TW201545021A - Method of determining touch event in touch detection system - Google Patents

Abstract

A method of determining a touch event in a touch detection system includes transmitting at least one driving signal to a touch panel of the touch detection system; receiving a sensing signal corresponding to the driving signal from the touch panel; determining whether the touch event occurs by performing an initial digital operation on the sensing signal; determining whether the sensing signal is interfered with by a noise signal; and performing an entire determination on the sensing signal when the touch event is determined to occur or the sensing signal is determined to be interfered with by the noise signal.

Description

Method for judging touch events in touch detection system

The present invention relates to a method for determining a touch event in a touch detection system, and more particularly to a method for determining a touch event in a touch detection system through digital initial judgment.

In recent years, touch sensing technology has rapidly developed, and many consumer electronic products such as mobile phones, GPS navigator systems, tablets, personal digital assistants (PDAs) and The touch function is built into the laptop. In the above various electronic products, the area of the original display panel is given the function of touch sensing, that is, the original simple display panel is converted into the touch display panel with the touch recognition function. Depending on the structural design of the touch panel, it can be generally classified into an out-cell and an in-cell/on-cell touch panel. The external touch panel combines a separate touch panel with a general display panel, and the in-cell touch panel directly sets the touch sensing device on the inner side or the outer side of the substrate in the display panel.

Touch sensing technology can be divided into resistive, capacitive and optical. Capacitive touch panels have become the mainstream in the market due to their high sensitivity, high transparency, fast response and long service life. In a general capacitive touch detection system, a plurality of capacitors are disposed on the touch panel or the screen for performing touch detection. Conventional touch detection often requires a complete judgment to determine whether a touch event, a touch occurrence location, and a touch strength occur. For example, when a touch event occurs, the touch control module can perform an internal difference calculation on the sensing signals from different capacitors on the touch panel to determine the position where the touch occurs. Through the above method, the value of each sensing signal can be obtained to determine the touch intensity received at each position on the touch panel, thereby achieving accurate touch determination. The above method takes a long time and generates more power consumption in the touch detection system.

In addition, there are often noises (such as liquid crystal module noise (LCM noise)) in the sensing signal, and the noise will reduce the report rate of the touch event. In order to achieve better reporting rates, conventional noise detection and error correction methods often use powerful filters to filter out noise. However, powerful filters typically have a narrower bandwidth to control the passage of a particular signal, but a narrower bandwidth would correspond to a longer time consumption in the time domain. In addition, the touch control module can perform complex analog operations on the sensing signals to eliminate or reduce interference caused by noise.

However, the above complete judgment mechanism often requires complicated circuit design, and at the same time generates more power consumption and consumes more time, thereby reducing the performance of the touch detection system. In view of this, it is necessary to provide a better solution for the signal processing and operation of the touch sensing signal, thereby improving the performance of the touch detection system.

Therefore, the main purpose of the present invention is to provide a method for determining a touch event in a touch detection system through digital initial judgment, thereby realizing the advantages of reducing time and power consumption in the touch detection system.

The invention discloses a method for determining a touch event, which is used in a touch detection system. The method for determining a touch event includes transmitting a touch signal to the touch panel of the touch detection system, and receiving, from the touch panel, a sensing signal corresponding to the at least one driving signal; The signal is subjected to a digital initial judgment to determine whether a touch event occurs; whether the sensing signal is interfered by a noise signal; and when the touch event is determined or the sensing signal is received by the noise signal When the interference occurs, a complete judgment is performed on the sensing signal.

As described above, the conventional full judgment method is time consuming and power consuming, and therefore a better method for performing touch detection is needed to determine the touch event in the touch detection system. Generally, a touch control module of a touch detection system can transmit a driving signal to a capacitance on a touch screen or a touch panel, and receive a sensing signal from the capacitor to determine whether a touch event occurs, and A threshold value for determining a touch event may be preset for the sensing signal.

Please refer to FIG. 1 . FIG. 1 is a schematic diagram of determining a waveform of a touch event through a sensing signal. Figure 1 contains a threshold TH and a sense signal. If the sensing signal is lower than the threshold TH, it can be determined that the touch event occurs; conversely, if the sensing signal is higher than the threshold TH, no touch is generated on the touch panel.

As shown in FIG. 1, if the sensing signal indicates that a touch event occurs, the sensing signal needs high resolution. More specifically, the sensing signal should obtain an accurate signal value, and the different signal values of different sensing signals can be combined to further determine the touch information, such as the location of the touch event and the touch intensity. In this case, a complete judgment is required to calculate the touch information. On the other hand, if the sensing signal indicates that the touch event has not occurred, the above complete judgment is not required. Further, in the case where the touch event is judged by the threshold TH without further judgment, the sensing signal only needs low resolution. That is to say, since the above judgment contains only two kinds of judgment results, it can be represented by one bit, so a simple operation is sufficient to deal with the low resolution judgment manner. In this case, it is only necessary to perform a complete judgment with a higher resolution when the touch event occurs.

Please refer to FIG. 2 , which is a schematic diagram of a touch event on a touch panel 20 . As shown in FIG. 2, the touch event occurs at two points on the touch panel 20. In general, touch events are detected only in a single or a small number of locations on the entire touch panel, or even no touch events are detected at all. For most locations where no touch events occur, a full resolution of high resolution is not required.

It can be seen that, in terms of time, the touch event occurs only for part of the time during a period of time; in a spatial perspective, the touch event occurs only in a part of the entire touch panel. Therefore, in most of the time and in most spaces, the low resolution digitization initial judgment is sufficient for the signal processing of the sensing signal without the need for a complete judgment of high resolution.

Digital initialization can use a simple circuit structure to reduce power consumption and time consumption. However, the simplified initialization of digitalization will result in a decrease in noise detection capability. Fortunately, U.S. Patent Application Serial Nos. 14/607,031 and 14/285,604 provide a method for efficiently performing noise detection without the use of large filters (large filters containing complex circuits and requiring a significant amount of time). In addition, some regular noise can be eliminated or reduced by non-uniform sampling. These methods of detecting and reducing noise enable simple digital initialization to be implemented in touch detection systems.

Please refer to FIG. 3 , which is a schematic diagram of a touch detection process 30 according to an embodiment of the present invention. The touch detection process 30 can be implemented in any touch control module that can be used in various touch detection systems such as resistive, capacitive or optical. The touch detection process 30 includes the following steps:

Step 300: Start.

Step 302: Send at least one driving signal to one of the touch detection systems.

Step 304: Receive a sensing signal corresponding to the at least one driving signal from the touch panel.

Step 306: Perform a digitization initial judgment on the sensing signal to determine whether a touch event occurs. If the touch event occurs, step 310 is performed; if not, step 308 is performed.

Step 308: Determine whether the sensing signal is interfered by the noise signal. If yes, go to step 310; if no, go to step 312.

Step 310: Perform a complete judgment on the sensing signal.

Step 312: End.

According to the touch detection process 30, the touch control module transmits at least one driving signal to one of the touch detection systems, and receives a sensing signal corresponding to the at least one driving signal from the touch panel. Then, the touch control module performs a digital initial judgment on the sensing signal to determine whether a touch event occurs. The digital initial judgment can be completed by simply comparing the sensing signal with a threshold value (such as the threshold TH shown in FIG. 1) without separately determining other touch information, such as touch intensity, signal size, and Touch position, etc. Therefore, in the step of performing the digital initial judgment, the touch control module knows whether a touch event occurs, but cannot obtain complete information about the touch event, such as the location where the touch event occurs.

If the comparison result of the digital initial judgment indicates that the touch event occurs, the touch control module will then perform a complete judgment on the sensing signal to obtain complete touch information, thereby determining the touch position and/or the touch intensity. That is to say, in the step of performing the complete judgment, it is necessary to perform a more time-consuming high-resolution operation. On the other hand, if the comparison result of the digital initial judgment indicates that no touch event has occurred, the touch control module additionally determines whether the sensing signal is interfered by a noise signal. If the noise of the interference sensing signal is detected, the touch control module also initiates a complete judgment for the sensing signal to eliminate or reduce noise interference, and then determine the touch position and/or the touch intensity ( If there is a touch,). If no noise is detected, the touch control module will not perform a complete judgment on the sensing signal, in this case, saving time and power consumption.

It can be seen that the complete judgment with higher resolution and more time is only executed when it is judged that the touch event occurs or the sensing signal is judged to be interfered by the noise signal. In other words, if it is determined that no touch event has occurred and the sensing signal is not interfered by the noise signal, the complete judgment can be ignored.

In addition, as described above, for a touch panel, a complete judgment is not required in most of the time and in most spaces. Therefore, the present invention performs a complete judgment on all received sensing signals compared to the conventional touch control module, and the present invention only refers to when the digitization initial indication touch event occurs or the noise detection method indicates that the noise exists. Use the full judgment. In an embodiment, the complete determination may include a signal processing mechanism using a large filter to filter out or eliminate any possible noise. In another embodiment, the complete determination may include a maximum likelihood operation method for estimating the touch intensity corresponding to each of the sensing signals, so that the touch control module can accurately calculate the touch. Control position and / or touch strength. Compared to digital initial judgment, a complete judgment (such as large filter or maximum likelihood operation) provides a higher resolution touch judgment, which requires much more computation time than the computational time required for digital initialization. Therefore, in the touch detection process 30, reducing the number of times the full judgment is used can achieve the advantages of reducing time consumption and reducing power consumption.

It should be noted that the sequence of steps 306 and 308 can be mutually exchanged, that is, the touch control module can determine the occurrence of the touch event after determining whether the noise signal exists. In this case, if either of the noise signal and the touch event occurs, a complete judgment can still be performed.

In general, the noise detection signals of the touch detection system can be divided into two types: regular noise and irregular noise. In order to avoid false touch reporting, regular noise and irregular noise must be eliminated or reduced. The irregular noise can be processed by the noise detection method described in U.S. Patent Application Serial Nos. 14/607,031 and 14/285,604, and the rule noise can be eliminated by non-uniform sampling in the digital initial judgment. The rule noise may be any type of noise generated by a regular operation in an electronic system associated with the touch detection system, such as liquid crystal module noise (LCM noise) or liquid crystal display (liquid) Other people in the crystal display, LCD) system are noise. For example, the regular noise can be generated by a circuit device in the liquid crystal display system. When the circuit device generates a noise signal, the related information is sent for the time when the noise signal reaches the sensing line on the touch panel. Therefore, the touch detection system knows which of the sense signals are present in the interference of the rule noise.

Please refer to FIG. 4A and FIG. 4B. FIG. 4A and FIG. 4B are schematic diagrams showing non-uniform sampling by one of the sensing signals interfered by the regular noise signal. Figure 4A shows the presence of several regularly occurring noise signals on the sense signal, and Figure 4B shows the waveform of the same sense signal after non-uniform sampling. As shown in FIG. 4A, the value of the sensing signal is approximately between -0.1 and 0.1, and the sensing signal is severely interfered by the noise signal, and the range of the noise signal can reach -1 to 1. As can be seen from Figure 4A, the noise signal on the sensing signal obviously affects the judgment result of the touch event. According to the non-uniform sampling, at least one segment of the sensing signal may be deleted before the sensing signal is sampled, wherein the deleted segment is the portion interfered by the regular noise. In other words, since the touch detection system knows where the noise interference occurs, the portion of the sense signal that is disturbed by noise can be eliminated by non-uniform sampling, as shown in FIG. 4B. Therefore, the touch detection system only samples the portion of the sensed signal that is not disturbed by noise.

It is worth noting that the signal processing mechanism used to perform complete judgments is usually signal processing in the frequency domain, which often requires the use of powerful filters to eliminate noise signals. In this case, when using filtering The more powerful the device, the more time it takes to process the signal. On the other hand, unlike the conventional complete judgment method, the digitization initial judgment of the present invention uses non-uniform sampling in the time domain to eliminate the interference of the regular noise, and the implementation manner is relatively simple, and can be used in a small time and in use. Solve noise problems in the case of less complex circuits. For example, in an embodiment, non-uniform sampling can be implemented by a multiplexer having two inputs, an output, and a control terminal controlled by a control signal, wherein an input The terminal receives the sensing signal and the other input receives the zero potential. During the period when the sensing signal is interfered by the regular noise (such as time point A), the control signal can control the multiplexer output zero potential; during the period when the sensing signal is not interfered by the regular noise (such as time point B), the control signal The multiplexer output sensing signal can be controlled. In other embodiments, non-uniform sampling may also be implemented by other means, without being limited thereto.

Please refer to FIG. 5, which illustrates the advantages of the above non-uniform sampling, which shows a line graph of the normalized error of the sampling result of the sensing signal interfered by the noise, wherein the value 1 Represents accurate sampling results, and the values 1.1, 1.2, 1.3, and 1.4 represent the error of the sampling results of the sensing signals of 10%, 20%, 30%, and 40%, respectively. Curve L1 corresponds to the sensing signal before non-uniform sampling, and curve L2 corresponds to the sensing signal after non-uniform sampling. As shown in Fig. 5, due to the interference of the noise, the sampling result has an error of about 30% to 40%. After the non-uniform sampling, the error can be greatly reduced to 0% to 5%. It can be seen that non-uniform sampling has a strong effect of reducing errors. In addition, since the error size drops to about one-eighth of the original, the sensing signal can be amplified eight times before entering the analog-to-digital converter (ADC) of the touch control module, so that the analog digital The dynamic range of the converter is increased by 3 bits, which greatly enhances the performance of the analog digital converter.

The operation of non-uniform sampling can be described by the following general equation:

,

among them, Represents a sensing signal that can be divided into a signal component And a noise component , Represents a basic signal, such as a basic sine wave or square wave, It represents the time sequence remaining after the sensing signal deletes at least one segment, and the deleted segment is the portion of the sensing signal that is interfered by the noise. As shown in the general equation, the sensing signal can be divided into signal components and noise components, so by choosing the appropriate Can effectively eliminate noise components.

In addition, noise that cannot be eliminated by non-uniform sampling (e.g., irregular noise) can be detected by the noise detection method described in U.S. Patent Application Serial Nos. 14/607,031 and 14/285,604. Please refer to FIG. 6 and FIG. 7 . FIG. 6 is a schematic diagram of a touch panel 600 according to an embodiment of the present invention, and FIG. 7 is a schematic diagram of data distribution when the touch panel 600 is driven. As shown in FIG. 6, the touch panel 600 includes a plurality of driving lines TX_1-TX_M and a plurality of sensing lines RX_1-RX_N for sensing touch gestures on the touch panel 600, wherein M and N are greater than A positive integer of 1. The driving circuit of the touch panel 600 can transmit the plurality of driving signals Y1 Y Ym to the driving lines TX_1 ～ TX_M in a time period having a specific time length to drive the sensing lines RX_1 R RX_N to generate a plurality of Sensing signals X1 to Xn, where m and n are positive integers greater than one.

Referring to FIG. 7, the horizontal axis represents the time interval, and the timing thereof is increased from left to right. The vertical axis represents the driving direction of the touch panel 600, and is sequentially scanned from the top to the bottom by the driving line TX_1 to the driving line TX_M. In the present exemplary embodiment, the time interval includes a plurality of time slots TS1 to TSn. In the area 706, the data Cji+Nji indicated at the intersection of the driving lines TX_1-TX_M and the sensing lines RX_1-RX_N represents the capacitance value Cji generated by the touch gesture and the noise signal generated by the external influence of the touch panel 600. The sum of Nji, where j is a positive integer from 1 to M, i is a positive integer from 1 to n, and M, n are positive integers greater than one. The noise signal Nji may include various noises that cannot be eliminated by non-uniform sampling, such as irregular noise. In the area 704, the sum signals RX Sum_1 to RX Sum_n indicated by the positions of the sensing lines RX_1 to RX_N of FIG. 6 represent that in this time interval, a touch control module calculates the sensing signals X1 X Xn respectively. The sum of the signal values obtained. That is to say, the sum signal RX Sum_i represents the sum of the data obtained by the sensing line RX_I from the respective driving lines TX_1 to TX_M in the sub-interval TSi of this time interval, where I is a positive integer from 1 to N. For example, the sum signal RX Sum_1 represents the sum of C11+N11 to CM1+NM1 in the subinterval TS1 of this time interval. The sum signal RX Sum_1~RX Sum_n can be expressed by the following formula:

RX Sum_i=

Among them, RX Sum_i represents the sum signal, Cji represents the capacitance value generated by the touch gesture, and Nji represents the noise generated by the touch panel 600 by the external influence, wherein j is a positive integer from 1 to M, and i is from 1 A positive integer to n, M, n is a positive integer greater than one.

In the exemplary embodiment, each of the driving signals Y1 Y Ym has a first polarity pattern and a second polarity pattern. During this time interval, the operation results of the first polarity pattern and the second polarity pattern of each of the driving signals Y1 to Ym are substantially zero. In this example, the operations of the first polarity pattern and the second polarity pattern of each of the driving signals Y1 to Ym can be summed, that is, in the region 702, corresponding to the positions of the driving lines TX_1 to TX_M of FIG. The sums TX Sum_1 to TX Sum_M of the respective driving signals Y1 to Ym are zero, respectively, indicating that the sum of the first polarity pattern and the second polarity pattern of each of the driving signals Y1 to Ym is substantially zero during this time interval.

For example, four driving signals Y1 to Y4 are taken as an example. In the exemplary embodiment, in the time interval including the two sub-intervals TS1 and TS2, the polarity distribution states of the driving signals Y1 to Y4 are as shown in Table 1 below:

In Table 1, "1" indicates that the drive signals Y1 to Y4 have the first polarity pattern in the corresponding sub-interval, and "-1" indicates that the drive signals Y1 to Y4 have the second polarity pattern in the corresponding sub-interval. Therefore, in the column of the driving line TX_1, after the time interval including the two sub-intervals TS1 and TS2 passes, the sum of the first polarity pattern and the second polarity pattern of the driving signal Y1 is substantially zero. The polarity distribution states of the driving signals Y2 to Y4 of the driving lines TX_2 to TX_4 can be deduced by analogy. In addition, the polarity distribution patterns of the respective driving signals Y1 to Y4 are not limited to those shown in Table 1. Other examples are shown in U.S. Patent Application Nos. 14/607,031 and 14/285,604, the disclosures of each of which are hereby incorporated herein.

Referring to FIG. 6 and FIG. 7 again, and in conjunction with the driving concept disclosed in the embodiment of Table 1, the touch control module of the touch panel 600 can separately calculate the sensing signal X1 in a time interval of a specific time length. The sum of the signal values of Xn to obtain the sum signal RX Sum_1~RX Sum_n. Then, the touch control module recalculates the sum signals RX Sum_1 to RX Sum_n to obtain the sum NF of the sum signals RX Sum_1 to RX Sum_n, that is, NF=RX Sum_1+RX Sum_2+...+RX Sum_(n-1)+RX Sum_n = .

The sum NF obtained by the touch control module calculating the sum signal RX Sum_1 - RX Sum_n represents the noise generated by the external influence of the touch panel 600. Therefore, by using the above-described noise detection method, the noise signal generated by the external influence can be quickly and correctly estimated.

It can be seen that, in the absence of noise, the sum of the first polarity pattern and the second polarity pattern of the driving signal is substantially zero regardless of whether there is a touch event on the touch panel 600. Therefore, if the sum NF is any non-zero value, it can be regarded as noise interference, and the noise signal can be detected by the above method. For example, the step 308 of the touch detection process 30 can be implemented by using the touch detection method, and the sum NF is obtained to determine whether the sensing signal contains noise. If the sum NF is equal to zero, it can be judged that there is no noise in the sensing signal; if the sum NF is not equal to zero, it can be judged that the sensing signal is interfered by the noise signal, and then the complete judgment is used to process the noise signal. In another embodiment, the touch control module can also be preset to use a threshold value of the sum NF. If the sum NF exceeds the threshold, the sensing signal can be judged to be interfered by the noise signal.

Please refer to FIG. 8. FIG. 8 is a schematic diagram of an operation mode of the digital control initial judgment and complete judgment of the touch control module according to the embodiment of the present invention. As shown in FIG. 8, the touch control module can schedule the time period to reserve a plurality of digitization judgment times for digitization initial judgment and a plurality of complete judgments in an alternate manner for a period of time. The complete judgment time, wherein each digitization judgment time in the plurality of digitization judgment times is immediately before a complete judgment time in the plurality of complete judgment times. During each digitization judgment time, a bitwise initialization and a noise detection method can be performed. If the digital initial judgment or noise detection method indicates that a complete judgment is required due to the occurrence of a touch event or noise interference, the touch control module performs a complete judgment within the next complete judgment time (as shown in FIG. 8). The first complete judgment time is shown). If the digital initial judgment and the noise detection method respectively indicate that the touch event and the noise interference have not occurred, and thus the complete judgment is not required, the touch control module does not perform the complete judgment in the next complete judgment time, and the touch control The module will wait until the next digitization decision time, and then begin the digital initial judgment (as shown in the second complete judgment time in Figure 8). In the above way, the complete judgment will only be carried out in a small or part of the time, which can reduce the power consumption. However, this scheduling method is relatively simple and does not reduce the time consumption. In other embodiments, the next-time initialization may be directly performed when the complete judgment is not needed, so as to reduce the consumption of time.

It is worth noting that in addition to the above-mentioned signal processing methods using large filters and maximum likelihood operations, the complete judgment can also be realized by a series of digital judgments to achieve high resolution. More specifically, although the first-time initialization can only achieve low-resolution touch detection, high-resolution touch detection can be realized by performing a series of digital determinations.

For example, please refer to FIG. 9. FIG. 9 is a schematic diagram of another operation mode of the digital control initial judgment and complete judgment of the touch control module according to the embodiment of the present invention. As shown in Fig. 9, a complete judgment can be composed of four digital judgments that are identical or similar to the initial judgment of digitization. In this example, the touch control module can perform the digitization determination one or two times to determine whether a touch event occurs and determine whether the sensing signal is interfered by noise. Other digitization decisions are performed as necessary, that is, when a touch event or noise signal is detected. For example, in FIG. 9, a complete judgment time includes four digitization determination times, wherein each digitization determination time can perform a bitwise determination. The touch control module may first perform the digitization determination in the first and second digitization determination time, and determine whether it needs to be executed more times according to the judgment result obtained in the first and second digitization judgment times. Digital judgment. The judgment result obtained by each of the above-mentioned digitization determinations indicates whether a touch event and a noise signal are present, and the noise signal can be judged according to the sum signal obtained by the sensing signal according to the noise detection method. If the touch event or the noise signal is detected, the touch control module can further perform the digital determination in the third and fourth digitization determination time to obtain the touch position information with higher resolution and / or eliminate noise interference. On the other hand, if no touch events or noise signals are detected, the digitization judgments in the third and fourth digitization judgment times will not be executed.

Please continue to refer to Figure 9, which illustrates how the operation of a series of digital determinations can be combined with the above-described noise detection method. In the third complete judgment time shown in FIG. 9, the touch control module may first perform the digitization judgment in the first and second digitization judgment times, and determine the judgment of the second digitization bit determination. The result is disturbed by noise. In this case, the touch control module further performs the digitization determination in the third and fourth digitization determination times. Then, the touch control module obtains four determination results corresponding to the sensing signals of the four-digit determination, and determines whether the determination result is interfered by the noise signal. The touch control module may select at least one of the determination results that are determined not to be interfered by the noise to determine touch information related to the touch event, such as a touch position. As shown in the third complete judgment time of Figure 9, the judgment results obtained by the second and third digitization determinations are subject to noise interference, and the touch control module thus selects the first and fourth digitizations. The judgment result obtained is judged to determine the occurrence of the touch event and/or the touch position.

It is worth noting that, according to the noise detection method described in U.S. Patent Application Serial No. 14/607,031, the sum signal obtained in different time intervals can be recombined to obtain another sum NF' whose value is smaller than the original sum NF. That is to say, the sum signal corresponding to the sum NF' is less subject to noise interference with respect to the sum signal corresponding to the sum NF. Please refer to Figure 6 and Figure 7 again. The touch control module can obtain the sum of the signal values of the first sum signals A, B, C, and D corresponding to the first sum signals A, B, C, and D, respectively, corresponding to the sensing lines RX_1 R RX_4 in the first time interval. NF3 (NF3=A+B+C+D) represents the noise signal value calculated by the touch control module after executing the first noise detection method. Then, the touch control module obtains second sum signals A', B', C', and D' corresponding to the sensing lines RX_1 - RX_4 in the second time interval, and the second sum signals A', B', C The sum of the signal values of 'and D' NF4 (NF4=A'+B'+C'+D') represents the noise signal value calculated by the touch control module after executing the second noise detection method. .

In this exemplary embodiment, the touch control module may replace some or all of the first sum signals A, B, and C with at least one of the second sum signals A', B', C', and D'. D, such that the sum of the signal values NF5 after the second sum signal A', B', C', and D' and the first sum signal A, B, C, and D are recombined is smaller than the signal of the first sum signal before recombination The sum of the values is NF3. In this way, after performing any possible reorganization of the sum signal, the best summation signal combination, that is, the combination most uninterrupted by noise, can be judged by finding the smallest sum. Compared with the method of removing the judgment result that the sum is not equal to zero, the reorganization and selection method can more accurately determine the touch event and the touch position. It should be noted that, in the embodiment illustrated in FIG. 9, although a sum of the plurality of sum signals is interfered by the noise, the partial or majority sum signal included in the sum is still accurate. Therefore, through reorganization, these accurate sum signals can be combined with other accurate sum signals obtained in other time intervals. In this case, more valid data in the sum signal can be saved to obtain more accurate touch judgment. .

Please refer to FIG. 10 , which is a schematic diagram of a touch control module performing a series of digitization determinations and a reorganization of a sum signal according to an embodiment of the present invention. As shown in FIG. 10, each large block represents a digitization judgment time, which can be regarded as a time interval for generating a judgment result, wherein the judgment result can be four sum signals (eg, sum signals A1 to A4, B1). ~B4, C1 to C4 or D1 to D4) are summed up to give the total sum. After the touch control module performs the digitization determination within the four digitization determination time, the sums SA, SB, SC, and SD corresponding to each digitization determination may be respectively obtained, where SA is equal to the sum signal A1, A2. The sum of A3 and A4, SB is equal to the sum of the sum signals B1, B2, B3 and B4, SC is equal to the sum of the sum signals C1, C2, C3 and C4, and SD is equal to the sum of the sum signals D1, D2, D3 and D4. Then, the touch control module performs reorganization. For example, as shown in FIG. 10, the sum signals A1, B1, C1, and D1 can be combined with each other to obtain a sum SA', and the sum signals A2, B2, C2, and D2 can be combined with each other. And to obtain a sum SB', the sum signals A3, B3, C3 and D3 can be combined to obtain a sum SC', and the sum signals A4, B4, C4 and D4 can be combined to obtain a sum SD'. More specifically, the touch control module can combine the sum signals of any of the sum signals A1 to A4, B1 to B4, C1 to C4, and D1 to D4 to obtain the sum. In one embodiment, the touch control module can find the minimum sum to obtain four or any number of sum signals that are most free of noise interference, and select these sum signals to determine touch information, such as touch. The occurrence of an event and/or the location of the touch, etc. On the other hand, the touch control module can find the sum of less than a threshold and obtain the sum signal included in the sum(s). The touch control module determines the touch information based on the sum signals. As shown in FIG. 10, after several reorganizations, the touch control module can determine that the sum signals A2, A3, A4, B2, C1, C4, D1, D2, and D3 are not interfered with by noise, and select these The sum signal is used to determine the touch information. In this case, optimal touch information can be obtained by selecting all sum signals that are not subject to noise interference and excluding all sum signals that are subject to noise interference.

In summary, the present invention provides a method for determining a touch event in a touch detection system. A simpler digital initial judgment can replace the conventional complete judgment to determine whether a touch event occurs. In order to improve the noise detection capability, non-uniform sampling can be used to eliminate or reduce the regular noise. The noise detection method implemented by the sum of the sensing signals with different polarity patterns can be used to eliminate or reduce the irregular noise. . Although the complete judgment has a higher resolution, the circuit is more complicated and requires more time and power consumption. Therefore, only when the digitalization first judges that the touch event occurs or the sensing signal is judged to be interfered by noise. use. In this way, the present invention can achieve the effect of reducing time and power consumption. The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

TH‧‧‧ threshold
20‧‧‧Touch panel
30‧‧‧ Touch detection process
300-312‧‧‧ steps
L1, L2‧‧‧ curve
600‧‧‧ touch panel
702, 704, 706‧‧‧ areas
TX_1~TX_M‧‧‧ drive line
RX_1～RX_N‧‧‧Sense line
Y1～Ym‧‧‧ drive signal
X1～Xn‧‧‧Sense signal
TS1~TSn‧‧‧ subinterval
Capacitance value generated by C11～CMn‧‧‧ touch gesture
N11 ~ NMn‧‧‧ noise signal
RX Sum_1~RX Sum_n, A1～A4, B1～B4, C1～C4, D1～D4‧‧‧sum signal
TX Sum_1~TX Sum_M, NF, SA, SB, SC, SD, SA', SB', SC', SD'‧‧‧

The first figure is a waveform diagram for judging a touch event through a sensing signal. Figure 2 is a schematic diagram of a touch event on a touch panel. FIG. 3 is a schematic diagram of a touch detection process according to an embodiment of the present invention. 4A and 4B are schematic diagrams of non-uniform sampling of one of the sensing signals interfered by the regular noise signal. Figure 5 is a line graph showing the normalized error of the sensing signal sampled by the noise interference. FIG. 6 is a schematic diagram of a touch panel according to an embodiment of the present invention. FIG. 7 is a schematic diagram showing the distribution of data when the touch panel is driven. FIG. 8 is a schematic diagram of an operation mode of the digital control initial judgment and complete judgment of the touch control module according to the embodiment of the present invention. FIG. 9 is a schematic diagram showing another operation mode of the digital control initial judgment and the complete judgment of the touch control module according to the embodiment of the present invention. FIG. 10 is a schematic diagram of a manner in which the touch control module performs a series of digitization determinations and the summation signal is reorganized according to an embodiment of the present invention.

30‧‧‧ Touch detection process

300~312‧‧‧Steps

Claims (10)

A method for determining a touch event, comprising: transmitting at least one driving signal to a touch panel of the touch detection system; receiving, from the touch panel, corresponding to the at least one driving a signal sensing signal; performing a digital initial judgment on the sensing signal to determine whether a touch event occurs; determining whether the sensing signal is interfered by a noise signal; and determining that the touch event occurs Or determining that the sensing signal is interfered by the noise signal, performing a complete judgment on the sensing signal. The method of claim 1, further comprising: when determining that the touch event has not occurred and determining that the sensing signal is not interfered by the noise signal, the complete determination is not performed on the sensing signal. The method of claim 1, wherein the complete determination comprises a series of digitization decisions. The method of claim 1, wherein the complete determination comprises a maximum likelihood operation or a signal processing mechanism using a filter. The method of claim 1, wherein the step of performing the digitization initial judgment on the sensing signal comprises: performing a non-uniform sampling on the sensing signal. The method of claim 5, wherein the step of performing the non-uniform sampling on the sensing signal comprises: deleting at least one segment of the sensing signal, wherein the at least one segment is before sampling the sensing signal It is interfered by a regular noise. The method of claim 6, wherein the operation of the non-uniform sampling is described by the following general form equation: , among them, Representing the sensing signal, which is divided into a signal component And a noise component , Representing a basic signal, Then, it represents a time sequence that the sensing signal remains after deleting the at least one segment. The method of claim 1, further comprising: a plurality of digitization determination times for the digitization initial judgment and a plurality of complete judgment times for the complete judgment are reserved in an alternating manner, wherein the plurality of complete determination times Each digitization determination time in the digitization determination time is immediately before a complete judgment time in the plurality of complete judgment times. The method of claim 1, wherein the complete determination provides a higher resolution than the digital initialization. The method of claim 1, further comprising: determining whether a plurality of determination results of the sensing signal are interfered by the noise signal; and selecting, using the plurality of determination results, that the noise signal is determined not to be received by the noise signal At least one of the interference results determines a touch information related to the touch event.