern 10 installed in the BM is also several tens% of the pixel area, and the electrostatic capacity formed in the formula 4 is also several tens% The area can be arbitrarily adjusted, and there is no trouble in touch detection.

Another advantage of the embodiment as shown in FIG. 22 is that the transmittance of the pixel is higher than that of other touch screens because there is no substance existing in the transmissive region of the pixel. In addition, in the case of a touch screen for forming a sensor pattern made of a transparent conductive material, index matching is performed to prevent visual recognition of a transparent conductive material. In the embodiment of FIG. 22, such a process can be eliminated.

In the embodiment of FIG. 22, the dot is 6 x 5 (width x length). However, the present invention is not limited to this, and the number of the dots, which are several tens to several hundreds or more, can do. In this embodiment, the dot is divided by the color filter. However, as in the PDP having no color filter and the partition between the pixels is divided into the barrier ribs, The concept of the present embodiment can be applied to all the embodiments having the same configuration.

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 and scope of the invention as defined by the appended claims. Will be clear to those who have knowledge of.

10: sensor pattern 10a: x-axis linear sensor pattern
10b: y-axis linear sensor pattern 12: charging means
14: touch detection unit 14a: ADC
18: Amplifier 18a: Differential amplifier
19: comparator 22: sensor signal line
22a: transparent signal line 22b: metal signal line
25: finger 28: memory part
30: drive IC 30a: master drive IC
30b: Slave drive IC 31: Driving part
33: timing control section 35: signal processing section
37: alternating voltage generation unit 40: CPU
41a: opposing area portion 41b: connecting portion
42: intersection 43: common voltage detector
45: common voltage receiving unit 47: selector
50: substrate 52: protective panel
57: Adhesive member 58: Air gap
59: connection part 60: drive IC
90: Active area 92: Invisible area
94: Communication channel 96: FPC
97: FPC 98: ultraviolet ray hardening resin
200: Display device 205: TFT substrate
210: liquid crystal layer 215: color filter
220: common electrode 230: sealant
242: gate line 244: data line
246: common electrode line 248: pixel electrode line
250: TFT 251: gate electrode
253: source electrode 255: drain electrode
257: semiconductor layer 270: dot
275: BM

Claims (5)

In a touch screen panel,
A sensor pattern in which island shapes isolated in an active region of the substrate are arranged in a matrix form; And
A sensor signal line formed across the active region to connect the sensor pattern and a drive IC,
The drive IC,
An auxiliary capacitor having one side connected to the sensor pattern;
Charging means for charging electric charges to the sensor pattern and the auxiliary capacitor; And
Touch detection means for detecting a touch based on a voltage change value in response to a driving voltage applied to the auxiliary capacitor in a state where the charged charge is isolated
Touch screen panel that includes. The method of claim 1,
And the sensor pattern and the sensor signal line are formed of the same material. 3. The method of claim 2,
The sensor pattern and the sensor signal line is formed of a transparent conductive material. The method of claim 1,
And the sensor pattern and the sensor signal line are formed on the same layer. The method of claim 1,
The line width of the sensor signal line is different in line width according to the position of the sensor pattern on the substrate.

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