KR100979394B1 - Touchpad for capacitive touch coordinate sensing - Google Patents

Abstract

The present invention relates to a touch pad for sensing two-dimensional touch coordinates, and more particularly, to a touch pad capable of reducing the size of a minimum area where coordinate detection is impossible in a touch pad that senses touch coordinates by using a change in the capacitance.

In order to achieve the object of the present invention, since the touch pad has a plurality of pattern lines connected to one sensor line, it is possible to form a smaller pattern at the same resolution, further reducing the size of the minimum area where coordinate detection is impossible. Can be.

Touch pad, pattern, sensor line, pattern line

Description

TOUCH PAD FOR SENSING THE COORDINATE OF TOUCHING BY MEASURING AN ELECTRIC CAPACITANE THEREON}

The present invention relates to a touch pad for detecting two-dimensional touch coordinates, and more particularly, to a touch pad for reducing the size of a minimum area where coordinate detection is impossible in a touch pad capable of sensing touch coordinates using a change in capacitance. .

Touch pads used in notebook computers are increasingly being used as input devices to replace mice. In particular, in recent years, the use of the touch screen in which a transparent touch pad is inserted on the LCD screen in a wireless device such as a mobile phone, PDA, portable game console, etc. is increasing.

The method of detecting the coordinates of the touch pad touched by the pad detects a change in capacitance generated when a conductor held by a human finger or a human hand contacts the pad surface and calculates X and Y coordinates in contact on a two-dimensional plane. It is. Coordinate values are repeatedly detected at predetermined intervals, and the moving speed or direction of the finger is calculated in consideration of the detected coordinate values and the change in time. In addition, since the difference in contact area occurs according to the magnitude of the force that the finger presses, and as a result, the magnitude of the detected capacitance is different, the strength of the contact may be measured and used based on the magnitude of the detected capacitance. It is also indicated in the Z direction.

1 is a plan view of a touch pad according to the prior art.

In order to detect the coordinates on the pad, sensor lines crossing each other are arranged in a matrix form. The touch pad of FIG. 1 has three rows (ROW1, ROW2, ROW3) in the X direction and three columns (COL1, COL2, COL3) in the Y direction. The number of rows and columns varies depending on the target area and shape of the coordinate detection.

On the other hand, if the touch pad is composed only of conductive lines, it is difficult to secure sufficient capacitance, so after forming a pattern of a certain shape made of a conductive material such as gold, copper, copper, etc. as shown in 110 or 120 of FIG. The patterns are connected by a pattern line made of a conductive material. The shape of the pattern may be any shape such as a circle, a triangle, a square, a rhombus, and the like, and FIG. 1 illustrates a pattern consisting of a rhombus and a triangle for explanation.

The shape of the pattern does not need to be constant at all positions, and circles, triangles, squares, etc. may be randomly arranged at each position. That is, the term 'pattern' used in the present specification is used only to mean a figure occupying a certain area of the touch pad in order to secure capacitance, and the figure is limited to a specific shape or a certain regularity. It is not intended to be used to limit what must be arranged.

Patterns belonging to the same row are connected to one of the row sensor lines ROW1, ROW2 and ROW3, and patterns belonging to the same column are connected to one of the column sensor lines COL1, COL2 and COL3. In FIG. 1, in order to distinguish the row-sensing pattern 110 from the column-sensing pattern 120, the row-sensing pattern 110 is shown in white and a constant pattern is inserted into the column-sensing pattern 120. However, these materials are not different from each other, and as described above, conductors such as copper, copper, gold, and silver may be used. The row-sensing patterns 110 are connected to the row-sensing patterns 110 located in the same row through the row-pattern line 150, and the column-sensing patterns 120 connect the column-pattern lines 160. Through the heat-sensitive patterns 120 located in the same column. The reason for having such a structure is that the row-sensing pattern 110 is for detecting the row (Y coordinate) to which the finger touches, and the column-sensing pattern 120 is for detecting the column (X coordinate) to be contacted. to be.

In Fig. 1, the shape of the row-sensing pattern located at the outermost left side of the same row is triangular, and the row-sensor line is connected to this triangular row-sensing pattern. Similarly, the bottom-most heat-sensing pattern of the same row is triangular in shape and the heat-sensor line is connected to this triangular heat-sensing pattern. The row-sensor line and the column-sensor line are connected to circuitry that measures capacitance and calculates the position of the touching coordinates at regular intervals.

Since the touch pad detects the capacitance, the surface of the touch pad and the row-sensing pattern 110 and the column-sensing pattern 120 are separated by using an insulator, and typically a row-sensing pattern for the detection of sophisticated capacitance. 110 and heat-sensitive pattern 120 are located on the same layer. On the other hand, since the row-pattern line 150 and the column-pattern line 160 cross each other, it is necessary to separate them into different layers using an insulator. In FIG. 1, the row-pattern line 150 is positioned on the same layer as the row-sensing pattern 110 and the column-sensing pattern 120, and the column-pattern line 160 is positioned below one layer so that two lines are separated. It prevented crossing. The heat-pattern line 160 and the heat-sensing pattern 120 are connected by via holes 130 that drill the insulating layer up and down.

On the other hand, since the change in the sensor capacitance should be made as large as possible to facilitate detection, it is desirable to form the pattern as closely as possible. Referring to FIG. 1, when a human finger touches the touch pad, the capacitance of the row-sensing pattern 110 and the column-sensing pattern 120 existing near the touched position of the finger is changed by the capacitance of the human body. do. The change in capacitance causes a change in one or more of the signals output to the row sensor lines ROW1, ROW2, ROW3 via the row-pattern line 150 connected to the row-sensing pattern 110, and the row sensor line The circuit portion connected to the circuit detects the Y coordinate of the position where the finger touched through the change of the signal. In addition, the change in capacitance causes a change in one or more of the signals output to the thermal sensor lines COL1, COL2, COL3, via the heat-pattern line 160 connected to the heat-sensitive pattern 120, and the heat The circuit portion connected to the sensor line detects the X coordinate of the position where the finger touched through the change of such a signal. Thus, in order to sense the position, the object or finger must be in contact with both the row-sensing pattern 110 and the column-sensing pattern 120 simultaneously.

Therefore, when the finger touches only in the circle 140 shown in Fig. 1, only the capacitance of the heat-sensing pattern 120 is changed, so that only the x coordinate (heat) of the contacted position can be detected. That is, the circle 140 represents the maximum size of the contact area where the coordinate determination is impossible when the human finger is in contact. In more detail, when the maximum area of contact by hand is 14, the value of COL3 on the X axis is easily detected due to a sufficient change in the capacitance of the heat-sensing-pattern 120, but the pattern (row-sensing on the Y axis) is easily detected. -The pattern 110 does not detect the coordinates of the Y axis because there is no contact area. In other words, the value appearing on the actual Y axis is not zero due to the parasitic capacitor component, but the value is so small that it is not easy to find the actual coordinates. In other words, in order to find the exact coordinates, the contact area must be larger, and at small contact areas, it is almost impossible to find the coordinates. In the prior art, in order to minimize the area where the coordinate detection is impossible in order to improve the sensitivity of the touch pad, the pattern has to be more densely arranged. When the patterns are densely arranged, the number of sensor lines is increased by that amount, resulting in an increase in manufacturing cost of the touch pad.

Touch pads that detect changes in capacitance are affected by environmental changes, such as temperature and humidity, and noise signals coming from the power source. In order to facilitate the distinction between the noise signal and the actual contact signal, it is desirable to allow the change in the capacitance sensed in the X direction and the change in the capacitance sensed in the Y direction to be detected at the same level. In the prior art, even if the contact is more than 140, there may be a large difference in the capacitance sensed by X and Y according to the contact position, which caused the incorrect touch coordinate detection.

As described above, when a human finger touches the touch pad, an area of the touch pad may be hardly detected. In the present invention, it is intended to improve the sensitivity of the touch pad by minimizing the size of the hard to detect area.

In order to achieve the object of the present invention, the touchpad of the present application includes a plurality of row-sensing patterns; A plurality of row-pattern lines, each row-pattern line connecting a plurality of row-sensing patterns located in the same row of the plurality of row-sensing patterns; A plurality of heat-sensing patterns; A plurality of column-pattern lines, each column-pattern line connecting a plurality of heat-sensing patterns located in the same column of the plurality of heat-sensing patterns; A plurality of row-sensor lines connectable to circuitry for sensing a touched position; And a plurality of column-sensor lines connectable to circuitry, each of the plurality of row-sensor lines being connected to two or more adjacent row-pattern lines of the plurality of row-pattern lines, and a plurality of column-sensor lines Each of is connected to two or more adjacent column-pattern lines of the plurality of column-pattern lines.

Preferably, in the touchpad of the present invention, the first layer comprising an insulating material; A second layer comprising a plurality of row-sensing patterns, a plurality of row-sensing patterns, and a plurality of row-pattern lines; A third layer comprising an insulating material; And a fourth layer comprising a plurality of heat-pattern lines, the third layer having a plurality of via holes connecting each of the plurality of heat-sensing patterns to a corresponding heat-pattern line of the plurality of heat-pattern lines. The plurality of first pattern lines are a plurality of row-pattern lines, and the plurality of second pattern lines are a plurality of column-pattern lines.

Preferably, in the touchpad of the present invention, the first layer comprising an insulating material; A second layer comprising a plurality of row-sensing patterns, a plurality of row-sensing patterns, and a plurality of column-pattern lines; A third layer made of an insulating material; And a fourth layer comprising a plurality of row-pattern lines, the third layer having a plurality of via holes connecting each of the plurality of row-sensing patterns to a corresponding row-pattern line of the plurality of row-pattern lines. The plurality of first pattern lines are a plurality of column-pattern lines, and the plurality of second pattern lines are a plurality of row-pattern lines.

Preferably, in the touchpad of the present invention, the fourth layer further includes circuit elements and conductive lines, and each of the plurality of first pattern lines is connected to the fourth layer through via holes.

Preferably, in the touchpad of the present invention, a fifth layer comprising an insulating material; And a sixth layer including circuit elements and conductive lines, wherein each of the plurality of first pattern lines is connected to the sixth layer through a via hole, and each of the plurality of second pattern lines is a sixth layer through a via hole. Is connected to.

Preferably, in the touchpad of the present invention, a fifth layer comprising an insulating material; A sixth layer having a ground potential; A seventh layer comprising an insulating material; And an eighth layer including circuit elements and leads, wherein the sixth layer is connected to the eighth layer through via holes, and each of the plurality of first pattern lines is connected to the eighth layer through via holes, Each of the second pattern lines of is connected to the eighth layer through via holes.

Preferably, in the touchpad of the present invention, there is provided a touch pad comprising: a first layer having a plurality of row-sensing patterns, a plurality of row-pattern lines, and a first insulator; And a second layer having a plurality of column-sensing patterns, a plurality of column-pattern lines, and a second insulator, wherein the plurality of row-sensing patterns and the plurality of row-pattern lines are formed on the first insulator The plurality of column-sensing patterns and the plurality of column-pattern lines are formed on the second insulator, and the plurality of row-pattern lines and the plurality of column-pattern lines are orthogonal.

Preferably, in the touchpad of the present invention, the first layer further comprises a plurality of second column-pattern lines, and the second layer further comprises a plurality of second row-pattern lines, and the plurality of second columns Each of the pattern lines connects a row-sensing pattern located in the same column of the plurality of row-sensing patterns and connected to the same row-sensor line, and each of the second row-pattern lines is one of a plurality of column-sensing patterns Connect heat-sensing patterns located in the same row and connected to the same column-sensor line.

Preferably, in the touch pad of the present invention, each of the plurality of row-sensor lines is connected to two or more adjacent row-pattern lines of the plurality of row-pattern lines through a row-sensing pattern located at the edge of the touch pad; Each of the plurality of heat-sensor lines is connected to two or more adjacent heat-pattern lines of the plurality of heat-pattern lines through a heat-sensing pattern located at the edge of the touch pad.

In the present invention, a plurality of pattern lines are connected to one sensor line, thereby reducing the size of the contact area that cannot be determined at the same resolution, thereby improving the sensitivity of the touch pad. In addition, since the size of the pattern is subdivided and mixed, it is possible to increase the linearity of the capacitance value measured at the X and Y direction (row and column direction) coordinate detection.

2 shows a plan view of a touch pad according to a first embodiment of the present invention.

In the present invention, the terms "sensor line" and "pattern line" will be used differently. "Sensor line" is defined as the line that connects to the sensor circuitry that handles changes in sensed capacitance. On the other hand, the "pattern line" refers only to a portion in which a pattern formed on the pad portion is electrically connected to form a line.

In general, the resolution and the construction cost of the sensor circuit increase in proportion to the number of sensor lines. That is, when the same sensor circuit is used, the resolution is determined according to the number of sensor lines.

Referring to FIG. 2, a row-pattern line 230 connecting the row-sensing patterns and a column-pattern line 240 connecting the column-sensing patterns are shown, and the row-pattern line and the column are shown. A row-sensor line 250 and a column-sensor line 260 are shown, each connected to a pattern line and connectable to a position sensing circuit. One row-sensor line 250 is connected to two row-pattern lines 230, and one column-sensor line 260 is connected to two column-pattern lines 240. That is, in the invention of the first embodiment, two pattern lines are connected to one sensor line.

Due to this structure, the touch pad of FIG. 2 forms a pattern four times per unit area. For example, when the number of row-sensor lines is 640 and the number of column-sensor lines is 480, the row-pattern lines are 1280, which is twice the number of row-sensor lines, and the number of column-pattern lines is 960. As a result, the number of patterns per unit area is increased by four times and the size of the pattern is reduced to about one quarter.

Meanwhile, FIG. 2 illustrates a circle 220 having the same size as the circle 140, which is an area in which the X and Y coordinates cannot be detected at the same time in the conventional touch pad illustrated in FIG. 1. In the touch pad illustrated in FIG. 2, an area where the X and Y coordinates cannot be detected at the same time is illustrated by a circle 210. Comparing the circle 210 and the circle 220, it can be seen that the non-contact area of the touch pad according to the first embodiment of FIG. 2 is much smaller than that of the conventional touch pad. That is, even in the case of touch pads having the same resolution, since the patterns are more densely arranged, the area where the X and Y coordinates cannot be detected at the same time is reduced, so that the sensitivity of the touch pad is improved based on the coordinate detection capability. There is.

3A shows a side view of a touch pad according to a first embodiment of the present invention.

The touch pad circuit of FIG. 3A includes a touch pad part 340 and a sensor circuit part 310, and the touch pad part 340 has a laminated structure composed of a total of four layers. The touch pad unit 340 may include an insulating cover on the first layer 350, a row and heat sensing pattern and a row-pattern line on the second layer 360, a PCB insulating layer and a fourth layer on the third layer 370 ( 380 is provided with thermal-pattern lines and circuit element wiring.

An insulation cover 350 is disposed on the first layer to form a flat surface, and the capacitance is measured by insulating between the finger to be touched and the pattern of the second layer. The second layer 360 includes the row-sensing patterns, column-sensing patterns, and row-pattern lines shown in FIG. 2. Since the row-sensing pattern and the column-sensing pattern are located on the same second layer, there is an advantage in that the amount of change in the correction capacitance at the time of contact is similar, which simplifies the processing of the touch in the circuit portion. On the other hand, since the column-pattern line crosses the row-pattern line when the second layer is located, the column-pattern line is located on the fourth layer. The second and fourth layers are insulated by the PCB substrate of the third layer, and the heat-pattern line located in the fourth layer and the heat-sensing pattern of the second layer are connected through the via hole 330. The row-pattern line of the second layer is connected to the fourth layer 380 using one or more via holes 320 per pattern line. The laminated structure of FIG. 3 is only one example for describing the technical idea of the present invention, and the present invention is not limited to the present invention having the laminated structure shown in FIG. 2. This can be clearly seen from other embodiments described below.

3B shows a side view of a touch pad according to a second embodiment of the present invention.

Unlike the touch pad shown in FIG. 3A, the sensor circuit portion 420 is positioned below the touch pad portion 340. That is, the touch pad illustrated in FIG. 3B has the same structure as that of the touch pad of FIG. 3A, and the first, second, third, and fourth layers, but the circuit elements and the conductors are positioned on the sixth layer 420, and the sixth layer. An insulating layer is positioned in the fifth layer 410 between 420 and the thermal-pattern line of the fourth layer. The row-pattern line of the second layer is directly connected to the circuit elements of the sixth layer through the via hole 320, and the column-pattern line of the fourth layer is connected to the sixth through one or more via holes 325 per line. Connected to the circuit elements of the layer. The touch pad shown in FIG. 3B may be used when there is not enough space on the left and right sides.

3C shows a side view of a touch pad according to a third embodiment of the present invention.

The touch pad of FIG. 3C further includes a ground layer 430 inserted between the fifth and sixth layers of the touch pad of FIG. 3B. The ground layer 430 is connected to the sixth layer through the ground via hole 440. Due to the circuit elements located in the sixth layer and external noise, the patterns and lines located in the first and third layers may be interfered with, and thus, the ground layer may be inserted therebetween to block the influence from the outside. .

4 shows a top view of a touch pad according to a fourth embodiment of the present invention.

One row-sensor line 250 is connected to four row-pattern lines, and one column-sensor line 260 is connected to four column-pattern lines. Therefore, since the number of patterns per unit area is increased by 16 times than the touch pad shown in FIG. 2, the area capable of simultaneously detecting X and Y coordinates is reduced, thereby improving sensitivity.

5 is a plan view of each layer of the touch pad according to the fifth embodiment of the present invention.

Instead of forming a sensor pattern on a PCB board, a sensor pattern is often implemented on a flexible PCB (FPCB) or indium tin oxide (ITO) film. If a sensor is implemented on the screen, such as a touch screen, a transparent conductor such as an ITO film is used. In this case, since the via hole cannot be used, as shown in FIG. 5, a pattern in one direction may be formed per ITO film, and the two films may be overlapped to detect X and Y coordinates. That is, the picture shown on the left of FIG. 5 is a pattern and a pattern line which can detect a row, and the picture shown on the right is a pattern and a pattern line which can detect a column, and these two films overlap. Embodiment 1 is that one row-sensor line 250 is connected to two row-pattern lines 230 and one column-sensor line 260 is connected to two column-pattern lines 240. Like, but the patterns are located on different layers. Such a touchpad can be used when the thickness of the film is very thin so that there is no significant difference in the capacitance of patterns located on different layers.

FIG. 6A illustrates a floor plan view of two layers of a touch pad according to a sixth embodiment of the present invention, and FIG. 6B illustrates a plan view of a touch pad in which two layers shown in FIG. 6A are stacked.

In the touchpad shown in FIG. 6A, respective patterns connected to the same sensor line are connected in a mesh shape. That is, the row-sensing patterns connected to the row-sensor line 250 are connected by the line 610 in the column direction, and the column-sensing patterns connected to the column-sensor line 260 are the lines 620 in the row direction. ) Is connected.

ITO conductors have a higher surface resistance than conductors such as copper used in ordinary PCBs. Due to such a resistance component, a change in sensitivity for each position of the sensor signal may be a problem, and in order to solve this problem, a touch pad having the same mesh structure as described above may be configured. 6B shows a plan view of a pad in which each layer on which a column-sensitive pad and a row-sensitive pad are formed is stacked.

In addition, this invention is not limited to the said Example, It can variously deform and implement within the range which does not deviate from the technical summary of this invention.

1 is a plan view of a touch pad according to the prior art.

2 shows a plan view of a touch pad according to a first embodiment of the present invention.

3A shows a side view of a touch pad according to a first embodiment of the present invention.

3B shows a side view of a touch pad according to a second embodiment of the present invention.

3C shows a side view of a touch pad according to a third embodiment of the present invention.

4 shows a top view of a touch pad according to a fourth embodiment of the present invention.

5 is a plan view of each layer of the touch pad according to the fifth embodiment of the present invention.

6A shows a floor plan view of two layers of a touch pad according to a sixth embodiment of the present invention.

FIG. 6B illustrates a plan view of a touch pad in which two layers shown in FIG. 6A are stacked.

* Description of the symbols for the main parts of the drawings *

230: row-pattern line 240: column-pattern line

250: row-sensor line 260: column-sensor line

210: area not detected simultaneously in X and Y coordinates

220: area not detected simultaneously in X and Y coordinates

Claims (10)

A plurality of row-sensing patterns; A plurality of row-pattern lines, each of the row-pattern lines connecting the plurality of row-sensing patterns located in the same row of the plurality of row-sensing patterns; A plurality of heat-sensing patterns; A plurality of heat-pattern lines, each of the heat-pattern lines connecting the plurality of heat-sensing patterns located in the same column of the plurality of heat-sensing patterns; A plurality of row-sensor lines connectable to circuitry for sensing a touched position; And A plurality of heat-sensor lines connectable to said circuit portion, Each of the plurality of row-sensor lines is connected to at least two adjacent row-pattern lines of the plurality of row-pattern lines, and each of the plurality of column-sensor lines is adjacent two of the plurality of column-pattern lines Connected to at least one column-pattern line, the plurality of row-sensing patterns and the plurality of column-sensing patterns are formed separately so as not to overlap each other on the same layer, and the plurality of row-pattern lines and the plurality of columns The pattern line is formed on different layers of a touch pad made of a plurality of layers and separated by an insulator. The method of claim 1, A first layer comprising an insulating material; A second layer formed on a lower surface of the first layer and including the plurality of row-sensing patterns, the plurality of column-sensing patterns, and the plurality of row-pattern lines; A third layer formed on the bottom surface of the second layer and comprising an insulating material; And A fourth layer formed on a bottom surface of the third layer, the fourth layer including the plurality of thermal-pattern lines, The third layer has a plurality of via holes connecting each of the plurality of heat-sensing patterns to a corresponding one of the plurality of heat-pattern lines; The plurality of first pattern lines are the plurality of row-pattern lines, And the plurality of second pattern lines are the plurality of heat-pattern lines. The method of claim 1, A first layer comprising an insulating material; A second layer formed on a bottom surface of the first layer and including the plurality of row-sensing patterns, the plurality of column-sensing patterns, and the plurality of column-pattern lines; A third layer formed on a lower surface of the second layer and made of an insulating material; And A fourth layer formed on a lower surface of the third layer, the fourth layer including the plurality of row-pattern lines, The third layer has a plurality of via holes connecting each of the plurality of row-sensing patterns to a corresponding row-pattern line of the plurality of row-pattern lines, The plurality of first pattern lines are the plurality of heat-pattern lines, And a plurality of second pattern lines are the plurality of row-pattern lines. The method according to claim 2 or 3, The fourth layer further includes a circuit element and a conductor, Each of the plurality of first pattern lines is connected to the fourth layer through a via hole of the third layer. The method according to claim 2 or 3, A fifth layer formed on a lower surface of the fourth layer and including an insulating material and having a plurality of via holes; And A sixth layer formed on a lower surface of the fifth layer and including a circuit element and a conductive line; Each of the plurality of first pattern lines is connected to the sixth layer through via holes in the third layer and the fifth layer, Each of the plurality of second pattern lines is connected to the sixth layer through a via hole in the fifth layer. The method according to claim 2 or 3, A fifth layer formed on a lower surface of the fourth layer and including an insulating material and having a plurality of via holes; A sixth layer formed on the bottom surface of the fifth layer and having a ground potential; A seventh layer formed on a bottom surface of the sixth layer and including an insulating material and having a plurality of via holes; And An eighth layer formed on a lower surface of the seventh layer and including a circuit element and a conductive line; The sixth layer is connected to the eighth layer through a via hole in the seventh layer, Each of the plurality of first pattern lines is connected to the eighth layer through via holes in the third, fifth and seventh layers, Each of the plurality of second pattern lines is connected to the eighth layer through via holes in the fifth and seventh layers. The method of claim 1, A first layer having said plurality of row-sensing patterns, said plurality of row-pattern lines, and a first insulator; And A second layer formed on a bottom surface of the first layer, the second layer including the plurality of heat-sensing patterns, the plurality of heat-pattern lines, and a second insulator, The plurality of row-sensing patterns and the plurality of row-pattern lines are formed on the first insulator, and the plurality of the plurality of column-sensing patterns and the plurality of column-pattern lines are formed on a second insulator And the plurality of row-pattern lines and the plurality of column-pattern lines are orthogonal to each other. The method of claim 7, wherein The first layer further comprises a plurality of second heat-pattern lines, The second layer further comprises a plurality of second row-pattern lines, Each of the plurality of second column-pattern lines connects a row-sensing pattern located in the same column of the plurality of row-sensing patterns and connected to the same row-sensor line, Each of the plurality of second row-pattern lines connect a column-sensing pattern located in the same row of the plurality of column-sensing patterns and connected to a same column-sensor line. The method of claim 1, Each of the plurality of row-sensor lines is connected to two or more adjacent row-pattern lines of the plurality of row-pattern lines through a row-sensing pattern located at an edge of the touch pad, Each of the plurality of heat-sensor lines is connected to two or more adjacent heat-pattern lines of the plurality of heat-pattern lines through a heat-sensing pattern located at an edge of the touch pad. The method of claim 1, The shape of the row-sensing pattern and the column-sensing pattern may be arbitrarily selected from circles, triangles, and squares.

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