TWI541691B - Touching trace estimating method - Google Patents

Description

Touch track estimation method

The present invention relates to a touch determination mechanism, and more particularly to a touch track estimation method.

For a touch device, it is very important to make the user's touch action accurately respond to the operating system. One of the most common ways to increase the accuracy of touch is to use weights to calculate the position of the touch. As shown in FIG. 1A, when a touch object (such as a stylus or a finger) is pressed on the screen, the pressing data D _n-1 , D are respectively generated on the scanning lines X _n-1 , X _n and X _n+1 . _{When n} and D _n+1 , the following weight calculation method is used to obtain the precise position of the touch object P ₁ :P ₁ =(D _n-1 *X _n-1 +D _n *X _n +D _{n+ 1} *X _n+1 )/(D _n-1 +D _n +D _n+1 )

With such weight calculation, the accuracy of the actual position control of the touch object can be increased. However, this method creates another problem when used on the edge of the touch area.

1B, the touch object is assumed at the edge of the touch zone, and which scan line X _n-1, X _n and X _{n + 1} relative positions unchanged. It is further assumed that since the touch object is located at the edge of the touch area, the scan line X _n-1 does not exist. In this way, the precise position P ₂ of the touch object obtained by the original weight calculation method becomes: P ₂ =(D _n *X _n +D _n+1 *X _n+1 )/(D _n +D _n+1 )

Obviously, if the precise position of the touch object is calculated in the above manner, the most extreme condition is that the precise position P ₂ falls on the scanning line X _n . When the user touches the scan line X _n to the edge of the touch area, as in the area A ₁ shown in FIG. 1C , the operating system cannot react relatively.

The invention provides a touch track estimation method to compensate for the defect that the above operating system cannot respond.

The touch track estimation method provided by one embodiment of the present invention is suitable for estimating a touch track generated by moving a touch object. The touch track estimation method obtains a plurality of original touch points continuously appearing in the first area, and then calculates the original touch points according to the position difference of the adjacent two of the original touch points and the sensing time interval. Average extension speed. Finally, it is determined whether to extend the touch track according to the average extension speed.

The invention determines whether it is necessary to actively extend the touch trajectory according to the extension speed of the touch point. Thereby, the change of the touch track can be appropriately extended to make up for the defect that the original system cannot respond to the touch event at the edge of the touch panel.

A ₁ ‧‧‧Area

D, E, X _max ‧‧‧ values

D _n , D _n+1 , D _n-1 ‧‧‧ Press data

P ₁ , P ₂ ‧‧ ‧ precise location

S ₁ ‧‧‧First area

S ₂ ‧‧‧Second area

S200~S204‧‧‧ implementation steps of an embodiment of the present invention

S702~S716‧‧‧ implementation steps of an embodiment of the present invention

S7040~S7044‧‧‧ implementation steps of an embodiment of the present invention

S7140~S7144‧‧‧ implementation steps of an embodiment of the present invention

T ₁ , T ₂ , T ₃ ‧‧‧ original touch points

T _A1 , T _A2 , T _A3 , T _A4 ‧‧‧ Touch points

T _B1 , T _B2 , T _B3 , T _B4 ‧‧‧ virtual touch points

_{V 1, V 2, V 3} , V 4, V A, V B ‧‧‧ extends touch point speed

X _n , X _n+1 , X _n-1 ‧‧‧ scan lines

30‧‧‧Touch panel

300‧‧‧ dotted line

300a‧‧‧ border

FIG. 1A is an energy-position block diagram of the prior art for calculating the position of a touch object in a weight manner in the center of the touch area.

FIG. 1B is a prior art method for calculating a touch by weight in the edge of the touch area. The energy-position block diagram of the object location.

FIG. 1C is a schematic diagram of an existing touch area and an edge area that the system cannot react.

2 is a flow chart of a method for estimating a touch trajectory according to an embodiment of the invention.

FIG. 3 is a schematic diagram showing the relationship between a touch panel and a touch point position according to an embodiment of the invention.

Fig. 4 is a partially enlarged schematic view showing the contents shown in Fig. 3.

Figure 5 is a graph showing the relationship of lateral (X) coordinate axis transitions in accordance with an embodiment of the present invention.

Fig. 6 is a partially enlarged schematic view showing the contents shown in Fig. 3.

FIG. 7A is a flow chart of an embodiment of step S204 of FIG. 2.

Figure 7B is a flow chart of an embodiment of step S704 of Figure 7A.

Figure 7C is a flow chart of an embodiment of step S714 of Figure 7A.

Please refer to FIG. 2 , which is a flowchart of a method for estimating a touch track according to an embodiment of the present invention. In this embodiment, first, a plurality of original touch points continuously appearing in a specific area are obtained in step S200, and then the original touch is calculated according to the obtained related information of the original touch points in step S202. The average extension speed of the handle. In short, the average extension speed can be calculated from the difference in time between the two consecutive original touch points (hereinafter referred to as the sensing time interval) and the difference in position. After the average extension speed is calculated according to step S202, it is determined whether to make a virtual extension of the touch track based on the average extension speed (step S204).

The above steps will be further explained with reference to the drawings. Please refer to FIG. 3 , which is a schematic diagram showing the relationship between the touch panel and the position of the touch point according to an embodiment of the invention. In the embodiment, the touch panel 30 is divided into the first area S ₁ and the second area S ₂ by the dashed line 300 , and the first area S ₁ is touched by the touch object or close to the touch panel 30 . The original touch points T ₁ , T ₂ and T ₃ generated by the touch panel periodic sensing. In the design, the area of the touch panel 300 that cannot be sensed by the touch panel 300 is divided into the foregoing second area S ₂ , and other areas of the touch panel 300 are divided into the foregoing first area S ₁ , but Not limited to this.

As shown in FIG. 3, in the first case, the original touch points generated by the movement of the touch object appear in the order of T ₁ to T ₂ and then to T ₃ . The positional difference between T ₁ and T ₂ of the original and the original touch point of the touch point T ₁ and the sensing time interval between the ₂ T, can be calculated, including the rate and direction comprising, from the original touch point T ₁ extends to the original touch point extension speed V _{1 of the} original touch point T ₂ . Similarly, according to the positional difference between _the original and the touch _{point. 3} T T T ₂ and the original touch point between the sensing time interval _{T. 3,} it can be calculated, including the rate and direction comprising, from the original touch The handle point T ₂ extends to the original touch point extension speed V _{2 of the} original touch point T ₃ .

In other words, in the first case described above, the touch track composed of the original touch points T ₁ , T ₂ and T ₃ is from the edge of the first area S ₁ (here, the boundary 300a) The center is extended. This case indicates that the touch object may enter the first area S ₁ from the second area S ₂ , but because the second area S ₂ cannot respond to the touch object, no original touch point is generated. Therefore, in this case, you should consider whether to extend the beginning of the touch track appropriately.

Please refer to FIG. 4 , which is a partial enlarged view of the content shown in FIG. 3 , wherein the original touch points T ₁ , T ₂ and T ₃ , the touch point extension speeds V ₁ and V _{2 ,} and the boundary of the first area S ₁ . The relationship between 300a is the same as that shown in FIG. 3, and therefore will not be described again. 4, in addition to _an original touch point T ₂ calculated from the touch point speed V ₁ and extending to the original touch point T ₂ calculated from the original touch point from the original touch point T _{T. 3} In addition to the touch point extension speed V ₂ , there is also a touch point extension speed V _A between the original touch point T ₁ and the original touch point T ₃ .

It must be reminded that the directional segments marked V ₁ , V ₂ and V _A here only provide the direction of the extension speed of each touch point, and the ratio of the length of the line segment does not represent the numerical ratio of the extension speed of each touch point. . In this embodiment, the touch point extension speed V _{A is} actually an average of the touch point extension speed V ₁ and the touch point extension speed V ₂ , that is, the average extension speed mentioned in FIG. 2 . In other embodiments, other parameters related to the change speed of the touch point position may be considered as the average extension speed. For example, the touch point extension speed V ₁ may be directly used as the average extension speed, thereby Reduce the number of calculations required.

Since the original touch point is determined in the embodiment shown in FIG. 4 is moved to the center from the edge of the first region S _1, it should further determines whether to begin extending the touch track. In order to determine whether to extend the beginning of the touch track, firstly, the first one of the original touch points, that is, the original touch point T ₁ , must be used as a reference, against the average extension speed direction, according to the average extension speed value. The position of the predicted touch point corresponding to the time point of one sensing time interval before the original touch point T ₁ is estimated.

If the touch point extension speed V _{A is taken} as the average extension speed, the position of the predicted touch point that meets the above conditions will be at the position of the touch point T _A1 as shown in FIG. 4 . As the average extension speed changes, the position of the touch point T _A1 has several possibilities: outside the second area S ₂ , outside the first area S ₁ and within the second area S ₂ , and the first region S _1. When the position of the touch point T _A1 appears outside the second area S2, it means that the touch object is not in the position that can make the touch panel 30 react, so there is no need to consider whether to extend the touch track. Conversely, when the position of the touch point T _A1 appears within the first area S ₁ , it indicates that the touch object does not approach the touch at the time point of a sensing time interval before the original touch point T _{1 .} Panel 30, so there is no need to extend the touch track.

In contrast, if the position of the touch point T _A1 is outside the first area S ₁ and within the second area S ₂ as shown in FIG. 4 , it means that the touch object is likely to be at the original touch point T _{1 .} At the time point of the previous sensing time interval, the touch panel 30 is already approached, but the touch panel 30 cannot be successfully sensed because of the location. For this situation, the virtual touch point T _{B1 is} added to the boundary line of the touch panel 30, and the touch panel 30 outputs the virtual touch before outputting the coordinates of the original touch point T ₁ . Point T _B1 coordinates; or, in other words, the beginning of the entire touch track is converted from where the original original touch point T ₁ is located to where the virtual touch point T _B1 is located.

The boundary line of the touch panel 30 refers to a virtual line composed of points having coordinate limits in the touch point coordinates output by the touch panel 30. More specifically, if the lateral coordinate value in the touch point coordinates output by the touch panel 30 falls between -254 and 255, all the output touch point coordinates have a lateral coordinate value of -254 or 255. Point, it will form two virtual lines; similarly, if the vertical coordinate value in the touch point coordinates output by the touch panel 30 falls between 0 and 127, all the output touch point coordinates have longitudinal coordinates. Points with a value of 0 or 127 also form two virtual lines.

Generally, if the touch panel 30 directly outputs the coordinate position of the original touch point, the boundary line of the touch panel 30 is the sensing area. The boundary of the normal sensing operation is performed, that is, the broken line 300 shown in FIG. However, if the touch panel 30 further converts the coordinate position of the original touch point into another set of coordinates and then outputs the boundary line of the touch panel 30, the boundary line of the converted coordinate axis is the boundary of the converted coordinate axis.

Please refer to FIG. 5, which is a relationship diagram of lateral (X) coordinate axis conversion according to an embodiment of the present invention. In this embodiment, the X coordinate of the original touch point is converted into the EX coordinate and then outputted according to the following manner, so that the conversion curve between the X coordinate and the EX coordinate can be obtained as shown in FIG. 5: when X E: EX=[E/(ED)]×(XD)

When E<X<(X _max -E): EX=X

When X (X _max -E): EX = [E / (ED)] × [X - (X _{max -} D)] + X _max

The position of the X coordinate indicated by the value D is equivalent to the position of the boundary 300a shown in FIG. The area where the X coordinate on the left side is less than or equal to the value D and the area where the X coordinate on the right side is greater than or equal to the value X _max -D is called the Dead Zone because the touch object cannot be detected. Through the coordinate conversion, the coordinates of the area where the touch object can actually be detected (for example, the first area S1 shown in FIG. 3) can be converted into coordinates of a larger area (for example, the second area S2 shown in FIG. 3). . The value E in Fig. 5 can be changed as needed, and the value D is determined when the touch panel 30 is manufactured. Therefore, if the value E becomes larger, the range of the area where the touch point accuracy changes will become larger; if the value E becomes smaller, the area of the touch point accuracy will become smaller, but The magnitude of the change in accuracy will be larger than the former. The specific choice can be set by the manufacturer or the user.

As is known to those skilled in the art, such coordinate conversion can also be applied to the ordinate at the same time, and the conversion manner is the same, and will not be described herein.

Looking back, please refer to Figure 4 and Figure 5 at the same time. If the touch panel 30 directly outputs the coordinates of the touch point, the position of the virtual touch point T _B1 is directly output, and the position of the horizontal coordinate at the output is equivalent to the position of the value D of the X coordinate; If the touch panel 30 outputs the converted coordinates after the coordinate conversion, the position of the lateral coordinate when the virtual touch point T _B1 is output is equivalent to the position of the value 0 of the EX coordinate.

Referring to FIG. 4 again, the situation when the touch point extension speed V _{A is used} as the average extension speed is previously described. Next, the case where the touch point extension speed V _{1 is used} as the average extension speed will be described.

As described above, in order to determine whether to extend the beginning of the touch track, it is first necessary to estimate the original touch point based on the value of the average extension speed against the direction of the average extension speed based on the original touch point T ₁ . The position of the predicted touch point corresponding to the time point of the sensing time interval before T ₁ . Therefore, when the touch point extension speed V _{1 is taken} as the average extension speed, the predicted touch point meeting the above condition appears at the position of the touch point T _A2 as shown in FIG. 4 .

Similarly, as the average extension speed changes, the position of the touch point T _A2 has several possibilities: outside the second area S ₂ , outside the first area S ₁ and within the second area S ₂ and S ₁ of the first region. When the position of the touch point T _A2 appears outside the second area S2, it means that the touch object is not in the position that can make the touch panel 30 react, so there is no need to consider whether to extend the touch track. Conversely, when the position of the touch point T _A2 appears within the first area S ₁ , it indicates that the touch object does not approach the touch at the time point of a sensing time interval before the original touch point T _{2 .} Panel 30, so there is no need to extend the touch track. If the position of the touch point T _A2 is outside the first area S ₁ and within the second area S ₂ as shown in FIG. 4 , it means that the touch object is likely to be before the original touch point T ₁ . At that point in time when the sensing time interval is approaching the touch panel 30, the touch panel 30 cannot be successfully sensed because of the location. For this situation, the virtual touch point T _{B2 is} added to the boundary line of the touch panel 30, and the touch panel 30 outputs the virtual touch before outputting the coordinates of the original touch point T ₁ . The coordinates of point T _B2 ; or, in other words, the beginning of the entire touch track is converted from where the original original touch point T ₁ is located to where the virtual touch point T _B2 is located.

Please refer to Figure 3 again. The original touch points generated by the movement of the touch object have been specifically explained in the order of T ₁ to T ₂ to T ₃ in the previous description. Next, the situation in which the original touch points generated by the movement of the touch object appear in the order of T ₃ to T ₂ to T ₁ will be described. As shown in the figure, since the original touch points appear in the order of T ₃ to T ₂ to T ₁ , the position difference between the original touch points T ₃ and T ₂ and the original touch points T ₃ and T are The sensing time interval between ₂ can calculate the original touch point extending speed V ₃ extending from the original touch point T ₃ to the original touch point T ₂ including the direction and the rate. Similarly, according to the positional difference between _the original and the touch point T _{T. 1} and ₂ with the original touch point T between the sensing time T _{interval. 1,} may calculate the direction and rate comprise including, from the original touch The handle point T ₂ extends to the original touch point extension speed V _{4 of the} original touch point T ₁ .

In other words, in the present case, the touch track composed of the original touch points T ₃ , T ₂ and T ₁ extends from the center of the first region S ₁ to the edge (here, the boundary 300 a ) . This case indicates that the touch object may enter the second area S ₂ from the first area S ₁ , but the original area is not generated because the second area S ₂ cannot respond to the touch object. Therefore, in this case, it should be considered whether to extend the end of the touch track appropriately.

Please refer to FIG. 6 , which is a partial enlarged view of the content shown in FIG. 3 , wherein the original touch points T ₁ , T ₂ and T ₃ , the touch point extension speeds V ₃ and V _{4 ,} and the boundary of the first area S ₁ . The relationship between 300a is the same as that shown in FIG. 3, and therefore will not be described again. 6, in addition to the touch point from the original to the original touch point T ₃ T ₂ calculated touch point obtained by extending velocity V ₃ and the touch point from the original to the original touch point T ₂ T ₁ calculated In addition to the touch point extension speed V ₄ , there is also a touch point extension speed V _B between the original touch point T ₃ and the original touch point T ₁ . Similarly, the directional segments labeled V ₃ , V _{4 ,} and V _B are merely directions for providing the speed at which each touch point extends. The ratio of the length of the line segments does not represent a numerical ratio of the speed at which each touch point extends. In this embodiment, the touch point extension speed V _{B is} actually an average of the touch point extension speed V ₃ and the touch point extension speed V ₄ , that is, the aforementioned average extension speed. In other embodiments, other parameters related to the change speed of the touch point position may be considered as the average extension speed. For example, the touch point extension speed V ₄ may be directly used as the average extension speed, thereby Reduce the number of calculations required.

Since the original touch point is determined in the embodiment shown in FIG. 6 is moved toward the edge from the center of the first region S _1, it should be extended further determines whether the end of the touch track. In order to determine whether to extend the end of the touch track, it is first necessary to use the last one of the original touch points, that is, the original touch point T ₁ as a reference, along the average extension speed direction, according to the average extension speed value. The position of the predicted touch point corresponding to the time point of one sensing time interval after the original touch point T ₁ is estimated.

If the touch point extension speed V _{B is taken} as the average extension speed, the position of the predicted touch point that meets the above conditions will be at the position of the touch point T _A3 as shown in FIG. 6 . As the average extension speed changes, the position of the touch point T _A3 has several possibilities: outside the second area S ₂ , outside the first area S ₁ and within the second area S ₂ , and the first region S _1. When the position of the touch point T _A3 appears outside the second area S2, it means that the touch object is not in the position that can make the touch panel 30 react, so there is no need to consider whether to extend the touch track. Conversely, when the position of the touch point T _A3 appears within the first area S ₁ , it indicates that the touch object does not approach the touch at the time point of a sensing time interval after the original touch point T _{1 .} Panel 30, so there is no need to extend the touch track. And if the position of the touch point T _A3 as shown in Figure 6 than in the first region S ₁ and S ₂ in the second region, the touch object indicates a most likely after the original touch point T ₁ At that point in time when the sensing time interval is approaching the touch panel 30, the touch panel 30 cannot be successfully sensed because of the location. For this situation, in this embodiment, a virtual touch point T _{B3 is} added on the boundary line of the touch panel 30, and the touch panel 30 increases the output virtual touch after outputting the coordinates of the original touch point T ₁ . The coordinates of the control point T _B3 ; or, in other words, the end of the entire touch track is converted from where the original original touch point T ₁ is located to where the virtual touch point T _B3 is located.

In another embodiment, if the touch point extension speed V _{4 is used} as the average extension speed, in order to determine whether to extend the end of the touch track, the original touch point T ₁ must also be used as the reference, and the average extension speed is followed. Direction, estimating the position of the predicted touch point corresponding to the time point of one sensing time interval after the original touch point T ₁ according to the value of the average extension speed. Therefore, when the touch point extension speed V _{1 is taken} as the average extension speed, the predicted touch point meeting the above conditions may appear at the position of the touch point T _A4 as shown in FIG. 6 .

Similarly, as the average extension speed changes, the position of the touch point T _A4 may also have the following possible conditions: outside the second area S ₂ , outside the first area S ₁ and in the second area Within S ₂ and within the first region S ₁ . Among them, if the first two possible conditions, then there is no need to consider whether to extend the touch track. If the position of the touch point T _A4 is outside the first area S ₁ and within the second area S ₂ as shown in FIG. 6 , the embodiment adds a virtual layer on the boundary line of the touch panel 30 . Touching the point T _B4 and causing the touch panel 30 to additionally output the coordinates of the virtual touch point T _B4 after outputting the coordinates of the original touch point T ₁ ; or, in other words, making the end of the entire touch track Where the original original touch point T ₁ is located is converted to where the virtual touch point T _B4 is located.

Similarly, the coordinate calculation of these touch points or the calculation of each extension speed can be operated on the basis of coordinate conversion.

In combination with the above embodiments, the touch track estimation method provided by the present invention can be further summarized into the steps shown in FIG. 7A, FIG. 7B and FIG. 7C. As shown in FIG. 7A, step S204 in the original FIG. 2 may further include steps S702 to S716. In step S702, it is determined whether the original touch point extends from the edge of the first area to the center of the first area. If yes, step S704 is performed to extend the beginning of the touch track; if not, step S712 is performed to further determine the original Whether the touch point extends from the center of the first area to the edge of the first area; if yes, step S714 is performed to extend the end of the touch track; if not, step S716 is performed to determine not to extend the touch track. The sequence of steps S702 and S712 can be reversed without affecting the final result.

As shown in FIG. 7B, step S704 in the original FIG. 7A may further include steps S7040 to S7044. Step S7040 is to estimate the time of a sensing time interval before the earliest occurrence of the original touch point according to the value of the average extension speed, based on the earliest occurrence of the original touch point, against the direction of the average extension speed. The position of the predicted touch point corresponding to the point is determined; step S7042 determines whether the position of the previously estimated predicted touch point is located in a specific area (for example, outside the first area and within the second area), and if so, Then, step S7044 is performed to add a corresponding virtual touch point to the output data. Previously, the beginning of the touch track is changed to where the virtual touch point is located.

As shown in FIG. 7C, step S714 in the original FIG. 7A may further include steps S7140 to S7144. Step S7140 is based on the latest occurrence of the original touch point, and along the direction of the average extension speed, estimating a sensing time interval after the latest occurrence of the original touch point according to the value of the average extension speed. The position of the predicted touch point corresponding to the time point is determined; step S7142 determines whether the position of the previously estimated predicted touch point is located in a specific area (for example, outside the first area and within the second area), If yes, step S7144 is performed to add a corresponding virtual touch point to the output data, so as to make the end of the touch track become the location of the virtual touch point.

In summary, the embodiments of the present invention determine whether an active extension touch track is required according to the extension speed of the original touch point. Thereby, the change of the touch track can be appropriately extended to make up for the defect that the original system cannot respond to the touch event at the edge of the touch panel.

S200~S204‧‧‧ implementation steps of an embodiment of the present invention

Claims (9)

A touch trajectory estimation method is suitable for estimating a touch trajectory generated by moving a touch object, the touch trajectory estimation method comprising: obtaining a plurality of original touch points continuously appearing in a first area; Calculating an average extension speed of the original touch points according to a difference in position between the two adjacent touch points and a sensing time interval; estimating a position of the predicted touch point according to the average extension speed; and if Predicting the position of the touch point outside the first area and in a second area covering the first area, adding a virtual touch point to a boundary line having an output coordinate boundary. The method for estimating a touch track according to the first aspect of the invention, wherein estimating the position of the predicted touch point according to the average extension speed comprises: determining whether the original touch points are from the edge of the first area The center of the first area extends; and if the original touch points extend from the edge of the first area to the center of the first area, the beginning of the touch track is extended. The touch track estimation method of claim 2, wherein determining whether the original touch points extend from an edge of the first area to a center of the first area comprises: when the original touch points When extending away from a specific edge of the first area, it is determined that the original touch points extend from the edge of the first area toward the center of the first area. The touch track estimation method according to claim 2, wherein if the original touch points extend from the edge of the first area to the center of the first area, extending the beginning of the touch track, The method includes: estimating, in the direction of the average extension speed, the direction of the average extension speed, and estimating the previous one of the original touch points before the first occurrence of the original touch points The position of the predicted touch point corresponding to the time point of the time interval; and the beginning of the touch track is where the virtual touch point is located. The touch track estimation method of claim 4, further comprising: converting coordinates of the original touch points in the first area to corresponding ones of the plurality of converted touch points in the second area; a coordinate; and a distance between the converted touch points in the second area as a position difference of the corresponding adjacent ones of the original touch points, and the average extension speed is calculated accordingly. The method for estimating a touch track according to the first aspect of the invention, wherein estimating the position of the predicted touch point according to the average extension speed comprises: determining whether the original touch points are from the center of the first area The edge of the first area extends; and if the original touch points extend from the center of the first area to the edge of the first area, the end of the touch track is extended. The method for estimating a touch trajectory according to claim 6, wherein determining whether the original touch points are from the center of the first area to the first area The edge extension includes: when the original touch points extend to a specific edge of the first area, determining that the original touch points extend from a center of the first area to an edge of the first area. The touch track estimation method according to claim 6, wherein if the original touch points extend from the center of the first area to the edge of the first area, extending the end of the touch track, The method includes: estimating, according to the latest occurrence of the original touch points, a time of the sensing time interval after the latest occurrence of the original touch points along the direction and the value of the average extension speed The position of the predicted touch point corresponding to the point; and the end of the touch track is where the virtual touch point is located. The method for estimating a touch track according to claim 8 , further comprising: converting coordinates of the original touch points in the first area to corresponding ones of the plurality of converted touch points in the second area; a coordinate; and a distance between the converted touch points in the second area as a position difference of the corresponding adjacent ones of the original touch points, and the average extension speed is calculated accordingly.