Touch detection device for suppressing EMI influence

Abstract

A touch detection device includes: a panel including a plurality of electrodes regularly arranged along rows and columns; a multiplexer which is connected by a connecting line and an electrode arranged in a specific column, and which forms a sensing channel by connecting the plurality of electrodes in rows or columns; and a sensor driving section operably coupled to the multiplexer and controlling a driving signal applying a voltage waveform of a specific period to the electrodes. The sensor driver may apply drive signals in the form of pulses having different drive frequencies for each particular row.

Description

Technical Field

[0001] This invention relates to a driving method for a touch panel. More specifically, this invention relates to a frequency hopping mechanism for a touch panel detection device that can suppress EMI effects. Background Technology

[0002] Electromagnetic interference (EMI) is unwanted noise or interference in an electrical path or circuit generated by an interference source; it is also known as radio frequency interference. EMI can cause electronic equipment to malfunction, fail, or stop operating completely. EMI can be caused by both natural and man-made interference sources. The effects of EMI can be reduced by using high-quality electronic equipment, electrical shielding, and real-time error correction. A common example of EMI is the electrical noise heard when a mobile phone is placed near a powered audio device or speaker.

[0003] The movement of electric charge generates a magnetic field, and a moving magnetic field generates an electric current. Conductors can function through radio wave antennas. High-power electrical interference sources and radio interference sources can cause unwanted effects on distant devices. As electronic devices become smaller, faster, denser, and more sensitive, they become more susceptible to radio waves, resulting in EMI (Electronic Interference Equipment).

[0004] This EMI can originate from multiple sources of interference. For example, high-power wireless and power interference sources can cause unwanted EMI. Poorly designed consumer electronic devices can also cause EMI in other devices.

[0005] On the other hand, touch panels include multiple electrodes. A finger or stylus provides input by changing the capacitance between these electrodes. When detecting input from a finger or stylus, the touch panel must apply a drive signal to the drive circuitry. The EMI generated by this drive signal affects the multiple electrodes and / or drive circuitry in the panel, thus degrading the detection performance. Summary of the Invention

[0006] Technical issues

[0007] The technical problem to be solved by this invention is to overcome this difficulty. Specifically, the technical problem to be solved by this invention is to provide a driving method for a touch panel that can reduce the impact of EMI in the touch panel.

[0008] The technical problem to be solved by the present invention is to reduce interference with adjacent electronic devices based on the occurrence of EMI peaks in a specific row of a touch panel.

[0009] The technical problem to be solved by the present invention is to provide a driving method for a touch panel that can reduce the occurrence of EMI peaks in electronic devices equipped with touch panels.

[0010] However, the technical problem to be solved by the present invention is not limited to the technical problem described herein, and another technical problem not mentioned can be clearly understood by those skilled in the art through the description of the present invention.

[0011] Technical solution

[0012] In this invention, the touch detection device includes: a panel comprising a plurality of electrodes regularly arranged along rows and columns; a multiplexer connected to the electrodes arranged in a specific column via connecting lines, and forming a sensing channel by connecting the plurality of electrodes in rows or columns; and a sensor driver operatively coupled to the multiplexer and controlling a drive signal that applies a voltage waveform of a specific period to the electrodes. The sensor driver can apply a drive signal in the form of pulses with different drive frequencies to each specific row. If the EMI radiation of the specific connecting line to which the drive signal is applied is higher than a threshold value, the sensor driver can apply a signal of a reverse voltage waveform to one of the electrodes in a row adjacent to the specific row. The length of the connecting lines can be set differently depending on the position of the electrodes arranged in the specific row.

[0013] According to an embodiment, the sensor driving unit applies a first driving signal at a first driving frequency to the first row, applies a second driving signal at a second driving frequency to the second row adjacent to the first row, applies an N-1 driving signal at an N-1 driving frequency to the N-1 row, and may apply an N-1 driving signal at an N-1 driving frequency to the N-1 row adjacent to the N-1 row.

[0014] According to an embodiment, the sensor driving unit applies pulse-type driving signals with different driving frequencies to the specific row in a first frame that includes multiple pulses, and determines the start point of a second frame adjacent to the first frame based on the timing that coincides with the falling edge of the driving signal of the first frame. In the second frame, it applies pulse-type driving signals with different driving frequencies to the specific row, and determines the start point of a third frame adjacent to the second frame based on the timing that coincides with the falling edge of the driving signal of the second frame. In the third frame, it applies pulse-type driving signals with different driving frequencies to the specific row, and the driving voltage applied to the specific row can be set to different driving frequencies in the first frame, the second frame, and the third frame.

[0015] According to an embodiment, the sensor driving unit applies a first driving signal of a first driving frequency to the first row in a first frame including multiple pulses, and applies a driving signal of one of the second to N driving frequencies other than the first driving frequency in a second frame adjacent to the first frame, and may apply a driving signal of another driving frequency other than the first driving frequency in a third frame adjacent to the second frame.

[0016] According to an embodiment, if the EMI radiation of a specific connection line to which the drive signal is applied is below a critical value, the sensor driver applies drive signals of the first to Nth drive frequencies to the first to Nth rows. If the EMI radiation of the specific connection line exceeds the critical value, the drive frequencies of the drive signals applied to the first to Nth rows can be changed to different drive frequencies.

[0017] According to an embodiment, when the EMI radiation of a specific connection line exceeds a critical value, the sensor driving unit can determine the specific driving frequency and the frequency offset such that the frequency offset between the specific driving frequency of the specific row corresponding to the specific connection line and the adjacent driving frequency of the adjacent row adjacent to the specific row is greater than the critical value.

[0018] According to an embodiment, if the EMI radiation of the specific connection line in the first frame exceeds a critical value, the sensor driving unit changes the driving frequency of the driving signals applied to the first to Nth rows in the second frame to different driving frequencies, and sets the second frame period of the second frame to be shorter than the first frame period of the first frame. If the EMI radiation of the specific connection line in the second frame exceeds a critical value, the driving frequency of the driving signals applied to the first to Nth rows in the third frame changes to different driving frequencies, and the third frame period of the third frame can be set to be shorter than the second frame period of the second frame.

[0019] According to an embodiment, when the EMI radiation of the specific connection line in the second frame is less than a critical value, the sensor driving unit changes the driving frequency of the driving signal applied to the first to Nth rows in the third frame to different driving frequencies, and sets the third frame period of the third frame to be longer than the second frame period of the second frame. Furthermore, when the EMI radiation of the specific connection line in the third frame is lower than the second critical value of the critical value, the driving frequency of the driving signal applied to the first to Nth rows can be maintained.

[0020] According to an embodiment, when the EMI radiation exceeds the second threshold but is below the second threshold, the sensor driving unit can change the driving frequency of the driving signals applied to the first to Nth rows in the fourth frame adjacent to the third frame to different driving frequencies, and can set the fourth frame period of the fourth frame to be shorter than the third frame period of the third frame.

[0021] According to an embodiment, the sensor driving unit, in conjunction with the EMI detection unit, determines whether the EMI peak value at a specific frequency is less than a critical length or decreases to a predetermined value based on the maximum value. If the determination result is that the EMI peak value decreases, the driving frequency can be set to repeat the frequency hopping result in which the driving frequency in the first frame, the second frame, and the third frame is changed. Moreover, the sequence of driving frequencies can be repeated, thereby repeating the order of the first frame, the second frame, and the third frame.

[0022] According to an embodiment, when the sensor driving unit, in conjunction with the EMI detection unit, determines whether the EMI peak value at a specific frequency is less than a critical length or decreases to a predetermined value based on the maximum value, and the determination result indicates that the EMI peak value has not decreased, it can detect the rising edge and falling edge of the driving signal of the voltage waveform for the specific column or specific row, detect the first area of ​​the rising edge and the falling edge, and change the area of ​​the second driving signal of the reverse voltage waveform corresponding to the first area, thereby eliminating the EMI component of the voltage waveform.

[0023] Invention Effects

[0024] According to the present invention, by frequency hopping of the driving voltage in the row direction, a driving voltage in the reverse voltage mode is applied to adjacent columns, thereby reducing the amount of EMI radiation at a specific frequency.

[0025] According to the present invention, a driving method for a touch panel that can reduce EMI interference can be provided. By frequency hopping of the driving voltage for each frame in the row direction, a driving voltage in the reverse voltage form can be applied to adjacent columns, thereby reducing EMI interference with adjacent electronic devices.

[0026] According to the present invention, when the length of the specific connection line is higher than the critical length, the sensor driving unit applies a second driving signal of a reverse voltage waveform to the electrode of one of the two rows adjacent to the specific row; when the length of the specific connection line is lower than the critical length, the second driving signal and the third driving signal of the reverse voltage waveform can be applied to the electrodes of the two rows adjacent to the specific row respectively.

[0027] The effects of this invention are not limited to those mentioned above, and those skilled in the art will gain a clear understanding of other unmentioned technical issues through the following description. Attached Figure Description

[0028] Figure 1 This is a block diagram showing the detailed configuration of the touch detection device according to the present invention;

[0029] Figure 2 It is a graph showing the relationship between signal repeatability and EMI peak / EMI average / quasi-peak values;

[0030] Figure 3 It is a graph showing that each row is sensing at the same frequency;

[0031] Figure 4 It is a graph showing that each frame is sensed at the same frequency;

[0032] Figure 5 A graph showing each row being sensed at a different frequency;

[0033] Figure 6 It is a graph showing that each row is sensed at a different frequency;

[0034] Figure 7 This is a graph showing the expected EMI results for each frequency according to the present invention;

[0035] Figure 8 This is a graph showing the results of reducing EMI peaks according to the present invention;

[0036] Figure 9 This is a conceptual diagram illustrating the elimination of EMI components in sensor signals;

[0037] Figure 10 This displays square wave signals with different conversion rates.

[0038] (Explanation of reference numerals in the attached diagram)

[0039] 10: Touch detection device

[0040] 100: Touch panel

[0041] 110a, 110b, 110c, 110d: Sensor channels

[0042] 110 to 119, 120 to 129, 130 to 139, 140 to 149: Electrodes

[0043] CL1 to CL4: Connecting wires

[0044] 200: Multiplexer

[0045] 210, 220, 230, 240: Multiplexer 1, Multiplexer 2, Multiplexer 3, Multiplexer 4

[0046] 300: Sensor Driver Unit

[0047] F1, F2, F3: Frame 1, Frame 2, Frame 3

[0048] 400: EMI Testing Department Detailed Implementation

[0049] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Prior to this, the terms or phrases used in this specification and claims should not be limited to their ordinary or dictionary meaning. Inventors should interpret them as meanings and concepts consistent with the technical spirit of the invention, in accordance with the principle of appropriately defining terms and concepts to best interpret their own invention. Accordingly, it should be understood that the embodiments described in this specification and the configurations shown in the figures are merely the most preferred embodiments of the present invention and do not represent all the technical spirit of the invention. Therefore, various equivalents and modifications may exist in place of them at the time of this application.

[0050] Figure 1 This is a block diagram showing the detailed configuration of the touch detection device according to the present invention. (Refer to...) Figure 1 The touch detection device 10 can be configured to include a panel 100, a multiplexer 200, and a sensor driver 300.

[0051] The touch detection device 10 may include: a panel 100 including a plurality of electrodes arranged regularly along rows and columns; a multiplexer 200 forming a plurality of sensing channels (110a to 110d) by electrically connecting a portion of the electrodes; and a sensor driver 300 providing drive signals to the sensing channels (110a to 110d). The sensor driver 300 may control the same or different drive signals to be output to different sensing channels. The sensor driver 300 may control the timing of the rising / falling edges between adjacent rows to be different, or, as described later, control the voltage waveform to apply drive signals in opposite directions.

[0052] like Figure 1 As shown, the panel 100 according to the present invention can be a self-dot type panel. In the self-dot type panel 100, multiple electrodes are arranged regularly along rows and columns. In the self-dot type panel 100, multiple electrodes are arranged regularly along rows and columns. Figure 1 As shown, the electrodes can be square. According to an embodiment not shown, the electrodes can have shapes such as rhombuses and triangles, and can be configured to be complementary to electrodes in adjacent rows or columns.

[0053] Multiple electrodes can function by using a finger, stylus, or the like to provide touch input, along with a single electrode that forms a capacitor. For example, as the finger, stylus, or the like approaches the panel 100 where multiple electrodes are arranged, the capacitance of the capacitor formed with the electrodes increases. On the other hand, as the finger, stylus, or the like moves away from the panel 100 having multiple electrodes, the capacitance of the capacitor formed with the electrodes decreases.

[0054] The multiplexer 200 may include multiple switches (210 to 240). The multiple switches (210 to 240) can be implemented by the multiplexer, or they can be implemented by connecting only the electrodes of some channels.

[0055] Multiple electrodes are connected to multiplexer 200 via conductive wires. Multiplexer 200 connects the electrodes in rows or columns to form sensing channels (110a to 110d). Figure 1 In the illustrated embodiment, multiple electrodes are connected in the thermal direction to form a sensing channel (110a to 110d). In an embodiment not shown, multiple electrodes are connected in a row to form a sensing channel.

[0056] The sensor driving unit 300 detects touch input from fingers, styluses, etc. by providing a driving signal to the sensing channels (110a to 110d). Figure 1 The embodiment shown illustrates an example of detecting touch input for a single driver unit on a single panel 100. However, it is not limited to this; multiple sensor drivers can also be controlled by a separate main control unit (not shown), and each sensor driver can drive a sensing channel (110a to 110d) separately.

[0057] The sensor driving unit 300 can provide identical driving signals to the left column (L) and right column (R) included in the sensing channels (110a to 110d). For example, the sensor driving unit 300 can synchronize the rising edges of the driving signals provided to the left column (L) and the right column (R). The falling edges of the driving signals provided to the left column (L) and the right column (R) can be synchronized with each other, but are not limited thereto. For example, the sensor driving unit 300 can set a phase difference between the driving signals provided in one sensing channel (110) and another adjacent sensing channel to prevent identical edges from overlapping.

[0058] The sensor driving unit 300 can provide drive signals with mutually inverted relationships to the left column (L) and right column (R) included in the sensing channels (110a to 110d). As shown, the rising edge of the drive signal provided by the sensor driving unit 300 to the left column (L) and the falling edge of the drive signal provided to the right column (R) can be synchronized with each other. The falling edge of the drive signal provided to the left column (L) and the rising edge of the drive signal provided to the right column (R) can be synchronized with each other, but is not limited to this. For example, the sensor driving unit 300 can set a phase difference between the drive signals provided to one sensing channel (110) and another adjacent sensing channel.

[0059] On the other hand, panel 100 may include multiple electrodes arranged along rows and row rules. The electrodes can be arranged in the 1st row, 2nd row, and even the 8th and 9th rows. Relatedly, the number of rows of electrodes is not limited to 9 and can be changed depending on the application. Multiple rows of electrodes can be arranged in the 2nd row, and even N-1 and Nth rows. Electrodes can be arranged in the 1st column, 2nd column, 3rd column, and 4th column. Relatedly, the number of columns of electrodes is not limited to 4 and can be changed depending on the application.

[0060] Electrodes arranged in the first column can form a first sensing channel (110a). The first sensing channel (110a) may include multiple electrodes (110 to 119) arranged in multiple rows. Electrodes arranged in the second column can form a second sensing channel (110b). The second sensing channel (110b) may include multiple electrodes (120 to 129) arranged in multiple rows. Electrodes arranged in the third column can form a third sensing channel (110c). The third sensing channel (110c) may include multiple electrodes (130 to 139) arranged in multiple rows. Electrodes arranged in the fourth column can form a fourth sensing channel (110d). The fourth sensing channel (110d) may include multiple electrodes (140 to 149) arranged in multiple rows. Relatedly, the number of rows of electrodes is not limited to nine and can be varied depending on the application.

[0061] The multiplexer 200 can be connected to electrodes arranged in a specific row via connecting lines (CL1, CL2, CL3, CL4). The sensor driver 300 can be operatively coupled to the multiplexer 200. The sensor driver 300 can control a drive signal for a specific periodic voltage waveform via electrodes (110, 120, 130, 140).

[0062] The connecting lines in column 1 (CL1) may include connecting lines 1 through 10 (CL10 through CL19). The connecting lines in column 2 (CL2) may include connecting lines 1 through 10 (CL20 through CL29). The connecting lines in column 3 (CL3) may include connecting lines 1 through 10 (CL30 through CL39). The lengths of the connecting lines (CL1, CL2, CL3, CL4) may vary depending on the position of the electrodes configured in a particular row.

[0063] This invention relates to a method for reducing electromagnetic interference (EMI) of touch panels by variably applying the touch sensing frequency to each row or touch frame, thereby effectively reducing EMI, especially the average and quasi-peak values.

[0064] EMI average (EMI AVERANGE) and quasi-peak (QUSSIPEAK) are EMI results closely related to signal repeatability. EMI average displays the average value of the signal at a specific frequency during the scan period, while quasi-peak displays the repeatability and signal magnitude at that specific frequency during the scan period. Relatedly, Figure 2 This is a graph showing the relationship between signal repeatability and EMI peak / EMI average / quasi-peak values. For example... Figure 2 As shown, the more repetitive the EMI equal-frequency signal, the greater its impact on the average and quasi-peak values. Due to this frequency repetition, EMI is a major concern and is difficult to avoid in typical touch-driving methods.

[0065] Figure 3 It is a graph showing that each row is sensing at the same frequency. Figure 4 It is a graph showing that each frame is sensed at the same frequency.

[0066] Sensing can be performed at the same frequency from the first row to the last row, such as... Figure 2 As shown. The sensing from the first row to the last row consists of a group called a 1-Frame, which receives input from multiple frames and calculates the touch input. From an EMI perspective, this sensing is the main factor that increases the average and quasi-peak EMI by repeating the sensing countless times at the same frequency, and the average or quasi-peak gradually converges to the peak as the number of repetitions increases.

[0067] The technical problem this invention aims to solve is precisely this difficulty. Relatedly, Figure 5 A graph showing each row being sensed at a different frequency. Figure 6 It is a graph showing that each row is sensing at a different frequency.

[0068] Not all lines and frames use the same sensing frequency, but... Figure 4 As shown, the sensing frequency of each row is different, or as... Figure 5 As shown, the sensing frequency can be used in each frame. Accordingly, it is very effective in reducing the average and quasi-peak EMI, and can achieve a spread spectrum-like effect by dispersing the frequency, thus reducing the EMI peak.

[0069] Figure 5 The technical name is "row frequency hopping," which adjusts the sensing frequency by changing the sensor's charging or discharging time for each row. Figure 2 (a) and (b) have the same frequency but different frequencies, like Figure 5 The charging time and frequency are adjusted in the same way as shown in (a) and (b). Different changes are made for each row to avoid repeating the same frequency, thereby reducing the average EMI and quasi-peak (QUSSIPEAK) at specific frequencies where repeatability is important. Furthermore, it is characterized by the fact that touch performance is not degraded.

[0070] Figure 7 This is a graph showing the expected EMI results according to the present invention. Figure 8 This displays the expected average EMI (EMI AVRERANGE) and QUSSIPEAK result values ​​when applying row frequency hopping. Figure 7 (a) is a general sensor. Figure 7 (b) is row frequency hopping. As the frequency increases, the signal also increases, but the magnitude of the EMI signal will decrease significantly.

[0071] Figure 8 This is a graph showing the results of reducing EMI peaks according to the present invention. Furthermore, by using multiple frequencies, it achieves an effect similar to spread spectrum, which transmits data as a widely dispersed frequency. Figure 8 As shown, the signal emitted at a specific frequency is dispersed across multiple frequencies to reduce the influence of the specific frequency, thereby reducing the EMI peak.

[0072] "Row frequency hopping" allows the use of different sensing frequencies for each row. The method of using different sensing frequencies for each row and frame is called "frame frequency hopping." Figure 6 The first frame (F1) in (a) has ended sensing and Figure 5 After sensing begins in frame 2 (F2) of (b), the system is driven at a different frequency than that used in frame 1, thereby reducing the EMI peak / average / quasi-peak levels, similar to "row frequency hopping". Since both EMI reduction methods can be applied multiple times instead of once, specific frequencies detrimental to EMI can be effectively dispersed, thus effectively reducing the EMI of the touch component.

[0073] The following is for reference Figure 1 , Figures 4 to 8 The touch detection device 10 according to the present invention will be described below. The touch detection device 10 may be configured to include a panel 100, a multiplexer 200, and a sensor driver 300.

[0074] The touch detection device 10 may include a panel 100 comprising a plurality of electrodes arranged regularly along rows and columns; a multiplexer 200 for forming a plurality of sensing channels (110a to 110d) by electrically connecting a portion of the electrodes; and a sensor drive unit 300 for providing drive signals to the sensing channels (110a to 110d). The multiplexer 200 may be connected via electrodes (110, 120, 130, 140) arranged in specific columns and connecting lines (CL1, CL2, CL3, CL4). The lengths of the connecting lines (CL1, CL2, CL3, CL4) may vary depending on the position of the electrodes arranged in a specific row.

[0075] Multiplexer 200 can form a sensing channel by connecting multiple electrodes in rows or columns. Sensor driver 300 can be operatively coupled to multiplexer 200. Sensor driver 300 can apply a drive signal with a voltage waveform of a specific period to the electrodes by control.

[0076] The sensor driving unit 300 can apply driving signals with pulse patterns of different driving frequencies to specific rows. The sensor driving unit 300 can apply a 0th driving signal with a 0th driving frequency to row 0. The sensor driving unit 300 can apply a 1st driving signal with a 1st driving frequency to row 1. The sensor driving unit 300 can apply a 2nd driving signal with a 2nd driving frequency to the 2nd row adjacent to row 1. The sensor driving unit 300 can apply an (N-1)th driving signal with an (N-1)th driving frequency to row N-1. The sensor driving unit 300 can apply an Nth driving signal with an Nth driving frequency to the Nth row adjacent to row N-1.

[0077] The sensor driving unit 300 can apply a driving signal with a pulse pattern having a different driving frequency to each specific row in a first frame (F1) including multiple pulses. The sensor driving unit 300 can determine the start point of a second frame adjacent to the first frame (F1) based on the timing of the falling edges of the driving signals in the first frame (F1). The sensor driving unit 300 can apply driving signals with pulse patterns having different driving frequencies to each specific row in the second frame. The sensor driving unit 300 can determine the start point of a third frame (F3) adjacent to the second frame based on the timing of the falling edges of the driving signals in the second frame. The sensor driving unit 300 can apply driving signals with pulse patterns having different frequencies to each specific row in the third frame (F3). Relatedly, the driving voltage applied to the specific row can be set to different driving frequencies in the first frame (F1), second frame (F2), and third frame (F3).

[0078] The sensor driving unit 300 can apply a first driving signal of a first driving frequency to the first row in a first frame (F1) that includes multiple pulses. The sensor driving unit 300 can apply a driving signal of one of the second to N driving frequencies other than the first driving frequency in a second frame adjacent to the first frame (F1). The sensor driving unit 300 can apply a driving signal of another driving frequency other than the driving frequencies in the first and second frames (F1, F2) in a third frame (F3) adjacent to the second frame (F2).

[0079] The sensor driving unit 300 can determine whether the EMI radiation level of a specific connection line to which the driving signal is applied is below a threshold value, or control the driving frequency differently depending on whether the threshold value is exceeded. If the EMI radiation level of the specific connection line to which the driving signal is applied is below the threshold value, the sensor driving unit 300 can apply driving signals of driving frequencies 1 to 9 to rows 1 to 9. If the EMI radiation level of the specific connection line exceeds the threshold value, the sensor driving unit 300 can change the driving frequency of the driving signals applied to rows 1 to 9 to different driving frequencies.

[0080] When the EMI radiation of a specific connection line exceeds a critical value, the sensor driving unit 300 can adjust the specific driving frequency of the specific row corresponding to the specific connection line and the adjacent driving frequency of the adjacent row next to the specific row. The sensor driving unit 300 can determine the specific driving frequency and frequency offset such that the frequency offset between the specific driving frequency of the specific row and the adjacent driving frequency of the adjacent specific row is higher than the critical value.

[0081] Relatedly, if the EMI radiation in row N-1 exceeds the critical value, the drive frequency in row N-1 can be set to the lowest frequency (longest period), such as... Figure 3 As shown. On the other hand, a specific drive frequency and frequency offset can be determined by setting the drive frequency of the Nth row adjacent to the (N-1)th row to the highest frequency (shortest period), so that the frequency offset is higher than a critical value. In addition, the frequency offset can be determined so that the frequency offset of the drive frequency of the (N-2)th row adjacent to the (N-1)th row is higher than the critical value of the drive frequency of the (N-1)th row.

[0082] If the EMI radiation of a specific connection line in the first frame (F1) exceeds a critical value, the sensor driving unit 300 can change the driving frequency of the driving signals applied to rows 1 to N in the second frame (F2) to different driving frequencies. The sensor driving unit 300 can set the second frame period of the second frame (F2) to be shorter than the first frame period of the first frame (F1).

[0083] If the EMI radiation of a specific connection line in the second frame (F2) exceeds a critical value, the sensor driving unit 300 can change the driving frequency of the driving signals applied to rows 1 to N in the third frame (F3) to different driving frequencies. The sensor driving unit 300 can set the third frame period of the third frame (F3) to be shorter than the second frame period of the second frame (F2).

[0084] If the EMI radiation level of the specific connection line in the second frame (F2) is below a critical value, the sensor driving unit 300 can change the driving frequency of the driving signals applied to rows 1 to N in the third frame (F3) to different driving frequencies. The sensor driving unit 300 can set the third frame period of the third frame (F3) to be longer than the second frame period of the second frame (F2).

[0085] When the EMI radiation of the specific connection line described in the third frame (F3) is lower than the second critical value of the critical value, the sensor driving unit 300 can maintain the driving frequency of the driving signals applied to the first to Nth rows.

[0086] If the EMI radiation exceeds but is below the second threshold, the sensor driving unit 300 can change the driving frequency of the driving signals applied to rows 1 to N in the fourth frame adjacent to the third frame (F3) to different driving frequencies. The sensor driving unit 300 can also set the fourth frame period of the fourth frame to be shorter than the third frame period of the third frame (F3).

[0087] The sensor driving unit 300 can be linked with the EMI detection unit 400 to determine whether the EMI peak value at a specific frequency is less than a critical length or whether it has decreased to a predetermined value based on the maximum value. The sensor driving unit 300, upon determining the result, such as... Figure 9 As shown, when the EMI peak decreases, the drive frequency can be set so that the frequency hopping result of changing the drive frequency in the first frame (F1), the second frame (F2), and the third frame (F3) is repeated. The sensor drive unit 300 can repeat the sequence of drive frequencies, thereby repeating the order of the first frame (F1), the second frame (F2), and the third frame (F3).

[0088] On the other hand, the sensor driving unit 300 can control the driving signal between adjacent rows in different ways according to the EMI radiation level of a specific connection line to which the driving signal is applied. Relatedly, Figure 9 This is a conceptual diagram illustrating the elimination of EMI components in sensor signals. On the other hand, Figure 10 It displays square wave signals with different slew rates.

[0089] Reference Figure 9 To reduce electromagnetic interference (EMI) of the touch panel, a reverse voltage driving signal, which is a square wave waveform used as the sensing waveform, can be used. The reverse method eliminates EMI by generating an electromagnetic field opposite to the sensing waveform.

[0090] The driving signal of a specific periodic voltage waveform can form a first area (A) between the rising edge and the falling edge. The reverse method can more effectively eliminate the sensing signal by changing the second area (B) of the reverse region of the reverse voltage waveform.

[0091] EMI primarily occurs during the timing of the rising / falling edges of the sensing waveform; the greater the intensity, the greater the EMI. The reverse approach eliminates EMI by causing the sensing waveform to fall within the rising range of the same intensity and rise within the falling range. This can be achieved through opposing electromagnetic fields.

[0092] The results of the reverse approach will vary depending on the design and implementation. In particular, the larger the TSP (Touch Sensor Panel), the more likely the sensor arrays will deviate in terms of identical physical characteristics, resulting in variations in the EMI radiation of each sensor drive array. To compensate for this, the EMI component of the sensor waveform can be minimized by increasing or decreasing the second area (B) of the reverse voltage waveform corresponding to the heat generated by the sensor drive.

[0093] Reference Figure 10 EMI is closely related to the slew rate of the voltage waveform. Higher resistance and capacitance values ​​result in higher output voltage. Figure 10 (a) Waveforms with lower morphological transition rates. On the other hand, lower capacitance values ​​result in higher output... Figure 10 (b) Waveforms with higher slew rates. When comparing EMI radiation levels, waveforms with higher slew rates are preferred. Figure 10 (b) The waveform exhibits a greater amount of EMI radiation.

[0094] Reference Figure 1 , Figures 9 to 10 The touch detection device 10 according to the present invention will be described. The touch detection device 10 can be configured to perform sensing sequentially from the first row (Row_0) to the tenth row (Row_9). EMI mainly occurs in the range of rising / falling sensing voltage. On the other hand, since the wiring length, sensor area, etc., of each sensor are different, the resistance value, capacitance value, etc., are also different, and thus the EMI radiation amount is also different. It can be said that the different switching rates of the sensing waveforms of each sensor are the main reason for the mutual deviation of the EMI radiation amount of each sensor.

[0095] On the other hand, the sensor driving unit 300 can not only control the starting points of the falling edge and the rising edge, but also eliminate EMI components of the voltage waveform by changing the second area (B) of the reverse voltage waveform. Relatedly, the sensor driving unit 300 can detect the rising edge and falling edge of a specific row or a specific line of voltage waveform drive signals. The sensor driving unit 300 can detect the first area (A) between the rising edge and the falling edge. The sensor driving unit 300 can eliminate EMI components in the voltage waveform corresponding to the first area (A) by changing the second area (B) of the second drive signal of the reverse voltage waveform.

[0096] Relatedly, the sensor drive unit 300 can be linked with the EMI detection unit 400 to determine whether the EMI peak value at a specific frequency is less than a critical length or has decreased to above a predetermined value based on the maximum value. If it is determined that the EMI peak value has not decreased, the sensor drive unit 300 can detect a first area (A) between the rising edge and the falling edge. The sensor drive unit 300 can eliminate the EMI component in the voltage waveform by changing the second area (B) of the second drive signal of the reverse voltage waveform corresponding to the first area (A).

[0097] The above describes a touch detection device for suppressing EMI effects according to the present invention. The technical effects of the touch detection device for suppressing EMI effects can be summarized as follows, but are not limited thereto.

[0098] According to the present invention, the touch detection device has the advantage of effectively suppressing EMI effects.

[0099] According to the present invention, the amount of EMI radiation at a specific frequency can be reduced by frequency hopping of the driving voltage in the row direction.

[0100] According to the present invention, a driving method for a touch panel that can reduce EMI interference with adjacent electronic devices is provided. This method reduces EMI interference by applying a driving voltage in the reverse voltage mode to adjacent columns through frequency hopping of the driving voltage for each frame in the row direction.

[0101] The effects of the present invention are not limited to those mentioned above, and other technical problems not mentioned will become clear from the following description.

[0102] The above description illustrates specific embodiments of the present invention, but these are merely examples and the invention is not limited thereto. Those skilled in the art can make changes or modifications to the described embodiments without departing from the scope of the invention, and various modifications and variations can be made within the equivalent scope of the technical spirit of the invention and the claims described below.

Claims

1. A touch detection device, characterized in that, include: A panel comprising multiple electrodes arranged regularly along rows and columns; A multiplexer that is connected to electrodes arranged in a specific column via connecting lines, and forms a sensing channel by connecting the multiple electrodes in rows or columns; as well as A sensor driver unit, operably coupled to a multiplexer, controls a drive signal that applies a voltage waveform of a specific period to the electrodes. The length of the connecting line is set differently depending on the position of the electrodes configured in a particular row, and the sensor driver applies a drive signal in the form of pulses with different drive frequencies for each particular row.

2. The touch detection device according to claim 1, characterized in that, The sensor driving unit applies a first driving signal at a first driving frequency to the first row, applies a second driving signal at a second driving frequency to the second row adjacent to the first row, applies an N-1 driving signal at an N-1 driving frequency to the N-1 row, and applies an N-1 driving signal at an N-1 driving frequency to the N-1 row adjacent to the N-1 row.

3. The touch detection device according to claim 2, characterized in that, The sensor driving unit applies pulse-type driving signals with different driving frequencies to the specific row in a first frame that includes multiple pulses, and determines the start point of a second frame adjacent to the first frame based on the timing that coincides with the falling edge of the driving signal in the first frame. In the second frame, it applies pulse-type driving signals with different driving frequencies to the specific row, and determines the start point of a third frame adjacent to the second frame based on the timing that coincides with the falling edge of the driving signal in the second frame. In the third frame, it applies pulse-type driving signals with different driving frequencies to the specific row, and the driving voltage applied to the specific row is set to different driving frequencies in the first frame, the second frame, and the third frame.

4. The touch detection device according to claim 2, characterized in that, The sensor driving unit applies a first driving signal with a first driving frequency to the first row in the first frame, which includes multiple pulses, and applies a driving signal with a driving frequency of one of the second to N driving frequencies other than the first driving frequency in the second frame adjacent to the first frame, and applies a driving signal with another driving frequency other than the driving frequencies in the first and second frames in the third frame adjacent to the second frame.

5. The touch detection device according to claim 3, characterized in that, If the EMI radiation of a specific connection line to which the drive signal is applied is below a critical value, the sensor driver applies drive signals of drive frequencies of 1 to N to the 1st to Nth rows. If the EMI radiation of a specific connection line exceeds the critical value, the drive frequencies of the drive signals applied to the 1st to Nth rows are changed to different drive frequencies.

6. The touch detection device according to claim 5, characterized in that, If the EMI radiation of a specific connection line exceeds a critical value, the sensor driving unit determines the specific driving frequency and the frequency offset such that the frequency offset between the specific driving frequency of the specific row corresponding to the specific connection line and the adjacent driving frequency of the adjacent row adjacent to the specific row is greater than the critical value.

7. The touch detection device according to claim 6, characterized in that, If the EMI radiation of the specific connection line in the first frame exceeds a critical value, the sensor driving unit changes the driving frequency of the driving signals applied to the first to Nth rows in the second frame to different driving frequencies, and sets the second frame period of the second frame to be shorter than the first frame period of the first frame. If the EMI radiation of the specific connection line in the second frame exceeds a critical value, the sensor driving unit changes the driving frequency of the driving signals applied to the first to Nth rows in the third frame to different driving frequencies, and sets the third frame period of the third frame to be shorter than the second frame period of the second frame.

8. The touch detection device according to claim 7, characterized in that, If the EMI radiation of the specific connection line in the second frame is less than a critical value, the sensor driving unit changes the driving frequency of the driving signal applied to the first to Nth rows in the third frame to different driving frequencies, and sets the third frame period of the third frame to be longer than the second frame period of the second frame. If the EMI radiation of the specific connection line in the third frame is lower than the second critical value of the critical value, the driving frequency of the driving signal applied to the first to Nth rows is maintained.

9. The touch detection device according to claim 7, characterized in that, When the EMI radiation exceeds the second threshold but is below the second threshold, the sensor driving unit changes the driving frequency of the driving signals applied to rows 1 to N in the fourth frame adjacent to the third frame to different driving frequencies, and sets the fourth frame period of the fourth frame to be shorter than the third frame period of the third frame.

10. The touch detection device according to claim 7, characterized in that, The sensor driving unit, in conjunction with the EMI detection unit, determines whether the EMI peak value at a specific frequency is less than a critical length or decreases to a predetermined value based on the maximum value. If the determination result is that the EMI peak value decreases, the driving frequency is set to repeat the frequency hopping result in which the driving frequency in the first frame, the second frame, and the third frame is changed. The sequence of driving frequencies is repeated, thereby repeating the order of the first frame, the second frame, and the third frame.

11. The touch detection device according to claim 7, characterized in that, When the sensor driving unit, in conjunction with the EMI detection unit, determines whether the EMI peak value at a specific frequency is less than a critical length or decreases to a predetermined value based on the maximum value, and the determination result indicates that the EMI peak value has not decreased, it detects the rising edge and falling edge of the driving signal of the voltage waveform according to the specific column or specific row, and detects the first area of ​​the rising edge and the falling edge, and changes the area of ​​the second driving signal of the reverse voltage waveform corresponding to the first area, thereby eliminating the EMI component of the voltage waveform.

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