Abstract
A touchpad and its force-sensing data correction method are provided. The touchpad has a force-sensing layer and a touch-sensing layer. The force-sensing layer has multiple force-sensing points. The touch-sensing layer has multiple touch-sensing points. One force-sensing point corresponds to n touch-sensing points. The force-sensing information received by the force-sensing layer is adjusted by using the touch-sensing information received by the touch-sensing layer, so that the resolution of the adjusted force-sensing information is higher than the resolution of the original received force-sensing information. In this way, the purpose of calibrating the force-sensing information is achieved, so as to improve the accuracy of determining the force applied by the object during the operation of the touchpad.
Claims
1. A force-sensing data calibration method of a touchpad, wherein the touchpad comprises a force-sensing layer and a touch-sensing layer, the force-sensing layer includes multiple force-sensing points arranged in a matrix, the touch-sensing layer includes multiple touch-sensing points arranged in a matrix, each of the force-sensing points corresponds to n of the touch-sensing points, n is a positive integer greater than 1, and the method comprises steps of: a. receiving a first force-sensing information detected by the force-sensing layer, and receiving a touch-sensing information detected by the touch-sensing layer; and b. adjusting the first force-sensing information according to the touch-sensing information to obtain a second force-sensing information, wherein a resolution of the second force-sensing information is greater than a resolution of the first force-sensing information.
2. The method as claimed in claim 1, wherein the force-sensing points include x*z force-sensing points; the touch-sensing points include y*z touch-sensing points; y is equal to x*n; x and z are positive integers greater than or equal to 1, and y is a positive integer greater than 1; in the step a, the first force-sensing information includes x*z first force-sensing values respectively corresponding to the x*z force-sensing points; and the step b comprises steps of: b1. designating each of the first force-sensing values in the first force-sensing information to coordinates of n of the touch-sensing points as n second force-sensing values so that y*z second force-sensing values are obtained to constitute a third force-sensing information; and b2. adjusting the third force-sensing information according to the touch-sensing information to constitute the second force-sensing information.
3. The method as claimed in claim 2, wherein the step b2 comprises steps of: b21. selecting an effective touch range based on the touch-sensing information, and obtaining an effective force range by projecting orthographically the effective touch range to the third force-sensing information; and b22. retrieving the second force-sensing values of the effective force range to constitute the second force-sensing information.
4. The method as claimed in claim 2, wherein the step b2 comprises steps of: b21. selecting an effective touch range based on the touch-sensing information, and obtaining an effective force range by projecting orthographically the effective touch range to the third force-sensing information; and b22. retrieving a correction value from the touch-sensing values in the effective touch range; and b23. obtaining multiple third force-sensing values by calculating the second force-sensing values in the effective force range with the correction value, wherein the third force-sensing values constitute the second force-sensing information.
5. The method as claimed in claim 1, wherein the force-sensing points include x*z force-sensing points; the touch-sensing points include y*z touch-sensing points; y is equal to x*n; x and z are positive integers greater than or equal to 1, and y is a positive integer greater than 1; in the step a, the first force-sensing information includes x*z first force-sensing values respectively corresponding to the x*z force-sensing points; and the step b comprises steps of: b1. designating one of the touch-sensing value of n of the touch-sensing points corresponding to one of the force-sensing points as a base value; b2. obtaining y*z fourth force-sensing values by calculating the first force-sensing values respectively with the corresponding base values, wherein the y*z fourth force-sensing values constitute the second force-sensing information.
6. The method as claimed in claim 1, wherein the force-sensing points include x*z force-sensing points; the touch-sensing points include y*z touch-sensing points; y is equal to x*n; x and z are positive integers greater than or equal to 1, and y is a positive integer greater than 1; in the step a, the first force-sensing information includes x*z first force-sensing values respectively corresponding to the x*z force-sensing points; and the step b comprises steps of: b1. designating one of the touch-sensing value of n of the touch-sensing points corresponding to one of the force-sensing points as a base value; b2. obtaining y*z fourth force-sensing values by calculating the first force-sensing values respectively with the base values; b3. selecting an effective touch range based on the touch-sensing information, and obtaining an effective force range by projecting orthographically the effective touch range to the third force-sensing information; b4. retrieving the fourth force-sensing values in the effective force range to constitute the second force-sensing information.
7. The method as claimed in claim 1, wherein the force-sensing points include x*z force-sensing points; the touch-sensing points include y*z touch-sensing points; y is equal to x*n; x and z are positive integers greater than or equal to 1, and y is a positive integer greater than 1; in the step a, the first force-sensing information includes x*z first force-sensing values respectively corresponding to the x*z force-sensing points; and the step b comprises steps of: b1. designating one of the touch-sensing value of n of the touch-sensing points corresponding to one of the force-sensing points as a base value; b2. obtaining y*z fourth force-sensing values by calculating the first force-sensing values respectively with the base values; b3. selecting an effective touch range based on the touch-sensing information, and obtaining an effective force range by projecting orthographically the effective touch range to the third force-sensing information; b4. retrieving a correction value from the touch-sensing values in the effective touch range; and b5. obtaining multiple fifth force-sensing values by calculating the fourth force-sensing values in the effective force range with the correction value, wherein the fifth force-sensing values constitute the second force-sensing information.
8. The method as claimed in claim 4, wherein the correction value is a maximum value in the effective touch range.
9. The method as claimed in claim 7, wherein the correction value is a maximum value in the effective touch range.
10. The method as claimed in claim 4, wherein a calculating formula in the step b23 is that each of third force-sensing values is equal to a corresponding one of the second force-sensing values times a corresponding one of the touch-sensing values divided by the correction value.
11. The method as claimed in claim 7, wherein a calculating formula in the step b5 is that each of fifth force-sensing values is equal to a corresponding one of the fourth force-sensing values times a corresponding one of the touch-sensing values divided by the correction value.
12. The method as claimed in claim 6, wherein each of the base values is a maximum value, an average value or a sum of the touch-sensing values of the corresponding n of the touch sensing points.
13. The method as claimed in claim 7, wherein the corresponding base value for each force-sensing point is a maximum value, an average value or a sum of the touch-sensing values of the corresponding n of the touch sensing points.
14. The method as claimed in claim 6, wherein a calculating formula in the step b2 is that each of fourth force-sensing values is equal to a corresponding one of the first force-sensing values times a corresponding one of the touch-sensing values divided by the corresponding base value.
15. The method as claimed in claim 7, wherein a calculating formula in the step b2 is that each of fourth force-sensing values is equal to a corresponding one of the first force-sensing values times a corresponding one of the touch-sensing values divided by the corresponding base value.
16. The method as claimed in claim 1, wherein in the step b, determining as an invalid force-sensing point when the force-sensing point has the first force-sensing value smaller than a force-sensing threshold and excluding the force-sensing point from the second force-sensing information.
17. The method as claimed in claim 1, wherein in the step b, determining as an invalid touch-sensing point when the touch-sensing point has the touch-sensing value smaller than a touch-sensing threshold and excluding a force-sensing point from the second force-sensing information corresponding to the invalid touch-sensing point.
18. The method as claimed in claim 12, wherein in the step b, determining as an invalid touch-sensing point when the touch-sensing point has the touch-sensing value smaller than a touch-sensing threshold and excluding a force-sensing point corresponding to the invalid touch-sensing point from the second force-sensing information.
19. A touchpad comprising: a substrate having a force-sensing layer including multiple force-sensing points arranged in a matrix; a touch-sensing layer including multiple touch-sensing points arranged in a matrix, and each of the force-sensing points corresponds to n of the touch-sensing points, n is a positive integer greater than 1; a protective layer, and the touch-sensing layer disposed between the substrate and the protective layer; a deformable unit disposed between the substrate and the touch-sensing layer; and a controller electrically connected to the force-sensing layer and the touch-sensing layer, and executing following steps: a. receiving a first force-sensing information detected by the force-sensing layer, and receiving a touch-sensing information detected by the touch-sensing layer; and b. adjusting the first force-sensing information according to the touch-sensing information to obtain a second force-sensing information, wherein a resolution of the second force-sensing information is greater than a resolution of the first force-sensing information.
20. The touchpad as claimed in claim 19, wherein the touch-sensing layer comprises a driving electrode layer and a receiving electrode layer; the driving electrode layer is disposed between the receiving electrode layer and the force-sensing layer; the driving electrode layer and the receiving electrode layer generate coupling capacitance to generate the touch-sensing information; and the driving electrode layer and the force-sensing layer generate coupling capacitance to generate the first force-sensing information.
21. The touchpad as claimed in claim 19, wherein the force-sensing points include x*z force-sensing points; the touch-sensing points include y*z touch-sensing points; y is equal to x*n; x and z are positive integers greater than or equal to 1, and y is a positive integer greater than 1; in the step a, the first force-sensing information includes x*z first force-sensing values respectively corresponding to the x*z force-sensing points; and the step b comprises steps of: b1. designating each of the first force-sensing values in the first force-sensing information to coordinates of n of the touch-sensing points as n second force-sensing values so that y*z second force-sensing values are obtained to form a third force-sensing information; and b2. adjusting the third force-sensing information according to the touch-sensing information to constitute the second force-sensing information.
22. The touchpad as claimed in claim 19, wherein the force-sensing points include x*z force-sensing points; the touch-sensing points include y*z touch-sensing points; y is equal to x*n; x and z are positive integers greater than or equal to 1, and y is a positive integer greater than 1; in the step a, the first force-sensing information includes x*z first force-sensing values respectively corresponding to the x*z force-sensing points; and the step b comprises steps of: b1. designating one of the touch-sensing value of n of the touch-sensing points corresponding to one of the force-sensing points as a base value b2. obtaining y*z fourth force-sensing values by calculating the first force-sensing values respectively with the corresponding base values, wherein the y*z fourth force-sensing values constitute the second force-sensing information.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1A is a side view in partial section of a touchpad in accordance with the present invention;
[0011] FIG. 1B is a block diagram of a part of the elements of the touchpad in FIG. 1A;
[0012] FIG. 2 is an illustrative view of the sensing traces of the touch-sensing layer of the touchpad in FIG. 1;
[0013] FIG. 3 is an illustrative view of the driving traces and the force-sensing traces of the touchpad in FIG. 1;
[0014] FIGS. 4A and 4B are illustrative views of the touch-sensing information of a force-sensing data calibration method in accordance with the present invention;
[0015] FIG. 5 is an illustrative view of a first force-sensing information of a force-sensing data calibration method in accordance with the present invention;
[0016] FIGS. 6A and 6B are illustrative views of a third force-sensing information of a force-sensing data calibration method in accordance with the present invention;
[0017] FIG. 7 is an illustrative view of a first embodiment of a second force-sensing information of a force-sensing data calibration method in accordance with the present invention;
[0018] FIG. 8A is an illustrative view of a second embodiment of a second force-sensing information of a force-sensing data calibration method in accordance with the present invention;
[0019] FIG. 8B is an illustrative view of a calculation of the second force-sensing information in FIG. 8A;
[0020] FIG. 9A is an illustrative view of a third embodiment of a second force-sensing information of a force-sensing data calibration method in accordance with the present invention;
[0021] FIG. 9B is an illustrative view of a calculation of the second force-sensing information in FIG. 9A;
[0022] FIG. 10A is an illustrative view of an initial state of a fourth embodiment of a second force-sensing information of a force-sensing data calibration method in accordance with the present invention;
[0023] FIG. 10B is an illustrative view of a final state of the second force-sensing information in FIG. 10A;
[0024] FIG. 10C is an illustrative view of a calculation of the second force-sensing information in FIG. 10B.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0025] With reference to the attached drawings, the present invention is described by means of the embodiment(s) below where the attached drawings are simplified for illustration purposes only to illustrate the structures or methods of the present invention by describing the relationships between the components and assembly in the present invention. Therefore, the components shown in the figures are not expressed with the actual numbers, actual shapes, actual dimensions, or the actual ratio. Some of the dimensions or dimension ratios have been enlarged or simplified to provide a better illustration. The actual numbers, actual shapes, or actual dimension ratios can be selectively designed and disposed and the detailed component layouts may be more complicated.
[0026] With reference to FIGS. 1A and 1B, a touchpad in accordance with the present invention comprises a substrate 10, a protective layer 20, a deformable unit 30, a touch-sensing layer 40, a force-sensing layer 50 and a controller 60. The deformable unit 30 is disposed between the substrate 10 and the protective layer 20. The touch-sensing layer 40 is disposed between the protective layer 20 and the deformable unit 30. The force-sensing layer 50 is disposed between the deformable unit 30 and the substrate 10. In one embodiment, the force-sensing layer 50 is mounted on the substrate 10. The controller 60 is electrically connected to the force-sensing layer 50 and the touch-sensing layer 40 through the substrate 10.
[0027] With reference to FIGS. 1 to 3, the touch-sensing layer 40 includes multiple touch-sensing points 400 arranged in a matrix. The force-sensing layer 50 includes multiple force-sensing points 500 arranged in a matrix. A coverage of each force-sensing point 500 corresponds to a coverage of n force-sensing points 400. The “n” is a positive integer greater than 1. As the embodiment shown in FIGS. 2 and 3, one of the force-sensing points 500 corresponds to three of the touch-sensing points 400.
[0028] With reference to FIG. 1, in one embodiment, the touch-sensing layer 40 comprises a driving electrode layer 41 and a receiving electrode layer 42. The driving electrode layer 41 is disposed between the receiving electrode layer 42 and the force-sensing layer 50. The driving electrode layer 41 and the receiving electrode layer 42 generate coupling capacitance as a touch-sensing information TI. The driving electrode layer 41 and the force-sensing layer 50 generate coupling capacitance as a first force-sensing information FI.sub.1.
[0029] With reference to FIGS. 1 to 3, in one embodiment, the driving electrode layer 41 includes multiple driving traces 411. The driving traces 411 are arranged in parallel and spaced apart. The receiving electrode layer 42 includes multiple receiving traces 421. The receiving traces 421 are arranged in parallel and spaced apart. The driving traces 411 are perpendicular to the receiving traces 421. The force-sensing layer 50 includes multiple sub-force sensing traces 511. The sub force-sensing traces 511 are arranged in parallel and spaced apart. Each sub force-sensing trace 511 aligns with one of the receiving traces 421 and is perpendicular to the driving traces 411. The adjacent n sub force-sensing traces 511 are connected in parallel to form a force-sensing trace 51 so that each of the force-sensing traces 51 corresponds ton of the receiving traces 421. An intersection point of one of the driving traces 411 and one of the receiving races 421 is one of the touch-sensing points 400. An intersection point of one of the driving traces 411 and one of the force-sensing traces 51 is one of the force-sensing points 400. Taking z driving traces 411, x force-sensing traces 51, and y receiving traces 421 as an example, x*z force-sensing points 500 and y*z touch-sensing points 400 are formed, where x*n=y. The “x” and “z” are positive integers greater than or equal to 1, and the “y” is a positive integer greater than 1.
[0030] When a plurality of objects contact the protective layer 20, each of the touch-sensing points 400 generates different coupling capacitances corresponding to the distance between the touch points of the touch objects. Each of the force-sensing points 500 also generates different coupling capacitances corresponding to the downward pressure of the touch object. For example, as shown in FIG. 4A, the sensing value matrix drawn by the coupling capacitances generated by each touch-sensing point 400 constitutes a touch-sensing information TI. As shown in FIG. 5, the sensing value matrix drawn by the coupling capacitances generated by each force-sensing point 500 constitutes a first force-sensing information FI.sub.1. Since the number of the force-sensing points 500 is 1/n of the number of the touch-sensing points 400, the resolution of the first force-sensing information FI.sub.1 is lower than that of the touch-sensing information TI. The controller 60 adjusts the first force-sensing information FI.sub.1 according to the touch-sensing information TI to obtain a second force-sensing information with a higher resolution so as to improve the accuracy of judging the force and coordinate of the touch object. The following describes different embodiments of a calibration method in accordance with the present invention for adjusting the first force-sensing information FI.sub.1 according to the touch-sensing information TI, and takes the touch-sensing information TI (including 24*16 touch-sensing values 401, each of the touch-sensing values 401 corresponding to the capacitance variation of each of the touch-sensing points 400) shown in FIG. 4A and the first force-sensing information FI.sub.1 (including 8*16 first force-sensing values 501, and each of the first force-sensing values 501 corresponds to the capacitance variation of each of the force-sensing points 500) shown in FIG. 5 as examples, but not limited thereto.
First Embodiment
[0031] With reference to FIGS. 4A to 7, the first force-sensing values 501 (as shown in FIG. 5) in the first force-sensing information FI.sub.1 are designated as the n second force-sensing values 502 according to the coordinates of the n touch-sensing points 400 (as shown in FIG. 6A). The second force-sensing values 502 constitute a third force-sensing information FI.sub.3. Then, the resolution of the first force-sensing information FI.sub.1 (8*16) is expanded to the resolution of the third force-sensing information FI.sub.3 (24*16). The resolution of the third force-sensing information FI.sub.3 is proportional to the resolution of the touch-sensing information TI, and then the third force-sensing information FI.sub.3 is adjusted according to the touch-sensing information TI to obtain the second force-sensing information FI.sub.21. In this embodiment, the aforementioned calibration method selects an effective touch range ETR according to the touch-sensing information TI (as shown in FIG. 4B). Then, according to the effective touch range ETR, an orthographic projection in the third force-sensing information FI.sub.3 correspondingly obtains an effective force-sensing range EFR (as shown in FIG. 6B). Next, the second force-sensing values 502 in the effective force-sensing range EFR are used to constitute the second force-sensing information FI.sub.21 (as shown in FIG. 7). The effective touch range ETR may be the coordinate and contour range of the touch object relative to the touchpad. For example, for the touch-sensing information TI shown in FIG. 4A, it is assumed that the sensing value is greater than 100 as the effective sensing value. As shown in FIG. 4B, the coordinates (8,7)˜(8,9), (9,6)˜(9,9), and (10,7)˜(10,9) are selected as an effective touch range ETR. The coordinates (14,7)˜(14,8), (15,6)˜(15,8), (16,6)˜(16,9), and (17,7)˜(17,8) are selected as another effective touch range ETR. In the third force-sensing information FI.sub.3 shown in FIG. 6B, the orthographic projection corresponding to the coordinates (8,7)˜(8,9), (9,6)˜(9,9), and (10,7)˜(10,9) is an effective force-sensing range EFR. The orthographic projection corresponding to the coordinates (14,7)˜(14,8), (15,6)˜(15,8), (16,6)˜(16,9), and (17,7)˜(17,8) is another effective force-sensing range EFR. Then, as shown in FIG. 7, the second force-sensing information FI.sub.21 is constituted of the second force-sensing values 502 in the corresponding effective force-sensing ranges EFR. The second force-sensing values 502 in the remaining unselected areas may be ignored or regarded as 0 in the second force-sensing information FI.sub.21. The obtained second force-sensing information FI.sub.21 is determined according to the effective touch range ETR by the touch-sensing information TI. Therefore, the noise interference in the non-object touching area is excluded, and the accuracy of judging the force exerted by the object is effectively improved.
Second Embodiment
[0032] With reference to FIGS. 4A to 6C and 8A, the first force-sensing values 501 (as shown in FIG. 5) in the first force-sensing information FI.sub.1 are designated as the n second force-sensing values 502 according to the coordinates of the n touch-sensing points 400 (as shown in FIG. 6A). The second force-sensing value 502 constitutes a third force-sensing information FI.sub.3. Then the resolution of the first force-sensing information FI.sub.1 (8*16) is expanded to the resolution of the third force-sensing information FI.sub.3 (24*16) to match the resolution of the touch-sensing information TI. The third force-sensing information FI.sub.3 is adjusted according to the touch-sensing information TI to obtain the second force-sensing information FI.sub.21. In this embodiment, the aforementioned calibration method selects an effective touch range ETR according to the touch-sensing information TI (as shown in FIG. 4B). Then according to the effective touch range ETR, an orthographic projection in the third force-sensing information FI.sub.3 correspondingly obtains an effective force-sensing range EFR (as shown in FIG. 6B). Then, a correction value is extracted from the touch-sensing values 401 corresponding to the effective touch range EFR. Then, each of the second force-sensing values 502 in the effective force-sensing range EFR is calculated according to the correction value to obtain a corresponding third force-sensing value 503. The second force-sensing information FI.sub.22 is constituted by the third force-sensing value 503. For example, for the touch-sensing information TI shown in FIG. 4A, it is assumed that the sensing value is greater than 100 as the effective sensing value. As shown in FIG. 4B, the coordinates (8,7)˜(8,9), (9,6)˜(9,9), and (10,7)˜(10,9) are selected as an effective touch range ETR. The coordinates (14,7)˜(14,8), (15,6)˜(15,8), (16,6)˜(16,9), and (17,7)˜(17,8) are selected as another effective touch range ETR. In each effective touch range ETR, a value is determined as a correction value, such as the maximum value in the effective touch range ETR. In the third force-sensing information FI.sub.3 shown in FIG. 6B, the orthographic projection corresponding to the coordinates (8,7)˜(8,9), (9,6)˜(9,9), and (10,7)˜(10,9) is an effective force-sensing range EFR. The orthographic projection corresponding to the coordinates (14,7)˜(14,8), (15,6)˜(15,8), (16,6)˜(16,9), and (17,7)˜(17,8) is another effective force-sensing range EFR. Finally, the third force-sensing value 503 shown in FIG. 8A is obtained after the second force-sensing value 502 in the corresponding effective force-sensing range EFR is corrected by the correction value. The second force-sensing information FI.sub.22 is constituted by the third force-sensing value 503. Many kinds of operation formulas may be used, and the following formulas are examples, but not limited thereto. The following calculation symbols are used, “e” represents the second force-sensing value, “f” represents the touch-sensing value, and “g” represents the correction value. The formula may be:
[00001]
[0033] For example, the second force-sensing value 502 of the coordinates (8, 8) to (10, 8) in the third force-sensing information FI.sub.3 shown in FIG. 8B are used as an example. The second force-sensing values 502 of these coordinates are 94, 114, and 114, respectively. The maximum touch-sensing value 401 selected in the corresponding effective touch-sensing range ETR is 3856 as the correction value. The third force-sensing values 503 obtained in the second force-sensing information FI.sub.22 are 42, 114, and 30, respectively, after calculation according to the aforementioned formula. In this way, in addition to eliminating the noise interference in the non-object touch area through the effective touch range ETR, the accuracy of judging the force applied by the object is effectively improved. The force-sensing values are corrected through the touch-sensing value, so that the force-sensing information is more in line with the shape of the area touched by the touch object, and the accuracy of the force-sensing information is improved.
Third Embodiment
[0034] With reference to FIGS. 4A, 5 and 9, the first force-sensing values 501 (as shown in FIG. 5) in the first force-sensing information FI.sub.1 correspond to the coordinates of the n touch-sensing points 400 (as shown in FIG. 4A). A base value is retrieved from the n touch-sensing values 401. The base value may be the maximum value, the average value or the sum value of the n touch-sensing values 401. After each of the first force-sensing values 501 is calculated according to the corresponding base value, n fourth force-sensing values 504 are obtained (as shown in FIG. 9A). The second force-sensing information FI.sub.23 is constituted by the fourth force-sensing values 504. Many kinds of operation formulas may be used, and the following formulas are examples, but not limited thereto. As shown in FIG. 9B, one of the first force-sensing values 501 corresponds to three of the touch-sensing values 401. For example, the first force-sensing value of the coordinate (5,7) in the first force-sensing information FI.sub.1 is used as an example, which corresponds to the coordinates (15,7)˜(17,7) in the touch-sensing information TI. The maximum value of the touch-sensing values of the coordinates (15,7)˜(17,7) is 3496, which is used as the base value. The following calculation symbols are used, “ ” represents the first force-sensing value, “j” represents the touch-sensing value, and “k” represents the base value. The formula may be:
[00002]
[0035] Then, as shown in FIG. 9B, the fourth force-sensing values 504 of the coordinates (15,7) to (17,7) are 129, 234, 46, respectively. In particular, in order to avoid the negative sensing value becoming a larger positive sensing value after the calculation, the corresponding fourth force-sensing value 504 may be 0 or ignored if the maximum value of the touch-sensing values 401 is a negative value or 0. Correcting the force-sensing values by the touch-sensing values makes the force-sensing information more in line with the shape of the area contacted by the touch object, and further the accuracy of the force-sensing information is improved.
Fourth Embodiment
[0036] Further, the result of the previous embodiment may be selected an effective touch range ETR according to the touch-sensing information TI (as shown in FIG. 4B). According to the effective touch range ETR, an orthographic projection in the second force-sensing information FI.sub.23 as shown in FIG. 9A is correspondingly provided to obtain an effective force-sensing range EFR (as shown in FIG. 10A). Still further, after the effective force-sensing range EFR is obtained, the maximum value in the effective touch range ETR is further used as a correction value. After each of the fourth force-sensing values 504 in the effective force-sensing range EFR is calculated according to the correction value, a corresponding fifth force-sensing value 505 is obtained. A second force-sensing information FI.sub.24 is constituted by the fifth force-sensing value 505. Many kinds of operation formulas may be used, and the following formulas are examples, but not limited thereto. The following calculation symbols are used, “e” represents the fourth force-sensing value, “f” represents the touch-sensing value, and “g” represents the correction value. The formula may be:
[00003]
[0037] For example, the fourth force-sensing value 504 of the coordinates (8, 8) to (10, 8) in the second force-sensing information FI.sub.23 shown in FIG. 10A are used as an example. The fourth force-sensing values 504 of these coordinates are 94, 114, and 30, respectively. The maximum touch-sensing value 401 selected in the corresponding effective touch-sensing range ETR is 3856 as the correction value. The fifth force-sensing values 505 obtained in the second force-sensing information FI.sub.24 are 42, 114, and 8, respectively, after calculation according to the aforementioned formula as shown in FIG. 10C. In this way, in addition to eliminating the noise interference in the non-object touch area through the effective touch range ETR, the accuracy of judging the force applied by the object is effectively improved. The force-sensing values are corrected through the touch-sensing value, so that the force-sensing information is more in line with the shape of the area touched by the touch object, and the accuracy of the force-sensing information is improved.
[0038] Moreover, the second force-sensing information FI.sub.21, FI.sub.22, FI.sub.23, FI.sub.24 obtained by the calibration method as described may be processed by an image filter to remove noise and make the edge of the image presented by each adjacent force-sensing value in the second force-sensing information smoother.
[0039] Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
