KR20090002537A - Touch coordinate recognition method and touch screen device for performing the same - Google Patents

Abstract

A touch coordinating method using a bending wave and a touch screen apparatus for implementing the same are provided to recognize touch coordinates by using the different transfer characteristic of the bending wave. First to fourth bending wave sensors are arranged on four corners of a base substrate. If bending wave is generated by touch operation, the first bending wave sensor recognizes bending wave. The second bending wave sensor(S2) recognizes the bending wave after a first time from a time recognizing touch by the first bending wave sensor. The third bending wave sensor recognizes the bending wave after a second time from a time recognizing touch. The third bending wave sensor recognizes the bending wave after a third time from a time recognizing touch.

Description

Touch coordinate recognition method and touch screen device for performing the same {METHOD FOR RECOGNIZING A TOUCH POSITION AND TOUCH-SCREEN DEVICE FOR PERFORMING THE SAME}

1A is a block diagram of a general infrared touch screen.

FIG. 1B is a block diagram illustrating the principle of an infrared touch screen by simplifying the structure shown in FIG. 1A.

2A is a conceptual diagram schematically illustrating a touch screen device using a bending wave according to the present invention.

FIG. 2B is a waveform diagram illustrating bending waves detected by the first to fourth bending wave sensors illustrated in FIG. 2A.

3 is a flowchart illustrating a touch coordinate recognition method according to the present invention.

4A to 4D are conceptual views illustrating a coordinate calculation process corresponding to touch coordinates generated according to the present invention.

FIG. 5 is a flowchart for explaining an example of the bending wave signal processing shown in FIG. 3.

6A through 6C are waveform diagrams for describing signals corresponding to respective steps illustrated in FIG. 5.

FIG. 7 is a block diagram illustrating a touch screen device to which a signal processing technique applying the wavelet shown in FIG. 5 is applied.

8 is a flowchart for explaining another example of the bending wave signal processing shown in FIG. 3.

9A to 9F are waveform diagrams for describing signals corresponding to respective steps illustrated in FIG. 8.

FIG. 10 is a block diagram illustrating a touch screen device to which a signal processing technique applying the short kernel method illustrated in FIG. 8 is applied.

11A shows a short kernel with a sample rate of 100 Khz and a specific period (frequency) of 1740 Hz, and FIG. 11B shows a short kernel with a sample rate of 100 KHz and a specific frequency of 6740 Hz.

FIG. 12 is a flowchart for explaining another example of the bending wave signal processing shown in FIG. 3.

13A to 13F are waveform diagrams for describing signals corresponding to each step illustrated in FIG. 12.

FIG. 14 is a block diagram illustrating a touch screen device to which a signal processing technique applying the time difference of arrival shown in FIG. 12 is applied.

FIG. 15 is a block diagram illustrating a cross correlation unit (cross correlation unit) illustrated in FIG. 14.

FIG. 16 is a block diagram illustrating a unit cross-correlation unit illustrated in FIG. 15.

The present invention relates to touch coordinate recognition, and more particularly, to a touch coordinate recognition method using a bending wave and a touch screen device for performing the same.

In recent years, electronic displays, which are interactive displays, are widely used in all aspects of life. In the past, the use of electronic displays was mainly limited to computing applications such as desktop computers and notebook computers, but as processing power became more readily available, such performance was integrated into a wide variety of applications. For example, electronic displays are commonly found in a wide variety of applications such as cash registers, game machines, car navigation systems, restaurant management systems, vegetable shop checkout lines, gas pumps, information kiosks, and hand-held data notebooks. have.

The touch screen device is an interactive system that allows the user to perform a desired operation by directly pressing the display device. From touch screens, information, and information systems to control monitoring of automation processes in each industrial site, and to replacement of various operations. Widely used.

Among the touch screen devices, the infrared touch screen includes a light emitting part emitting infrared light on the upper side and the right side of the plane, and a light receiving part detecting the infrared rays on the lower side and the left side so as to be positioned at positions opposite to the respective light emitting parts. According to the pressing of the two infrared receivers that are not detected is configured to recognize the coordinates of the pressed position.

1A is a block diagram of a general infrared touch screen.

Referring to FIG. 1A, an infrared touch screen includes a plurality of light emitting parts 2 positioned at a predetermined distance apart from each other on a top side and a right side of a plane of a touch screen 1, and a bottom side of a plane of the touch screen 1. And a plurality of light receiving units 3 disposed on the left side to face each of the plurality of light emitting units 2, and a control unit 4 that detects the push coordinates of the touch screen 1 by receiving a detection result of the light receiving unit 3. ). Here, the light emitting unit 2 includes a light emitting diode, and the light receiving unit 3 includes a light receiving diode.

FIG. 1B is a block diagram illustrating the principle of an infrared touch screen by simplifying the structure shown in FIG. 1A.

Referring to FIG. 1B, the light emitter 2 and the light receiver 3 are operated under the control of the controller 4, and the infrared light emitted from the light emitter 2 is detected by the light receiver 3, and the light receiver 3 ) Is applied to the controller 4 again.

In this process, if the area between the light emitting unit 2 and the light receiving unit 3, ie, the touch screen 1 is pressed, infrared rays generated by the light emitting unit 2 are not detected by the light receiving unit 3. The control unit 4 receiving the detection result of the light receiving unit 3 may detect that the pressing occurs.

Interactive displays, on the other hand, often include some form of touch sensitive screen. Integrating visual displays and touch sensing panels has become increasingly common with the advent of the next generation of portable multimedia devices. One popular contact detection technique called Surface Acoustic Wave (SAW) uses high frequency wavelengths that propagate on the surface of a glass screen. Attenuation of the wavelengths resulting from the contact of the finger with the glass screen surface is used to detect the contact location. The SAW uses a "time-of-flight" technique where the time for which disturbance reaches pickup sensors is used to detect the contact location. Such an approach is possible if the medium behaves in a non-distributed manner such that the speed of the wavelength does not change much over the frequency range of interest.

On the other hand, vibration is usually generated when an impact is applied to the plate. The flexible wave or bending wave generated by the vibration has a characteristic of being transmitted to the outside at the point of impact. The bending wave has different characteristics to be transmitted for each frequency and has a characteristic that a high frequency is transmitted faster than a low frequency.

Therefore, the technical problem of the present invention has been made in view of the above, an object of the present invention is to provide a touch coordinate recognition method using a bending wave for recognizing touch coordinates using different transfer characteristics of the bending wave.

Another object of the present invention is to provide a touch screen device for performing the above touch coordinate recognition method.

In order to realize the above object of the present invention, a touch coordinate recognition method using a bending wave according to an embodiment includes (a) receiving a plurality of bending waves generated according to a touch of a touch screen, and (b) the bending Removing the reflected waves included in the waves, and calculating touch coordinates by calculating reception times between the bending waves for each of the bending waves from which the reflected waves are removed.

In accordance with another aspect of the present invention, there is provided a touch screen device including: a touch screen panel, a reflection wave removing unit, and a Fourier transform unit; It includes arithmetic processing unit and position estimation. The touch screen panel has first, second, third and fourth bending wave sensors disposed on the same substrate. The reflected wave removing unit removes the reflected wave included in the bending wave signals provided from each of the bending wave sensors. The Fourier transform unit performs a Fourier transform on each of the bending wave signals from which the reflected wave is removed. The calculation processor calculates a delay time of the bending wave for each sensor for each of the Fourier transformed bending wave signals. The position estimator estimates touch coordinates of the touch screen based on the calculated delay time.

In accordance with another aspect of the present invention, a touch screen device includes a touch screen panel, an analog-digital converter, a reflected wave remover, a Fourier transform, a wavelet coefficient generator, a continuous wavelet converter, Location estimation and touch drivers. The touch screen panel has first, second, third and fourth bending wave sensors disposed on the same substrate. The analog-digital conversion unit receives the bending wave signals provided from each of the bending wave sensors and digitally converts them. The reflected wave removing unit removes the reflected wave included in each of the digitally converted bending wave signals. The Fourier transform unit performs a Fourier transform on each of the bending wave signals from which the reflected wave is removed. The wavelet coefficient generation unit generates wavelet coefficients based on the center frequency of each channel of the Fourier transformed bending wave signals, and generates a wavelet packet using the generated wavelet coefficients. The continuous wavelet converter extracts visual information of a frequency corresponding to the highest value by convolutionally generating the wavelet packets for each frequency and the bending wave signals. The position estimator calculates time differences by calculating time differences between the time informations, and estimates touch coordinates based on the calculated time differences. The touch driver is provided with the estimated touch coordinates.

In accordance with another aspect of the present invention, there is provided a touch screen device including a touch screen panel, an analog-digital converter, a reflected wave remover, a Fourier transform, a short kernel coefficient generator, a cross-correlation unit, and a position. An estimator and a touch driver. The touch screen panel has four bending wave sensors disposed on the same substrate. The analog-digital converting unit receives a bending wave signal provided from each of the bending wave sensors and digitally converts them. The reflected wave removing unit removes the reflected wave included in the digitally converted bending wave signal. The Fourier transform unit performs a Fourier transform on each of the bending wave signals from which the reflected wave is removed. The short kernel coefficient generation unit generates a short kernel coefficient according to a center frequency common to four channels, and calculates a short kernel waveform based on the generated short kernel coefficient. The cross-correlation unit correlates the short kernel waveform and the digitally converted bending waves with each other to extract visual information of a frequency corresponding to the highest value. The position estimator calculates time differences by calculating time differences between the time informations, and estimates touch coordinates based on the calculated time differences. The touch driver is provided with the estimated touch coordinates.

In accordance with another aspect of the present invention, a touch screen device includes a touch screen panel, an analog-digital conversion unit, a reflection wave removal unit, a Fourier transform unit, a cross correlation unit, a position estimation unit, and a touch driver. Include. The touch screen panel has four bending wave sensors disposed on the same substrate. The analog-to-digital converter receives the bending wave signals provided from each of the bending wave sensors and digitally converts them. The reflected wave removing unit removes the reflected wave included in the digitally converted bending wave signal. The Fourier transform unit performs a Fourier transform on each of the bending wave signals from which the reflected wave is removed. The cross-correlation unit cross-corresponds each of the Fourier transformed bending wave signals to calculate reception times of the bending waves received by the respective bending wave sensors. The position estimator calculates time differences by calculating time differences between the time informations, and estimates touch coordinates based on the calculated time differences. The touch driver is provided with the estimated touch coordinates.

According to the touch coordinate recognition method and the touch screen device for performing the same, each of the plurality of bending wave sensors disposed in the touch screen device is generated by the vibration of the touch moment, and receives a bending wave having different transmission characteristics Through the bending wave signal processing technology, the touch coordinates can be recognized by calculating the delay time of the bending wave for each sensor.

Hereinafter, with reference to the accompanying drawings, it will be described in detail the present invention.

2A is a conceptual diagram schematically illustrating a touch screen device using a bending wave according to the present invention. FIG. 2B is a waveform diagram illustrating bending waves detected by the first to fourth bending wave sensors illustrated in FIG. 2A.

Referring to FIG. 2A, a touch screen device using a bending wave according to the present invention includes a base substrate SUB and first, second, third and fourth bending wave sensors disposed at four corners of the base substrate SUB. It includes these (S1, S2, S3, S4). The bending wave or flexural wave is a dispersive wave whose propagation speed is proportional to the square root of frequency. Therefore, a bending wave having a relatively small wavelength has a characteristic that a propagation speed is larger than that of a bending wave having a relatively long wavelength.

In FIG. 2A, τ1 is a time required for the first bending wave sensor S1 to recognize after the bending wave is generated at the touch position T0, and τ2 is a second time after the bending wave is generated at the touch position T0. The time required for the bending wave sensor S2 to be recognized, τ3 is the time required for the third bending wave sensor S3 to recognize after the bending wave is generated at the touch position T0, and τ4 is the touch position T0. ) Is a time required for the fourth bending wave sensor S4 to recognize after the bending wave is generated. Further, δ1 is the time between the bending wave detection time of the first bending wave sensor S1 and the bending wave detection time of the second bending wave sensor S2, and δ2 is the bending wave detection time of the first bending wave sensor S1. And time between the bending wave detection time of the third bending wave sensor S3 and δ3 is the time between the bending wave detection time of the first bending wave sensor S1 and the bending wave detection time of the fourth bending wave sensor S4. .

In operation, the first to fourth bending wave sensors S1, S2, S3, and S4 disposed at four corners of the base substrate SUB may be configured according to transfer characteristics of the bending wave generated by the vibration of the touch moment. Receive signals with different delay times.

Accordingly, according to the present invention, by applying various bending wave signal processing techniques to the received signals, the touch coordinates are calculated by calculating the delay time of the bending wave for each bending wave sensor.

Referring to FIG. 2B, when a bending wave is generated by a touch operation at the touch position T0, the first bending wave sensor S1 recognizes the bending wave. The second bending wave sensor S2 recognizes the bending wave after the first time δ1 elapses from the touch recognition time of the first bending wave sensor S1, and the third bending wave sensor S2 detects the touch recognition time. The bending wave is recognized after the second time δ2 has elapsed, and the fourth bending wave sensor S3 recognizes the bending wave after the third time δ3 has elapsed from the touch recognition time.

In an ideal case, as shown in FIG. 2B, the waveforms of the bending waves collected by the respective bending wave sensors S1, S2, S3, and S4 are substantially the same.

However, since the outer portion of the base substrate serves as the interface of the medium, the reflected wave is generated in response to the bending wave. Therefore, the reflected wave acts as a noise component to the bending waves collected by the respective bending wave sensors S1, S2, S3, and S4. In addition, distortion occurs in the waveform of the bending wave depending on the state of the surface according to the area of the base substrate.

Accordingly, in the present invention, the initial detection time of each of the bending wave waveforms is more accurately calculated by removing noise components included in the bending waves collected by the bending wave sensors S1, S2, S3, and S4.

3 is a flowchart illustrating a touch coordinate recognition method according to the present invention.

Referring to FIG. 3, it is checked whether a bending wave according to a touch is received (step S100).

If it is checked in step S100 that the bending wave according to the touch is received, the bending waves received for each bending wave sensor are collected (step S200).

Subsequently, signal processing is performed on the received bending wave (or bending wave) to obtain reception time information of the received bending waves (step S300). The signal processing procedure described above may be performed in various ways. For example, it may be performed by a signal processing technique using a Wavelet Transform, or may be performed by a Short Kernel Method (SKM), or a Time Difference Of Arrival (TDOA) technique. It may also proceed by.

Subsequently, the touch area is calculated based on the signal processed in step S300 (step S400). Different equations for calculating touch coordinates are applied according to the calculated touch area.

Subsequently, touch coordinates (touch positions) are calculated based on the touch area calculated in step S400 and the obtained reception time information (step S500).

4A to 4D are conceptual views illustrating a position calculation process corresponding to touch areas generated according to the present invention. In particular, FIG. 4A illustrates a case where a touch occurs in the first side plane region, FIG. 4B illustrates a case where a touch occurs in the second side plane region, and FIG. 4C illustrates a touch occurs in the third side plane region. 4D shows a case where a touch is generated in the fourth side plane area.

<First side plane area mode>

As shown in FIG. 4A, when a touch occurs in the first side plane region proximate to the first bending wave sensor S1, the first bending wave sensor S1 first detects the bending wave according to the touch. The first side plane region satisfies the conditions t12 ≧ 0, t13 ≧ 0, and t14 ≧ 0. Here, t12 is a value obtained by subtracting the detection time of the second bend wave sensor S2 from the detection time of the first bend wave sensor S1, and t13 is the third bend at the detection time of the first bend wave sensor S1. The detection time of the wave sensor S3 is subtracted, and t14 is a value obtained by subtracting the detection time of the fourth bending wave sensor S4 from the detection time of the first bending wave sensor S1.

The first points x1 and y1 of the first side plane region where the touch is generated define a plurality of right triangles together with the first to fourth bending wave sensors. Four equations may be derived as shown in Equation 1 below to correspond to the defined right triangle.

Here, m is the length of the first side of the base substrate, and n is the length of the second side of the base substrate. In FIG. 4A, m is a distance between the first bending wave sensor S1 and the second bending wave sensor S2 or the third bending wave sensor S3 and the fourth bending wave sensor S4, and n is the first bending wave sensor. The distance between the wave sensor S1 and the third bending wave sensor S3 or the second bending wave sensor S2 and the fourth bending wave sensor S4.

Further, first, second, third and fourth distances r1, r2, r3 between the first point x1 and y1 and the first to fourth bending wave sensors S1, S2, S3 and S4. , r4) may be defined as in Equation 2 below.

Here, Cg is a constant set according to the material of the base substrate. For example, the group velocity of sound passing through the air is approximately 340 m / sec at room temperature, and the group velocity of sound passing through the glass is approximately 3,000 m / sec to 5,000 m / sec.

When the first, second, third and fourth distances r1, r2, r3, and r4 defined in Equation 2 are substituted into Equation 1, Equation 3 below may be obtained.

Accordingly, the position of the first points x1 and y1 of the first side plane region where the touch is generated may be obtained through Equation 3 described above.

<2nd side plane area mode>

As shown in FIG. 4B, when a touch is generated in the second side plane region adjacent to the second bending wave sensor S2, the second bending wave sensor S2 first detects the bending wave according to the touch. The second side planar region satisfies the conditions t21 ≧ 0, t23 ≧ 0, and t24 ≧ 0. Here, t21 is a value obtained by subtracting the detection time of the first bend wave sensor S1 from the detection time of the second bend wave sensor S2, and t23 is the third bend at the detection time of the second bend wave sensor S2. The detection time of the wave sensor S3 is subtracted, and t24 is a value obtained by subtracting the detection time of the fourth bending wave sensor S4 from the detection time of the second bending wave sensor S2.

The first points x2 and y2 of the second side plane region where the touch is generated define a plurality of right triangles together with the first to fourth bending wave sensors. Four equations corresponding to the defined right triangle may be derived as in Equation 4 below.

Here, m is the length of the first side of the base substrate, and n is the length of the second side of the base substrate. In FIG. 4B, m is the distance between the first bending wave sensor S1 and the second bending wave sensor S2 or the third bending wave sensor S3 and the fourth bending wave sensor S4, and n is the first bending wave sensor. The distance between the wave sensor S1 and the third bending wave sensor S3 or the second bending wave sensor S2 and the fourth bending wave sensor S4.

Further, first, second, third and fourth distances r1, r2, r3 between the second point x2 and y2 and the first to fourth bending wave sensors S1, S2, S3 and S4. , r4) may be defined as in Equation 5 below.

Here, Cg is a constant set according to the material of the base substrate.

When the first, second, third and fourth distances r1, r2, r3, r4 defined in Equation 5 are substituted into Equation 4, Equation 6 may be obtained.

Therefore, the positions of the second points x2 and y2 of the second side plane region where the touch is generated may be obtained through Equation 6 described above.

<Third side plane area mode>

As shown in FIG. 4C, when a touch occurs in the third side plane region proximate to the third bending wave sensor S3, the third bending wave sensor S3 first detects the bending wave according to the touch. The third side planar region satisfies the conditions of t31 ≧ 0, t32 ≧ 0, and t34 ≧ 0. Here, t31 is a value obtained by subtracting the detection time of the first bend wave sensor S1 from the detection time of the third bend wave sensor S3, and t32 is the second bend at the detection time of the third bend wave sensor S3. The detection time of the wave sensor S2 is subtracted, and t34 is a value obtained by subtracting the detection time of the fourth bending wave sensor S4 from the detection time of the third bending wave sensor S3.

The third points x3 and y3 of the third side plane region where the touch is generated define a plurality of right triangles together with the first to fourth bending wave sensors. Four equations corresponding to the defined right triangle may be derived as in Equation 7 below.

Here, m is the length of the first side of the base substrate, and n is the length of the second side of the base substrate. In FIG. 4A, m is a distance between the first bending wave sensor S1 and the second bending wave sensor S2 or the third bending wave sensor S3 and the fourth bending wave sensor S4, and n is the first bending wave sensor. The distance between the wave sensor S1 and the third bending wave sensor S3 or the second bending wave sensor S2 and the fourth bending wave sensor S4.

In addition, first, second, third and fourth distances r1, r2, and r3 between the third point x3 and y3 and the first to fourth bending wave sensors S1, S2, S3 and S4. , r4) may be defined as Equation 8 below.

Here, Cg is a constant set according to the material of the base substrate.

When the first, second, third and fourth distances r1, r2, r3, and r4 defined in Equation 8 are substituted into Equation 7, the following Equation 9 can be obtained.

Therefore, the position of the third point (x3, y3) of the third side plane region where the touch is generated can be obtained through the above equation (9).

<4th side plane area mode>

As shown in FIG. 4D, when a touch occurs in the fourth side plane region proximate the fourth bending wave sensor S4, the fourth bending wave sensor S4 first detects the bending wave according to the touch. The fourth side plane region satisfies the conditions of t41 ≧ 0, t42 ≧ 0, and t43 ≧ 0. Here, t41 is a value obtained by subtracting the detection time of the first bend wave sensor S1 from the detection time of the fourth bend wave sensor S4, and t42 is the second bend at the detection time of the fourth bend wave sensor S4. The detection time of the wave sensor S2 is subtracted, and t43 is a value obtained by subtracting the detection time of the third bending wave sensor S3 from the detection time of the fourth bending wave sensor S4.

The fourth points x4 and y4 of the fourth side plane region where the touch is generated define a plurality of right triangles together with the first to fourth bending wave sensors. Four equations corresponding to the defined right triangle may be derived as in Equation 10 below.

Here, m is the length of the first side of the base substrate, and n is the length of the second side of the base substrate. In FIG. 4A, m is a distance between the first bending wave sensor S1 and the second bending wave sensor S2 or the third bending wave sensor S3 and the fourth bending wave sensor S4, and n is the first bending wave sensor. The distance between the wave sensor S1 and the third bending wave sensor S3 or the second bending wave sensor S2 and the fourth bending wave sensor S4.

Further, first, second, third and fourth distances r1, r2, r3 between the fourth point x4 and y4 and the first to fourth bending wave sensors S1, S2, S3 and S4. , r4) may be defined as in Equation 11 below.

Here, Cg is a constant set according to the material of the base substrate.

When the first, second, third and fourth distances r1, r2, r3, r4 defined in Equation 11 are substituted into Equation 10, Equation 12 may be obtained.

Therefore, the positions of the fourth points x4 and y4 of the fourth side plane region where the touch is generated may be obtained through Equation 12 described above.

Next, embodiments for calculating the delay time of each bending wave sensor for calculating the touch coordinates, that is, various bending wave signal processing techniques, will be described.

Example 1 Coordinate Recognition Method Using Continuous Wavelet Transform

FIG. 5 is a flowchart for explaining an example of the bending wave signal processing shown in FIG. 3. 6A through 6C are waveform diagrams for describing signals corresponding to respective steps illustrated in FIG. 5. In particular, a bending wave signal processing technique employing a continuous wavelet transform (CWT) is shown.

5 to 6C, digital conversion is performed on each of the bending wave signals collected for each channel (step S311). For example, the bending wave detected by the bending wave sensor has a relatively large amplitude at the beginning of the touch, as shown in FIG. 6A, and has a relatively decreasing amplitude as time passes. In this embodiment, the channel is used in terms of the respective bending wave sensors.

Subsequently, band pass filtering or adaptive filtering is performed on the digitally converted bending wave signal, so that the reflected wave included in the bending wave is removed (step S312).

Subsequently, a frequency analysis operation of converting the bending wave in the time domain into the frequency domain through Fourier transform (FFT) for each channel is performed (step S313).

Subsequently, a wavelet coefficient according to common center frequencies for each channel is generated, and a wavelet packet as shown in FIG. 6B is generated using the generated wavelet coefficient (step S314). The wavelet transform is characterized in that the signal is analyzed in a non-uniform frequency band using a window in which the size of the region is variable.

Where you want low frequency information more accurately, you use the window of long time period and where you want high frequency information, use the window of short time period. For example, the discrete wavelet transform, DWT (m, k) is represented by equation (13).

은, 스케일(Scale)을 나타내는 변수,

은 시프트(Shift)를 나타내는 변수, 그리고

은 마더 웨이브렛(Mother Wavelet)과 같은 신호 성분,

는 마더 웨이브렛이고, k는 입력 신호에서 특정한 샘플 값을 나타내는 정수이다.here,

Is a variable representing a scale,

Is a variable representing a shift, and

Is a signal component such as the mother wavelet,

Is a mother wavelet and k is an integer representing a particular sample value in the input signal.

On the other hand, since the approximation resulted from the wavelet transform is represented by the low frequency component of the signal, and the detail value represents the high frequency component, the process of performing the discrete wavelet transform is performed by the high pass filter (HPF) and the low pass filter. By two filtering operations using (LPF).

)은 대부분 짧고 진동적인 함수로서 적분값이 영(Zero)이고, 양끝에서 급격히 감쇄하는 형태를 가진다. In addition, the multi-resolution of the wavelet transform uses a wavelet filter bank to divide the signal into various types of high pass filter components.

) Is mostly a short and vibratory function whose integral value is zero and rapidly decays at both ends.

Subsequently, continuous wavelet transform (CWT) is performed by continuously convolving the wavelet packets for each frequency and the digitally converted bending waves with each other (step S315). Through the continuous wavelet transformation, time information of a frequency corresponding to the highest value is extracted in an area to which a scale value with respect to time is mapped as shown in FIG. 6C. In FIG. 6C, the touch visual information obtained corresponding to the highest value is approximately 4.5 ms.

Example 1 Touch Screen Device Using Continuous Wavelet Conversion

FIG. 7 is a block diagram illustrating a touch screen device to which a signal processing technique employing the wavelet shown in FIG. 5 is applied. In particular, a block diagram illustrating a bending wave signal processing technique employing a continuous wavelet transform (CWT) is shown. The continuous wavelet transform is a suitable signal processing technique in consideration of the characteristics of the bending wave since the magnitude of the frequency according to time is expressed in three dimensions.

5 to 7, the touch screen device 100 according to the first embodiment of the present invention may include a touch screen panel 110, an analog-digital converter 120, a reflected wave remover 130, and a Fourier transform. The unit 140 includes a wavelet coefficient generator 150, a continuous wavelet converter 160, a position estimator 170, and a touch driver 180. The analog-to-digital converter 120, the reflected wave remover 130, the Fourier transform 140, the wavelet coefficient generator 150, the continuous wavelet transform 160 and the position estimator shown in FIG. 170 may be implemented in hardware, or may be implemented in software or programmatically. If implemented in hardware, it is obvious that it may be implemented on a single chip only for convenience of explanation.

The touch screen panel 110 includes first to fourth bending wave sensors S1, S2, S3, and S4 disposed at four corner regions of the base substrate, as shown in FIG. 2A. The first to fourth bending wave sensors S1, S2, S3, and S4 detect bending waves generated by a touch and provide them to the analog-digital converter 120.

The analog-to-digital converter (ADC) 120 digitally converts each of the four channels of the analog type bending wave signals collected by the first to fourth bending wave sensors S1, S2, S3, and S4. The reflection wave removing unit 130 and the continuous wavelet converter 160 are provided.

The reflected wave remover 130 removes the reflected wave component from each of the bend wave signals through band pass filtering or adaptive filtering to obtain a simplified waveform, and the reflected wave is removed from the bent wave to the fast Fourier transform unit (FFT) 140. to provide.

The fast Fourier transform unit 140 obtains the center frequencies fc from each of the four bent waves by performing the fast Fourier transform in order to obtain a waveform having only the dominant characteristic in the bending wave from which the reflected wave is removed.

The wavelet coefficient generator 150 generates wavelet coefficients based on the center frequencies for each channel, and generates a wavelet packet as shown in FIG. 6B by using the generated wavelet coefficients. The conversion unit 160 is provided.

The continuous wavelet converter 160 generates wavelet packets for each frequency using the reference wave packets generated by the wavelet coefficient generator 150 to form the first to fourth bend wave sensors S1, S2, S3, and S4. Time information of the frequency corresponding to the highest value in the region where the scale value is mapped to time as shown in FIG. 6C by convolving the bending waves collected in the analog-to-digital converter 120 and digitally converted. Is extracted and provided to the position estimator 170. For example, when the wavelet packet having the center frequency of 1 KHz and the bending wave are convolved with each other, visual information of the peak point can be obtained. Through this process, touch visual information of the bending waves collected by the four bending wave sensors S1, S2, S3, and S4 are obtained.

In FIG. 6C, the touch visual information obtained corresponding to the highest value is approximately 4.5 ms.

The position estimator 170 calculates time differences between the touch time information of the bending waves detected by the four bending wave sensors S1, S2, S3, and S4, and calculates time differences, based on the calculated time differences. The touch coordinates are estimated after determining which side plane among the fourth side plane regions is generated.

For example, the detection time differences t12, t13, and t14 with the other bending wave sensors S2, S3, and S4 are calculated based on the first bending wave sensor S1, and t12≥0, t13≥0, When the condition of t14≥0 is satisfied, it is determined that the touch is generated at the first points (x1, x1) of the first side plane area, and the touch of the first points (x1, y1) is performed using Equation 3 described above. Estimate the coordinates.

Meanwhile, the detection time differences t21, t23, and t24 with the other bending wave sensors S1, S3, and S4 are calculated based on the second bending wave sensor S2, and t21 ≥ 0, t23 ≥ 0, t24 ≥ When the condition 0 is satisfied, it is determined that the touch is generated at the second points x2 and x2 of the first side plane area, and the touch coordinates of the second points x2 and y2 are determined using Equation 6 described above. Estimate.

Meanwhile, the detection time differences t31, t32, and t34 with the other bending wave sensors S1, S1, and S4 are calculated based on the third bending wave sensor S3, and t31≥0, t32≥0, t34≥ When the condition 0 is satisfied, it is determined that the touch is generated at the third point (x3, x3) of the first side plane area, and the touch coordinates of the third point (x3, y3) are determined using Equation 9 described above. Estimate.

Meanwhile, the detection time differences t41, t42, and t43 with the other bending wave sensors S1, S2, and S3 are calculated based on the fourth bending wave sensor S4, and t41≥0, t42≥0, t43≥ When the condition 0 is satisfied, it is determined that the touch is generated at the fourth points x4 and x4 of the first side plane region, and the touch coordinates of the fourth points x4 and y4 are determined using Equation 12 described above. Estimate.

The touch driver 180 receives the touch coordinate values estimated by the position estimator 170 and provides corresponding coordinates to a central processing unit (not shown) or a graphic controller of the host computer. The corresponding coordinates may be displayed on the display unit (not shown) in the form of an image such as an icon.

Example 2 Coordinate Recognition Method Using Short Kernel Method (SKM)

8 is a flowchart for explaining another example of the bending wave signal processing shown in FIG. 3. 9A to 9F are waveform diagrams for describing signals corresponding to respective steps illustrated in FIG. 8. In particular, a bending wave signal processing technique using the Short Kernel Method (SKM) is shown.

8 to 9F, digital conversion is performed on each of the bending wave signals collected for each channel (step S321). For example, even if it corresponds to a touch position, since the bending wave contains various noise components, it is impossible to confirm the correct touch position as shown in FIG. 9A. In addition, the bending wave detected by the bending wave sensor has a relatively large amplitude at the beginning of the touch, as shown in FIG. 9B, and has a relatively decreasing amplitude as time passes.

Subsequently, bandpass filtering or adaptive filtering is performed on the digitally converted bending wave signal to remove the reflected wave (step S322). The bending wave signal from which the reflected wave is removed may have a concentric shape around the touch position as shown in FIG. 9C.

Subsequently, a center frequency fc is obtained from each of the bending waves of each channel through frequency analysis through Fourier transform (FFT) for each channel (step S323). The waveform obtained through the Fourier transform is, for example, as shown in FIG. 9D. In FIG. 9D, the obtained center frequency fc is around 180 Hz.

Then, short kernel coefficients are generated according to common center frequencies for each channel, and a relatively short frequency waveform, that is, a short kernel as shown in FIG. 9E is generated from the generated short kernel coefficients (step S324).

Then, the time information of the frequency corresponding to the highest value is extracted through cross-correlation processing on the calculated short kernel waveform and the digitally converted bending waves (step S325). In other words, the calculated short kernel waveform (e.g., shown in FIG. 9e) and the digitally converted bending waves (e.g., shown in FIG. 9b) are continuously correlated to each other in an area where frequency versus time is mapped. Time information is extracted at the frequency corresponding to the highest value. The cross-correlation between the short kernel waveform shown in FIG. 9E and the bending wave shown in FIG. 9B obtains the waveform shown in FIG. 9F. In FIG. 9F, the frequency corresponding to the largest amplitude is the frequency corresponding to the highest value.

Here, the region where the frequency is mapped with respect to time is defined with the x-axis as the time axis and the y-axis as the frequency axis. The frequency axis of the y-axis is equidistantly spaced. On the other hand, an area (shown in FIG. 6C) to which time-frequency is employed in the wavelet method is also defined with the x-axis as the time axis and the y-axis as the frequency axis, but having different intervals according to the scale factor.

Example 2 Touch Screen Device Using Short Kernel Method (SKM)

FIG. 10 is a block diagram illustrating a touch screen device to which a signal processing technique applying the short kernel method illustrated in FIG. 8 is applied.

Referring to FIG. 10, the touch screen device 200 according to the second embodiment of the present invention may include a touch screen panel 110, an analog-digital converter 120, a reflected wave remover 130, and a Fourier transform 140. ), A short kernel coefficient generation unit 250, a cross-correlation unit (cross-correlation unit) 260, a position estimator 170, and a touch driver 180. In comparison with FIG. 7, the same reference numerals are given to the same components, and detailed description thereof will be omitted. The analog-to-digital converter 120, the reflected wave remover 130, the Fourier transform 140, the short kernel coefficient generator 250, and the cross-correlation unit (cross-correlation unit) 260 shown in FIG. The position estimator 170 may be implemented in hardware, or may be implemented in software or programmatically. If implemented in hardware, it is obvious that it may be implemented on a single chip only for convenience of description.

The short kernel coefficient generation unit 250 generates a short kernel coefficient based on a center frequency corresponding to each of the four bending waves, and calculates a relatively short frequency waveform (short kernel) from the generated short kernel coefficients. Typically, there is a dispersion of the bending wave at many frequencies in a particular signal corresponding to a particular phase velocity. Therefore, the purpose of the short kernel method is to amplify a given frequency in the time domain to help determine the most dominant frequency in the bending wave.

SKM disclosed in this embodiment is a digital signal processing technique, which is defined by the following equation (14).

Where SKM (j, k) is the cross-correlated j-th term currently performed at the k-th frequency, f is the write time from one accelerometer, and g is the short kernel fragment used to perform cross-correlation Where N1 is the number of data points in f and N2 is the number of data points in g.

Kernel with a specific period (frequency) within a short time through windowing techniques such as Hamming, Kaiser, Blackman, etc. Create cross-correlation with the time data collected from each sensor. For example, a short kernel having a sample rate of 100 Khz and a specific period (frequency) of 1740 Hz is obtained as shown in FIG. 11A, and a short kernel having a sample rate of 100 KHz and a specific frequency of 6740 Hz is shown in FIG. 11B.

The cross-correlation unit 260 continuously correlates the calculated short frequency waveform and the bending waves collected by the bending wave sensor and digitally converted by the analog-digital converter 120 to map the frequency with respect to time. Extracts visual information at a frequency corresponding to the highest value and provides it to the position estimator 170. For example, by correlating a relatively short frequency waveform having a center frequency of 1 KHz and a bending wave with each other, visual information of a peak point can be obtained. Through this process, the touch visual information of the bending waves collected by the four bending wave sensors is obtained.

Example 3 Coordinate Recognition Method Using Reach Time Difference (TDOA)

FIG. 12 is a flowchart for explaining another example of the bending wave signal processing shown in FIG. 3. 13A to 13F are waveform diagrams for describing signals corresponding to each step illustrated in FIG. 12. In particular, a bending wave signal processing technique using Time Difference Of Arrival (TDOA) is shown.

12 to 13F, digital conversion is performed on each of the bending wave signals collected for each channel (step S331). For example, the bending wave detected by the bending wave sensor has a relatively large amplitude at the beginning of the touch as shown in FIG. 13A, and has a relatively decreasing amplitude as time passes.

Subsequently, the reflected wave is removed by performing band pass filtering or adaptive filtering on the digitally converted bending wave signal (step S332).

Subsequently, frequency is analyzed for each channel through fast Fourier transform (FFT) to convert bending waves in the time domain into bending waves in the frequency domain (step S333). The signal converted into the bending waves of the frequency domain is for example as shown in FIG. 13B. Here, the relationship between the bending wave in the time domain and the bending wave in the frequency domain may be defined as in Equation 15 below.

Where x (nΔt) is a discrete pair of sample times defining the transformed waveform, X (kΔf) is a Fourier coefficient obtained by the discrete Fourier transform of x (nΔt), and Δt is the data The gain time between the points, Δf is the frequency interval in the frequency domain, k is the exponent for the calculation of discrete frequency components such as 0,1,2, ..., N-1, and n is 0,1, 2, ..., time sample exponent such as N-1.

Subsequently, a conjugate complex number is calculated corresponding to the bending waves of the frequency domain of each channel (step S334), and the imaginary component is removed by multiplying the bending waves of the frequency domain of each channel by the corresponding conjugate complex number (step S335). . The bending wave from which the imaginary component is removed is as shown in FIG. 13C, for example. Since the real component in the bending wave substantially defines the amplitude of the waveform, and the imaginary component defines the phase of the waveform, the magnitude of the amplitude between the waveform of the bending wave shown in FIG. 13B and the waveform of the bending wave shown in FIG. 13C is substantially same.

The bending wave of the frequency domain corresponding to an arbitrary channel may be calculated by Equation 14, and Equation 14 may be summarized as a sum of a real component and an imaginary component.

Therefore, when the bending wave of the frequency domain converted by step S333 is defined as <a + bj>, the conjugate complex number calculated by step S334 is calculated as <a-bj>. As a result, a <a ² +b ^2> is removed bending wave imaginary component by the step S334.

Subsequently, in response to the bending wave signal from which the imaginary component is removed, a signal in a frequency domain having a phase component mapped to the look-up table is generated to correct the phase difference of the bending wave (step S336). In general, since the transmission speed for each frequency is different, the signals of the bending waves collected by the respective bending wave sensors are different from each other, so that an accurate time delay cannot be calculated. However, when the phase difference correction is performed, even if the waveforms collected by each bending wave sensor are different from each other, each signal waveform can be converted into the same shape. Here, the magnitudes between the waveforms may be different from each other.

The look-up table defines signals having a phase component by defining a group velocity as a first axis and a frequency as a second axis.

Subsequently, an inverse Fourier transform is performed to convert the signal of the bending wave whose phase difference is corrected in the frequency domain back into the time domain (step S337). By step S337, a bending wave as shown in Fig. 13F is detected.

Next, a peak value is detected from the signal of the bending wave converted into the time domain, and time information corresponding to the detected peak value is extracted (step S338). For example, the time information extracted from the bending wave shown in FIG. 13F is approximately 250 ms.

Example 3 Coordinate Recognition Method Using Reach Time Difference (TDOA)

FIG. 14 is a block diagram illustrating a touch screen device to which the TDOA signal processing technique illustrated in FIG. 12 is applied. FIG. 15 is a block diagram illustrating a cross correlation unit (cross correlation unit) illustrated in FIG. 14.

14 and 15, the touch screen device 300 according to the third embodiment of the present invention may include a touch screen panel 110, an analog-digital converter 120, a reflected wave remover 130, and a fast Fourier. The converter 140 includes a cross-correlator 350, a position estimator 170, and a touch driver 180. In comparison with FIG. 7, the same reference numerals are given to the same components, and detailed description thereof will be omitted. The analog-to-digital converter 120, the reflected wave remover 130, the Fourier transform unit 140, the cross-correlation unit 350, and the position estimator 170 illustrated in FIG. 14 may be implemented in hardware. It may be implemented in software or programmatically. If implemented in hardware, it is obvious that it may be implemented on a single chip only for convenience of description.

The cross-correlation unit 350 includes a channel signal selector 352, a cross-correlation module unit 354, and a look-up table 356, and bend wave signals in the frequency domain provided by the fast Fourier transform unit 140. Receiving each and outputs the reception time of the bending waves received by the respective bending wave sensors to the position estimator 170 through the cross-correlation processing operation.

In detail, the channel signal selector 352 may include the first to fourth bend wave signals ch1, ch2, and the second to fourth bend wave sensors S1, S2, S3, and S4. One pair of ch3 and ch4) is selected and provided to the cross-correlation module unit 354. Here, the selected pair of bending waves may include first and second bending waves ch1 and ch2 and first and third bending wave sensors S1 and S3 corresponding to the first and second bending wave sensors S1 and S2. First and third bending waves ch1 and ch3 corresponding to the first and fourth bending waves ch1 and ch4 corresponding to the first and fourth bending wave sensors S1 and S4, and the like. That is, a total of 12 pairs of bending waves are provided to the cross-correlation module unit 354.

The cross-correlation module unit 354 includes first to twelfth cross-correlation modules 354A, 354B, 354C, ..., 354J, 354K, and 354L. Each of the cross-correlation modules 354A, 354B, 354C, ..., 354J, 354K, 354L receives a pair of bending wave signals corresponding to the pair of bending wave sensors and performs cross-correlation processing. After correcting the phase based on the signal stored in the table 356, the difference between the reception times received by the bending wave sensors, that is, the reception times are provided to the position estimator 170. FIG.

For example, the first cross-correlation module 354A may have a bending wave signal ch1 corresponding to the first bending wave sensor S1 and a bending wave signal ch2 corresponding to the second bending wave sensor S2. The cross-correlation processing operation is performed to provide the first estimation time t12 to the position estimator 170. The second cross-correlation module 354B performs cross-correlation processing on the bending wave signal ch1 corresponding to the first bending wave sensor S1 and the bending wave signal ch3 corresponding to the third bending wave sensor S3. Next, the second reception time t13 is provided to the position estimator 170. The twelfth cross-correlation module 354L cross-corresponds to the bending wave signal ch4 corresponding to the fourth bending wave sensor S4 and the bending wave signal ch3 corresponding to the third bending wave sensor S3. To provide the twelfth reception time t43 to the position estimator 170.

The lookup-table 356 maps signals having a phase component with group velocity defined as the first axis and frequency defined as the second axis.

FIG. 16 is a block diagram illustrating a cross-correlation module shown in FIG. 15.

15 and 16, the first cross-correlator module 354A includes a first cross-correlator 41, a second cross-correlator 43, and a subtractor 42.

The first cross-correlator 41 includes a first conjugate complex extractor 41A, a first conjugate complex multiplier 41B, a first phase difference corrector 41C, a first inverse Fourier transformer 41D, and a first peak detector 41E. It includes.

Specifically, the first conjugate complex extractor 41A extracts the conjugate complex number from the first bend wave ch1 converted into the frequency domain selected by the channel signal selector 352 and provides it to the first conjugate complex multiplier 41B. do. For example, a bending wave of a frequency domain corresponding to an arbitrary channel may be calculated by Equation 14, and Equation 14 may be summarized as a sum of a real component and an imaginary component. Therefore, when the first bending wave ch1 in the frequency domain is defined as <a + bj>, the first conjugate complex extractor 41A calculates <a-bj> as a conjugate complex number.

The first conjugate complex multiplier 41B receives the conjugate complex number of the first bending wave ch1 provided through the channel signal selector 352 and the first bending wave ch1 provided by the first conjugate complex extractor 41A. Multiply to remove imaginary components. In the present embodiment, the bending wave is removed <a ² +b ^2> imaginary component.

The first phase difference corrector 41C generates a signal in the frequency domain with the stored phase component mapped to the look-up table 356 based on the signal from which the imaginary part is removed. Since the propagation speed for each frequency is different, the signals collected by the bending wave sensors are different, and thus the accurate time delay cannot be calculated. However, when the phase difference correction is performed, even if the waveforms collected by the respective bending wave sensors are different from each other, each signal waveform can be converted into the same shape. Here, the magnitudes between the waveforms may be different from each other. The look-up table defines signals having a phase component by defining a group velocity as a first axis and a frequency as a second axis.

The first inverse Fourier transformer 41D converts the signal of the same waveform to the time domain.

The first peak detector 41E detects the time information corresponding to the maximum amplitude in the bending wave converted into the time domain and provides the subtractor 43 with the time information.

Meanwhile, the second cross-correlator 42 includes a second conjugate complex extractor 42A, a second conjugate complex multiplier 42B, a second phase difference corrector 42C, a second inverse Fourier transformer 42D, and a second peak detector ( 42E).

Specifically, the second conjugate complex extractor 42A extracts the conjugate complex number from the second bending wave ch2 transformed into the frequency domain selected by the channel signal selector 352 and provides it to the second conjugate complex multiplier 42B. do. For example, a bending wave of a frequency domain corresponding to an arbitrary channel may be calculated by Equation 14, and Equation 14 may be summarized as a sum of a real component and an imaginary component. Therefore, when the second bending wave ch2 in the frequency domain is defined as <c + dj>, the second conjugate complex extractor 42A calculates <c-dj> as a conjugate complex number.

The second conjugate complex multiplier 42B receives the conjugate complex number of the second bending wave ch2 provided through the channel signal selector 352 and the second bending wave ch2 provided from the second conjugate complex extractor 42A. Multiply to remove imaginary components. In this embodiment, the bending wave from which the imaginary component is removed is <c ² + d ² >.

The second phase difference corrector 42C generates a signal in the frequency domain with the phase component stored by being mapped to the look-up table 356 based on the signal from which the imaginary part is removed.

The second inverse Fourier transformer 42D converts the signal of the same converted waveform into the time domain.

The second peak detector 42E detects the time information corresponding to the maximum amplitude in the bending wave converted into the time domain and provides it to the subtractor 43.

The subtractor 43 subtracts the visual information of the second bending wave ch2 provided from the second peak detector 42E from the visual information of the first bending wave ch1 provided from the first peak detector 41E. A value t12 obtained by subtracting the detection time of the second bending wave sensor S2 from the detection time of the first bending wave sensor S1 is provided to the position estimating unit 170. In FIG. 16, the first cross-correlation module 354A illustrated in FIG. 15 has been described, but the same may be applied to the second to twelfth cross-correlation modules 354B, 354C,..., 354J, 354K, and 354L. have.

Accordingly, it is possible to calculate the time delay between the waveforms collected by each bending wave sensor.

As described above, according to the present invention, each of the plurality of bending wave sensors disposed in the touch screen device is generated by the vibration of the touch moment, and receives the bending wave having different transmission characteristics, thereby receiving the bending wave signal processing technology. By calculating the delay time of the bending wave for each sensor, the touch coordinates can be recognized. In particular, by performing the compensation process in the signal processing of the bending wave, it is possible to clearly distinguish the reception time of the bending wave received from different sensors.

Although described above with reference to the embodiments, those skilled in the art can be variously modified and changed within the scope of the present invention without departing from the spirit and scope of the invention described in the claims below. I can understand.

Claims (29)

(a) receiving a plurality of bending waves generated according to a touch of a touch screen; (b) removing the reflected waves included in the bending waves; And and (c) calculating touch coordinates by calculating reception times between the bending waves for each of the bending waves from which the reflected wave is removed. The method of claim 1, wherein the bending time of the bending wave is calculated using a wavelet method. The method of claim 2, wherein step (c) comprises: Fourier transforming the bending wave from which the reflected wave is removed; Generating a wavelet coefficient based on the Fourier transformed bending wave; And And converting wavelet packets corresponding to the generated wavelet coefficients and the bent waves into continuous wavelet to calculate time information of a frequency corresponding to a highest value. The method of claim 3, wherein the time information of the frequency corresponding to the highest value is extracted in a region to which a scale value is mapped with respect to time. The method of claim 3, wherein the touch area is calculated by calculating a reception time between the bending waves based on the calculated time information. The method of claim 1, wherein the calculation of the delay time of the bending wave is performed by using a short kernel method. The method of claim 6, wherein step (c) comprises: Fourier transforming the bending wave from which the reflected wave is removed; Generating short kernel coefficients based on the Fourier transformed bending wave; And And performing a cross-correlation process of the short kernel waveform corresponding to the generated short kernel coefficients and the bending waves to calculate time information of the parking number corresponding to the highest value. Coordinate recognition method. The method of claim 7, wherein the time information of the frequency corresponding to the highest value is extracted in a region to which a scale value is mapped with respect to time. The method of claim 8, wherein a touch area is calculated by calculating a reception time between the bending waves based on the calculated time information. The method of claim 1, wherein the calculation of the delay time of the bending wave is performed by a time difference of arrival method. The method of claim 10, wherein step (c) comprises: Fourier transforming the bending wave from which the reflected wave is removed; Removing an imaginary component from the Fourier transformed bending wave; And Compensating for the phase of the Fourier transformed bending wave from which the imaginary component is removed; Inverse Fourier transforming the phase compensated Fourier transformed bending wave; Calculating time information corresponding to the highest value in the inverse Fourier transformed bending wave; And Touch coordinate recognition method using a bending wave, characterized in that it comprises the step of calculating the time difference between the time information. The method of claim 9, wherein the touch area is calculated by calculating a reception time between the bending waves based on the calculated time information. A touch screen panel having first, second, third and fourth bending wave sensors disposed on the same substrate; A reflected wave removing unit for removing reflected waves included in the bending wave signals provided from each of the bending wave sensors; A Fourier transform unit for Fourier transform for each of the bending wave signals from which the reflected wave is removed; A calculation processor configured to calculate a delay time of each bending wave for each sensor for each of the Fourier transformed bending wave signals; And And a position estimator for estimating touch coordinates of the touch screen based on the calculated delay time. The touch screen device as claimed in claim 13, further comprising a touch driver provided with the estimated touch coordinates. The method of claim 13, wherein the operation processing unit A wavelet coefficient generator for generating wavelet coefficients based on the center frequency of each channel of the Fourier transformed bending wave signals and generating a wavelet packet using the generated wavelet coefficients; And And a continuous wavelet converting unit configured to continuously convolve the generated frequency wavelet packets and the bending wave signals to extract visual information of a frequency corresponding to a maximum value. The method of claim 13, wherein the operation processing unit A short kernel coefficient generation unit generating a short kernel coefficient according to a common frequency of four channels and calculating a short kernel waveform based on the generated short kernel coefficients; And a cross-correlation unit configured to correlate the short kernel waveform and the digitally converted bending waves with each other to extract visual information of a frequency corresponding to a maximum value. The touch processor of claim 13, wherein the operation processor comprises a cross-correlation unit configured to cross-correlate each of the Fourier transformed bending wave signals to calculate reception times of the bending waves received by the respective bending wave sensors. Screen device. A touch screen panel having first, second, third and fourth bending wave sensors disposed on the same substrate; An analog-digital converter configured to receive and convert digital bending wave signals provided from each of the bending wave sensors; A reflected wave removing unit removing the reflected wave included in each of the digitally converted bending wave signals; A Fourier transform unit for Fourier transform for each of the bending wave signals from which the reflected wave is removed; A wavelet coefficient generator for generating wavelet coefficients based on the center frequency of each channel of the Fourier transformed bending wave signals and generating a wavelet packet using the generated wavelet coefficients; A continuous wavelet converter configured to continuously convolve the generated frequency wavelet packets and the bending wave signals with each other to extract visual information of a frequency corresponding to a maximum value; A position estimator for calculating time differences by calculating time differences between the time informations, and estimating touch coordinates based on the calculated time differences; And And a touch driver provided with the estimated touch coordinates. A touch screen panel having four bending wave sensors disposed on the same substrate; An analog-to-digital converter configured to receive and convert the bending wave signals provided from each of the bending wave sensors; A reflected wave removing unit removing the reflected wave included in the digitally converted bending wave signal; A Fourier transform unit for Fourier transform for each of the bending wave signals from which the reflected wave is removed; A short kernel coefficient generation unit generating a short kernel coefficient according to a common frequency of four channels and calculating a short kernel waveform based on the generated short kernel coefficients; A cross-correlation unit configured to correlate the short kernel waveform and the digitally converted bending waves with each other to extract visual information of a frequency corresponding to a maximum value; A position estimator for calculating time differences by calculating time differences between the time informations, and estimating touch coordinates based on the calculated time differences; And And a touch driver provided with the estimated touch coordinates. A touch screen panel having four bending wave sensors disposed on the same substrate; An analog-to-digital converter configured to receive and convert the bending wave signals provided from each of the bending wave sensors; A reflected wave removing unit removing the reflected wave included in the digitally converted bending wave signal; A Fourier transform unit for Fourier transform for each of the bending wave signals from which the reflected wave is removed; A cross-correlation unit configured to cross-correlate each of the Fourier transformed bending wave signals to calculate reception times of the bending waves received by the respective bending wave sensors; A position estimator for calculating time differences by calculating time differences between the time informations, and estimating touch coordinates based on the calculated time differences; And And a touch driver provided with the estimated touch coordinates. The method of claim 10, wherein the cross-correlation portion Lookup table in which signals with phase components are defined by group speed as the first axis and frequency as the second axis A channel signal selection unit for selecting one pair of bending wave signals detected by the bending wave sensors; And And a cross-correlation module unit for receiving the pair of bending wave signals and performing cross-correlation processing, correcting a phase based on a signal stored in the lookup table, and calculating a reception time difference received from each bending wave sensor. Touch screen device. 21. The method according to any one of claims 18 to 20, wherein the first bending wave sensor is disposed corresponding to the origin, and the second bending wave sensor is spaced apart by m in the X-axis direction from the first bending wave sensor. The third bending wave sensor may be spaced apart from the first bending wave sensor by n in the y-axis direction, and the fourth bending wave sensor may be spaced apart from the second sensor by n in the y-axis direction. A value obtained by subtracting the detection time of the second sensor from the detection time of the first sensor is defined as t12, and a value obtained by subtracting the detection time of the third sensor from the detection time of the first sensor is defined as t13, When a value obtained by subtracting the detection time of the fourth sensor from the detection time of the first sensor is defined as t14, And the position estimating device determines that the first side planar region is close to the first bending wave sensor when the conditions t12≥0, t13≥0, and t14≥0 are satisfied. The method of claim 22, wherein when the touch area is the first side plane area, the touch coordinates (x1, y1) is

(here,

Touch screen device, characterized in that calculated by). 21. The method according to any one of claims 18 to 20, wherein the first bending wave sensor is disposed corresponding to the origin, and the second bending wave sensor is spaced apart by m in the X-axis direction from the first bending wave sensor. The third bending wave sensor may be spaced apart from the first bending wave sensor by n in the y-axis direction, and the fourth bending wave sensor may be spaced apart from the second sensor by n in the y-axis direction. A value obtained by subtracting the detection time of the first sensor from the detection time of the second sensor is defined as t21, and a value obtained by subtracting the detection time of the third sensor from the detection time of the second sensor is defined as t23, When t24 is defined as a value obtained by subtracting the detection time of the fourth sensor from the detection time of the second sensor, And the position estimating device determines that the second side planar region is close to the second bending wave sensor when the conditions of t21 ≥ 0, t 23 ≥ 0, and t 24 ≥ 0 are satisfied. The method of claim 24, wherein when the touch area is the second side plane area, the touch coordinates (x2, y2) is

(here,

Touch screen device, characterized in that calculated by). 21. The method according to any one of claims 18 to 20, wherein the first bending wave sensor is disposed corresponding to the origin, and the second bending wave sensor is spaced apart by m in the X-axis direction from the first bending wave sensor. The third bending wave sensor may be spaced apart from the first bending wave sensor by n in the y-axis direction, and the fourth bending wave sensor may be spaced apart from the second sensor by n in the y-axis direction. A value obtained by subtracting the detection time of the first sensor from the detection time of the third sensor is defined as t31, and a value obtained by subtracting the detection time of the second sensor from the detection time of the third sensor is defined as t32. When t34 is defined as a value obtained by subtracting the detection time of the fourth sensor from the detection time of the third sensor, And the position estimating device determines that the third side planar region is adjacent to the third bending wave sensor when the conditions of t31 ≥ 0, t32 ≥ 0, and t34 ≥ 0 are satisfied. 27. The method of claim 26, wherein when the touch area is the third side plane area, the touch coordinates (x3, y3) is

(here,

Touch screen device, characterized in that calculated by). 21. The method according to any one of claims 18 to 20, wherein the first bending wave sensor is disposed corresponding to the origin, and the second bending wave sensor is spaced apart by m in the X-axis direction from the first bending wave sensor. The third bending wave sensor may be spaced apart from the first bending wave sensor by n in the y-axis direction, and the fourth bending wave sensor may be spaced apart from the second sensor by n in the y-axis direction. A value obtained by subtracting the detection time of the first sensor from the detection time of the fourth sensor is defined as t41, and a value obtained by subtracting the detection time of the second sensor from the detection time of the fourth sensor is defined as t42, When a value obtained by subtracting the detection time of the third sensor from the detection time of the fourth sensor is defined as t43, And the position estimating unit determines that the fourth side plane region is close to the fourth bending wave sensor when the conditions of t41 ≥ 0, t 42 ≥ 0, and t 43 ≥ 0 are satisfied. The method of claim 28, wherein when the touch area is the fourth side plane area, the touch coordinates (x4, y4) is

(here,

Touch screen device, characterized in that calculated by).

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