Physical paper fast calibration device for paper screen synchronization and calibration method thereof

Abstract

The present application relates to teaching aid technical field, disclose a kind of for paper screen synchronization physical paper quick calibration device, including sheet, sheet is transparent material, sheet and the writing area size of electromagnetic handwriting board is identical, the front of sheet is engraved with the reference line identical with the reference line on physical paper, several reference points are equipped on reference line, sheet back is arranged with the sensing point of the position information of being able to be perceived by the touch input device of electromagnetic handwriting board in reference point corresponding position, fixed device is equipped on sheet, when sheet is placed on electromagnetic handwriting board, fixed device keeps all sensing point and touch input device sufficient contact.The present application further discloses a kind of calibration method for paper screen synchronization physical paper quick calibration device.The present application is used for paper screen synchronization physical paper quick calibration device and its calibration method, quick automatic calibration paper, greatly improve the use convenience under the condition of paper screen synchronization consistent display, improve the efficiency of practicing calligraphy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of teaching aids, in particular to a physical paper rapid calibration device for paper-screen synchronization and a calibration method thereof. BACKGROUND

[0002] With the rapid development of electronic information technology, paper-screen synchronization becomes possible. Paper-screen synchronization refers to that a user writes on ordinary paper with an ordinary pen, and an electronic handwriting device simultaneously senses the handwriting process of the user and displays the handwriting on the electronic device. Compared with traditional handwriting devices, paper-screen synchronization has the advantage of completely conforming to the writing habit of hand-eye coordination, that is, in the whole writing process, the visual feedback of the user is caused by the trace left on the paper by the pen in the hand, rather than by the screen as in traditional handwriting devices.

[0003] However, the handwriting is deformed, the pen tip tracking fails, and the size of the handwriting cannot be adjusted according to the size of the display area, and the like. To solve these problems, the reference point of the physical paper and the reference point of the handwriting device need to be aligned, and the alignment operation is very time-consuming under the requirement of an error of less than 0.1 mm precision. In particular, the alignment is not a one-time operation, and needs to be repeated every time the paper is changed. SUMMARY

[0004] The present application aims to solve the above technical problems, and provides a physical paper rapid calibration device for paper-screen synchronization and a calibration method thereof. The device can rapidly and automatically calibrate the paper, greatly improve the convenience of use under the condition of consistent display of paper-screen synchronization, and improve the efficiency of practicing writing. The consistent display refers to that the display device tracks the position of the pen tip on the physical paper in real time during the writing process, and places a region where the pen tip is currently located on the physical paper in the center region of the display window. The size of the displayed handwriting can be adjusted arbitrarily, and the position and the length-width ratio of the handwriting drawn on the virtual paper are consistent with those of the handwriting on the physical paper.

[0005] In order to achieve the above-mentioned purpose, the physical paper fast calibration device for paper screen synchronization designed by the application comprises a thin plate, the thin plate is made of transparent material, the surface of the thin plate is flat, the size of the thin plate is the same as that of the writing area on the electromagnetic handwriting board, the front surface of the thin plate is engraved with reference lines which are the same as those on the physical paper, a plurality of reference points are arranged on the reference lines, the reference points are points capable of reflecting the contour, shape, position, length and width information of the reference lines on the physical paper, for example, the start and end points, the midpoint of the reference lines, the four corner points of the checkboard, the intersection points of the two reference lines, the reference lines are defined as line segments or frames in order to facilitate the writer to arrange or standardize the handwriting, for example, the checkboard and the horizontal reference lines, the back surface of the thin plate is arranged with sensing points capable of sensing the position information of the sensing points by the touch input device of the electromagnetic handwriting board at the positions corresponding to the reference points, the thin plate is provided with a fixing device, when the thin plate is placed on the electromagnetic handwriting board, the fixing device keeps all the sensing points in sufficient contact with the touch input device, when the reference lines on the physical paper are completely overlapped with the reference lines on the thin plate, the fixing device keeps the physical paper from being deformed or twisted and keeps the physical paper from being moved during the whole handwriting process.

[0006] Preferably, the thickness of the thin plate is 0.5-2.5 mm, and the Z-direction bending deformation of the thin plate is less than 0.1 mm.

[0007] Preferably, the contact surface of the sensing points and the touch input device is circular, and the diameter is 0.1-0.3 mm.

[0008] Preferably, the reference lines comprise the checkboard, the rice-shaped grid, the horizontal reference lines or the vertical reference lines, and the line width and the line spacing are consistent with those on the common paper printed products on the market.

[0009] Preferably, the reference lines are the checkboard, and the reference points comprise the center point and the four corner points of the checkboard.

[0010] A use method of the physical paper fast calibration device for paper screen synchronization, comprising the following steps:

[0011] A) initializing the electromagnetic handwriting board: obtaining the maximum value (AX Max , AY Max ) and the minimum value (AX min , AY min ) of the electromagnetic handwriting board in the X and Y directions, and obtaining the maximum value (BX Max , BY Max ) and the minimum value (BX min , BY min), to obtain the type, number, and geometric positional relationship of the reference lines printed on the physical paper rapid calibration device;

[0012] B) Place the physical paper rapid calibration device on the electromagnetic handwriting board: the angle between the bottom edge of the physical paper rapid calibration device and the bottom edge of the writing area of ​​the electromagnetic handwriting board is less than 30 degrees, and keep the physical paper rapid calibration device fixed during the handwriting process.

[0013] C) Obtaining the position information of all sensing points on the physical paper rapid calibration device: Using the touch input device on the electromagnetic handwriting tablet, obtain the position information of all sensing points on the physical paper rapid calibration device. Then, convert the position coordinates of the sensing points in the touch input device coordinate system to the position coordinates in the electromagnetic handwriting tablet coordinate system. Let (u,v) represent the position coordinates obtained by the touch input device, and (s,t) represent the transformed position coordinates in the electromagnetic handwriting tablet coordinate system, where...

[0014]

[0015]

[0016] D) Calculate the positions of all reference points on the reference lines of the physical paper: Based on the positions of the sensing points obtained in step C) and the type, number, and geometric positional relationship of the reference lines on the physical paper rapid calibration device obtained in step A), calculate the positions of all reference points on the reference lines of the physical paper. Due to cost and technical limitations, the number of points that a touch input device can sense simultaneously is very limited relative to the number of reference points that need to be calibrated. Taking the electromagnetic handwriting tablet commonly found on the market as an example, the touch device can sense a maximum of 10 points simultaneously. Therefore, it is necessary to calculate the positions of all reference points on the reference lines that are not equipped with sensing points based on the known information such as the type, number, and geometric positional relationship of the reference lines, as well as the positions of a small number of sensing points pre-arranged on the reference lines.

[0017] E) Return the positions of the reference points to the application of the electromagnetic handwriting tablet: Return all the reference point positions calculated in step D) to the application to prepare for the next step of achieving consistent handwriting display on physical paper and display devices.

[0018] Preferably, when the reference line (2) is a grid and the number of sensing points (3) is 10, step D) calculating the positions of all reference points on the reference line (2) on the physical paper includes the following steps:

[0019] D1) Start: The positions of 10 sensing points acquired by the touch input device P = (p1, p2, ..., p...) 10), p i = (x i ,y i ), 1≤i≤10 as input parameters;

[0020] D2) Calculate the angle between the physical paper fast calibration device and the X axis of the writing plane, and set it as Angle;

[0021] D3) Rotate all points in set P with point p c as the center point and the rotation angle as Angle, where p c is the center point of set P;

[0022] D4) Sort all points in set P in ascending order of X and Y components, and set Q = (q1, q2,..., q 10 ) as the sorted result, where q1 is the center point of the first column of the first row of the checkboard, q2 is the center point of the fifth column of the first row of the checkboard, and so on, and q 10 is the center point of the seventh column of the seventh row of the checkboard;

[0023] D5) Calculate the center points of all checkboards in a 3x3 checkboard matrix according to the center points of two checkboards on the diagonal;

[0024] D6) Repeat step D5) until all center points of checkboards in a 7x9 checkboard matrix are calculated;

[0025] D7) Calculate the four corner points of all checkboards in a 7x9 checkboard matrix: take the center point C ij = (Px ij ,Py ij ) ∈ O c ,1≤i≤7,1≤j≤9, and the width K as the basis, calculate the four corner points CP1 ij ,CP2 ij ,CP3 ij ,CP4 ij of the i-th row and j-th column checkboard, where CP1 ij = (Px ij -K / 2,Py ij +K / 2), CP2 ij = (Px ij +K / 2,Py ij +K / 2), CP3 ij = (Px ij +K / 2,Py ij -K / 2), CP4 ij = (Px ij -K / 2,Py ij -K / 2), K is the width of the checkboard in the horizontal or vertical directionij the distance between two adjacent center points of the checkers;

[0026] D8) Rotate all the center points of the checkers and the four corner points by a rotation transformation with the center point p c , and the rotation angle -Angle, p c is the center point of all the center points of the checkers;

[0027] D9) End, return all the center points of the checkers and the four corner points to the application program of the electromagnetic handwriting board, and prepare for the next step of displaying consistent handwriting on the physical paper and the display device.

[0028] Preferably, in the step D2), the calculation of the angle Angle between the physical paper fast calibration device and the X axis of the writing plane includes the following steps:

[0029] D21) Start, take the 10 perceived point positions P = (p1, p2,..., pi,..., p10) obtained by the touch input device as the input parameters, pi = (xi, yi), 1≤i≤10; 10 i i i

[0030] D22) Calculate the distance between the two closest points: take one point from P, set it as p a , calculate the distance between p a and the other points, set p b to represent the point in the set P-p a closest to the point p a ;

[0031] D23) Calculate the angle b of the vector with the X axis of the writing plane, -π≤b≤π;

[0032] D24) Calculate the limit of the vector , use the following formula

[0033]

[0034] Determine the limit of the vector , where the symbol |·| represents taking the absolute value, set d to represent the vector angle corresponding to the minimum value, d∈{45°, 135°, -45°, -135°} ;

[0035] D25) Calculate the angle Angle = b-d, -π / 2≤Angle≤π / 2;

[0036] D26) End; return Angle to the calling program.

[0037] ​​​​Preferably, in the step D5), the center points of all the three-by-three squares in the square matrix are calculated according to the center points of two squares on the diagonal line, including the following steps:

[0038] D51) Start, input parameters are the center points of two squares on the diagonal line in the first row and the first column and the third row and the third column of the three-by-three square matrix, and are set as p 11 and p 33 ;

[0039] D52) Calculate the midpoint of p 11 and p 33 , and obtain the center point p 22 of the second row and the second column of the square;

[0040] D53) Take p 22 as the center point, rotate p 11 and p 33 by 90 degrees clockwise, and obtain the center point p 13 of the first row and the third column of the square, and the center point p 31 of the third row and the first column of the square;

[0041] D54) Calculate the midpoint of p 11 and p 13 , and obtain the center point p 12 of the first row and the second column of the square;

[0042] D55) Calculate the midpoint of p 11 and p 31 , and obtain the center point p 21 of the second row and the first column of the square;

[0043] D56) Calculate the midpoint of p 13 and p 33 , and obtain the center point p 23 of the second row and the third column of the square;

[0044] D57) Calculate the midpoint of p 31 and p 33 , and obtain the center point p 32 of the third row and the second column of the square;

[0045] D58) End; return the center points of all the three-by-three squares in the square matrix to the calling program.

[0046] Compared with the prior art, the present application has the following advantages:

[0047] 1. The electromagnetic handwriting device has a touch input function, which separates the alignment and writing steps, and the alignment operation is performed by a professional on a professional device, and the writer only needs to place the aligned physical paper on the writing area of the electromagnetic handwriting board, and the electromagnetic handwriting board actively senses the reference point of the paper, so as to quickly calibrate the paper.

[0048] 2. Compared with the current technology, the use burden of the writer, especially the children in the early stage of learning Chinese characters, can be reduced, the use convenience under the condition of synchronous and consistent display of paper screen can be greatly improved, and the efficiency of practicing Chinese characters can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 The structure diagram of the physical paper quick calibration device for paper screen synchronization of the present application;

[0050] Figure 2 The reference line engraved on the front of the physical paper quick calibration device for paper screen synchronization of the present application;

[0051] Figure 3 The arrangement diagram of the sensing point engraved on the back of the physical paper quick calibration device for paper screen synchronization of the present application;

[0052] Figure 4 The flow chart of the calibration method of the physical paper quick calibration device for paper screen synchronization of the present application;

[0053] Figure 5 The detailed flow chart of step D) in the method; Figure 4 The detailed flow chart of step D2) in the method;

[0054] The detailed flow chart of step D5) in the method; Figure 6 The detailed flow chart of step D2) in the method; Figure 5 The detailed flow chart of step D5) in the method.

[0055] The detailed flow chart of step D5) in the method. Figure 7 Figure 5 The detailed flow chart of step D5) in the method.

[0056] The component labels in the figure are as follows:

[0057] Sheet 1, reference line 2, sensing point 3. DETAILED DESCRIPTION

[0058] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0059] As Figure 1As shown in the figure, a physical paper fast calibration device for paper screen synchronization includes a thin plate 1, the thin plate 1 is transparent, the surface of the thin plate 1 is flat, and the size of the thin plate 1 is the same as the writing area on the electromagnetic handwriting board, the front of the thin plate 1 is engraved with the same reference line 2 as the reference line 2 on the physical paper, the reference line 2 is provided with a plurality of reference points, the reference points are points capable of reflecting the contour, shape, position, length and width information of the reference line 2 on the physical paper, the reference line 2 is a line segment or a frame defined for the convenience of the writer to arrange or standardize the handwriting, the back of the thin plate 1 is provided with sensing points 3 capable of sensing the position information of the sensing points 3 at the positions corresponding to the reference points, and the thin plate 1 is provided with a fixing device, when the thin plate 1 is placed on the electromagnetic handwriting board, the fixing device keeps all the sensing points 3 in full contact with the touch input device, and when the reference line 2 on the physical paper is completely overlapped with the reference line 2 on the thin plate, the fixing device keeps the physical paper from being deformed or twisted and keeps the physical paper from moving during the whole handwriting process.

[0060] In the embodiment, the thickness of the thin plate 1 is 0.5-2.5 mm, the Z-direction bending deformation of the thin plate 1 is less than 0.1 mm, the contact surface between the sensing point 3 and the touch input device is circular, and the diameter is 0.1-0.3 mm, as shown in the figure. Figure 3 As shown in the figure, the sensing points 3 are arranged at the center points of the cross-shaped grids.

[0061] In addition, the reference line 2 includes cross-shaped grids, rice-shaped grids, horizontal reference lines or vertical reference lines, as shown in the figure, which is a common cross-shaped grid example, if the reference line 2 is a cross-shaped grid, the reference points include the center points and four corner points of the cross-shaped grid. Figure 2

[0062] As shown in the figure, the use method of the physical paper fast calibration device for paper screen synchronization in the embodiment includes the following steps: Figure 4

[0063] A) Initialize the electromagnetic handwriting board: obtain the maximum value (AX Max , AY Max ) and the minimum value (AX min , AY min ) of the electromagnetic handwriting board in the X and Y directions, obtain the maximum value (BX Max , BY Max ) and the minimum value (BX min , BY min ) of the touch input device in the X and Y directions, and obtain the type, number and geometric position relationship of the reference line 2 printed on the physical paper fast calibration device;

[0064] ​​B) Place the physical paper rapid calibration device on the electromagnetic handwriting tablet: the angle between the bottom edge of the physical paper rapid calibration device and the bottom edge of the writing area of ​​the electromagnetic handwriting tablet is less than 30 degrees, and keep the physical paper rapid calibration device fixed during the handwriting process.

[0065] C) Obtaining the position information of all sensing points 3 on the physical paper rapid calibration device: Using the touch input device on the electromagnetic handwriting tablet, obtain the position information of all sensing points 3 on the physical paper rapid calibration device. Then, convert the position coordinates of the sensing points 3 in the touch input device coordinate system to the position coordinates in the electromagnetic handwriting tablet coordinate system. Let (u,v) represent the position coordinates obtained by the touch input device, and (s,t) represent the transformed position coordinates in the electromagnetic handwriting tablet coordinate system.

[0066]

[0067]

[0068] D) Calculate the positions of all reference points on reference line 2 on the physical paper: Based on the position of sensing point 3 obtained in step C) and the type, number and geometric position relationship of reference line 2 on the physical paper rapid calibration device obtained in step A), calculate the positions of all reference points on reference line 2 on the physical paper.

[0069] E) Return the positions of the reference points to the application of the electromagnetic handwriting tablet: Return all the reference point positions calculated in step D) to the application to prepare for the next step of achieving consistent handwriting display on physical paper and display devices.

[0070] Due to the wide variety of common reference lines, such as grid lines, cross lines, horizontal reference lines, and vertical reference lines, it is impossible to list them all due to space limitations. However, the basic idea is to use preset reference line information, the positions of perceived reference points, and the fixed positional relationship between the reference line and the perceived point 3 to calculate the positional information of all other reference points on the reference line.

[0071] The following explanation uses the grid as an example, such as the grid reference lines. Figure 2 As shown, the arrangement of sensing point 3 is as follows: Figure 3 As shown, Figure 3 The dots in the diagram indicate the locations of the sensor points 3. In this embodiment, there are 10 sensor points 3.

[0072] like Figure 5 As shown, step D) involves calculating the positions of all reference points on the reference line, including the following steps:

[0073] D1) Start: The positions of 10 sensing points acquired by the touch input device P = (p1, p2, ..., p...) 10 ), p i =(x i ,y i ), 1≤i≤10 are used as input parameters;

[0074] D2) Calculate the angle between the physical paper rapid calibration device and the X-axis of the writing plane, and denote it as Angle;

[0075] D3) For all points in set P, let point p c Perform a rotation transformation on the center point, with a rotation angle of Angle, where p c Let P be the center point of set P;

[0076] D4) Sort all points in set P in ascending order of their X and Y components. Let Q = (q1, q2, ..., q...). 10 If q1 is the sorted result, then q1 is... Figure 3 The center point of the first row and first column of the grid, q2 is Figure 3 The center point of the fifth column of the first row of the grid, and so on, q 10 for Figure 3 The center point of the seventh row and seventh column of the grid;

[0077] D5) Calculate based on the center points of the two diagonal grids. Figure 3 The center point of all grid cells in a three-row, three-column grid;

[0078] D6) Repeat step D5) until... Figure 3 The center point of all grid cells in the 7x9 grid matrix has been calculated.

[0079] D7) Calculation Figure 3 The four corner points of all grid cells in a 7x9 grid matrix: with the center point C of the grid cell as the reference point. ij =(Px ij ,Py ij )∈O c Based on the conditions 1≤i≤7, 1≤j≤9, and width K, calculate the four corner points CP1 of the i-th row and j-th column of the grid. ij CP2 ij CP3 ij CP4 ij CP1 ij =(Px ij -K / 2,Py ij +K / 2), CP2 ij =(Px ij +K / 2,Py ij+ K / 2), CP3 ij = (Px ij + K / 2, Py ij - K / 2), CP4 ij = (Px ij - K / 2, Py ij - K / 2), K is the distance between two centers of the two adjacent squares in the horizontal or vertical direction; ij

[0080] D8) Rotate all the centers of the squares and the four corners with p c as the center of rotation, the rotation angle is -Angle, p c is the center of all the centers of the squares;

[0081] D9) End, return all the centers of the squares and the four corners to the application program of the electromagnetic handwriting tablet, and prepare for the next step to display consistent handwriting on the physical paper and the display device.

[0082] As shown in step D2), calculate the angle Angle between the physical paper fast calibration device and the X axis of the writing plane, including the following steps: Figure 6 D21) Start, take the 10 sensing points P = (p1, p2,..., pi,..., p10) obtained by the touch input device as the input parameters, pi = (xi, yi), 1≤i≤10; 10 i i i

[0083] D22) Calculate the distance between the two closest points: take one point from P, set it as p a , calculate the distance between p a and the other points, set p b to represent the point in the set P-p a closest to the point p a ;

[0084] D23) Calculate the angle b between the vector

[0085] and the X axis of the writing plane, -π≤b≤π; D24) Calculate the direction limit to which the vector

[0086] belongs, using the following formula

[0087]

[0088] Determine the vector ​​​​​​where | · | denotes taking the absolute value, let d denote the vector angle corresponding to the minimum value, d ∈ {45°, 135°, -45°, -135°};

[0089] D25) Calculate the angle, Angle = b - d, -π / 2≤ Angle≤ π / 2;

[0090] D26) End; return Angle to the caller.

[0091] As shown in FIG. 5, for step D5), the center points of all the three-by-three square checkers in the three rows and three columns are calculated according to the center points of the two checkers on the diagonal line, including the following steps: Figure 7 Figure 3

[0092] D51) Start, input the center points of the two checkers on the diagonal line in the first row and first column and third row and third column in the three-by-three square checker matrix, let them be p 11 and p 33 ;

[0093] D52) Calculate the midpoint of p 11 and p 33 , get the center point of the second row and second column checker p 22 ;

[0094] D53) Take p 22 as the center point, rotate p 11 and p 33 by 90 degrees clockwise, get the center point of the first row and third column checker p 13 , and the center point of the third row and first column checker p 31 ;

[0095] D54) Calculate the midpoint of p 11 and p 13 , get the center point of the first row and second column checker p 12 ;

[0096] D55) Calculate the midpoint of p 11 and p 31 , get the center point of the second row and first column checker p 21 ;

[0097] D56) Calculate the midpoint of p 13 and p 33 , get the center point of the second row and third column checker p 23 ;

[0098] D57) Calculate the midpoint of p 31 and p 33 ​​The midpoint of the grid is used to obtain the center point p of the third row and second column of the grid. 32 ;

[0099] D58) End; returns the center point of all grid cells in the three-row, three-column grid to the calling program.

[0100] Similarly, if the input is two center points on another diagonal, the steps are the same, except that the third step of rotating 90 degrees clockwise is replaced with rotating 90 degrees counterclockwise, so they will not be described again.

[0101] The above embodiments only use the grid paper as an example for illustration, and Figure 3 The given arrangement of sensing point 3 is just one of many arrangements. For example, sensing point 3 can also be arranged at the four corners of the grid matrix, or the center point of all other grids can be calculated using two grids on the diagonal of the grid matrix. Considering that these schemes all use the preset reference line 2 information, the position of the sensed reference point, and the fixed positional relationship between reference line 2 and sensing point 3 to calculate the information of all other reference points on reference line 2, due to space limitations, they will not be described in detail in this patent application text, but such implementation schemes should all be within the scope of protection of this patent.

Claims

1. A physical paper rapid calibration device for paper-screen synchronization, comprising a thin plate (1), characterized in that: The thin plate (1) is made of transparent material. The surface of the thin plate (1) is flat, and the writing area of ​​the thin plate (1) is the same size as that of the electromagnetic handwriting tablet. Physical paper is placed on the thin plate (1). The front of the thin plate (1) is engraved with reference lines (2) that are the same as those on the physical paper. Several reference points are provided on the reference lines (2). The reference points are points that can reflect the outline, shape, position, length, and width information of the reference lines (2) on the physical paper. The reference lines (2) are line segments or lines defined to facilitate the writer's arrangement or standardization of handwriting. The back of the thin plate (1) is provided with sensing points (3) that can be sensed by the touch input device of the electromagnetic handwriting tablet to detect their position information at the position corresponding to the reference point. The thin plate (1) is provided with a fixing device. When the thin plate (1) is placed on the electromagnetic handwriting tablet, the fixing device keeps all the sensing points (3) in full contact with the touch input device. When the reference line (2) on the physical paper is completely aligned with the reference line (2) on the thin plate, the fixing device keeps the physical paper from deforming or twisting and remains stationary throughout the handwriting process.

2. The physical paper rapid calibration device for paper-screen synchronization as described in claim 1, characterized in that: The thickness of the thin plate (1) is 0.5~2.5 mm, and the Z-direction bending deformation of the thin plate (1) is less than 0.1 mm.

3. The physical paper rapid calibration device for paper-screen synchronization as described in claim 1, characterized in that: The contact surface between the sensing point (3) and the touch input device is circular with a diameter of 0.1~0.3 mm.

4. The physical paper rapid calibration device for paper-screen synchronization as described in claim 1, characterized in that: The reference lines (2) include grid lines, cross grid lines, horizontal reference lines, or vertical reference lines.

5. The physical paper rapid calibration device for paper-screen synchronization as described in claim 1, characterized in that: The reference line (2) is a grid, and the reference point includes the center point and four corner points of the grid.

6. A method of using the physical paper rapid calibration device for paper-screen synchronization as described in any one of claims 1 to 5, characterized in that: Includes the following steps: A) Initialize the electromagnetic handwriting tablet: Obtain the maximum values ​​of the electromagnetic handwriting tablet in the X and Y directions. and minimum value Get the maximum values ​​of the touch input device in the X and Y directions. and minimum value To obtain the type, quantity and geometric position relationship of the reference lines (2) printed on the physical paper rapid calibration device; B) Place the physical paper rapid calibration device on the electromagnetic handwriting board: the angle between the bottom edge of the physical paper rapid calibration device and the bottom edge of the writing area of ​​the electromagnetic handwriting board is less than 30 degrees, and keep the physical paper rapid calibration device fixed during the handwriting process. C) Obtain the position information of all sensing points (3) on the physical paper rapid calibration device: Obtain the position information of all sensing points (3) on the physical paper rapid calibration device through the touch input device on the electromagnetic handwriting board, and then convert the position coordinates of the sensing points (3) in the touch input device coordinate system to the position coordinates in the electromagnetic handwriting board coordinate system. This indicates the position coordinates obtained by the touch input device. This represents the position coordinates in the transformed electromagnetic handwriting tablet coordinate system, where ， ； D) Calculate the position of all reference points on the reference line (2) on the physical paper: Based on the position of the sensing point (3) obtained in step C) and the type, quantity and geometric position relationship of the reference line (2) on the physical paper rapid calibration device obtained in step A), calculate the position of all reference points on the reference line (2) on the physical paper. E) Return the positions of the reference points to the application of the electromagnetic handwriting tablet: Return all the reference point positions calculated in step D) to the application to prepare for the next step of achieving consistent handwriting display on physical paper and display devices.

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