KR101996955B1 - Touch panel, position sensing method of touch panel and integrated circuit - Google Patents

Abstract

The touch panel according to an embodiment of the present invention includes a first Y electrode line and a second Y electrode line which are adjacent to each other and are divided into at least two main sections and at least two main sections and each of which is divided into at least two sub sections; And a TD electrode line crossing the first Y electrode line and the second Y electrode line, wherein a potential difference at a first point in time according to a touched position between the adjacent first and second Y electrode lines Value and a potential value applied to the TD electrode line at the second time point so as to have a potential value at a boundary point of the adjacent sub-section to detect the touched position.
A method of detecting a position of a touch panel according to an exemplary embodiment of the present invention includes dividing a first Y electrode line and a second Y electrode line, which are disposed to intersect with a TD electrode line and are adjacent to each other, into at least one main section, A first step of obtaining a potential difference between the first Y electrode line and the second Y electrode line; A second step of re-dividing the touched main section into at least two sub-sections and applying a potential to the TD electrode line so as to have a potential value at a boundary point of the sub-section; And a third step of detecting a touched position by comparing the potential difference value in the first step with the potential value applied in the second step.
An integrated circuit according to an embodiment of the present invention includes a positive input terminal receiving a different first input signal according to a touched position, a negative input terminal receiving a second input signal, and a comparator comparing the first input signal and the second input signal A plurality of comparators having output terminals for outputting signals; A voltage applying unit connected to the positive input terminal and the negative input terminal for applying a drive voltage; And an operation unit for reading a comparison signal of the plurality of comparators and generating a position signal.

Description

TECHNICAL FIELD [0001] The present invention relates to a position detection method and an integrated circuit for a touch panel, a touch panel,

The present invention relates to a capacitive touch panel, a method of detecting the position of a touch panel, and an integrated circuit.

2. Description of the Related Art Generally, an input device such as a personal computer, a portable communication device, or another personal-purpose information processing device has a touch panel in which a user directly touches a screen with a hand or a pen to input information .

The touch panel is simple, has few malfunctions, is easy to carry, can input characters without any other input device, and has a merit that a user can easily recognize a usage method.

Such a touch panel may be a capacitive type which forms an equal potential in the conductive film and detects a position where a voltage change of the upper and lower plates due to the contact is detected.

Typical usage of the touch panel is to select the function by touching the display portion of the switch that drives the desired function among the selection switches displayed on the panel.

However, in the case of sketching and handwriting input of characters using the same touch panel, the higher the position detection resolution is, the more smooth the input becomes possible. Especially, when a stylus pen used in place of a finger, such as a stylus pen, is input using a delicate tip, high resolution is preferable.

However, in such a case, productivity is decreased because the number of comparators mounted between adjacent electrode lines increases.

It is an object of the present invention to provide a means for detecting a touch position at a high resolution as required in a capacitive touch panel without increasing the number of comparators.

The touch panel according to an embodiment of the present invention includes a first Y electrode line and a second Y electrode line which are adjacent to each other and are divided into at least two main sections and at least two main sections and each of which is divided into at least two sub sections; And a TD electrode line crossing the first Y electrode line and the second Y electrode line, wherein a potential difference at a first point in time according to a touched position between the adjacent first and second Y electrode lines Value and a potential value applied to the TD electrode line at the second time point so as to have a potential value at a boundary point of the adjacent sub-section to detect the touched position.

A method of detecting a position of a touch panel according to an exemplary embodiment of the present invention includes dividing a first Y electrode line and a second Y electrode line, which are disposed to intersect with a TD electrode line and are adjacent to each other, into at least one main section, A first step of obtaining a potential difference between the first Y electrode line and the second Y electrode line; A second step of re-dividing the touched main section into at least two sub-sections and applying a potential to the TD electrode line so as to have a potential value at a boundary point of the sub-section; And a third step of detecting a touched position by comparing the potential difference value in the first step with the potential value applied in the second step.

An integrated circuit according to an embodiment of the present invention includes a positive input terminal receiving a different first input signal according to a touched position, a negative input terminal receiving a second input signal, and a comparator comparing the first input signal and the second input signal A plurality of comparators having output terminals for outputting signals; A voltage applying unit connected to the positive input terminal and the negative input terminal for applying a drive voltage; And an operation unit for reading a comparison signal of the plurality of comparators and generating a position signal

According to the embodiment of the present invention, in the capacitive touch panel, the touch position can be detected at a high resolution as needed without increasing the number of comparators.

1 is a view showing a region T in contact with a touch panel using a finger.
2 is a view showing a region T in contact with the touch panel using a pen.
3 is a view showing a distance dependency of C _M for realizing 1/9 resolution for X electrode lines.
4 is a diagram showing an example of segmenting the RF line pitch.
5 is a block diagram of the position detection circuit of the RX line.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The details of other embodiments are included in the detailed description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings.

1 is a view showing a region T in contact with a touch panel using a finger.

In the present invention, the touch panel may include a conventional touch screen or a touch pad capable of simultaneously performing functions of a display unit for outputting information and an input unit for inputting a signal. The present invention is not limited thereto.

The touch panel may include a touch screen including a plurality of X electrode lines TX1 to TXn and a plurality of Y electrode lines RX1 to RXm formed to be arranged to be crossed with each other with an insulating layer interposed therebetween on a transparent substrate have.

In the projected capacitive sensing type, when a finger or a pen touches the touch panel, a projected capacitance is generated in the contact area, and the X electrode lines (TX ₁ ~ TX _n) and Y electrode lines (RX ₁ ~ RX _m) projected capacitance (projection capacitance of: using the C _M), the developing is reduced by the negative is formed in accordance with the touch of the pen capacitance to detect the presence or absence of the touch .

As shown in FIG. 1, when the area T that is in contact with the adjacent Y electrode lines is wider than the pitch of the adjacent Y electrode lines Rx ₁ and RX ₂ It is judged that it is touching.

2 is a view showing a region T in contact with the touch panel using a pen. Since the width of the area T contacting the pitch Lp of the Y electrode lines RX is narrow, the positional information of where the center of the contact area T of the pen and the touch panel is located on the RX line, A position resolution higher than the pitch Lp is required.

3 is a graph showing dependence of C _M on X electrode lines. Generally, the C _M value is given as a function of the touch location. The function of the pen position to which C _M is touched depends on the pattern of the X electrode lines (TX ₁ to TX _n ) and the Y electrode lines (RX ₁ to RX _m ).

In the following description of the RX ₁ line ₂ lines RX which are adjacent to this second 1 Y electrode lines, it will be described as an example of the 2 Y electrode lines. C _M is defined for every line that affects the organic potential and has a value that decreases toward the symmetry about the line. In FIG. 3, in order to simplify the explanation, it is assumed that the interval 0? X? Lp changes to a one-dimensional function of X. That is, C _M1 and C _M2 are given as a function of position X. C _M0 is a component that affects the RX ₀ line, and C _M1 is a component that affects the R _X1 line.

When the mutual capacitance value between the X electrode lines TX ₁ to TX _n and the Y electrode lines RX ₁ to RX _m changes, the X electrode line is capacitive coupled to V _DD at the time of driving, The potential change? V _RX is generated in the Y electrode line. The touched position is detected from the change of the amount of change.

C _M1 and C _M2 are mutual capacitances between the TX line and the RX ₁ and RX ₂ lines, and mutual capacitance changes also occur depending on the touch position. X is the position coordinate, and the center of the RX ₁ line is set to 0 and the center of the RX ₂ line is set to Lp.

The value of C _M can be expressed as follows.

In the above equation, C _D represents a capacitance of a dummy capacitor.

4 is a diagram showing an example of segmenting the RF line pitch. Lp / 4? X <Lp / 4 (main section 0), Lp / 4? X <3Lp / 4 (main section 1), 3Lp / 4 &amp;le; X &lt; 5Lp / 4 (segment 3).

When the section is divided as described above, the section 3 of the RX ₁ -RX ₂ pair and the main section 0 of the adjacent RX ₂ -RX ₃ pair become the same section and are duplicated. Therefore, the description will be omitted for the sake of simplicity.

The reason why the interval is set to 0? X <Lp / 4 and -Lp / 4? X <Lp / 4 is that the influence of C _M1 also reaches RX ₀ -RX ₁ .

In order to detect the position at a higher resolution, the main section is again divided into sub sections. The number of divisions of the sub-section may vary depending on the required touch location resolution.

In detecting 1 / n resolution of sub-section division at 1 / n resolution of the pen touch position, a section generated by dividing the RX ₁ -RX ₂ section by n-1 is set as a section length of one sub section, And arranges the sub-sections so that the center becomes X = 0.

For example, as shown in FIG. 4, in the case of detection with a resolution of 1/9, the sub-section division is such that the RX ₁ -RX ₂ section is divided into 8 equal parts, and thus the length of one sub section is equal to Lp / 8. The sub-section is arranged such that the X-coordinate value of the center of one sub-section becomes zero. Therefore, the X-coordinates of the boundary points of the sub-section of the main section 0 are -3Lp / 16, -Lp / 16, + Lp / 16, and +3 Lp / 16.

In the same manner, the X coordinates at the boundary of the sub-section belonging to the main section 1 are +5 Lp / 16, +7 Lp / 16, +9 Lp / 16, and +11 Lp / 16. The length of the sub-section existing at both ends is Lp / 16.

The process for increasing the touch position detection resolution is roughly divided into two steps.

The first step detects the coordinates of the pen touch position at resolution 1/3. The second step performs position detection of high resolution based on the pen touch position detection result at the resolution obtained in the first step.

In this step, a method of successive comparison may be used.

The presence or absence of the pen touch is detected in the first step. In the first step, since the resolution is low and the amount of data is small, the presence or absence of the touch of the pen can be easily and quickly detected.

Next, in the second step, only the portion having the pen touch is selectively operated. The TX line which is judged as not having the pen touch is not operated. There is an advantage that the number of TX lines operated for a high-resolution touch detection position is smaller as the detection operation time can be shortened.

The first step will be described in more detail below. The present invention is a differential signal sensing for detecting a difference between two signals, and always treats signals of two adjacent Y electrode lines as a pair signal.

According to the embodiment of the present invention, a plurality of comparators are connected between two Y electrode lines adjacent to each other, and a touch position on the touch screen can be detected according to an output code configured using output values of the comparators.

Pen touch position detection algorithm in addition to (and lower the output of the comparator 1-1 outputs the upper bits, the comparator 1-2 bits), the digital output code 2b O ₁ of the RX ₁ -RX ₂ pair, RX ₀ adjacent to the left- RX Digital output of ₁ pair 2b code O ₀ Or the digital output 2b code O ₂ of the RX ₂ -RX ₃ pair adjacent to the right side is required, either or both of them are shown.

First, a ground voltage (GND) is applied to the X electrode lines (TX ₁ to TX _n ). To this end, a ground voltage GND may be applied to another TD electrode line TD formed in a direction crossing the Y electrode lines RX ₁ to RX _m .

Then, at time point t1, the V _DD voltage is applied to the TX ₁ line. Accordingly, the potential of the RX line ₁ is generated, the potential variation △ VRX the RX line by a capacitive coupling capacitive by C _M1. The RX line is precharged to the initial V _DD / 2.

The formula describing the potential VRX ₁ (t1) of the RX ₁ line in accordance with the potential dependency of C _M1 is as follows.

Where C _s represents the capacitance of the sampling voltage holding capacitors and C _E represents the capacitance of each of the coupling capacitors at the intersections of the X and Y electrode lines.

Similarly, shown in an RX _0, RX _2, RX potential of the _third line _{VRX 0 (t1), VRX 2} (t1), VRX 3 (t1), the expression described by reflecting the position dependency of C _M1 and C _M2.

At the time t1, the potential of each RX line can be detected by the above equation. As a result, VRX ₀ (t1) becomes the sampling capacitor C _S0a of the comparator 0-1 and VRX ₁ (t1) becomes the sampling capacitor C _S1a And the sampling capacitor C _S0d of the comparator 0-2, and VRX ₂ (t1) is the sampling capacitor C _S2a of the comparator 2-1 And the sampling capacitor C _S1d of the comparator 1-2, and VRX ₃ (t1) is the sampling capacitor C _S3a of the comparator 3-1 And the sampling capacitor C _S2d of the comparator 2-2.

Next, in order to realize the resolution 1/3, TD is driven to V _DD / 2 at the time point t3. Thus, the following equation is established.

Then, turning off the switches S0b, S0c, S1b, S1c, S2b and S2c at time t4 results in VRX ₀ (t3) being the sampling capacitor C _SOc of the comparator 0-2 and VRX ₁ (t3) 2 sampling capacitor C _S1c And the sampling capacitor C _S0b of the comparator 0-1, and VRX ₂ (t3) is the sampling capacitor C _S2c of the comparator 2-2 And the sampling capacitor C _S1b of the comparator 1-1, and VRX ₃ (t3) is the sampling capacitor C _S3c of the comparator 3-2 And the sampling capacitor C _S2b of the comparator 2-1, respectively.

When the differential sensing is activated by activating the comparators 0-1, 0-2, 1-1, 1-2 and so on at the time t8, the differential voltages satisfy the following equations, respectively.

If Vcomp1-1 is equal to or larger than 0, the comparator 1-1 outputs a digital signal 1, and if it is less than 0, it outputs 0. If the output of the comparator 1-1 is an upper bit and the output of the comparator 1-2 is a lower bit, If the code is represented by O ₁ , from Equations (8) and (9), O ₁ [00] and -Dp / 4? X <Lp / 4 are set to decimal {0}. For Lp / 4≤X <3Lp / 4 O 1 [01], and this, in decimal system (decimal) {1}. 3Lp / 4≤X For _{<5Lp / 4 O 1 [11} ], and this, in decimal system (decimal) {2}. That is, O ₁ indicates the pen touch position.

In the same manner, when the codes O ₀ and O ₂ are obtained from the equations (6), (7), and (11) and described by the code sequence of O ₀ → O ₁ → O ₂ , , That is, in the interval 0, the code sequence of O ₀ ? O ₁ ? O ₂ becomes [11]? [00]? [01], i.e., {2}? {0}? {1}. In the case of Lp / 4? X <3Lp / 4, the code sequence of O ₀ ? O ₁ ? O ₂ becomes [11]? [01]? [00], i.e., {2}? {1}? {0} . In the case of 3Lp / 4? X <5Lp / 4, the code sequence of O ₀ ? O ₁ ? O ₂ becomes [01]? 11?? 00, that is, {1}? {2}? {0} .

All codes other than the above three code strings become [01]. Accordingly, if there is no pen touch, the code string of O ₀ ? O ₁ ? O ₂ becomes [01]? [01]? [01], i.e., {1}? {1}? {1}. In the case of -Lp / 4≤X <Lp / 4, if one left-side output code is added, [01] → [11] → [00] → [01] becomes 3Lp / 4≤X < 4, if one right output code is added, [01] → [11] → [00] → [01] becomes impossible to distinguish the two. However, the former shifts one block to the left. It can be seen that when the shift is corrected, both represent the same area at the position of the pen touch.

Since there is no adjacent left pair in the leftmost pair, the pen touch in this area is not considered. This applies equally to the rightmost pair.

If there is a pen touch at the leftmost pair, the code string of O ₀ ? O ₁ ? O ₂ is changed to O ₀ ? O ₁ ? O 0 in the case of X <Lp / 4 according to the position of the pen touch, The code string of ₂ is [00]? [01]? [01]. In the case of Lp / 4? X <3Lp / 4, that is, in the case of the interval 1, the code string of O ₀ ? O ₁ ? O ₂ becomes [01]? [00]? [01]. In the case of 3Lp / 4? X <5Lp / 4, that is, in the case of the interval 2, the code string of O ₀ ? O ₁ ? O ₂ becomes [11]? [00]? [01].

As described above, the code line of the pen touch position 3Lp / 4? X <5Lp / 4 of the pair of the leftmost end (RX ₀ -RX ₁ pair) and the pen row of the RX ₁ -RX ₂ pair pen- <Lp / 4 becomes the same code string.

Similarly, if there is a pen touch in the pair at the rightmost end, the code string of O _{n -3} ? O _{n -2} ? O _{n -1} can be changed in the case of -Lp / 4? X <Lp / 4 , And in the interval 0, the code sequence of O _{n -3} ? O _{n -2} ? O _{n -1} becomes [01]? [11]? [00]. In the case of Lp / 4? X <3Lp / 4, that is, in the case of the interval 1, the code string of O ₀ ? O ₁ ? O ₂ becomes [01]? [11]? [01]. In the case of 3Lp / 4? X, that is, in the case of the interval 2, the code string of O ₀ ? O ₁ ? O ₂ becomes [01]? [01]? [11].

The output code (for example, O ₃ code) of the RX pair other than the RX pair adjacent to the left and right sides of the pen-touched RX pair is always [01]. In this case, since the projection capacitance does not occur, the following equation is satisfied.

VRX ₃ (t1) is held at the sampling capacitor C _S3a of the comparator 3-1 and VRX ₄ (t1) is held at the sampling capacitor C _S3d of the comparator 3-2, as in the case where there is a pen touch.

At the time t3, the following equation is satisfied.

VRX ₃ (t3) is held at the sampling capacitor C _S3c of the comparator 3-2 and VRX ₄ (t3) is held at the sampling capacitor C _S3b of the comparator 3-1, as in the case where the potential level pen touch is present. The difference input of each comparator satisfies the following equation.

From the above, the following rules can be derived.

In the leftmost pair (RX ₀ -RX ₁ pair), when O ₀ = [00] = {0}, the pen touches the interval 0 of RX ₀ -RX ₁ . In the case of O ₀ = [01] = {1}, O ₁ = [00] = {0}, the pen touches section 1 of RX ₀ -RX ₁ . In the case of O ₀ = [11] = {2}, O ₁ = [00] = {0}, the pen touches section 2 of RX ₀ -RX ₁ .

A pair of the right end (RX _n-1 -RX _n pairs) in the case of _{O n -2 = [11] =} {2}, O n -1 = [01] = {1}, Penn RX _{n -1} -RX Touching on segment 1 of _n . O _{n -1} = [11] = {2}, the pen touches the section 2 of RX _{n -1} -RX _n .

Pair other than the both ends (RX _k -RX _{k + 1} pair) is _{O k -1 = [11] =} {2}, O k = [01] = {1}, O k + 1 = [00] = { 0}, the pen touches the interval 1 of RX _{k -1} -RX _k . _{O k -1 = [01] =} {1}, O k = [11] = {2}, O k +1 = In [00] = {0}, the pen interval of RX _{k -1 k} -RX 2.

When it does not apply to any of the above rules, it is determined that there is no pen touch.

When touching the third section of RX ₁ -RX ₂ , the position is detected by interpreting it as being included in the main section 0 of RX ₀ -RX 1.

The second step will be described in more detail below. The same operation is basically performed even when a pen touch occurs in the main section 0 in the first step or when a pen touch occurs in the main section 1, but each case will be described separately.

First, a case where a pen touch exists in the main section 0 is detected at a resolution of 1/9. It is determined which sub-section the pen touch position is located to obtain 1/9 resolution. The specific sequence of the sub-section in which the pen touch exists is as follows.

The value of C _M is specified in the above equations (1) and (2). For example, when the pen is touched at a position of X &lt; 0, the difference between potentials RX ₀ and RX ₁ induced in RX ₀ and RX ₁ when TX is driven to V _DD satisfies the following equation.

If the sub-interval if the touch pen to the 0s1 and 0s2 boundary point Xp = -3Lp / 16, the difference voltage is generated in the RX ₁ and RX ₀ will satisfy the following equation.

When the pen touch position is located on the left side of the boundary point, the differential voltage reflecting the actual pen touch position becomes smaller than the expression (15). That is, if (Formula 15) - (Formula 16) &lt; 0, it can be determined that the pen touch position X exists on the left side of Xp, that is, in the sub-interval 0s1.

The pen touch position detection is performed using this principle. Equation (16) represents a reference potential that provides a reference for comparison when determining whether the pen touch position is on the left or right side of the boundary point.

In the case where the pen touches the boundary point Xp = + 3Lp / 16 of the sub-intervals 0s4 and 0s5, the same can be said as when the pen touches Xp = -3Lp / 16. In this case, however, attention is paid to the difference between potentials VRX1 and VRX2 induced in RX1 and RX2, and the following expression can be obtained.

If the pen touches the boundary point Xp = + 3Lp / 16 between the sub-intervals 0s4 and 0s5, the differential voltage satisfies the following equation.

It can be seen from the above equation that the reference voltage is equal to the reference voltage of the boundary point between the subintervals 0s1 and 0s2. This is because CM ₁ is the center of symmetry of X = 0, and CM ₀ and CM ₂ are centered around X = 0. From this, since the voltage for driving TD becomes the same value, the differential voltage comparison of the symmetric boundary point can be performed at the same time. If the pen touch position is equal to (Equation 17) - (Equation 18) &gt; 0, it is determined that the pen touch position X exists on the right side of Xp, that is, in the sub section 0s5.

Hereinafter, the operation of the basic circuit will be described with reference to FIG.

The second step has two cycles (2-1 and 2-2), and when the pen touch position is present in the sub-interval 0s1 or 0s5, it specifies which one is in the 2-1 cycle. When the pen touch position is other than (0s2, 0s3, 0s4), it is specified as one in the cycle 2-2.

2-1 cycle, and drives the TX at the time t1, the potential of the organic _{(VRX 0 (t1), VRX} 1 (t1), VRX 2 (t1)) each RX line. At time t2, one input switch of the comparator is turned off, and the organic voltage is held in the sampling capacitor Cs. That is, the switches S0a, S0d, S1a, S1d, S2a, and S2d are turned off.

VRX ₀ (t1) is the sampling capacitor C _S0a of the comparator 0-1, and VRX ₁ (t1) is the sampling capacitor C _S1a And the sampling capacitor C _S0d of the comparator 0-2, and VRX ₂ (t1) is the sampling capacitor C _S2a of the comparator 2-1 And the sampling capacitor C _S1d of the comparator 1-2.

TD is driven at 5VDD / 8 at time t3, and potentials VRX0 (t3), VRX1 (t3), and VRX2 (t3) are induced in each RX line.

Specifically, when the pen is touched at the driven boundary point, a potential equal to the difference of the potentials induced in the first Y electrode line and the adjacent second Y electrode line is applied to the TD so as to be induced at the time t3 .

That is, the amount of charge Q is proportional to the product of the capacitance C and the potential difference V, and the capacitance of the touched region changes, so that the amount of charge in the touched region changes. In consideration of this, the V applied to the TD is changed at the time t3 and compared with the potential obtained at the time t1 (see Equations 15 and 16 and related description).

Accordingly, it is determined whether the potential obtained at the time t1 is higher than the potential obtained at the time t3, and the position of the touched region is detected.

At time t4, switches S0b, S0c, S1b, S1c, S2b, and S2c are turned off. VRX ₀ (t3) is the sampling capacitor C _S0c of the comparator 0-2, and VRX ₁ (t3) is the sampling capacitor C _S1c And the sampling capacitor C _S0b of the comparator 0-1, and VRX ₂ (t3) is the sampling capacitor C _S2c of the comparator 2-2 And the sampling capacitor C _S1b of the comparator 1-1.

As a result, the input differential voltages of the comparators 0-2 and 1-2 satisfy the following equation.

Thus, the result of Equation (15) - (Equation 16) becomes the output of the comparator 0-2 (with the opposite polarity), and the result of Equation (17) (With the opposite polarity).

Accordingly, when the output of the comparator 0-2 becomes 1 (DELTA Vcomp0-2 > 0), it is determined that the pen touch position is in the sub-interval 0s1.

When the output of the comparator 1-2 becomes 0 (DELTA Vcomp1-2 &lt; 0), it is determined that the pen touch position is in the sub period 0s5.

In this case, the comparators 0-1 and 1-1 satisfy the following equations.

Next, the 2-2 cycle drives TX at the point of time t1, and turns on the potentials VRX0 (t1), VRX1 (t1), and VRX2 (t1) to the respective RX lines.

Similarly, at the time t2, one of the input switches of the comparator is turned off, and these organic voltages are held in the sampling capacitor.

At the time of t3 to drive the TD 7V _DD / 8, and the organic potential _{(VRX 0 (t3), VRX} 1 (t3), VRX 2 (t3)) for each RX line.

Calculating the reference voltage at the boundary point Xp = -Lp / 16 between the subintervals 0s2 and 0s3 and the boundary point Xp = + Lp / 16 between the subintervals 0s3 and 0s4 results in the following expression.

Accordingly, TD is driven at 7V _DD / 8. The difference voltages of the comparators 0-2 and 1-2 satisfy the following equations.

Therefore, when the pen touch position is discriminated as one of 0s2, 0s3, and 0s4 in the 2-1 cycle, if the output of the comparator 0-2 is 1 (? Vcomp0-2> 0), it is determined that the pen touch position is in the subinterval 0s2 . If the output of the comparator 1-2 is 0 (DELTA Vcomp1-2 &lt; 0), it is determined that the pen touch position is in the sub-interval 0s4. If the output of the comparator 0-2 is 0 or the output of the comparator 1-2 is 1, it is determined that the pen touch position is in the sub-interval 0s3. The position of the pen touch can be detected at a resolution of 1/9 in the main section 0 by the above process.

There is a pen touch in the main section 1 and the process of detecting the position at 1/9 resolution is almost the same as the above. In the main section 1, however, symmetric boundary points of sub-sections are also symmetrical in that X = Lp / 2 is symmetrical center, since C _M1 and C _M2 are centered symmetrically on X = Lp / 2.

Considering this, the reference voltage at the boundary between the subintervals 1s1 and 1s2 is calculated, and the following equation is established.

The reference voltage at the boundary point between the subintervals 1s4 and 1s5 is calculated, the following equation is established.

When TD is driven at 3V _DD / 8 in the cycle of 2-1, the differential voltages of the comparators 1-1 and 1-2 are as follows.

Accordingly, when the output of the comparator 1-2 is 1 (DELTA Vcomp1-2 > 0), it is determined that the position of the pen touch is in the sub section 1s1. If the output of 1-1 is 0 (DELTA Vcomp1-1 &lt; 0), it is determined that the position of the pen touch is in the sub-interval 1s5.

In the cycle 2-2, TD is driven to VDD / 8. The reason is that the reference voltage at the boundary between the subintervals 1s2 and 1s3,

, And the reference voltage at the boundary point between the subintervals 1s3 and 1s4,

. TD is driven to V _DD / 8, the difference voltages of the comparators 1-1 and 1-2 are,

. Therefore, when it is determined that the pen position is one of 1s2, 1s3 and 1s4 in the 2-1 cycle, if the output of the comparator 1-2 is 1 (? Vcomp0-2> 0), the pen touch position is in the subinterval 1s2 . If the output of the comparator 1-1 is 0 (DELTA Vcomp1-2 &lt; 0), it is determined that the pen touch position is in the sub section 1s4. If the output of the comparator 1-1 is 1 or the output of the comparator 1-2 is 0, it is determined that the pen touch position is in the sub-interval 1s3. The output of the comparator 0-2 at this time does not contribute to the determination of the pen touch position since there is no comparison condition.

As described above, detection of the pen touch position at resolution 1/9 has been described. If the resolution is 1/4 or 1/5, the second step is sufficient for one cycle. Also, if the resolutions are 1/6, 1/7, 1/8, 1/9, the second step requires two cycles. When 1/9 or more resolution is required, the second step requires three cycles or more.

Further, since the pen touch position can be known in the first step, the TX line determined not to have a pen touch need not be driven in the second step. That is, there is no need to perform a full scan of TX, and only a required TX line can be selectively driven, so that the TX scan time in the second step can be shortened.

The level of the TX driving potential may be increased not only by V _DD but by, for example, 2V _DD only in the second step. In this case, the electric potential induced in the RX line also doubles. In the second step, since only the necessary TX line is selectively driven, power consumption does not increase significantly even if the TX drive level is doubled. Also, if the TX driving level is doubled, the settling time of the TX line potential becomes long. However, since the necessary TX line is selectively driven, the influence of the increase of the correction time on the entire detection time is small and doubled The detection resolution can be improved.

The driving algorithm related to the above-described method of operating the touch panel may be applied to an integrated circuit (IC), and the integrated circuit may be implemented by being applied to a driving chip of a touch panel.

The integrated circuit (IC) 200 includes a positive input terminal receiving a different first input signal, a negative input terminal receiving a second input signal, and a second input signal comparing the first input signal and the second input signal, A plurality of comparators having output terminals for outputting signals; A voltage applying unit 150 connected to the positive input terminal and the negative input terminal for applying a drive voltage; And an operation unit (100) for reading a comparison signal of the plurality of comparators and generating a position signal.

The voltage difference between the positive input terminal and the negative input terminal is divided into at least two main sections and at least two sub sections for re-dividing each of the at least two main sections. The voltage applied by the voltage applying section 150 Becomes a voltage at a boundary point of the adjacent sub-section.

The operation unit 100 compares the potential difference applied by the voltage application unit to have a potential difference value according to a touched position at a positive input terminal and a negative input terminal and a potential value at a boundary point between the adjacent sub- Thereby detecting the touched position.

Also, when the plurality of comparators connected in parallel are grouped, the calculating unit 100 may generate a position signal by receiving a comparison signal of the adjacent group of comparators.

In addition, the integrated circuit can be mounted on a touch panel alone or in a single chip (ONE-CHIP) integrated with a chip of an individual portable terminal or an LCD driving chip.

The features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

Claims (15)

A first Y electrode line and a second Y electrode line which are adjacent to each other and are divided into at least two sub-sections for re-dividing at least two main sections and the at least two main sections, respectively; And
And a TD electrode line crossing the first Y electrode line and the second Y electrode line,
And a potential difference value at a first time point according to a touched position between the adjacent first and second Y electrode lines and a potential value at a boundary point between the adjacent sub- A touched position is detected by comparing one potential value,
The step of applying a potential to the TD electrode line includes a first cycle in which a touch region of a sub section formed at both ends of the left and right ends is first determined; And
And a second cycle for determining a touch area in a sub-section formed in the center area. The method according to claim 1,
Wherein the sub-section includes an odd number of sub-sections. 3. The method of claim 2,
Wherein a width of a sub-section disposed at both ends of the sub-section is half the width of a sub-section disposed at the center. The method of claim 3,
Wherein the center of the middle sub-section of the sub-section matches the center of the main section including the middle sub-section. The method of claim 3,
Wherein a distance between the first Y electrode line and the second Y electrode line is Lp, and a width of a sub-section disposed at both ends is Lp / 16. A first Y electrode line and a second Y electrode line which are adjacent to each other and are divided into at least two main sections and sub sections,
Detecting a touched position by comparing a potential difference value corresponding to a touched position between the adjacent first and second Y electrode lines and a potential value at a boundary point of the sub section,
And applying a potential to the TD electrode line so as to have a potential value at the sub-section boundary point,
The step of applying a potential to the TD electrode line includes a first cycle in which a touch region of a sub section formed at both ends of the left and right ends is first determined; And
And a second cycle for determining a touch area in a sub-section formed in the center area. The first Y electrode line and the second Y electrode line intersecting the TD electrode line and dividing the first Y electrode line and the second Y electrode line which are adjacent to each other into at least one main section, A first step of obtaining a potential difference;
A second step of re-dividing the touched main section into at least two sub-sections and applying a potential to the TD electrode line so as to have a potential value at a boundary point of the sub-section;
And a third step of detecting a touched position by comparing the potential difference value in the first step with the potential value applied in the second step,
The second step is a first cycle in which a touch region of a sub-section formed at left and right ends is first determined. And
And a second cycle for determining a touch area in a sub-section formed in the middle area. delete 8. The method of claim 7,
Wherein the first cycle uses a difference between a difference voltage reflecting a position of a touched area and a difference voltage at a boundary point of a sub section. delete A plurality of input terminals for receiving a first input signal different from each other according to a touched position, a negative input terminal for receiving a second input signal, and an output terminal for outputting a comparison signal of the first input signal and the second input signal Of comparator;
A voltage applying unit connected to the positive input terminal and the negative input terminal for applying a drive voltage; And
And an operation unit for reading a comparison signal of the plurality of comparators to generate a position signal,
Wherein the voltage difference between the positive input terminal and the negative input terminal is divided into at least two main sections and at least two sub sections for re-dividing each of the at least two main sections,
Wherein the voltage applied by the voltage application unit is a voltage at a boundary point between adjacent sub-sections. delete 12. The method of claim 11,
The operation unit compares a potential value applied by the voltage application unit to have a potential difference value according to a touched position at a positive input terminal and a negative input terminal and a potential value at a boundary point between adjacent sub- . 14. The method of claim 13,
Wherein the operation unit receives a comparison signal of a comparator of another adjacent group and generates a position signal when the plurality of comparators connected in parallel are grouped. 12. The method of claim 11,
Wherein the integrated circuit is mounted on a touch panel alone or in a single chip (ONE-CHIP) integrated with a chip of an individual portable terminal or an LCD driving chip.

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