TWI453650B - Method for calibrating coordinate on resistive touch panel - Google Patents

Description

Resistive touch screen coordinate correction method

The invention relates to a resistance touch screen coordinate calibration method, in particular to a good correction coordinate and scale touch screen coordinate correction method.

Generally, the touch panel is disposed on a display panel to form a touch screen, and a menu or an icon displayed on the display panel can be quickly accessed by the user by touching the touch screen. The operation is performed, so the coordinate relationship between the touch screen and the display panel affects the accuracy of the operation.

The conventional resistive touch screen coordinate correction method predefines two points on the screen, namely, the upper left point A and the lower right point B. For example, in the touch screen 100 of the first figure, the point A and the point B are selected by the software prompt. After the contact resistive touch panel corresponds to the two points A and B, the two coordinate values are obtained, and the relative coordinates corresponding to the screen are calculated by using the two coordinate values. In this method, if there is a problem in the area where the touch panel A or B is located, an incorrect coordinate value is obtained, and the relative coordinates on the screen are calculated to cause an error.

In view of the above-mentioned background of the invention, in order to meet the requirements of the industry, one of the objects of the present invention is to provide a resistive touch screen coordinate correction method, which reduces the influence of the problematic coordinate value on the correction calculation, and can be obtained in the correction calculation. The preferred ratio of the touch panel to the screen.

In order to achieve the above object, in accordance with an embodiment of the present invention, a method for correcting a resistive touch screen coordinate is provided, comprising the steps of: providing a plurality of sampling points on a touch screen to obtain coordinates of the plurality of sampling points, There are X coordinates and Y coordinates respectively; from the plurality of sampling points, the X coordinate of the ideal starting point and the X coordinate of the ideal ending point are calculated; from the plurality of sampling points, the Y coordinate and the ideal ending point of the ideal starting point are calculated. The Y coordinate; the origin offset and the X and Y coordinates of the ideal end point are used to calculate an origin offset and a ratio mapped to the touch screen.

In an embodiment, the method further includes: storing the origin offset and the ratio in a register of the touch screen.

In an embodiment, when the plurality of sampling points are 4 sampling points, the step of calculating the X coordinate of the ideal starting point and the X coordinate of the ideal ending point includes: defining two horizontal lines from the four sampling points and Two diagonal lines, calculate the difference between the two horizontal lines and the X coordinate values of the starting point and the ending point of the two diagonal lines, and compare the absolute values of the difference values, and the absolute value of the difference value is the maximum value The X coordinates of the starting point and the ending point are respectively the X coordinate of the ideal starting point and the X coordinate of the ideal ending point; the steps of calculating the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point, including: 4 sampling points , defining 2 vertical lines and 2 diagonal lines, calculating the difference between the 2 vertical lines and the Y coordinate values of the starting point and the ending point of the 2 diagonal lines, and comparing the absolute values of the difference values to the difference The Y coordinate of the starting point and the ending point of the line whose absolute value is the maximum value is the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point, respectively.

In an embodiment, when the plurality of sampling points are 9 sampling points, the step of calculating the X coordinate of the ideal starting point and the X coordinate of the ideal ending point includes: defining three horizontal lines from the nine sampling points and 2 diagonals, calculate (the X coordinate value of the starting point of each line plus one-half of the difference between the X coordinate value of the starting point and the ending point of the line) minus the absolute value of the X coordinate value of the midpoint of the line As the X comparison value, the X coordinates of the start and end points of the line corresponding to the minimum value of the X comparison values are respectively defined as The X coordinate of the starting point and the X coordinate of the ideal ending point; the steps of calculating the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point, including: defining three vertical lines and two pairs from the nine sampling points The angle, the calculation (the Y coordinate value of the starting point of each line plus one-half of the difference between the Y coordinate value of the starting point and the ending point of the line) minus the absolute value of the Y coordinate value of the midpoint of the line, as Y The comparison value is defined as the Y coordinate of the starting point and the ending point of the line corresponding to the minimum value of the Y comparison values, respectively, and the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point.

In an embodiment, when the plurality of sampling points are 25 sampling points, the step of calculating the X coordinate of the ideal starting point and the X coordinate of the ideal ending point includes: defining five horizontal lines from the 25 sampling points and 2 diagonals, calculate (the X coordinate value of the starting point of each line plus one-half of the difference between the X coordinate value of the starting point and the ending point of the line) minus the absolute value of the X coordinate value of the midpoint of the line , as the XA comparison value, recalculate (the X coordinate value of the starting point of each line plus one quarter of the difference between the X coordinate value of the starting point and the ending point of the line) minus the second point of the line (ie, the starting point) The absolute value of the X coordinate value of the point is defined as the ideal starting point as the XB comparison value, which is the X coordinate of the start and end points of the line corresponding to the minimum value of the XA comparison value of each line and the sum of the XB comparison values. The X coordinate and the X coordinate of the ideal end point; the step of calculating the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point, including: defining 5 vertical lines and 2 diagonal lines from the 25 sampling points, and calculating (The Y coordinate value of the starting point of each line plus one-half of the difference between the Y coordinate value of the starting point and the ending point of the line) The absolute value of the Y coordinate value of the midpoint of the line is calculated as the YA comparison value, and then subtracted (the Y coordinate value of the starting point of each line plus one quarter of the difference between the Y coordinate value of the starting point and the ending point of the line) The absolute value of the Y coordinate value of the second point of the line (ie, the next point of the starting point), as the YB comparison value, the starting point and the ending point of the line corresponding to the minimum value of the sum of the YA comparison value of each line and the YB comparison value The Y coordinates are defined as the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point.

In the above method, the step of calculating an origin offset and a ratio mapped to the touch screen by using the ideal starting point and the X and Y coordinates of the ideal ending point includes: providing resolution of the touch screen Degree; calculate the ratio as the absolute value of the difference between (the resolution ^* 4/5) / the coordinate value of the ideal starting point and the ideal ending point as the ratio; calculate the origin offset to the ideal starting point The coordinate value - (the absolute value of the difference between the ideal starting point and the coordinate value of the ideal ending point ^* (5/4)/10) is used as the origin offset.

In summary, according to the resistive touch screen coordinate correction method of the present invention, according to the actual correction accuracy requirement, 4, 9 or 25 sampling points are selected for correction, and the problematic coordinate value is corrected for the correction calculation. The effect can be obtained in the correction calculation to obtain a better ratio of the touch panel to the screen.

1~25‧‧‧ sampling point

H1~H5‧‧‧ horizontal line

V1~V5‧‧‧ vertical line

D1, D2‧‧‧ diagonal

100‧‧‧ touch screen

200‧‧‧ display screen

S120~S180‧‧‧Step procedure

The first figure shows a schematic representation of sampling points according to the prior art.

The second figure shows a flow chart of a touch screen coordinate correction method according to an embodiment of the invention.

The third figure shows a schematic diagram of four sampling points in accordance with an embodiment of the present invention.

The fourth figure shows a schematic diagram of nine sampling points in accordance with an embodiment of the present invention.

The fifth figure shows a schematic diagram of 25 sampling points in accordance with an embodiment of the present invention.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments. In the drawings, the same elements are denoted by the same symbols.

Referring to the second figure, a method for correcting a resistive touch screen coordinate according to an embodiment of the present invention includes the following steps: providing a plurality of sampling points on a touch screen to obtain the complex The coordinates of the plurality of sampling points respectively have an X coordinate and a Y coordinate (step S120); from the plurality of sampling points, the X coordinate of the ideal starting point and the X coordinate of the ideal ending point are calculated (step S140); Sampling point, calculating the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point (step S160); calculating an origin offset and a mapping by using the ideal starting point and the X and Y coordinates of the ideal ending point The ratio to the touch screen (step S180).

Specifically, referring to the third figure, the third figure shows a schematic diagram of a touch screen coordinate correction method for four sampling points according to an embodiment of the present invention. The touch screen coordinate correction method of the present invention can be implemented by a program, for example, on the display (touch) screen 200 (the display screen overlaps with the touch screen), prompting the user to touch the four samples in the third figure. Point, then the device or system, according to the user's touch, obtain coordinates of 4 sampling points, respectively (X ₁ , Y ₁ ), (X ₂ , Y ₂ ), (X ₃ , Y ₃ ), (X ₄ , Y ₄ ).

From the four sampling points (X ₁ , Y ₁ ) to (X ₄ , Y ₄ ), two horizontal lines H1, H2 and two diagonal lines D1 and D2 are defined, and the two horizontal lines H1, H2 and 2 are calculated. The difference between the X coordinate values of the starting point and the ending point of the diagonal lines D1 and D2, for example, the calculated difference values are (X ₁ - X ₂ ), (X ₃ - X ₄ ), (X ₁ - X ₄ ), respectively. (X ₂ -X ₃ ), comparing the absolute values of the differences (|X ₁ -X ₂ |, |X ₃ -X ₄ |, |X ₁ -X ₄ |, |X ₂ -X ₃ |) , the X coordinate of the starting point and the ending point of the line of the maximum value in |X ₁ -X ₂ |, |X ₃ -X ₄ |, |X ₁ -X ₄ |, |X ₂ -X ₃ | The X coordinate of the point and the X coordinate of the ideal end point, for example, the maximum value is |X ₃ -X ₄ |, then the line is H2, and the X coordinates of the start and end points are X ₃ and X ₄ , respectively, the ideal starting point The X coordinate is X ₃ and the X coordinate of the ideal end point is X ₄ .

Then, the step of calculating the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point includes: defining four vertical lines V1 from the four sampling points (X ₁ , Y ₁ )~(X ₄ , Y ₄ ) , V2 and two diagonal lines D1, D2, calculate the difference between the two vertical lines V1, V2 and the Y coordinate values of the start and end points of the two diagonal lines D1, D2, for example, the calculated difference values respectively For (Y ₁ -Y ₃ ), (Y ₂ -Y ₄ ), (Y ₁ -Y ₄ ), (Y ₂ -Y ₃ ), compare the absolute values of the differences (|Y ₁ -Y ₃ |, |Y ₂ -Y ₄ |, |Y ₁ -Y ₄ |, |Y ₂ -Y ₃ |), |Y ₁ -Y ₃ |, |Y ₂ -Y ₄ |, |Y ₁ -Y ₄ |, The Y coordinate of the starting point and the ending point of the line of |Y ₂ -Y ₃ | is the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point, respectively, for example, the maximum value is |Y ₁ -Y ₄ | The line is D1, and the Y coordinates of the start and end points are Y ₁ and Y ₄ , respectively, the Y coordinate of the ideal starting point is Y ₁ , and the Y coordinate of the ideal ending point is Y ₄ . Therefore, the coordinates of the ideal starting point are (X ₃ , Y ₁ ), and the coordinates of the ideal ending point are (X ₄ , Y ₄ ).

Furthermore, the step of calculating an origin offset and a ratio mapped to the touch screen by using the ideal starting point and the X and Y coordinates of the ideal ending point includes: providing resolution of the touch screen Calculate the ratio to (the resolution ^* 4/5) / the absolute value of the difference between the ideal starting point and the coordinate value of the ideal ending point as the ratio; calculate the origin offset to the ideal starting point The coordinate value - (the absolute value of the difference between the coordinate value of the ideal starting point and the ideal ending point ^* (5/4)/10) is used as the origin offset.

Taking the above four sampling points as an example, the coordinates of the ideal starting point are (Xi_start, Yi_start), for example, (X ₃ , Y ₁ ), and the coordinates of the ideal ending point are (Xi_end, Yi_end), for example, (X ₄ , Y ₄ ), the resolution of the touch screen is X_resolution and Y_resolution, assuming X_resolution=Y_resolution=4095 and the maximum width or length of the screen is 4/5 of the resolution, and the ratio RX of the X-axis can be obtained by the following formula (1) It is calculated that the ratio RY of the Y-axis can be calculated by the following formula (2). (The number between two "|" indicates the absolute value of the number, for example |AB| means the absolute value of (AB))

Then, the origin offsets Xoffset and Yoffset can be calculated by the following equations (3) and (4).

Referring to the fourth diagram, the fourth diagram shows a schematic diagram of nine sampling points in accordance with an embodiment of the present invention. Similarly, for example, on the display screen, the user is prompted to touch the nine sampling points in the fourth figure, and then the device or system obtains the coordinates of the nine sampling points according to the user's touch, respectively (X ₁ , Y ₁ )~(X ₉ , Y ₉ ).

The steps of calculating the X coordinate of the ideal starting point and the X coordinate of the ideal ending point include: defining three horizontal lines H1 to H3 from the nine sampling points (X ₁ , Y ₁ )~(X ₉ , Y ₉ ) Two diagonal lines D1 and D2 (the same as the third figure, so the figure is not shown in the fourth figure, except that the start and end points of the diagonal line D1 are (X ₁ , Y ₁ ) and (X ₉ , Y ₉ ), The start and end points of the diagonal line D2 are (X ₃ , Y ₃ ) and (X ₇ , Y ₇ ), and the X comparison value Xcomp_n of each line n is calculated by the following formula (5):

Here, Xcomp_n represents the X comparison value of the line n, Xn_start represents the X coordinate value of the starting point of the line n, Xn_end represents the X coordinate value of the end point of the line n, and Xn_mid represents the X coordinate value of the point in the sampling point of the line n. For example, X comparison values of the respective lines H1 to H3 and D1 and D2 are calculated, and Xcomp_H1, Xcomp_H2, Xcomp_H3, Xcomp_D1, and Xcomp_D2 are calculated, and the X comparison values are compared. Then, the X coordinates of the start point and the end point of the line corresponding to the minimum value among the X comparison values (3 horizontal lines H1 to H3 and 2 diagonal lines D1 and D2 Xcomp_n) are selected, respectively, which are defined as ideal starting points. The X coordinate and the X coordinate of the ideal end point. In an embodiment, for example, the Xcomp_n value of the line H3 is a minimum value, and the X coordinate X ₇ of the starting point of the line H3 and the X coordinate X _{9 of the} ending point are respectively defined as the X coordinate Xi_start of the ideal starting point and the X coordinate of the ideal ending point. Xi_end.

Furthermore, in the case of 9 sampling points, the steps of calculating the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point include: by the 9 sampling points (X ₁ , Y ₁ ) ~ (X ₉ , Y ₉ ), define three vertical lines V1 to V3 and two diagonal lines D1 and D2 (the same as the third figure, so not shown in the fourth figure), calculate the Y comparison value of each line n by the following formula (6) Xcomp_n:

Here, Ycomp_n represents the Y comparison value of the line n, Yn_start represents the Y coordinate value of the start point of the line n, Yn_end represents the Y coordinate value of the end point of the line n, and Yn_mid represents the Y coordinate value of the point among the sampling points of the line n. Then, the Y coordinates of the start and end points of the line corresponding to the minimum value among the Y comparison values (3 vertical lines V1 to V3 and 2 diagonal lines D1 and D2 Ycomp_n) are selected, respectively, as ideal starting points. The Y coordinate and the Y coordinate of the ideal end point. In an embodiment, for example, the Ycomp_n value of the line V2 is a minimum value, and the Y coordinate Y ₂ of the starting point of the line V2 and the Y coordinate Y _{8 of the} ending point are respectively defined as the Y coordinate Yi_start of the ideal starting point and the Y coordinate of the ideal ending point. Yi_end.

Referring to a fifth diagram, a fifth diagram shows a schematic diagram of 25 sampling points in accordance with an embodiment of the present invention. Similarly, for example, on the display screen, the user is prompted to touch the 25 sampling points in the fifth figure, and then the device or system obtains the coordinates of the 25 sampling points according to the user's touch, respectively (X ₁ , Y ₁ )~(X ₂₅ , Y ₂₅ ).

The step of calculating the X coordinate of the ideal starting point and the X coordinate of the ideal ending point includes: defining five horizontal lines H1 to H5 from the 25 sampling points (X ₁ , Y ₁ )~(X ₂₅ , Y ₂₅ ) Two diagonal lines D1, D2, (same as the third figure, so not shown in the fifth figure, except for the start and end points of the diagonal line D1 (X ₁ , Y ₁ ) and (X ₂₅ , Y ₂₅ ) The start and end points of the diagonal line D2 are (X ₅ , Y ₅ ) and (X ₂₁ , Y ₂₁ ), and the XA comparison value XAcomp_n of each line n is calculated by the following formula (7):

Then, the XB comparison value XBcomp_n of each line n is calculated by the following formula (8):

Where XAcomp_n represents the XA comparison value of line n, Xn_start represents the X coordinate value of the starting point of line n, Xn_end represents the X coordinate value of the end point of line n, Xn_mid represents the X coordinate value of the point in the sampling point of line n, and Xn_2 represents The X coordinate value of the second point of the line n (ie, the next point of the starting point), for example, the starting point of the horizontal line H4 is point 16, the second point of the line n (the next point of the starting point) Xn_2 is the point 17, and the X coordinate of the point Xn_2 The value is X ₁₇ .

Then, XW_n of each line n is calculated as the sum of the XA comparison value XAcomp_n and the XB comparison value XBcomp_n by the following equation (9): XW_n = XAcomp_n + XBcomp_n (9)

XW_n of each line n is compared, and the X coordinates of the start and end points of the line corresponding to the minimum value of the XW_n are respectively defined as the X coordinate of the ideal starting point and the X coordinate of the ideal ending point.

The step of calculating the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point includes: defining, by the 25 sampling points, five vertical lines V1 to V5 and two diagonal lines D1 and D2 by the following formula (10) ) Calculate the YA comparison value YAcomp_n for each line n:

Then, the YB comparison value YBcomp_n of each line n is calculated by the following formula (11):

Where YAcomp_n represents the YA comparison value of line n, Yn_start represents the Y coordinate value of the starting point of line n, Yn_end represents the Y coordinate value of the end point of line n, Yn_mid represents the Y coordinate value of the point of the sampling point on line n, and Yn_2 represents The Y coordinate value of the second point of the line n (ie, the next point of the starting point), for example, the starting point of the vertical line V3 is point 3, the second point of the line n (the next point of the starting point) Yn_2 is the point 8, and the point Y of the point Yn_2 The coordinate value is Y ₈ .

Then, YW_n of each line n is calculated as the sum of the YA comparison value YAcomp_n and the YB comparison value XBcomp_n by the following equation (12): YW_n = YAcomp_n + YBcomp_n (12)

The YW_n of each line n is compared, and the Y coordinates of the start and end points of the line corresponding to the minimum value of the YW_n are respectively defined as the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point.

As described above, the ideal starting point defined by the above method and the X and Y coordinates of the ideal ending point (9 or 25 sampling points) can calculate an origin offset and a ratio mapped to the touch screen. . The step of calculating the origin offset and the ratio mapped to the touch screen includes: providing a resolution of the touch screen; calculating the ratio to (resolution ^* 4/5) / ideal starting point and ideal The absolute value of the difference between the coordinate values of the end point is used as the ratio; the origin offset is calculated as the coordinate value of the ideal starting point - (the absolute value of the difference between the coordinate value of the ideal starting point and the ideal ending point ^* (5/4)/10) as the origin offset.

For example, the coordinates of the ideal starting point are (Xi_start, Yi_start), and when the coordinates of the ideal ending point are (Xi_end, Yi_end), the resolution of the touch screen is X_resolution and Y_resolution, assuming X_resolution=Y_resolution=4095 and the maximum width of the screen. Or the length is 4/5 of the resolution, and the ratio RX of the X-axis can be calculated by the above formula (1), and the ratio RY of the Y-axis can be calculated by the above formula (2). Then, the origin offsets Xoffset and Yoffset can be calculated by the above equations (3) and (4).

In summary, according to the resistive touch screen coordinate correction method of the present invention, according to the actual correction accuracy requirement, 4, 9 or 25 sampling points are selected for correction, and the problematic coordinate value is corrected for the correction calculation. The effect can be obtained in the correction calculation to obtain a better ratio of the touch panel to the screen.

The present invention has been described in detail with reference to the preferred embodiments of the present invention, and the scope of the invention is not limited thereto, and it is understood that various modifications and changes can be made without departing from the spirit and scope of the invention. In addition, any of the objects or advantages or features of the present invention are not required to be achieved by any embodiment or application of the invention. In addition, the abstract sections and headings are only used to assist in the search of patent documents and are not intended to limit the scope of the invention.

S120~S180‧‧‧Step procedure

Claims (5)

A resistive touch screen coordinate correction method includes the following steps: providing a plurality of sampling points on a touch screen, obtaining coordinates of the plurality of sampling points, respectively having an X coordinate and a Y coordinate; and the plurality of sampling points Calculating the X coordinate of the ideal starting point and the X coordinate of the ideal ending point; from the plurality of sampling points, calculating the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point; ending with the ideal starting point and the ideal The X and Y coordinates of the point, calculate an origin offset and a ratio mapped to the touch screen; wherein an origin offset is calculated from the ideal starting point and the X and Y coordinates of the ideal ending point And a step of mapping the ratio to the touch screen, comprising: providing a resolution of the touch screen; calculating the ratio to (resolution * 4/5) / coordinates of the ideal starting point and the ideal ending point The absolute value of the difference is used as the ratio; the origin offset is calculated as the coordinate value of the ideal starting point - (the absolute value of the difference between the coordinate value of the ideal starting point and the ideal ending point * (5/4) / 10) as the origin offset. The method of claim 1, wherein the plurality of sampling points are four sampling points, the step of calculating the X coordinate of the ideal starting point and the X coordinate of the ideal ending point, including: by the four Sampling point, defining 2 horizontal lines and 2 diagonal lines, calculating the difference between the 2 horizontal lines and the X coordinate values of the starting point and the ending point of the 2 diagonal lines, and comparing the absolute values of the difference values to the difference The X coordinate of the start and end points of the line whose absolute value is the maximum value is the X coordinate of the ideal starting point and the X coordinate of the ideal end point; the step of calculating the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point, The method includes: defining, by the four sampling points, two vertical lines and two diagonal lines, and calculating a difference between the two vertical lines and the Y coordinate values of the starting point and the ending point of the two diagonal lines, and comparing the differences The absolute value of the value, the Y coordinate of the starting point and the ending point of the line whose absolute value is the absolute value of the difference is the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point, respectively. The method of claim 1, wherein the plurality of sampling points are 9 sampling points, the step of calculating the X coordinate of the ideal starting point and the X coordinate of the ideal ending point, including: 9 Sampling point, define 3 horizontal lines and 2 diagonal lines, calculate (the X coordinate value of the starting point of each line plus one-half of the difference between the X coordinate value of the starting point and the ending point of the line) minus the middle of the line The absolute value of the X coordinate value of the point, as the X comparison value, the X coordinate of the start and end points of the line corresponding to the minimum value among the X comparison values, respectively defined as the X coordinate and the ideal end point of the ideal starting point. The X coordinate; the step of calculating the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point, including: defining three vertical lines and two diagonal lines from the nine sampling points, and calculating (the Y coordinate of the starting point of each line) The value plus one-half of the difference between the Y coordinate value of the start and end points of the line) minus the absolute value of the Y coordinate value of the midpoint of the line, as the Y comparison value, the smallest of the Y comparison values The Y coordinate of the start and end points of the line corresponding to the value is defined as the Y coordinate and the ideal end of the ideal starting point. The Y coordinate of the point. The method of claim 1, wherein the plurality of sampling points are 25 sampling points, the step of calculating the X coordinate of the ideal starting point and the X coordinate of the ideal ending point, including: by the 25 Sampling point, define 5 horizontal lines and 2 diagonal lines, calculate (the X coordinate value of the starting point of each line plus one-half of the difference between the X coordinate value of the starting point and the ending point of the line) minus the middle of the line The absolute value of the X coordinate value of the point, as the XA comparison value, is calculated (the X coordinate value of the starting point of each line plus one quarter of the difference between the X coordinate value of the starting point and the ending point of the line) minus the line The absolute value of the X coordinate value of the second point (ie, the next point of the starting point) is used as the XB comparison value, and the X coordinate of the start point and the end point of the line corresponding to the minimum value of the sum of the XA comparison value of each line and the XB comparison value, The X coordinates defined as the ideal starting point and the X coordinates of the ideal ending point; the steps of calculating the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point, including: 25 sampling points, define 5 vertical lines and 2 diagonal lines, calculate (the Y coordinate value of the starting point of each line plus one-half of the difference between the starting point and the ending point Y value of the line) minus this The absolute value of the Y coordinate value of the midpoint of the line is calculated as the YA comparison value, and is subtracted (the Y coordinate value of the starting point of each line plus one quarter of the difference between the Y coordinate value of the starting point and the ending point of the line) minus The absolute value of the Y coordinate value of the second point of the line (ie, the next point of the starting point), as the YB comparison value, the starting point and the ending point of the line corresponding to the minimum value of the sum of the YA comparison value of each line and the YB comparison value The Y coordinate is defined as the Y coordinate of the ideal starting point and the Y coordinate of the ideal ending point. The method of any one of claims 1 to 4, further comprising: storing the origin offset and the ratio in a register of the touch screen.