KR101666580B1 - Touch Detection Method - Google Patents

Abstract

The present invention relates to a method of detecting touch coordinates corresponding to a touched portion, the method comprising: receiving a plurality of measured values corresponding to a plurality of coordinates defined by a plurality of rows and a plurality of columns, respectively; Generating a plurality of sensor values each corresponding to the plurality of measured values; Detecting peak coordinates of each of the plurality of rows and the plurality of columns in accordance with the plurality of sensor values; Detecting, among the peak coordinates, effective coordinates in which other peak coordinates are located within a first distance; And detecting touch coordinates in which a comparison coordinate having a sensor value equal to or greater than a threshold value is located within a second distance among the valid coordinates, wherein the step of detecting touch coordinates includes: Generating the threshold value according to a sensor value; And detecting touch coordinates in which a comparison coordinate having a sensor value equal to or greater than a threshold value determined in accordance with a sensor value of effective coordinates is located within a second distance from among the effective coordinates.

Touch Detection, Photo Sensor, Threshold

Description

[0001] Touch Detection Method [

The present invention relates to a touch detection method, and more particularly to a method of detecting coordinates of a touched portion from a plurality of measured values by receiving a plurality of measured values respectively corresponding to amounts of light applied to respective coordinates from a plurality of photosensors will be.

2. Description of the Related Art Generally, personal computers, portable communication devices, and other personal-purpose information processing devices constitute interfaces with users by using various input devices such as a keyboard, a mouse, and a digitizer. On the other hand, as the development of mobile communication equipments is expanded, it is difficult to improve the completeness of the product as an input device such as a keyboard and a mouse, so that it is simpler and can reduce malfunctions, . In response to this demand, a touch panel has been proposed in which a user directly touches the screen with a hand or a pen to input information.

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

The touch panel includes a resistive type in which a metal electrode is formed on an upper plate or a lower plate in accordance with a method of detecting a touched portion to determine a touched position as a voltage gradient according to resistance in a state in which a DC voltage is applied, Capacitive type that detects a touching part by detecting a position where a voltage change of the upper and lower plate due to a touch is formed by forming a constant potential on the conductive film, and reads the LC value induced by touching the conductive film An electro-magnetic type for detecting an indented portion, and an image processing type for detecting a touched portion by analyzing image data.

The touch panel of the image processing method includes a plurality of photo sensors arranged corresponding to a plurality of coordinates and outputting measurement values corresponding to the amounts of light applied to the respective coordinates, Analyzes the image data corresponding to a plurality of measurement values outputted by the respective sensors, and detects touch coordinates corresponding to the touched portion. The touch panel of the image processing method can detect the touch more precisely according to the touch detection method of detecting the touch by analyzing the characteristics of the photosensor and a plurality of measured values.

In the touch detection method according to the related art, a plurality of sensor values are generated by removing a reference value from a plurality of measurement values, and touch coordinates having sensor values of a predetermined threshold value or more among a plurality of coordinates are detected. That is, the coordinates whose sensor value is greater than or equal to the predetermined threshold value are detected as the touch coordinates, and the coordinates whose sensor value is less than the predetermined threshold value are not detected as the touch coordinates.

The threshold value is arbitrarily determined by the user or designer in consideration of the sensitivity of noise and touch sensing. At this time, when the threshold value is set small, it becomes vulnerable to noise. On the other hand, when the threshold value is set large, the touched portion can also be regarded as a non-touched portion, so that the touch coordinates can not be properly detected.

As described above, in the conventional touch detection method, when the touch coordinates are detected depending on a predetermined threshold value that is arbitrarily determined, an error due to noise or an error that can not detect a touched portion output with a sensor value smaller than a threshold value Or the like is generated, so that the touch detection can not be properly performed. Therefore, since the performance of the touch panel is highly dependent on the threshold value, the reliability of the touch panel is lowered.

Accordingly, the present invention provides a touch detection method capable of improving the reliability of a touch panel by detecting a touch using a variable threshold value.

According to the present invention, there is provided a method of detecting touch coordinates corresponding to a touched portion, comprising the steps of: receiving a plurality of measurement values respectively corresponding to a plurality of coordinates defined by a plurality of rows and a plurality of columns; step; Generating a plurality of sensor values each corresponding to the plurality of measured values; Detecting peak coordinates of each of the plurality of rows and the plurality of columns in accordance with the plurality of sensor values; Detecting, among the peak coordinates, effective coordinates in which other peak coordinates are located within a first distance; And detecting a touch coordinate where a comparison coordinate having a sensor value equal to or greater than a threshold value is located within a second distance among the effective coordinates. The step of detecting the touch coordinates may include: generating the threshold value according to a sensor value of one selected effective coordinate among the effective coordinates; And detecting touch coordinates in which a comparison coordinate having a sensor value equal to or greater than a threshold value determined in accordance with a sensor value of effective coordinates is located within a second distance from among the effective coordinates.

As described above, the touch detection method according to the present invention detects a touch coordinate corresponding to a touched portion by using a threshold value derived from a plurality of measured values instead of the arbitrarily determined predetermined threshold value. Accordingly, it is possible to prevent an error due to noise or an error that can not detect a touched portion output with a sensor value smaller than a threshold value, so that the performance of the touch panel does not depend on the threshold value, Reliability for performance can be improved.

Hereinafter, a touch detection method according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, a touch panel according to an embodiment of the present invention will be described.

FIG. 1 is a block diagram showing a touch panel according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the logic unit shown in FIG.

First, a touch panel according to an embodiment of the present invention includes a sensor unit 100 for generating a plurality of measurement values respectively corresponding to a plurality of coordinates defined by a plurality of rows and a plurality of columns, And a logic unit 200 receiving a plurality of measured values and detecting touch coordinates corresponding to the touched portion.

The sensor unit 100 is arranged so as to correspond to a plurality of coordinates defined by a plurality of rows and a plurality of columns, and outputs a plurality of measurement values respectively corresponding to the plurality of coordinates. At this time, the sensor unit 100 includes a plurality of photo sensors arranged corresponding to a plurality of coordinates, respectively. The photoelectric sensor 100 measures the light intensity As shown in FIG. Or the sensor unit 100 includes a plurality of first electrodes and second electrodes which are arranged so as to cross each other so as to generate a plurality of capacitances respectively corresponding to a plurality of coordinates, Output. As described above, the sensor unit 100 can be applied to any of a plurality of coordinates, so long as it can output a plurality of measured values varying according to a touch.

2, the logic unit 200 includes a sensor value generation unit 210 that generates a plurality of sensor values each corresponding to a plurality of measurement values input from the sensor unit 100, A peak coordinate detecting unit 220 for detecting peak coordinates of each of a plurality of rows and a plurality of columns by using an effective coordinate detecting unit 230 for detecting effective coordinates in which other peak coordinates are located within a first distance among a plurality of peak coordinates And a touch coordinate detector 240 for detecting touch coordinates in which comparison coordinates having a sensor value equal to or greater than a threshold value are located within a second distance among the effective coordinates.

Next, a touch detection method for detecting touch coordinates corresponding to a touched portion of the logic unit 200 will be described.

FIG. 3 is a flowchart illustrating a touch detection method according to an embodiment of the present invention, and FIG. 4 is a flowchart illustrating detailed steps of detecting touch coordinates shown in FIG. 5A and 5B are flowcharts showing the steps of retrieving the comparison coordinates shown in FIG. 4 and detecting the comparison coordinates.

As shown in FIG. 3, the touch detection method according to the embodiment of the present invention may include receiving a plurality of measurement values corresponding to a plurality of coordinates from the sensor unit 100 (S100) (S120) of detecting a peak coordinate of each of a plurality of rows and a plurality of columns in accordance with a plurality of sensor values, a step (S130) detecting effective coordinates in which peak coordinates are located, and detecting touch coordinates in which comparison coordinates having sensor values of a threshold value or more determined in accordance with sensor values of effective coordinates are located within a second distance (S140).

In the step of receiving a plurality of measured values (S100), as described above, the plurality of measured values correspond to a plurality of coordinates defined by a plurality of rows and a plurality of columns, respectively, . ≪ / RTI >

In step S110 of generating a plurality of sensor values, the plurality of sensor values are generated by subtracting a plurality of background reference values corresponding to a plurality of coordinates from a plurality of measured values, respectively. This is for the purpose of analyzing only the change of each of a plurality of coordinates by the touch only by removing the performance deviation of each of the plurality of photosensors.

The step of detecting peak coordinates (S120) includes the steps of detecting peak coordinates of each of a plurality of rows and detecting peak coordinates of each of the plurality of columns. At this time, in the step of detecting the peak coordinates of each of the plurality of rows, the peak coordinates corresponding to one of the plurality of rows are determined as the coordinates having the largest sensor value among the at least one coordinates arranged in one row . Likewise, in the step of detecting the peak coordinates of each of the plurality of columns, the peak coordinate corresponding to one of the plurality of columns is determined as the coordinate having the largest sensor value among at least one coordinate disposed in one column.

In the effective coordinate detection step (S130), the effective coordinates are detected as peak coordinates in which the different peak coordinates are located within the first distance among the peak coordinates of each of the plurality of rows and the plurality of columns. For example, if the first distance is a distance that is spaced by one coordinate, effective coordinates may be detected through an algorithm that searches for another peak coordinate within a 3x3 matrix in which one peak coordinate is centered. On the other hand, the first distance may be determined as a distance that is separated by one or more coordinates in consideration of the touch performance and the computation time.

The step of detecting the touch coordinates (S140) includes: selecting one effective coordinate among effective coordinates (S141) as shown in FIG. 4; generating a threshold value according to a sensor value of one selected effective coordinate (S142), searching for a comparison coordinate having a sensor value equal to or larger than a threshold value among neighbor coordinates located within a second distance in one effective coordinate corresponding to the selected effective coordinate (S143), determining whether the comparison coordinate is detected (S144). When the comparison coordinates are detected, the selected effective coordinates are detected as touch coordinates (S145), and whether or not all the valid coordinates are selected (S146).

In the step of generating the threshold value (S142), the threshold value is determined as a value proportional to the sensor value of one effective coordinate at a predetermined ratio. The threshold value is an effective range for selecting a coordinate having a relation between adjacent peripheral coordinates to be recognized as touch coordinates, and may be determined as a value corresponding to 70% to 90% of the sensor value of one effective coordinate. As described above, since the threshold value, which is an important one of the parameters for determining the touch coordinates, is newly updated for each effective coordinate, even when the touched portion is generated as a sensor value different from other touched portions, the threshold value corresponding to the effective coordinate By discriminating whether or not to touch, the touch can be detected. Accordingly, since the performance of the touch panel does not depend on the determination of the threshold value, the reliability of the performance of the touch panel can be improved.

In the step (S143) of retrieving the comparison coordinates, comparison coordinates having a sensor value equal to or greater than a threshold value among a plurality of neighboring coordinates disposed within a second distance from the selected one effective coordinate in all directions are searched. That is, the step of retrieving the comparison coordinates (step S143) is a step of searching for the comparison coordinates, as shown in Figs. 5A and 5B, of the plurality of first neighbor coordinates disposed within the second distance from the selected one effective coordinate in the first direction, (S1430) searching for a first comparative coordinate having a sensor value, and determining a second comparative coordinate having a sensor value that is greater than or equal to a threshold value among a plurality of second neighboring coordinates disposed within a second distance in a second direction opposite to the first direction, (S1431). The sensor coordinate value of the second comparative coordinate having a value larger than the threshold value among the plurality of third neighbor coordinates disposed within the second distance from the selected one effective coordinate in the third direction (S1432) of retrieving a third comparison coordinate and a sensor value of a threshold value or more among a plurality of fourth neighbor coordinates disposed within a second distance in a fourth direction opposite to the third direction from the selected one effective coordinate (S1433) of retrieving the fourth comparison coordinate. At this time, the second distance may be determined by a designer or a user, such as the first distance, to a distance that is spaced apart from one effective coordinate by one or more coordinates, in consideration of touch sensitivity and computation time.

If all of the first comparison coordinate, the second comparison coordinate, the third comparison coordinate, and the fourth comparison coordinate corresponding to one effective coordinate are detected in step S145 of detecting one effective coordinate as touch coordinates (S1440 ), One effective coordinate is detected as the touch coordinates.

Alternatively, if at least one of the first comparison coordinate, the second comparison coordinate, the third comparison coordinate, and the fourth comparison coordinate corresponding to one effective coordinate is detected in step S145 of detecting one effective coordinate as touch coordinates (S1441), and detects one effective coordinate as touch coordinates.

That is, the touch coordinates may be detected as effective coordinates in which all of the first comparison coordinates, the second comparison coordinates, the third comparison coordinates, and the fourth comparison coordinates are searched (S1440) depending on the type of the touch, At least one of the comparison coordinate, the second comparison coordinate, the third comparison coordinate, and the fourth comparison coordinate may be determined as the effective coordinate to be searched (S1440). For example, when detecting a circle-shaped touch, touch coordinates are detected as effective coordinates in which all of the first comparison coordinate, the second comparison coordinate, the third comparison coordinate, and the fourth comparison coordinate are searched (S1440). If a touch in which a shadow is left is mainly detected, the touch coordinates are detected as effective coordinates in which at least one of the first comparison coordinate, the second comparison coordinate, the third comparison coordinate, and the fourth comparison coordinate is searched (S1440).

Hereinafter, a touch detection method according to an embodiment of the present invention will be described with a simple example.

FIGS. 6A to 6G are step-by-step examples for explaining a touch detection method according to an embodiment of the present invention.

First, in step S110 of generating a plurality of sensor values, a plurality of measurement values corresponding to a plurality of coordinates (X, Y) defined by nine rows X1 to X9 and eight columns Y1 to Y8, It is assumed that a plurality of sensor values corresponding to a plurality of coordinates (X, Y) are generated, as shown in FIG. 6A, by subtracting a plurality of background reference values from each other.

In step S120 of detecting peak coordinates, the peak coordinates of each of the nine rows X1 to X9 are detected, and the peak coordinates of each of the eight columns Y1 to Y8 are detected.

That is, as shown in FIG. 6B, eight coordinates ((1,1), (1,2), (1,3), (1,4) (1, 4) having the maximum sensor value 3 among the peak values (1, 5), (1,6), (1,7) . Likewise, the eight coordinates ((2,1), (2,2), (2,3), (2,4), (2,5), (2, 3) having the maximum sensor value 10 among the peak values (2, 7), (2, 7) and (2, 8) This process is performed for each of the nine rows X1 to X9 to obtain the coordinates (1,4), (2,3), (3,3), (4,7), (5,5), , 2), (7,6), (8,6), and (9,8) are detected as the peak coordinates of the nine rows (X1 to X9), respectively.

As shown in FIG. 6B, nine coordinates ((1,1), (2,1), (3,1), (4,1), (3,1) having the largest sensor value 6 among the first row (Y1), (6,1), (7,1), (8,1) As shown in FIG. Similarly, nine coordinates ((1,2), (2,2), (3,2), (4,2), (5,2), (6,2 (2, 2) having the maximum sensor value 9 among the peak values (2, 2), (7, 2), (8, 2) and (9, 2) are detected as the peak coordinates of the second column Y2. This process is performed for each of the eight columns Y1 to Y8 and the coordinates (3,1), (2,2), (2,3), (8,4), (5,5), , 6), (4,7), and (9,8) are detected as the peak coordinates of the eight columns Y1 to Y8, respectively.

(1, 4), (2,3), (3,3), (4,7), (5,5), and (6,2) in the effective coordinate detection step (S130) ), (7,6), (8,6), (9,8), (3,1), (2,2), (2,3), (8,4) (8, 6), (4, 7), (9, 8)), it is determined whether other peak coordinates are located within the first distance, Detect with effective coordinates.

In other words, when the first distance is a distance that is spaced by one coordinate, as shown in FIG. 6C, the peak coordinates (3, 1) are obtained by locating the peak coordinates (2,2) within the first distance, (2, 2) are detected as effective coordinates by locating peak coordinates (3, 1), (2, 3) within a first distance, and peak coordinates (2, 2) and (1, 4) are located and detected as effective coordinates, and the peak coordinates (1,4) are detected as effective coordinates by locating the peak coordinates (2,3) within the first distance. Then, the peak coordinates (7, 6) and (8, 6) are located within the first distance and detected as effective coordinates. On the other hand, since the peak coordinates (4,7), (5,5), (6,2), (8,6), and (9,8) do not include other peak coordinates within the first distance, It does not.

Next, the step of detecting the touch coordinates (S140) selects one effective coordinate (S141), generates a threshold value in accordance with the sensor value of one selected effective coordinate (S142), and outputs the comparison coordinates as the generated threshold value (S143), and one effective coordinate is detected as touch coordinates in accordance with the search result (S144) of the comparison coordinates (S145).

For example, as shown in FIG. 6E, the effective coordinates ((3,3), (2,2), (2,3), (1,4), (7,6), (8,6) (S141), and generates a threshold value according to the sensor value 10 of the effective coordinates (3, 3) (S142). Assuming that the ratio of the threshold value to the sensor value of the effective coordinates is 80%, a threshold value corresponding to the sensor value 10 of the effective coordinates (3, 3) is generated as 8. [ Then, a comparison coordinate having a sensor value equal to or larger than the threshold value 8 is searched among a plurality of neighboring coordinates arranged in the second distance from the effective coordinates (3, 3). Here, assuming that the second distance is a distance that is spaced by two coordinates, the coordinates (2,2) having the sensor value (9) within the second distance to the left of the effective coordinate (3, 3) The coordinates (3, 3) having the sensor value (8) within the second distance to the lower side of the coordinates (3, 3) are retrieved.

In this state, if all of the first comparison coordinate, the second comparison coordinate, the third comparison coordinate, and the fourth comparison coordinate corresponding to one effective coordinate are searched (S1440) as shown in FIG. 5A, Assuming that the coordinates are detected with the touch coordinates, the coordinates having the sensor value equal to or higher than the threshold value 8 are not found in the second distance to the right side and the upper side of the effective coordinate (3, 3) It is not detected by touch coordinates. However, if at least one of the first comparison coordinate, the second comparison coordinate, the third comparison coordinate, and the fourth comparison coordinate corresponding to one effective coordinate is searched (S1441), as shown in FIG. 5B, (2, 2) and (3, 3) having a sensor value equal to or greater than the threshold value (8) within the second distance to the left and the lower side of the effective coordinate (3, 3) The effective coordinates (3, 3) are detected as touch coordinates.

Analysis of the effective coordinates (7, 6) in this way results in a threshold value of 4, which is 80% of the sensor value (5), corresponding to the effective coordinates (7, 6). If at least one of the first comparison coordinate, the second comparison coordinate, the third comparison coordinate, and the fourth comparison coordinate corresponding to one effective coordinate is searched (S1441), it is assumed that one effective coordinate is detected as touch coordinates The coordinates 6,6 and 8,6 having the sensor value equal to or greater than the threshold value 4 are retrieved within the second distance to the upper and lower sides of the effective coordinates 7 and 6 so that the effective coordinates 7,6 ) Is detected as touch coordinates.

(2, 2), (2, 2), (2, 3), (1,4), (8,6) , 4) are detected as touch coordinates because comparison coordinates having a sensor value equal to or greater than a threshold value of each effective coordinate are searched within a second distance, and effective coordinates (8, 6) are detected as effective coordinates (8, The comparative coordinate having the sensor value equal to or larger than the threshold value of the touch coordinate is not found, so that the touch coordinate is not detected.

6F, the effective coordinates ((3,3), (2,2), (2,3), (1,4), (7,6)) are detected as touch coordinates do.

If the coordinate having the sensor value equal to or larger than the predetermined threshold value 8 is regarded as touch coordinates as in the conventional touch detection method, since the effective coordinates 7, 6 have the sensor value 5, And effective coordinates (8, 6) are detected as touch coordinates because they have the sensor value (10). However, in the touch detection method according to the embodiment of the present invention, the threshold values corresponding to each of the effective coordinates are respectively set and the touch coordinates are determined according to whether there is a neighboring coordinate having a sensor value equal to or greater than a threshold value within a predetermined distance, The touch detection performance is not influenced by the value. Therefore, in the touch detection method according to the embodiment of the present invention, since the touch detection performance does not vary according to the threshold value, the reliability of the performance of the touch panel can be improved.

Next, results of an experiment in which a touch is detected by applying the touch detection method according to an embodiment of the present invention will be described.

FIGS. 7A to 7E show application examples of the touch detection method according to the embodiment of the present invention in stages.

In the touched portion as shown in Fig. 7A, a plurality of measured values corresponding to a plurality of coordinates are output as shown in Fig. 7B (S100).

When a plurality of measurement values are subtracted from a plurality of background reference values corresponding to the plurality of coordinates shown in Fig. 7C, a plurality of sensor values are generated as shown in Fig. 7D (S110).

Next, as indicated by a red dot in FIG. 7E, peak coordinates of each of a plurality of rows and a plurality of rows are detected according to the plurality of sensor values (S120).

Finally, the effective coordinates of the peak coordinates are detected (S130) and the touch coordinates of the effective coordinates are detected (S140), so that the touch coordinates are detected as indicated by the green dot in FIG. 7F.

As described above, the touch detection method according to the embodiment of the present invention detects effective coordinates highly likely to be touch coordinates, and generates a threshold value corresponding to effective coordinates according to the sensor value of effective coordinates. If there is a neighboring coordinate having a sensor value equal to or larger than a threshold value within a predetermined distance in all directions of the effective coordinates, the effective coordinate is determined as the touch coordinate. Thus, the threshold value is generated in correspondence with the effective coordinates, and is not fixed to an arbitrary value, so that the performance of the touch panel is not influenced by the threshold value, so that the reliability of the performance of the touch panel can be improved.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes may be made without departing from the technical spirit of the present invention.

1 is a block diagram showing a touch panel according to an embodiment of the present invention.

2 is a block diagram showing the logic unit shown in Fig.

3 is a flowchart illustrating a touch detection method according to an embodiment of the present invention.

FIG. 4 is a flowchart showing the detailed steps of detecting the touch coordinates shown in FIG.

FIGS. 5A and 5B are flowcharts illustrating a step of searching for a comparison coordinate corresponding to one effective coordinate shown in FIG. 4 and a step of detecting one effective coordinate by touch coordinates.

FIGS. 6A to 6F are diagrams for explaining an example of a touch detection method according to an embodiment of the present invention.

FIGS. 7A to 7F show application examples of the touch detection method according to the embodiment of the present invention in steps.

Claims (10)

A method of detecting touch coordinates corresponding to a touched portion, Receiving a plurality of measurement values respectively corresponding to a plurality of coordinates defined by a plurality of rows and a plurality of columns; Generating a plurality of sensor values each corresponding to the plurality of measured values; Detecting peak coordinates of each of the plurality of rows and the plurality of columns in accordance with the plurality of sensor values; Detecting, among the peak coordinates, effective coordinates in which other peak coordinates are located within a first distance; Determining a threshold value according to a sensor value of one selected effective coordinate among the effective coordinates; And Searching for a comparison coordinate having a sensor value equal to or greater than the threshold among effective coordinates located within a second distance from the selected one effective coordinate and detecting the selected effective coordinate as touch coordinates when the comparison coordinate is detected / RTI > delete The method according to claim 1, Wherein the step of retrieving the comparison coordinates comprises: Searching for a first comparison coordinate having a sensor value equal to or greater than the threshold among a plurality of first neighbor coordinates located within the second distance in the first direction from the one effective coordinate; Searching for a second comparison coordinate having a sensor value greater than or equal to the threshold value among a plurality of second neighboring coordinates disposed within the second distance in the second direction opposite to the first direction from the one effective coordinate; Searching for a third comparison coordinate having a sensor value equal to or greater than the threshold among a plurality of third neighbor coordinates disposed within the second distance in the third direction perpendicular to the first direction from the one effective coordinate; And Searching for a fourth comparison coordinate having a sensor value equal to or greater than the threshold among a plurality of fourth neighbor coordinates located within the second distance from the one effective coordinate in a fourth direction opposite to the third direction / RTI > The method of claim 3, Wherein the step of detecting the touch coordinates comprises: Detecting the selected one of the effective coordinates as touch coordinates when all the first comparison coordinates, the second comparison coordinates, the third comparison coordinates, and the fourth comparison coordinates are derived. The method of claim 3, Wherein the step of detecting the touch coordinates comprises: Detecting at least one of the first comparison coordinate, the second comparison coordinate, the third comparison coordinate, and the fourth comparison coordinate as the touch coordinates when the at least one of the first comparison coordinate, the second comparison coordinate, the third comparison coordinate, and the fourth comparison coordinate is derived. The method according to claim 1, Wherein the threshold value is proportional to a sensor value of the one effective coordinate at a predetermined ratio in the step of generating the threshold value corresponding to the sensor value of the one effective coordinate. The method according to claim 1, Wherein the plurality of sensor values are generated by subtracting a plurality of background reference values corresponding to the plurality of coordinates from the plurality of measurement values, respectively, in the step of generating the plurality of sensor values. A sensor unit arranged to correspond to a plurality of coordinates defined by a plurality of rows and a plurality of columns and outputting a measurement value corresponding to each of the plurality of coordinates, A sensor value generation unit for generating a plurality of sensor values respectively corresponding to the plurality of measured values received from the sensor unit, A peak coordinate detector for detecting peak coordinates of the plurality of rows and the plurality of columns using the plurality of sensor values, An effective coordinate detector for detecting an effective coordinate in which another peak coordinate is located within a first distance among the plurality of peak coordinates, A threshold value is determined according to a sensor value of one selected effective coordinate among the effective coordinates and a comparison coordinate having a sensor value equal to or greater than the threshold value among valid coordinates located within a second distance of the selected effective coordinate point is searched, And a touch coordinate detector for detecting the selected effective coordinate as touch coordinates when the comparison coordinate is detected. 9. The method of claim 8, Wherein the sensor unit includes a plurality of photosensors and outputs a measurement value with a light voltage corresponding to the amount of light incident on a portion where each of the photosensors is disposed. 9. The method of claim 8, Wherein the sensor unit includes a plurality of first electrodes and second electrodes arranged so as to cross each other such that a plurality of capacitances are generated so as to correspond to a plurality of left and right seats, .

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