Touch control circuit and touch detection method thereof

Abstract

The invention discloses a touch detection method which is used for judging whether to report points or not. The touch detection method comprises the following steps: obtaining a position of a touch point; determining a plurality of reference sensing pads according to the position of the touch point; determining a weight of each sensing pad of the plurality of reference sensing pads according to the position of the touch point; evaluating a first evaluation peak value according to the sensing quantities of the plurality of reference sensing pads and the corresponding weights; and judging whether the touch point is reported or not according to the first evaluation peak value and a first threshold value.

Description

Technical Field

[0001] The present application relates to a touch control circuit and a touch detection method thereof, and more particularly to a touch control circuit and a touch detection method thereof for improving reporting point stability. Background Art

[0002] With the rapid development of touch detection technology, touch screens have been widely used in a variety of electronic devices such as mobile phones, satellite navigation, tablet computers, personal digital assistants (PDAs), and laptop computers. Touch screens are easy to operate and intuitive to use, so they are popular among consumers and are becoming the mainstream trend of the market.

[0003] The existing touch detection technology determines whether to report a touch event by detecting the change in the inductive value of the inductive pad on the touch screen (in other words, determining whether it is in the Make state or the Break state). However, there are many factors that affect the inductive value measured by the inductive pad, including the distance between the finger (or stylus) and the touch screen, the size of the contact area, and the position of the finger touch. These factors will affect the determination of whether to report a point. For example, when a finger approaches the touch screen from far to near but has not actually touched the touch screen, it can be detected that the inductive value gradually changes from small to large. When the finger actually touches the touch screen and continues to press down, the contact area between the finger and the touch screen will increase accordingly, so that the total inductive value measured will also increase accordingly.

[0004] In actual applications, a touch event can only be reported when the finger is as close to the touch screen as possible. Therefore, based on the sensing amount measured by the sensing pad, the height of the finger (or stylus) relative to the touch screen surface is estimated and used to determine whether a touch event is reported. Summary of the invention

[0005] Therefore, an object of the present invention is to provide a touch control circuit and a touch detection method thereof, thereby improving the stability of reporting points.

[0006] The embodiment of the present invention discloses a touch detection method for determining whether to report a touch point. The touch detection method includes obtaining a position of a touch point; determining a plurality of reference sensing pads according to the position of the touch point; determining a weight of each of the plurality of reference sensing pads according to the position of the touch point; evaluating a first evaluation peak value according to the sensing amounts of the plurality of reference sensing pads and the corresponding weights; and determining whether the touch point is reported according to the first evaluation peak value and a first threshold value.

[0007] The embodiment of the present invention also discloses a touch control circuit for determining whether to report a point. The touch control circuit includes a driving circuit, a sensing circuit, and a processing unit. The driving circuit is coupled to a touch screen for providing a driving signal to the touch screen. The sensing circuit is coupled to a plurality of sensing pads of the touch screen. The processing unit is coupled to the driving circuit and the sensing circuit for executing a touch detection method, including obtaining a position of a touch point by the sensing circuit; determining a plurality of reference sensing pads according to the position of the touch point; determining a weight of each of the plurality of reference sensing pads according to the position of the touch point; evaluating a first evaluation peak value according to the sensing amounts of the plurality of reference sensing pads and the corresponding weights; and determining whether the touch point is reported according to the first evaluation peak value and a first threshold value. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram of estimating the height of a finger suspended in the air according to an embodiment of the present invention.

[0009] Figure 2 It is a schematic diagram of the test results of the first embodiment of the present invention.

[0010] Figure 3 FIG. 1 is a schematic diagram of a touch control system according to an embodiment of the present invention.

[0011] Figure 4 FIG. 4 is a schematic diagram of a touch detection process according to an embodiment of the present invention.

[0012] Figure 5 FIG. 1 is a schematic diagram of the sensing values ​​of some sensing pads according to an embodiment of the present invention.

[0013] Figure 6 Schematic diagram of the relationship between the total sensing amount and the finger's suspended height according to the first embodiment of the present invention.

[0014] Figure 7 FIG. 1 is a schematic diagram of a reference area and a corresponding threshold value according to an embodiment of the present invention.

[0015] Figure 8 Schematic diagram of the difference in sensing amount caused by the different relative positions of the touch point and the sensing pad in an embodiment of the present invention.

[0016] Fig. 9 Schematic diagram of a peak value evaluation process according to an embodiment of the present invention.

[0017] Fig.10 FIG. 1 is a schematic diagram of a reference sensor pad according to an embodiment of the present invention.

[0018] Fig.11 FIG. 1 is a schematic diagram of a reference sensor pad according to an embodiment of the present invention.

[0019] Fig.12FIG. 4 is a schematic diagram of the distance between a touch point and a sensor pad according to an embodiment of the present invention.

[0020] Fig.13 FIG. 4 is a schematic diagram of a touch detection process according to an embodiment of the present invention.

[0021] The reference numerals are described as follows:

[0022] 10: Touch screen

[0023] 100: Touch surface

[0024] 30: Touch system

[0025] 300: Touch screen

[0026] 302: Induction pad

[0027] 310: Touch control circuit

[0028] 312: driving circuit

[0029] 314: Processing unit

[0030] 316: Sensing circuit

[0031] 40: Touch detection process

[0032] 400~422: Steps

[0033] P1: Main sensor pad

[0034] P2: Reference sensor pad

[0035] P3: The sensor pad with the maximum induction (peak value)

[0036] T1, T2: threshold value

[0037] V sum Total induction

[0038] A1: Reference area

[0039] 80:Test fixture

[0040] TP1~TP6: Touch point

[0041] SP1~SP7: Induction pad

[0042] V sp : Induction peak

[0043] V cp :Evaluation peak

[0044] 90: Peak Assessment Process

[0045] 900~910: Steps

[0046] 1000, 1002, 1100: Reference induction pad

[0047] P c :First sensor pad

[0048] R: Predetermined length

[0049] (x TP ,y TP ):Touch point coordinates

[0050] (x1,y1)~(x9,y9): Center coordinates of the sensor pad

[0051] D1~D9: Distance between touch point and sensor pad center

[0052] 130: Touch detection process

[0053] 1300~1314: Steps DETAILED DESCRIPTION

[0054] Please refer to Figure 1 , Figure 1 Schematic diagram of evaluating the height of a finger (or stylus) in the air according to an embodiment of the present invention. In the embodiment of the present invention, the height of the finger in the air is estimated based on a touch surface 100 of a touch screen 10 as a reference point (the height in the air is 0). Figure 1 As shown in case (b), when the finger just touches the touch surface 100 of the touch screen 10, the suspended height is estimated to be 0. In this case, the finger touches the surface of the touch screen with the smallest contact area (the contact surface is a point). When the finger is suspended above the touch surface 100, the suspended height is estimated to be Figure 1 A positive value as shown in case (a). In case (a), the finger approaches but does not actually touch the touch surface 100. The touch screen 10 can detect the change in the sensing amount at this time and start to determine whether it is a touch event and report the point. After the finger touches the touch surface 100 and continues to press down, the suspended height is estimated as follows Figure 1 A negative value is shown in case (c). In case (c), the finger is actually in contact with the touch surface 100. As the finger continues to press down, the contact area increases, and the total sensing amount measured by the touch screen 10 also increases. It should be noted that case (c) may occur when a soft material is used for touch operation, such as a finger or a stylus with a rubber tip, but is not limited thereto.

[0055] Ideally, the touch point will be reported only when the finger is as close to the touch surface 100 as possible. However, since the prior art cannot accurately estimate the height of the finger in the air, when the finger is at the same vertical height and different horizontal positions, inconsistent reporting or non-reporting may occur. In practice, the tolerance range of inaccurate reporting must be controlled as small as possible, such as Figure 2 shown. Figure 2 This is a schematic diagram of the test results of the first embodiment of the present invention, which shows the percentage of test points at different horizontal positions using test fixtures of different thicknesses at various suspension heights, where the test fixture can be a round copper column used to simulate a finger or a stylus. Figure 2 As shown in the figure, the tolerance range of inaccurate reporting is between -250um and 300um of the suspended height. In other words, when the suspended height of the finger is between -250um and 300um, it is impossible to completely guarantee that at the same vertical height, each different horizontal position can have the same reporting result. It can only ensure that when the suspended height of the finger is higher than 300um, no reporting will be performed, and when the suspended height is lower than -250um, a reporting will be performed.

[0056] In order to reduce the tolerance range of inaccurate reporting, no matter where the finger falls on the touch screen 10, it is necessary to estimate the height of the finger more accurately. Therefore, the present invention provides a touch control circuit and a touch detection method thereof to improve the stability of reporting.

[0057] Please refer to Figure 3 , which is a schematic diagram of a touch control system 3 according to an embodiment of the present invention. The touch control system 3 can be applied to various electronic devices, such as mobile phones, satellite navigation, tablet computers, personal digital assistants, laptop computers, etc., but is not limited thereto. The touch control system 3 is arranged to execute the touch detection method for accurately reporting touch events in the embodiment of the present invention. It should be noted that the touch control system 3 is used to represent the necessary elements required to implement the embodiment of the present invention, and those skilled in the art can make different modifications and adjustments accordingly, but are not limited thereto.

[0058] The touch control system 3 includes a touch screen 300 and a touch control circuit 310. The touch screen 300 can be Figure 1The touch screen 10 shown may be, but is not limited to, a touch screen without a display function or a touch screen integrated with any type of display device. The touch screen 300 may include a plurality of sensing pads 302 for obtaining sensing values, wherein the sensing values ​​may be, but are not limited to, capacitance sensing values. The touch control circuit 310 may include a driving circuit 312, a processing unit 314, and a sensing circuit 316. The processing unit 314 is coupled to the driving circuit 312 and the sensing circuit 316, and is used to control the overall operation of the touch control system 30 and perform the touch detection method of the embodiment of the present invention. For example, the processing unit 314 may be a general-purpose processor, a microprocessor, or an application specific integrated circuit (ASIC), but is not limited thereto. The driving circuit 312 is coupled to the touch screen 300, and may operate according to the control instructions of the processing unit 314 to provide a driving signal to the touch screen 300. The sensing circuit 316 is coupled to the touch screen 300, and may operate according to the control instructions of the processing unit 314 to sense the touch screen 300 or receive the sensing result.

[0059] like Figure 4 As shown, the touch detection method of the present invention can be summarized as a touch detection process 40. The touch detection process 40 includes the following steps:

[0060] Step 400: Start.

[0061] Step 402 : Obtain the sensing quantities of the plurality of sensing pads 302 .

[0062] Step 404: Select at least one main sensing pad according to the threshold value T1.

[0063] Step 406: Determine whether at least one primary sensor pad is successfully selected. If yes, execute step 408; if no, execute step 418.

[0064] Step 408: Select a plurality of reference sensing pads according to at least one main sensing pad.

[0065] Step 410: Calculate a total sensing quantity according to a plurality of reference sensing pads.

[0066] Step 412: Estimate a reference area according to a sensing peak value and a total sensing amount.

[0067] Step 414: Obtain a threshold value T2 according to the reference area.

[0068] Step 416: Determine whether the total sensing amount is greater than the threshold value T2. If yes, execute step 420; if no, execute step 418.

[0069] Step 418: Determine that the state is Break.

[0070] Step 420: Determine that it is in the Make state and report the point.

[0071] Step 422: End.

[0072] According to the touch detection process 40, the touch system 30 determines whether a touch event is reported based on the sensing amounts of the plurality of sensing pads 302. The processing unit 314 first obtains the sensing amounts of the plurality of sensing pads 302 from the sensing circuit 316 (step 402), and selects at least one main sensing pad with a larger sensing amount based on a threshold value T1 (step 404). If at least one main sensing pad is successfully selected (step 406), the processing unit 314 may select a plurality of reference sensing pads based on the at least one main sensing pad to further determine whether to report a point (step 408); otherwise, the processing unit 314 may directly determine that the touch event is a Break state (step 418). After successfully selecting a plurality of reference sensing pads, the processing unit 314 may calculate a total sensing amount based on the plurality of reference sensing pads (step 410), and estimate a reference area accordingly (step 412). Based on the reference area, the processing unit 314 can obtain a threshold value T2 (step 414) and compare the total sensing amount with the threshold value T2 (step 416) to determine whether to report a point (step 418 or step 420). Accordingly, the processing unit 314 can control the reporting only when the height is below a specific suspension height (for example, below 300um).

[0073] Specifically, please refer to Figure 5 , which is a schematic diagram of the sensing amount of some sensing pads according to an embodiment of the present invention. According to the touch detection process 40, the processing unit 314 can obtain the following in step 402: Figure 5 The sensing amount shown (only part of the sensing pad is shown), wherein the sensing amount can be further used to determine whether it is a touch event to report a point.

[0074] The threshold value T1 is 120 for example. Please continue to refer to Figure 5 . The processing unit 314 selects the main sensing pad P1 in step 404, and selects the reference sensing pad P2 in step 408. In this embodiment, the main sensing pad can be determined according to the threshold value T1. For example, the sensing pad P1 whose sensing amount is greater than 120 (threshold value T1) can be selected as the main sensing pad. Further, in this embodiment, the reference sensing pad can be determined according to the main sensing pad. For example, the reference sensing pad P2 can be determined to include the main sensing pad P1 and the sensing pad within the range of 1 sensing pad unit extending outward, but is not limited thereto.

[0075] In step 410, the processing unit 314 calculates a total inductance V sum Specifically, the total inductance Vsum (For example, 1108) can be obtained by summing up the induction of each induction pad of the reference induction pad P2. In this embodiment, the total induction V sum It can be used as a basis for evaluating the height of the finger in the air, such as Figure 6 As shown, it shows the total inductance V sum The relationship between the total induction V sum When the total sensing value V sum When it is larger, it means that the distance between the finger and the touch surface 100 is closer, that is, the value of the suspended height is smaller at this time.

[0076] In step 412, the processing unit 314 further measures a sensing peak value V sp (e.g. 343) and the total induction V obtained in step 410 sum Estimate a reference area. Among them, the induction peak V sp is the maximum induction amount measured from the sensing pad P3 in the sensing pads 302. The reference area A1 can be estimated by the following formula, but is not limited thereto.

[0077]

[0078] Where Scale is a constant used to adjust the value of the reference area.

[0079] In steps 414 to 420, the processing unit 314 obtains the threshold value T2 corresponding to the reference area A1, and compares the threshold value T2 with the total sensing value V sum To determine whether to report a point. Specifically, the sensing area also affects the total induction V measured. sum For example, when the sensing area is larger (e.g., using a thicker test fixture), the total induction V sum In this case, even at the same suspension height, the larger the sensing area, the larger the total sensing amount measured. Therefore, the threshold value T2 used to determine the suspension height must be determined based on the reference area A1, which can be converted through a linear equation to obtain, such as Figure 7 shown. Figure 7 Schematic diagram of the reference area and its corresponding threshold value T2 according to an embodiment of the present invention. Accordingly, the processing unit 314 can obtain different threshold values ​​T2 according to different values ​​of the reference area, and thus determine whether the finger is below the required suspension height for reporting the point according to different sensing areas. sumWhen the total sensing value V is greater than the threshold value T2, the processing unit 314 determines it as a Make state and reports the touch event. sum When the touch event is less than the obtained threshold value T2, the processing unit 314 determines that the touch event is a Break state.

[0080] According to the touch detection process 40, the processing unit 314 considers the sensing area and the suspended height according to the sensing amount measured from the plurality of sensing pads 302 to determine whether to report a point. However, the touch detection process 40 ignores another important factor affecting the sensing amount, that is, the relative position of the finger and the sensing pad 302.

[0081] Please refer to Figure 8 , which is a schematic diagram of the difference in sensing caused by the different relative positions of the touch point and the sensing pad 302 when a test fixture 80 (used to simulate a finger or stylus) is at the same suspended height. When a touch point TP1 is approximately in the middle of the two sensing pads SP1 and SP2, the sensing values ​​measured by the sensing pads SP1 and SP2 are quite close. In this case, the sensing peak value V sp The measured value in the sensing pad SP1 is 738. When a touch point TP2 is approximately in the middle of the four sensing pads SP3-SP6, the sensing values ​​measured by the sensing pads SP3-SP6 are also quite close. In this case, the sensing peak value V sp The measured value in the sensing pad SP6 is 625. When a touch point TP3 falls within a single sensing pad SP7, the sensing value measured by the sensing pad SP7 is significantly higher than the sensing values ​​measured by the sensing pads around the sensing pad SP7. In this case, the sensing peak value V sp It can be measured as 897 in the sensing pad SP7. It can be seen that the measured sensing peak V sp Will vary significantly depending on the horizontal position of the touch point.

[0082] When determining whether a touch event is reported according to the touch detection process 40, the sensing peak value V sp The unstable measurement results will also lead to inaccurate estimation of the reference area A1. Therefore, it is urgent to further evaluate the Figure 8 A more accurate and consistent assessment of peak V cp , thereby improving the stability of reporting points.

[0083] The peak value evaluation method for improving touch detection of the present invention can be summarized as follows: Fig. 9 The peak value evaluation process 90 shown. The peak value evaluation process 90 includes the following steps:

[0084] Step 900: Start.

[0085] Step 902: Obtain a position of a touch point.

[0086] Step 904: Determine a plurality of reference sensing pads according to the position of the touch point.

[0087] Step 906 : Determine a weight of each of the plurality of reference sensor pads according to the position of the touch point.

[0088] Step 908: Estimate an evaluation peak value according to the sensing quantities of the plurality of reference sensing pads and their corresponding weights.

[0089] Step 910: End

[0090] According to the peak value evaluation process 90, a more accurate and consistent evaluation peak value V can be evaluated for the touch event. cp The processing unit 314 can determine whether the touch control system 30 is in the Make state or the Break state, and report the point accordingly.

[0091] Specifically, in step 902, the processing unit 314 obtains the position of the touch point of the touch event. The position can be regarded as the center point of the touch pressing position and can be obtained from the sensing circuit 316 by conventional methods.

[0092] In step 904, the processing unit 314 determines a plurality of reference sensing pads according to the position of the touch point obtained in step 902. Specifically, the plurality of reference sensing pads include a first sensing pad P where the touch point is located. c and around the first sensing pad P c The processing unit 314 can use the induction measured by multiple reference induction pads to estimate the peak value V cp .

[0093] In one embodiment, the plurality of reference sensing pads are a sensing pad matrix centered on the sensing pad where the touch point is located, and the sensing pad matrix is ​​an NxN matrix. For example, the sensing pad matrix can be a 3x3 matrix or a 5x5 matrix, but is not limited thereto. Please refer to Fig.10 , which is a schematic diagram of a reference sensor pad according to an embodiment of the present invention. Fig.10 As shown, the sensing pad where a touch point TP4 is located is the first sensing pad P c , and the first sensing pad P c and the first sensing pad P c In other words, when a 3x3 sensing pad matrix is ​​used, the reference sensing pad may include the first sensing pad P c and the first sensing pad P c A sensor pad that extends a sensor pad range in all directions, such as Fig.10When a 5x5 sensing pad matrix is ​​used, the reference sensing pad may include the first sensing pad P c and the first sensing pad P c A sensor pad that extends the range of two sensor pads in all directions, such as Fig.10 The sensing pad 1002 shown in FIG.

[0094] In one embodiment, the distance between the touch point and the center of each of the plurality of reference sensing pads is less than a predetermined length. Fig.11 , which is a schematic diagram of a reference sensor pad according to another embodiment of the present invention. Fig.11 As shown in FIG. 1 , a predetermined length R is used to determine a plurality of reference sensing pads. The sensing pad whose distance between the center point of the sensing pad and a touch point TP5 is less than the predetermined length R is the reference sensing pad. Fig.11 The sensor pad 1100 is shown.

[0095] In one embodiment, Fig.10 and Fig.11 The two methods for determining the reference sensing pad shown can be used simultaneously. In this embodiment, the reference sensing pad can be the intersection of the reference sensing pads selected according to the two different methods.

[0096] In step 906, the processing unit 314 determines the corresponding weight of each of the plurality of reference sensing pads according to the position of the touch point. Specifically, the corresponding weight of each of the plurality of reference sensing pads is determined according to the distance between the touch point and the center of each sensing pad. i The distance D between the centers i It can be calculated according to the following formula:

[0097] D i =|(x TP ,y TP )-(x i ,y i )| (Formula 2)

[0098] Among them, (x TP ,y TP ) is the coordinate of a touch point TP6, (x i ,y i ) is the sensing pad P i The center coordinates of Fig.12 shown. Fig.12 Schematic diagram of the distances D1 to D9 between the touch point TP6 and the sensing pads according to an embodiment of the present invention, wherein the reference sensing pads are a 3×3 sensing pad matrix. Preferably, the weight of each sensing pad of the plurality of reference sensing pads has a negative correlation with the distance between the touch point and the center of each sensing pad. That is, the distance D iThe larger the value of i The smaller the value, the smaller the value, and vice versa. Fig.12 In the embodiment, the weight of the sensing pad P5 needs to be greater than that of the sensing pad P7 (the weight W5 needs to be greater than the weight W7), because the distance D5 between the touch point TP6 and the center of the sensing pad P5 is smaller than the distance D7 between the touch point TP6 and the center of the sensing pad P7. In this embodiment, the weight represents the sensitivity of the sensing pad measured to the peak value V cp In addition, the weight of each sensor pad near the touch point is considered separately according to its distance from the touch point. Figure 8 The problem of inaccurate peak estimation caused by the different relative positions of the finger and the sensor pad is shown.

[0099] In step 908, the processing unit 314 calculates the weights W of the plurality of reference sensing pads according to the sensing values ​​of the plurality of reference sensing pads. i To estimate the peak value V of the touch point cp . Evaluate the peak V cp It can be calculated according to the following formula:

[0100]

[0101] Where n represents the number of reference sensing pads, W i Represents the sensor pad P i The corresponding weight, V i Represented by the sensor pad P i The measured induction.

[0102] Accordingly, according to the peak value evaluation process 90, a more accurate peak value can be evaluated. Therefore, the processing unit 314 can further evaluate the peak value V cp Determines whether to report the touch point.

[0103] According to an embodiment of the present invention, the peak value V is evaluated using cp The touch detection method can be summarized as a touch detection process 130 as shown in FIG. 13. The touch detection process 130 includes the following steps:

[0104] Step 1300: Start.

[0105] Step 1302: Obtain a first sensing result and evaluate a first evaluation peak value accordingly.

[0106] Step 1304: Determine whether the first evaluation peak value is greater than a first threshold value. If yes, execute step 1306; if no, execute step 1314.

[0107] Step 1306: Determine that it is in the Make state and report the point.

[0108] Step 1308: Obtain a second sensing result and evaluate a second evaluation peak value accordingly.

[0109] Step 1310: Determine a second threshold value according to a third evaluation peak value.

[0110] Step 1312: Determine whether the second evaluation peak value is greater than the second threshold value. If yes, execute step 1306; if no, execute step 1314.

[0111] Step 1314: Determine that the state is Break.

[0112] According to the touch detection process 130, the processing unit 314 continuously determines whether to report a touch event. The processing unit 314 can continuously obtain the sensing result from the sensing circuit 316 to calculate the evaluation peak according to the peak evaluation process 90. First, the processing unit 314 determines whether the touch system 30 is in the Make state or the Break state according to the first evaluation peak and the first threshold. When the touch system 30 is in the Make state, the processing unit 314 further determines whether to switch back to the Break state according to the second evaluation peak and the second threshold.

[0113] In step 1302, the processing unit 314 obtains the first sensing result and estimates a first evaluation peak value accordingly. The processing unit 314 may obtain the first sensing result required for estimating the first evaluation peak value from the sensing circuit 316, such as the position of the touch point and the sensing amount measured by the plurality of sensing pads 302. The first evaluation peak value may be estimated according to the peak value evaluation process 90.

[0114] In step 1304, the processing unit 314 compares the first evaluation peak value with the first threshold value, and determines whether to switch from the Break state to the Make state. Since the first evaluation peak value evaluated by the peak evaluation process 90 is stable and accurate, the processing unit 314 can more accurately evaluate the suspended height of the finger through the first evaluation peak value. Therefore, the first threshold value can be set to a fixed value, thereby effectively judging whether the suspended height corresponding to the first evaluation peak value is higher or lower than the expected boundary height for starting to report the point. When the first evaluation peak value is greater than the first threshold value, it means that the suspended height of the finger is lower than the boundary height for reporting the point. In other words, the distance between the finger and the surface of the touch screen 300 is close enough to report the point. In this case, the processing unit 314 decides to switch from the Break state to the Make state in step 1306; otherwise, the processing unit 314 decides to maintain the interrupt state in step 1314.

[0115] In step 1308, the processing unit 314 obtains the second sensing result and estimates a second evaluation peak value accordingly. The processing unit 314 may obtain the second sensing result required for estimating the second evaluation peak value from the sensing circuit 316, such as the position of the touch point and the sensing amount measured by the plurality of sensing pads 302. The second evaluation peak value may be estimated according to the peak value evaluation process 90. Specifically, at this time, the touch control system 30 is in the Make state, and the processing unit 314 continuously obtains the sensing result to further determine whether it is necessary to switch from the Make state to the Break state.

[0116] In step 1310, the processing unit 314 determines a second threshold value based on a third evaluation peak value. Since the operation of the finger on the touch screen 300 is constantly changing, including the contact area, movement speed, and suspension height, the evaluation peak value may also change at any time. Therefore, the second threshold value is used to detect whether the evaluation peak value drops sharply in the Make state, so as to determine whether it is necessary to switch to the Break state. For the stability of the reporting point, the processing unit 314 will switch from the Make state to the Break state only when the second evaluation peak value changes drastically (for example, drops sharply). In this embodiment, the second threshold value can be determined based on the third evaluation peak value, and the third evaluation peak value is determined by filtering the first evaluation peak value and the second evaluation peak value using a filter. The filter can be an infinite impulse response (IIR) filter, but is not limited to this. Specifically, the processing unit 314 continuously calculates the evaluation peak value based on the sensing results obtained by the sensing circuit 316, and inputs all the evaluation peak values ​​into the IIR filter for filtering to obtain the third evaluation peak value. The third evaluation peak value can be evaluated according to the following formula:

[0117] V IIR (t) = a × V IIR (t-1)+b×V CP (t) (Equation 4) Among them, V IIR (t) represents the IIR filtering result obtained at time point t (i.e., the third evaluation peak), V IIR (t-1) represents the IIR filtering result obtained at time point t-1, V CP (t) represents the latest evaluation peak value estimated at time point t, and a and b represent the coefficients used by the IIR filter, which need to be determined according to actual needs. In short, the third evaluation peak value of this embodiment is the result of filtering all past evaluation peak values ​​using the IIR filter. In this embodiment, the second threshold value can be set as follows:

[0118] TH Break =c×V IIR(t-1), 0<c<1 (Formula 5)

[0119] Among them, TH Break Represents the second threshold value, V IIR (t-1) represents the IIR filtering result obtained at time point t-1 (i.e., the previous third evaluation peak), and c represents a constant value used to determine the degree of change required to switch from the Make state to the Break state; for example, c can be set to 0.5, but is not limited to this.

[0120] It should be noted that the first threshold value used to determine the switch from the Break state to the Make state in step 1304 is a fixed value, and the second threshold value used to determine the switch from the Make state to the Break state in step 1310 is based on a variable value of the sensing amount.

[0121] In step 1312, the processing unit 314 compares the second evaluation peak value with the second threshold value, and determines whether to switch from the Make state to the Break state. When the second evaluation peak value is less than the second threshold value, the processing unit 314 decides to switch from the Make state to the Break state in step 1314 and stops reporting. When the second evaluation peak value is greater than the second threshold value, the processing unit 314 maintains the Make state in step 1306 and continues reporting.

[0122] Accordingly, the processing unit 314 uses the evaluation peak value to determine whether to report a touch point according to the touch detection process 130. This embodiment accurately evaluates the peak value by fully considering the influence of the distance between each sensor pad on the touch point, thereby avoiding the unstable peak value measured at different horizontal touch positions due to the low resolution of the sensor pad of the panel, thereby more accurately estimating the height of the finger in the air and improving the accuracy of reporting the touch point. Figure 2 The tolerance range of inaccurate reporting is thus greatly reduced. That is, reporting is performed only when the finger is close enough to the surface of the touch screen 300.

[0123] In summary, the present invention provides a touch control circuit and a touch detection method thereof for accurately estimating the peak value of the sensing amount and determining the reporting point, thereby improving the shortcomings of the prior art.

[0124] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A touch detection method for determining whether to report a point, characterized in that: include: Get a position of a touch point; Determining a plurality of reference sensing pads according to the position of the touch point; Determining a weight of each of the plurality of reference sensing pads according to the position of the touch point; Evaluate a first evaluation peak value according to the sensing quantities of the plurality of reference sensing pads and the corresponding weights; and According to the first evaluation peak value and a first threshold value, it is determined whether the touch point is reported.

2. The touch detection method according to claim 1, wherein: The plurality of reference sensing pads include a first sensing pad where the touch point is located and sensing pads surrounding the first sensing pad.

3. The touch detection method according to claim 1, wherein: The plurality of reference sensing pads are a sensing pad matrix centered on the sensing pad where the touch point is located, and the sensing pad matrix is ​​an NxN matrix.

4. The touch detection method according to claim 3, wherein: The sensor pad matrix is ​​a 3x3 matrix or a 5x5 matrix.

5. The touch detection method according to claim 1, wherein: A distance between the touch point and the center of each of the plurality of reference sensing pads is less than a predetermined length.

6. The touch detection method according to claim 1, wherein: The step of determining the weight of each of the plurality of reference sensing pads according to the position of the touch point comprises: The weight is determined according to a distance between the touch point and a center of each of the plurality of reference sensing pads.

7. The touch detection method according to claim 6, wherein: The weight of each of the plurality of reference sensing pads has a negative correlation with respect to the distance between the touch point and the center of each of the plurality of reference sensing pads.

8. The touch detection method according to claim 1, wherein: The step of judging whether the touch point is reported according to the first evaluation peak value and the first threshold value includes: In response to the first evaluation peak being greater than the first threshold value, switching from an off state to an on state and reporting a point; and In response to the first evaluation peak value being less than the first threshold value, maintaining the disconnected state.

9. The touch detection method according to claim 8, wherein: In response to being in the on state, the method further includes: Evaluating a second evaluation peak value of a new touch point; and According to the second evaluation peak value and a second threshold value, it is determined whether it is a new touch point report.

10. The touch detection method according to claim 9, wherein: The step of determining whether the new touch point is reported according to the second evaluation peak value and the second threshold value includes: In response to the second evaluation peak being greater than the second threshold value, maintaining the on state and reporting a point; and In response to the second evaluation peak being less than the second threshold value, switching from the on state to the off state.

11. The touch detection method according to claim 10, wherein: The second threshold value is determined according to a third evaluation peak value; and the third evaluation peak value is determined by using a filter to perform a filtering operation on the first evaluation peak value and the second evaluation peak value.

12. The touch detection method according to claim 11, wherein: The filter is an infinite impulse response filter.

13. A touch control circuit, used to determine whether to report a point, characterized in that: include: A driving circuit coupled to a touch screen for providing a driving signal to the touch screen; a sensing circuit coupled to the plurality of sensing pads of the touch screen; as well as A processing unit, coupled to the driving circuit and the sensing circuit, is configured to execute the following instructions: Obtaining a position of a touch point by the sensing circuit; Determining a plurality of reference sensing pads according to the position of the touch point; Determining a weight of each of the plurality of reference sensing pads according to the position of the touch point; Evaluate a first evaluation peak value according to the sensing quantities of the plurality of reference sensing pads and the corresponding weights; and According to the first evaluation peak value and a first threshold value, it is determined whether the touch point is reported.

14. The touch control circuit according to claim 13, wherein: The plurality of reference sensing pads include a first sensing pad where the touch point is located and sensing pads surrounding the first sensing pad.

15. The touch control circuit according to claim 13, wherein: The plurality of reference sensing pads are a sensing pad matrix centered on the sensing pad where the touch point is located, and the sensing pad matrix is ​​an NxN matrix.

16. The touch control circuit according to claim 15, wherein: The sensor pad matrix is ​​a 3x3 matrix or a 5x5 matrix.

17. The touch control circuit according to claim 13, wherein: A distance between the touch point and the center of each of the plurality of reference sensing pads is less than a predetermined length.

18. The touch control circuit according to claim 13, wherein: The step of determining the weight of each of the plurality of reference sensing pads according to the position of the touch point comprises: The weight is determined according to a distance between the touch point and a center of each of the plurality of reference sensing pads.

19. The touch control circuit according to claim 18, wherein: The weight of each of the plurality of reference sensing pads has a negative correlation with respect to the distance between the touch point and the center of each of the plurality of reference sensing pads.

20. The touch control circuit according to claim 13, wherein: The step of judging whether the touch point is reported according to the first evaluation peak value and the first threshold value includes: In response to the first evaluation peak being greater than the first threshold value, switching from an off state to an on state and generating the alarm point; and In response to the first evaluation peak value being less than the first threshold value, maintaining the disconnected state.

21. The touch control circuit according to claim 20, wherein: In response to being in the on state, the method further includes: Evaluating a second evaluation peak value of a new touch point; and According to the second evaluation peak value and a second threshold value, it is determined whether it is a new touch point report.

22. The touch control circuit according to claim 21, wherein: The step of determining whether the new touch point is reported according to the second evaluation peak value and the second threshold value includes: In response to the second evaluation peak being greater than the second threshold value, maintaining the on state and reporting a point; and In response to the second evaluation peak being less than the second threshold value, switching from the on state to the off state.

23. The touch control circuit according to claim 22, wherein: The second threshold value is determined according to a third evaluation peak value; and the third evaluation peak value is determined by using a filter to perform a filtering operation on the first evaluation peak value and the second evaluation peak value.

24. The touch control circuit according to claim 23, wherein: The filter is an infinite impulse response filter.

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