TWI691886B - Touch device and method for preventing inadvertent touch - Google Patents

Abstract

Provided is a touch control method for preventing inadvertent touch on a touch device. The touch device has a touch surface, and the touch surface is divided into a plurality of touch sensing areas. The method includes: acquiring touch sensing values of the touch sensing areas, and finding the touch sensing areas with touch sensing values greater than a preset area threshold by taking the touch sensing area with the largest touch sensing value as a starting point, so as to constitute a selected area range; finding the central area of the selected area range according to the edges of the selected area range; finding a selected edge of the selected area range according to the edges of the selected area range and the boundary of the touch surface; summing up the touch sensing values of the touch sensing areas in the selected edge of the selected area range as a first value, summing up the touch sensing values of the touch sensing areas in the central area of the selected area range as a second value, and calculating the ratio of the first value to the second value; and setting an inadvertent touch threshold based on the ratio for determining whether there is an inadvertent touch, wherein the closer the ratio is to 1, the smaller the inadvertent touch threshold is.

Description

Touch device and method for preventing accidental touch

The invention relates to the technical field of touch devices, in particular to a touch device and method for preventing false touch.

When using a touch device such as a touch pad, the touch pad is often prone to mis-touch due to the user's palm approaching the touch. In order to prevent unexpected mis-touch of the palm, the touch firmware needs to be used to calculate the sensing Whether the characteristic value conforms to the phenomenon of accidental touch, in order to suppress the behavior of accidental touch and avoid unexpected clicks and movements

The current method of preventing accidental touch by the touch device is mainly to determine whether it is a palm or other unintended finger accidental behavior based on the amount of induction generated by the object touch, so how to judge the touch is a palm error Touch or real touch, the algorithm and the appropriate threshold set by it become very important.

Taking the touchpad of a notebook computer as an example, as shown in FIG. 1, the touch area on the first area 11 in the center of the touchpad 10 and the second area 13 near the boundary usually show different amounts of induction , The reason is because the touch on the second area 13 usually has part of the palm touch beyond the sensing boundary and cannot be sensed by the sensing circuit of the touchpad 10, so the touch sensing information at the boundary Usually one less than the full sensor in the center Information. Accordingly, in the design of the touchpad to prevent accidental touches, the algorithmic threshold value of the palm error prevention of the first area 11 is generally relatively higher than the threshold value of the second area 13, that is, the first area 11 does not It is easy to set up false touches, and since the algorithm threshold for preventing palm false touches in the second area 13 near the border is low, less touch sensitivity can be judged as false touches, so it can meet the actual application situation.

Therefore, the conventional method for preventing false touches first needs to determine whether the touch of the palm is close to the second area 13 of the boundary by searching for whether the position of the relatively high peak (Peak) in the touch sensing area falls within the boundary range Inside, if so, the algorithm threshold value for preventing palm accidental touch is set to a lower value. However, under the condition of a large area of palm touch, the peak distribution in the touch sensing area usually exhibits a smooth top, so it is easy to cause the peak to jump and change position, so that the peak position is not fixed, or even jump out of the boundary range, and then Threshold values that lead to incorrect settings. Furthermore, because it is impossible to accurately know how far the peak position is from the boundary, and because the position determination is based on the sensor pitch of each touch sensor, the accuracy is poor and difficult to meet The actual demand, in addition, because there are only a few threshold conditions for switching between different regions, it is easy to cause the algorithm to have discontinuous problems in determining false touches, resulting in sometimes judged as false touches, and sometimes judged as The beating problem of legal touch.

Therefore, there are still many deficiencies in the design of conventional touch devices to prevent accidental touches, and there is a need to improve them.

The purpose of the present invention is mainly to provide a touch device and method for preventing accidental touches, which can accurately know the position of the palm distance boundary to set a suitable threshold value, so as to solve the aforementioned lack of conventional technology.

According to one feature of the present invention, the present invention provides a touch method for preventing accidental touch on a touch device. The touch device has a touch surface with a plurality of touch sensing units. The method includes Step: (A) Obtain the touch sensing value of the plurality of touch sensing units, and find the touch sensing with the touch sensing value greater than a preset area threshold from the touch sensing unit with the largest touch sensing value Unit to form a framed area range; (B) based on the edge of the framed area to find the central area of the framed area; (C) based on the edge of the framed area and the touch surface To find a frame selection edge of the frame selection area; (D) accumulate the touch detection value of the touch sensing unit in the frame selection edge of the frame selection area range to a first value, and accumulate the frame The touch sensing value of the touch sensing unit in the central area of the selected area range is a second value, and the ratio of the first value to the second value is calculated; and (E) based on the ratio, a false touch threshold is set Value for judging whether there is a false touch. The closer the ratio is to 1, the smaller the threshold for false touch.

According to another feature of the present invention, the present invention provides a touch device for preventing false touches, which includes: a touch surface having a plurality of touch sensing units, each touch sensing unit having a touch during a touch operation Sensing value; and a touch controller, coupled to the touch surface. The touch controller is used to: find a touch sensing unit with a touch sensing value greater than a preset area threshold from the touch sensing unit with the largest touch sensing value to form a frame selection area range; Frame the edge of the frame area to find the central area of the frame area; according to the edge of the frame area and the boundary of the touch device, find a frame edge of the frame area; accumulate The touch sensing value of the touch sensing unit in the frame selection edge of the frame selection area range is a first value, and the touch sensing value of the touch sensing unit in the central area of the frame selection area range is a second value Value, and calculate the ratio of the first value to the second value; and based on the ratio, set a false touch threshold for judging whether the false touch, where the closer the ratio is to 1, the false touch threshold The smaller. The embodiments of the present invention do not need to use more The threshold value of the touch threshold in each area is used to judge the false touch, but the real distance between the palm or finger and the touch boundary is flexibly used to determine whether the false touch is made. Therefore, the problem that the peak position of the conventional technology jumps and the peak position is not fixed can be solved.

The above summary and the following detailed description are of exemplary nature, and are intended to further illustrate the scope of patent application of the present invention, and other objects and advantages of the present invention will be explained in the subsequent description and drawings.

10: Touchpad

11: The first area

13: Second area

20: Touch device

21: Touch surface

23: Touch controller

211, 2111, 2113, 2115: touch sensing unit

51, 53, 71, 73: Central area

55, 57, 75, 77: Margin selection

A, B: area range

S401~S409: Steps

FIG. 1 schematically shows different touch areas of a touch pad of a conventional notebook computer.

FIG. 2 is a schematic diagram of an embodiment of the touch device of the present invention.

FIG. 3(A) schematically shows the distribution of touch sensing values of the touch sensing unit in the area range A of the central portion of the touch surface.

FIG. 3(B) schematically shows the distribution of touch sensing values of the touch sensing unit in the area range B of the boundary of the touch surface.

FIG. 4 shows a flowchart of a touch method for preventing accidental touch on a touch device.

FIG. 5(A) and FIG. 5(B) respectively show schematic diagrams of an object touching the center of the touch surface and an object touching the boundary of the touch surface to show an example of the present invention.

FIG. 6(A) shows that the relationship between the distance between the touch range and the boundary of the touch surface and the threshold value for false touch is a linear relationship.

FIG. 6(B) shows that the change relationship between the distance between the touch range and the boundary of the touch surface and the threshold value for false touch is a polynomial relationship.

FIG. 6(C) shows that the change relationship between the distance between the touch range and the boundary of the touch surface and the threshold value for false touch is a natural logarithmic relationship.

7(A) and 7(B) are schematic diagrams showing objects touching the upper boundary near the touch surface and objects touching the lower boundary near the touch surface, respectively, to show another example of the present invention.

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not intended to limit the present invention.

FIG. 2 is a schematic diagram of an embodiment of the touch device 20 of the present invention, wherein the touch device 20 has a touch surface 21 and a touch controller 23 coupled to the touch surface 21, the touch The control controller 23 is used to control the user's touch operation on the touch surface 21, and can perform false touch processing. The aforementioned touch surface 21 can have a plurality of touch sensing units, touch sensing units 211, each A touch sensing unit 211 has a touch sensing value during touch operation. Here, each touch sensing unit 211 corresponds to, for example, a sensing area composed of a driving line electrode and a sensing line electrode, which is familiar The person of touch technology is known, so the details will not be explained. Furthermore, when an object touches the touch surface 21, the touch sensing value of the touch sensing unit 211 in an area affected by the touch will become larger, and the touch controller 23 is read by The touch sensing value of the plurality of touch sensing units 211 can be used to know the occurrence of a touch event, that is, when the touch sensing value of the touch sensing unit 211 within an area range becomes larger, it can be determined that there is a The object touches the touch sensing unit 211 in the area range.

The touch device 20 of the present invention is read by the touch controller 23 A touch sensing value of the touch sensing unit 211 in an area range to calculate whether the touch area range is located in the center of the touch surface 21 or close to the boundary of the touch surface 21. In FIG. 2, there are shown an area range A and an area range B that are affected by the touch of an object, wherein the area range A is located at the center of the touch surface 21 and the area range B is located at the boundary of the touch surface 21, where The area affected by the touching of objects is shown in dashed lines for easy explanation.

FIG. 3(A) schematically shows the distribution of touch sensing values of the touch sensing unit 211 in the area range A of the central portion of the touch surface 21, wherein the pressure due to the object touching the area range A is The touch pressure point decreases outward, so the distribution of touch sensing values during large-area touch will decrease from the touch sensing unit 211 of the touch pressure center to the external touch sensing unit 211 in a gradient manner. 3(B) schematically shows the touch sensing value distribution of the touch sensing unit 211 in the area B of the boundary of the touch surface 21, similar to FIG. 3(A), the touch sensing value distribution is also caused by The touch sensing unit 211 at the center of pressure is gradually reduced toward the outer touch sensing unit 211. However, when approaching the boundary of the touch surface 21, since the actual area range B exceeds the touch surface 21, the touch near the boundary The touch sensing value of the control sensing unit 211 is still quite close to the touch sensing value of the touch sensing unit 211 in the pressure center. Based on the above, it can be known that the closer the touch sensing value at the edge of the area range affected by the object touch is to the touch sensing value at the center of the area range, the smaller the distance between the area range and the boundary of the touch surface 21 is, that is, The ratio of the touch sensing value at the edge of the area range to the touch sensing value at the center of the area range can be used to represent the distance between the area range and the border of the touch surface 21. When the ratio is closer to 1, the touch area range and the touch surface boundary The smaller the distance.

Based on the distribution of the touch sensing values shown in FIG. 3(A) and FIG. 3(B) above, the touch controller 23 can determine whether an area affected by the touch of the object is located on the touch surface 21 according to the aforementioned ratio The center of or close to the boundary of the touch surface 21 is used to further set a threshold value for false touch, for judging whether the touch is normal touch or false touch. Figure 4 shows a one-touch device A flow chart of a touch method for preventing accidental touch, and please refer to FIG. 5(A) and FIG. 5(B), which show that the object touches the center of the touch surface 21 and the object touches the touch surface, respectively The schematic diagram of the boundary of 21 shows an example of the present invention, wherein, as described above, the touch surface 21 of the touch device 20 has a plurality of touch sensing units, and the plurality of touch sensing units 211 follow the column (column ) Arranged in a row (row) arrangement, each touch sensing unit 211 has a touch sensing value during touch operation, 9 rows and 15 are shown in FIGS. 5(A) and 5(B) The row of touch sensing units 211, but the values in this row and column are only for illustrative purposes, and in practical applications, there are more rows and columns.

First, in step S401, the touch controller 23 obtains the touch sensing values of all the touch sensing units 211 on the touch surface 21, and finds the touch sensing unit 211 having the largest touch sensing value as a The peak touch sensing unit, as shown in FIG. 5(A), can find that the touch sensing unit 2111 has the largest touch sensing value (1869), so the touch sensing unit 2111 is the peak touch found The sensing unit, and in FIG. 5(B), it can be found that the touch sensing unit 2113 has the largest touch sensing value (1869), so the touch sensing unit 2113 is the peak touch sensing unit found.

Secondly, in step S403, the touch controller 23 uses the peak touch sensing unit as a starting point, and finds the touch sensing unit having a touch sensing value greater than a preset area threshold value around to form an object The range of the frame selection area affected by the touch is described in this embodiment by taking the preset area threshold of 400 as an example. As shown in FIG. 5(A), the touch sensing unit 2111 can find the touch area The touch sensing unit 211 with a control sensing value greater than 400 (as shown in FIG. 5(A) by the oblique line touch sensing unit 211), according to which a touch sensor with a touch sensing value greater than a preset area threshold is determined The minimum quadrilateral range of the control sensing unit 211 (that is, the quadrilateral range enclosed by the touch sensing unit 211 in the first row, the sixth row, the sixth column, and the eleventh column), thereby forming the frame selection area range . Similarly, in In FIG. 5(B), the touch sensing unit 2113 can find the touch sensing unit 211 with a touch sensing value greater than 400 (such as the touch sensing unit 211 marked with diagonal lines in FIG. 5(B)), According to this, a minimum quadrilateral range including the touch sensing unit 211 having a touch sensing value greater than a preset area threshold (that is, the touch of the first row, the fifth row, the sixth column, and the eleventh column) is determined The quadrilateral range enclosed by the control sensing unit 211), thus forming the frame selection area range. In this example, since the touch sensing units 211 are arranged in rows and columns, the frame selection area can be a quadrilateral area, but the invention is not limited to this. In other embodiments, the frame selection area can also be a circle Range, ellipse range or octagon range.

In step S405, the touch controller 23 searches for a central area of the frame selection area based on the edge of the frame selection area, where the touch controller 23 may use the frame selection based on the column The left and right edges of the area range are used to calculate the central area of the framed area, as shown in Figure 5(A), because the left and right edges of the framed area range are row 1 and row 6, respectively , According to the formula: Center=Left+((Right-Left+1)/2)=1+((6-1+1)/2)=4, where Center is the line sequence representing the central area and Right is the right side The row order of the edge and Left represent the row order of the left edge, so the central area 51 of the frame selection area range is the touch sensing unit 211 of the fourth row in the frame selection area range, similarly, as shown in FIG. 5(B) In the middle, because the left and right edges of the framed area range are row 1 and row 5, respectively, according to the formula: Center=Left+((Right-Left+1)/2)=1+((5-1+ 1)/2)=3.5, the integer is 3, so the central area 53 of the framed area range is the touch sensing unit 211 in the third row in the framed area range. In this embodiment, the touch controller 23 selects the left and right edges of the frame selection area range based on the row to find the central area of the frame selection area range, but the invention is not limited to this, as can be imagined Alternatively, the touch controller 23 may select the upper edge and the lower edge of the frame selection area range based on the columns to calculate the central area of the frame selection area range.

Furthermore, the touch controller 23 searches for a frame selection edge of the frame selection area range according to the edge of the frame selection area range and the boundary of the touch surface 21, as shown in FIG. 5(A), because The left edge of the frame selection area range is closest to the border of the touch surface 21, so the left edge of the frame selection area range is set to the frame selection edge 55. Similarly, as shown in FIG. 5(B), it is also the frame selection area range. The left edge is closest to the boundary of the touch surface 21, so the left edge of the frame selection area range is set as the frame selection edge 57.

Further, the touch controller 23 accumulates the touch sensing value of the touch sensing unit 211 in the frame selection edge 55 or 57 of the frame selection area range to a first value, and accumulates the central area 51 of the frame selection area range Or, the touch sensing value of the touch sensing unit 211 in 53 is a second value, and the ratio of the first value to the second value is calculated. As mentioned above, this ratio can represent the frame selection area range and the touch The distance of the boundary of face 21. In Figure 5(A), the first value is 26+146+550+492+126+42=1382, the second value is 1232+1812+1514+1201+1582+1665=9006, the first value is the second The ratio of the values is 1382/9006=0.153. Since this ratio is much smaller than 1, the distance between the frame selection area and the border of the touch surface 21 is large, so it can be determined that the object touches the center of the touch surface 21 instead of the border . Conversely, in Figure 5(B), the first value is 445+1533+1732+1869+1514+411=7152, the second value is 1348+1585+1610+1816+1769+1420=8923, the first value is The ratio of the second value is 7152/8923=0.801. Since this ratio is very close to 1, the distance between the frame selection area and the boundary of the touch surface 21 is extremely small, so it can be determined that the object is touching the boundary of the touch surface 21. According to this, the aforementioned ratio can be used as a judgment of the distance between the range where the object touches the touch surface 21 and the boundary of the touch surface 21, and the closer the touch range is to the boundary, the closer the ratio will be to 1, which is incorrect The contact conditions will be more relaxed.

In step S407, the touch controller 23 sets a false touch threshold according to the ratio for judging whether the false touch (that is, when the touch sensing amount is greater than the false touch threshold, It is determined to be a false touch), where the closer the ratio is to 1, the smaller the false touch threshold is, so that the conditions for establishing false touch are more relaxed. Furthermore, the relationship between the boundary distance represented by the ratio (the distance between the area affected by the touch of the object and the boundary of the touch surface 21) and the threshold value for false touch can be linear as shown in FIG. 6(A) Relationship, the polynomial relationship shown in FIG. 6(B), or the natural logarithmic relationship shown in FIG. 6(C), etc., so that it can avoid the jump caused by the discontinuity in the conventional technology in determining the wrong touch problem.

In step S409, when the touch controller 23 determines that there is a false touch, the operating system will perform a false touch processing procedure to eliminate the possible impact of the false touch.

In the foregoing step S405, it is explained that the touch controller 23 may also select the upper edge and the lower edge of the frame selection area range based on the columns to calculate the central area of the frame selection area range. For further explanation, FIG. 7(A) and FIG. 7(B) shows a schematic diagram of an object touching the upper boundary near the touch surface 21 and an object touching the lower boundary near the touch surface 21 to show another example of the present invention.

In FIG. 7(A), it can be found that the touch sensing unit 2115 has the largest touch sensing value (1611), so the touch sensing unit 2115 is used as the peak touch sensing unit, and the touch sensing value is found to be greater than The touch-sensing unit 211 with a preset area threshold (400), such as the touch-sensing unit 211 marked with diagonal lines in FIG. 7(A), accordingly constitutes a frame-selected area range affected by object touch (from the 9th) The range enclosed by the touch sensing unit 211 in the row, row 14, row 2, and row 7), and then, the touch controller 23 determines the upper edge (column 2) and the lower edge of the range of the frame selection area (Column 7), according to the formula: Center=Up+((Down-Up+1)/2)=2+((7-1+1)/2)=5.5, take the integer as 5, where Center is the representative The column order of the central area, Up is the column order of the upper edge, and Down is the column order of the lower edge. The central area 71 where the framed area range is calculated is the touch sensing unit of the fifth column in the framed area range 211. Furthermore, since the upper edge of the frame selection area is closest to the touch surface Boundary, so the upper edge of the frame selection area range is set as the frame selection edge 75. Further, the touch controller 23 accumulates the touch sensing value of the touch sensing unit 211 in the frame selection edge 75 of the frame selection area range A first value (161+840+1139+838+201+10=3189), and the touch sensing value of the touch sensing unit 211 in the central area 71 of the frame area is a second value (1611 +1401+1306+1402+1527+452=7699), and calculate the ratio of the first value to the second value as 3189/7699=0.414, because this ratio is close to the intermediate value of 0 and 1, it can be determined The object touches the center of the touch surface 21 close to the boundary.

In FIG. 7(B), it can be found that the touch sensing unit 2117 has the largest touch sensing value (1671), so the touch sensing unit 2117 is used as the peak touch sensing unit to find the touch sensing value around The touch sensing unit 211 greater than the preset area threshold (400), such as the touch sensing unit 211 marked with diagonal lines in FIG. 7(B), accordingly constitutes a framed area range affected by the object touch (from the The range enclosed by the touch sensing unit 211 in row 10, row 15, column 10, and column 15), and then, the touch controller 23 is based on the upper edge (column 10) and below of the frame selection area range Edge (column 15), according to the formula: Center=Up+((Down-Up+1)/2)=10+((15-10+1)/2)=13, calculate the central area of the framed area 73 is the touch sensing unit 211 in the 13th column in the frame selection area range. Furthermore, since the lower edge of the frame selection area range is closest to the boundary of the touch surface 21, the lower edge of the frame selection area range is set to Frame selection edge 77. Further, the touch controller 23 accumulates the touch sensing value of the touch sensing unit 211 in the frame selection edge 77 of the frame selection area range to a first value (84+894+1230+1013+ 281+1=3503), and the touch sensing value of the touch sensing unit 211 in the central area 73 of the frame area is a second value (1657+1497+1408+1480+1569+491=8102) And calculate the ratio of the first value to the second value as 3503/8102=0.432. Since this ratio is close to the intermediate value of 0 and 1, it can be determined that the object is touching the center of the touch surface 21 close to At the border.

As can be seen from the above description, the touch device and method for preventing false touches of the present invention can accurately know the position of an object, such as the palm, from the boundary of the touch surface during touch, and accordingly set a suitable threshold value for false touch, Therefore, the touch area does not need to be divided into different areas, which can improve the conventional technology and only use the peak position as the palm position to cause the inaccuracy problem caused by the peak jump, which can be applied to various touch devices, such as notebook computers The touchpad, the touchscreen of the notebook computer, the touchscreen of the mobile phone, the touchscreen of the tablet computer, etc., effectively prevent the influence caused by the accidental touch.

The above embodiments are only examples for the convenience of description, and the scope of rights claimed by the present invention should be subject to the scope of the patent application, and not limited to the above embodiments.

S401~S409: Steps

Claims (14)

A touch method for preventing accidental touch on a touch device. The touch device has a touch surface with a plurality of touch sensing units. The method includes the steps of: (A) acquiring the plurality of touches For the touch sensing value of the control sensing unit, the touch sensing unit with the largest touch sensing value finds a touch sensing unit with a touch sensing value greater than a preset area threshold around to form a frame selection area range; (B) According to the edge of the framed area to find the central area of the framed area; (C) Based on the edge of the framed area and the boundary of the touch surface to find the framed area A frame-selected edge of the range; (D) accumulate the touch-sensing value of the touch sensing unit in the frame-selected edge of the frame-selected area range, and accumulate the touch in the central area of the frame-selected area range The touch sensing value of the sensing unit is a second value, and the ratio of the first value to the second value is calculated; and (E) according to the ratio, a false touch threshold is set for judging whether the false touch is made, wherein , The closer the ratio is to 1, the smaller the threshold of false touch. The touch method as described in item 1 of the patent application scope, wherein in step (E), the ratio represents the distance between the framed area range and the boundary of the touch surface, and the distance and the threshold value for false touch The change relationship between them is a continuous change relationship. The touch method as described in item 2 of the patent application scope, wherein the continuous change relationship is a linear relationship, a polynomial relationship, or a natural logarithmic relationship. The touch method as described in item 1 of the patent application scope, wherein in step (A), a minimum quadrilateral range including touch sensing units having touch sensing values greater than a preset area threshold is used, and Constitute the framed area. The touch method as described in item 4 of the patent application scope, wherein in step (B), the central area of the framed area range is found based on the left and right edges of the framed area range. The touch method as described in item 4 of the patent application scope, wherein in step (B), the central area of the framed area range is found based on the upper and lower edges of the framed area range. The touch method as described in item 4 of the patent application scope, wherein in step (C), the edge of the frame selection area is closest to the boundary of the touch surface to find the frame selection edge. A touch device for preventing accidental touch includes: a touch surface with a plurality of touch sensing units, each touch sensing unit having a touch sensing value during touch operation; and a touch controller, coupled Connected to the touch surface, the touch controller is used to: find the touch sensing unit with the touch sensing value greater than a preset area threshold from the touch sensing unit with the largest touch sensing value to form a Framed area range; according to the edge of the framed area range, to find the central area of the framed area range; According to the edge of the framed area and the boundary of the touch surface, find a framed edge of the framed area; accumulate the touch sensing of the touch sensing unit in the framed edge of the framed area The value is a first value, the touch sensing value of the touch sensing unit in the central area of the framed area range is added to a second value, and the ratio of the first value to the second value is calculated; and according to the For the ratio, a threshold value for false touch is set for judging whether it is falsely touched. The closer the ratio is to 1, the smaller the threshold value for false touch. The touch device as described in item 8 of the patent application range, wherein the ratio represents the distance between the framed area range and the boundary of the touch surface, and the change relationship between the distance and the threshold value for false touch is Continuous change relationship. The touch device as described in item 9 of the patent application range, wherein the continuous change relationship is a linear relationship, a polynomial relationship, or a natural logarithmic relationship. The touch device as described in item 8 of the patent application range, wherein the frame selection area range is a minimum quadrilateral range including the touch sensing units having touch sensing values greater than a preset area threshold. The touch device as described in item 11 of the patent application scope, wherein the central area of the framed area range is found based on the left and right edges of the framed area range. The touch device as described in item 11 of the patent application scope, wherein the central area of the frame selection area range is found based on the upper and lower edges of the frame selection area range. The touch device as described in item 11 of the patent application range, wherein the frame selection edge is the edge closest to the boundary of the touch surface in the frame selection area range.

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