TWI401596B - Method for calibrating coordinates of touch screen - Google Patents

Description

Touch calibration method for touch screen

The invention relates to an index positioning technology, and in particular to a coordinate calibration method for a touch screen.

In recent years, due to the rapid development of technology, handheld devices, such as smart phones, personal digital assistants (PDAs), satellite navigation systems (GPS), etc., have become more and more popular. Since the above devices all use a touch screen, the technique of coordinate calibration between the touch sensor and the display device becomes very important. In the past, touch sensors generally used resistive sensors. Such resistive sensors must rely on pressure to sense the coordinates of the indicator on the screen. Since such hand-held devices currently use a liquid crystal screen, the resistive sensor must overlap the liquid crystal screen. Therefore, when pressed to the resistive sensor, the opposite is pressed against the liquid crystal screen. For a long time, the LCD screen may be damaged. In addition, the resolution of the resistive sensor is low, and there are often cases where the coordinate positioning is inaccurate.

In the prior art, there is also a touch sensor, which is a capacitive sensor. Capacitive sensors are widely used in touch screens of handheld devices. However, when the capacitive sensor is applied to the touch screen, there is a problem of accuracy due to the configuration of the coordinates of the capacitive touch panel and the configuration of the coordinates of the display.

In view of the above, an object of the present invention is to provide a coordinate calibration method for a touch screen for solving the problem that the coordinates of the capacitive touch panel are not matched with the coordinates of the display.

Another object of the present invention is to provide a coordinate calibration method for a touch screen for converting a coordinate of a capacitive sensor into a coordinate of a display panel.

To achieve the above or other objects, the present invention provides a coordinate calibration method for a touch screen, comprising the steps of: providing a display panel, wherein the display panel includes a plurality of display coordinates and a first axis display coordinate number in a first axis direction Providing a capacitive sensor, in the first axis direction, the capacitive sensor is configured with a plurality of sensing electrodes corresponding to a plurality of sensing coordinate values, wherein the capacitive sensor has a maximum sensing coordinate value; when the capacitive sensor is When touched, detecting a plurality of digit values corresponding to the sensing electrode; multiplying the digit value by the inductive coordinate value corresponding to each sensing electrode to obtain an additive value; dividing the additive value by the total of the digit values Combining an interpolated value; and multiplying the interpolated value by the first axis display coordinate number to obtain a calibration coordinate.

In addition, the present invention provides a coordinate calibration method for a touch screen. The method includes the following steps: providing a display panel, the display panel includes a plurality of display coordinates and a first axis display coordinate number in a first axis direction; providing a capacitive sensor in the first axis direction, the capacitive sensor Configuring a plurality of sensing electrodes corresponding to a plurality of sensing coordinate values, wherein the capacitive sensor has a maximum sensing coordinate value, and a first specific sensing electrode closest to a first edge of the capacitive sensor corresponds to seat The value is an initial value, and a coordinate value corresponding to a second specific sensing electrode closest to a second edge of the capacitive sensor is the same as the maximum sensing coordinate value; when the first edge is disposed on the minimum display coordinate of the display panel And the second edge is disposed on the maximum display coordinate of the display panel: the initial coordinate value corresponding to each sensing electrode is added with a preset coordinate value instead of the original sensing coordinate value; and the maximum sensing coordinate value is added to two The preset value of the preset coordinate value is replaced by the maximum sensing coordinate value, wherein the maximum sensing coordinate value is a coordinate value of the second edge; when detecting that only the first specific sensing electrode closest to the first edge is touched Time: determining whether the digit value corresponding to the first specific sensing electrode is greater than a reference digit value; when the digit value corresponding to the first specific sensing electrode is less than the reference digit value, according to the digit value and reference corresponding to the second specific sensing electrode The ratio of the digital value determines a first edge sensing coordinate value, wherein the first edge sensing coordinate value falls between the initial value and the first specific sensing electrode Between the sensing coordinate values; and dividing the first edge sensing coordinate value by the maximum sensing coordinate value, multiplying the first axis display coordinate number to obtain the calibration coordinate; and when detecting only the closest to the second edge When the second specific sensing electrode is touched: determining whether the digital value corresponding to the second specific sensing electrode is greater than a reference digital value; and when the digital value corresponding to the second specific sensing electrode is less than the reference digital value, according to the second specific sensing Determining a second edge sensing coordinate value corresponding to the ratio of the digital value of the electrode to the reference digit value, wherein the second edge sensing coordinate value falls between the maximum sensing coordinate value and the sensing coordinate value corresponding to the first specific sensing electrode And after dividing the second edge sensing coordinate value by the maximum sensing coordinate value, multiplying the first axis to display the coordinate number to obtain the calibration coordinate.

The invention provides a coordinate calibration method for a touch screen, the touch firefly The screen includes a display panel and a capacitive sensor. The method includes: obtaining, in a direction of the first axis, a touch object coordinate according to a capacitance change caused by a touch object to the capacitive sensor; adding a calibration value to the touch object coordinate to obtain a first coordinate; according to the capacitive type The theoretical total coordinate number of the sensor in the first axis direction and the resolution of the display panel in the first axis direction determine a conversion ratio; the first coordinate is multiplied by the conversion ratio to obtain a touch object corresponding to the second coordinate of the display panel.

The invention provides a coordinate calibration method for a touch screen, the touch screen comprising a display panel and a capacitive sensor. The method includes: detecting, in a direction of the first axis, a capacitance change caused by a touch to the capacitive sensor; obtaining a third coordinate corresponding to the capacitance change according to a lookup table; and the first axis according to the capacitive sensor The theoretical total coordinate number and the resolution of the display panel in the first axial direction determine a conversion ratio; the third coordinate is multiplied by the conversion ratio to obtain a touch object corresponding to the fourth coordinate of the display panel.

One aspect of the present invention is to use an interpolation method to calibrate the coordinate mismatch between the capacitive sensor and the display panel. On the other hand, since the capacitive sensor has a plurality of sensing electrodes, each of the sensing electrodes has a predetermined width. When only the edge sensing electrodes are touched, only the coordinates corresponding to the edge sensing electrodes can be calculated by interpolation, which may cause the edges of the display panel to be untouched. Therefore, in another aspect of the present invention, The coordinate value corresponding to the equivalent capacitance sensed by the edge sensing electrode is used to determine the coordinates of the edge, thereby solving the problem that the configuration of the coordinate of the capacitive touch panel does not match the coordinate configuration of the display.

The above and other objects, features and advantages of the present invention will become more <RTIgt; See below.

1 is a cross-sectional view showing the structure of a capacitive touch screen according to an embodiment of the invention. Referring to FIG. 1 , the capacitive touch screen includes a display module 40 and a capacitive sensor 41 . FIG. 2 is a structural top view of the capacitive sensor 41 according to an embodiment of the invention. Referring to FIG. 2, the capacitive sensor 41 includes a plurality of X-axis sensing electrodes X01 to X12 and a control circuit C10. Since the index is to be positioned, there must be an X-axis coordinate and a Y-axis coordinate. In this embodiment, only the method of positioning the X-axis coordinate is provided. The Y-axis coordinate positioning method can be the same as the X-axis coordinate positioning method. I will not repeat them here.

Since the capacitive sensor 41 has two sensing modes, it is a non-differential sensing and a differential sensing, respectively. That is to say, the non-differential sensing method is that each X-axis sensing line obtains a set of digit values related to the equivalent capacitance value, which is a conductor, generally refers to a finger, and touches the X-axis sensing line. The area is related to the distance from the X-axis sensing electrode. In this embodiment, the X-axis sensing electrodes X01 to X12 are exemplified by 12 sensing lines. In general, each X-axis sensing line can be divided into 64 coordinate positions between adjacent X-axis sensing lines. Here, 64 is used as an example. However, according to different applications and different precision, coordinate division will also be used. It is different. In addition, the coordinate of the first X-axis sensing line X01 is zero. Therefore, the X-axis coordinates of the capacitive sensor 41 have a total of 64 × (12 - 1) + 1 = 705 coordinates. In addition, the differential sensing method can obtain a set of digit values for every two X-axis sensing electrodes, so the X-axis coordinates of the capacitive sensor 41 have a total of 64×(12-2). +1=641 coordinates. The non-differential sensing method is used as an example to illustrate how to obtain a finger touch on the X-axis sensing electrode to obtain the X coordinate on the capacitive sensor 41.

3A and 3B are respectively schematic views for explaining a method of positioning the coordinates of the capacitive sensor 41 according to the embodiment of the present invention. Please refer to Figure 3A first. If the X-axis sensing lines X01~X12 are not touched, the corresponding digit value is 0. When the digital values of the 6th to 8th X-axis sensing lines X06~X08 are detected as 163, 185 and 70 respectively, the X-axis coordinates of the finger touching the capacitive sensor 41 can be calculated by interpolation: 64 × [(6-1) × 163 + (7-1) × 185 + (8-1) × 70] / (163 + 185 + 70) = 369.76.

Next, please refer to FIG. 3B. When the digital value of the first X-axis sensing line X01 is detected to be 200, the X-axis coordinate of the finger touching the capacitive sensor 41 is calculated by interpolation: 64×( 1-1) × 200 / 200 = 0.

The coordinates obtained above need to be converted to obtain the coordinate value of the display module 40. However, in recent years, electronic devices have become light, thin, short, and small, and thus the frame of the hand-held mobile device has become smaller and smaller, so that the capacitive sensor 41 must be the same size as the display area of the display module 40. However, the sensing lines X01 to X12 of the capacitive sensor 41 each have a certain line width. Figure 4 is a schematic diagram of the configuration of the coordinates of the capacitive touch panel, which does not match the configuration of the coordinates of the display. Referring to FIG. 4, when the finger touches the first X-axis sensing electrode X01 of the capacitive sensor 41, the obtained coordinate value is 0, but the sensing electrode X01 is off the screen. There is also a certain distance at the edge. In this case, if the finger points to the edge portion 701 of the display module 40, the coordinates of the display module 40 cannot be converted from the coordinates of the capacitive sensor 41. Moreover, if the center point of the first X-axis sensing line X01 is arranged at the edge of the display module 40, when the user touches the frame of the product, the user may accidentally touch the first of the capacitive sensor 41. The X-axis sensing electrode X01 will cause a problem in the sensing of the capacitive sensor 41 in the future.

In order to solve the above problems, in an embodiment of the present invention, a method of calibrating coordinates of a display panel and a capacitive sensor is proposed. The method acts on two regions, the first region being a linear region, that is, the central region 702 of the display module 40, and the second region being a non-linear region, that is, the edge portion 701 of the display module 40. The following is a description of the coordinates of the two regions. Before explaining the method of this embodiment, it is assumed that the resolution of the display module 40 is 240×320, that is, the X-axis has 240 pixels.

First, first explain the coordinate conversion method of the linear region. Fig. 5 is a schematic view showing a linear region of a non-differential sensing type capacitive sensor according to an embodiment of the present invention. Please refer to FIG. 5 first, because the linear area refers to the area where the capacitive sensor 41 can determine the coordinates. Here, it is assumed that the capacitive sensor 41 is a non-differential sensing capacitive sensor, and further assumes that the X-axis has 12 sensing lines, the Y-axis has 16 sensing lines, and each sensing line is adjacent to the adjacent sensing line. Can be divided into 64 coordinate positions, then the coordinates (1,1)~(703,959) can be obtained in this linear region. If the upper left corner of the sensor is to be positioned as the coordinate origin, the linear region needs to be translated by coordinates. Figure 6 is a diagram showing the coordinates of a non-differential sensing type capacitive sensor according to an embodiment of the present invention. Pan diagram. Please refer to Figure 6. After the linear region needs to be translated by coordinates, the starting point of the linear region is (33, 33) and the ending point of the coordinate is (735, 991).

Since it is assumed above that each of the X-axis sensing electrodes and the adjacent X-axis sensing electrodes can be divided into 64 coordinate positions, respectively, the capacitive sensor coordinates at the center of the first X-axis sensing line X01 need to be translated to 32. And the capacitive sensor coordinate at the center of the twelfth X-axis sensing electrode X12 needs to translate 704 + 32 = 736. Assuming that the finger presses the capacitive sensor 41 as shown in FIG. 6A, the X coordinate on the capacitive sensor 41 is 369.76. Next, by adding 32 to this coordinate, dividing the theoretical total coordinate number of the capacitive sensor by 64*12=768, and multiplying the X-axis resolution by 240, the X coordinate of the finger pressing on the display module 40 can be obtained. . Expressed as follows: X coordinate = (369.76 + 32) × 240 ÷ 768 = 133.9875 ≒ 134 (first divided by 768 and then multiplied by 240)

It can be understood from the above embodiments that the present invention adds a calibration value to the touch object coordinates calculated by the linear region to obtain a first coordinate. The "translation" described above causes the coordinate origin of the capacitive sensor to overlap the coordinate origin of the display. The first scale is multiplied by a ratio and converted into the second coordinate of the touch object on the display panel.

Next, the coordinate conversion method of the nonlinear region is explained. 7A to 7C are diagrams showing a comparison relationship of corresponding digital values when the conductor presses the X-axis sensing line on the capacitive sensor 41. Please refer to Figure 7A and Figure 7B first. It can be seen from Figure 7A and Figure 7B that when the conductor, generally a finger, presses the contact area of the sensing line X01, the equivalent of the sensing line X01 The larger the capacitance, the more the digital value will be. Big. Therefore, in this embodiment, it is mainly determined by the magnitude of the digital value corresponding to the first X-axis sensing electrode X01 that the X coordinate is located at 0 to 31.

Referring to FIG. 7C, when the finger is pressed against the first X-axis sensing line X01 of the capacitive sensor 41, only the digital value corresponding to the sensing line X01 is obtained. Here, a reference value is set in advance. For convenience of explanation, assume that this reference value is 160. That is to say, when only the digital value corresponding to the sensing electrode X01 is obtained, and the value is greater than or equal to 160, it is determined that the X coordinate is located at 32. When only the digit value corresponding to the sensing electrode X01 is obtained, and the value is equal to 80, it is determined that the X coordinate is located at 15. In short, the X coordinate is determined according to the proportional relationship between the digital value corresponding to the sensing electrode X01 and the above reference value. The determination manner of the above embodiment can be expressed as the following table.

Assuming that the X coordinate is 20, as long as the above ratio is calculated, the X coordinate on the screen can be obtained: X coordinate = 20 × 240 ÷ 768 = 6.25 ≒ 6 (excluding 768 and then 240)

It can be understood from the above embodiment that the coordinate origin in the nonlinear region is The coordinate origin of the display area overlaps. The present invention uses the lookup table to obtain the third coordinate of the touch object on the capacitive sensor. The third coordinate is multiplied by a ratio, and then converted into a fourth coordinate corresponding to the touch object on the display panel. .

Although the above embodiment operates only on the X-axis coordinates, those skilled in the art, with reference to the above embodiments, it should be understood that the Y-axis coordinates can also be calculated in the manner described above. Therefore, I will not repeat them here.

Next, when the capacitive sensor 41 is a differential sensing capacitive sensor, it means that only one set of digital values can be obtained for each of the two sensing electrodes. Fig. 8 is a view showing a linear region of a differential sensing type capacitive sensor according to an embodiment of the present invention. Assuming that there are a total of 12 X-axis sensing lines and 16 Y-axis sensing lines, it is assumed that each sensing line and the adjacent sensing line can be divided into 64 coordinate positions. Since only two sets of digit values can be obtained for each of the two sensing lines, the range of coordinates before the non-translation of the linear region is only (1,1)~(639,895). FIG. 9 is a schematic diagram showing the coordinate translation of the differential sensing type capacitive sensor according to the embodiment of the present invention. Please refer to Figure 9, after translation (65, 65) ~ (713, 959). The X coordinate range of the nonlinear region after translation is 0~64, 714~778.

First, first explain the coordinate conversion method of the linear region. Similarly, it is assumed that the control circuit C10 determines that the X coordinate is 369.76. When converting to the X coordinate on the display module 40, only the following calculation is required: (369.76+64) × 240 ÷ 768 = 135.55 ≒ 136 (first divided by 768 and then multiplied by 240)

The X coordinate on display module 40 is 136.

By the same token, when the finger is in the non-linear region, for example, the finger touches the left edge of the capacitive sensor 41, the control circuit C10 will only get The digital value corresponding to the sensing electrodes X01 and X02. There will also be a set of preset values set in advance. Suppose this preset is 192. In short, the X coordinate is determined according to the proportional relationship between the digital value corresponding to the sensing electrodes X01 and X02 and the above reference value. When the digit value corresponding to the obtained sensing electrodes X01 and X02 is between 94 and 96, it is determined that the X coordinate is located at 31. After that, as long as the determined coordinates are proportional, the X coordinate on the screen can be converted: the X coordinate on the screen = 31 × 240 ÷ 768 = 9.6875 ≒ 10. (first divide 768 and then multiply 240)

According to the above embodiment, the calibration methods of the following two coordinates can be arranged. 10 and 11 are flowcharts of a coordinate calibration method of a touch screen according to an embodiment of the present invention. Please refer to Figure 10 first. Figure 10 is assuming that the linear area overlaps the display area. This method includes the following steps:

Step S1000: Start.

Step S1001: providing a display panel, wherein the display panel comprises a plurality of display coordinates and a first axis display coordinate number in the first axis direction. For example, the display module 40 described above has a resolution of 240×320. The X axis has 240 pixels, which is 240 coordinates. Its maximum display coordinates are 239.

Step S1002: Providing a capacitive sensor. In the first axis direction, the capacitive sensor is configured with a plurality of sensing electrodes and corresponding to a plurality of sensing coordinate values, wherein the capacitive sensor has a maximum sensing coordinate value. For example, the above-mentioned capacitive sensor 41 is exemplified by a non-differential sensing capacitive sensor, which is configured with 12 sensing electrodes X01~X12, and X01 corresponds to coordinates 0, X02 corresponding coordinates 64, ..., X12 corresponding coordinates 704. its The maximum display coordinates are 704.

Step S1003: Determine whether the capacitive sensor is touched. If no, the process returns to step S1003 for continuous detection. When the determination is YES, step S1004 is performed.

Step S1004: Detecting a plurality of digit values corresponding to each of the sensing electrodes. As shown in Figure 3A, when a conductor, such as a finger, touches the sensing electrodes X6~X8 on the capacitive sensor, X6 will have a corresponding digit value of 163; X7 will have a corresponding digit value of 185; X8 will have The corresponding digit value is 70.

Step S1005: Multiplying the digit values by the inductive coordinate value corresponding to each of the sensing electrodes to obtain an additive value. Next, the above-mentioned digit value 163 is multiplied by 5 × 64; 185 is multiplied by 6 × 64; 70 is multiplied by 7 × 64. Therefore, the bonus value is 154,560.

Step S1006: dividing the addition value by the sum of the above digit values to obtain an interpolation value. Next, by dividing the above-mentioned addition value 154560 by (163 + 185 + 70), an interpolation value of 369.76 can be obtained, which is equivalent to the coordinates of the conductor touch capacitive sensor.

Step S1007: After dividing the interpolated value by the maximum inductive coordinate value, multiplying the first axis display coordinate number to obtain a calibration coordinate.

Step S1008: End.

Of course, this example can only be implemented when the display panel is disposed in the linear region of the capacitive sensor. When the edge of the capacitive sensor is closely arranged with the edge of the display area, the method of the embodiment of the present invention is changed to the following steps:

Step S1100: Start.

Step S1101: Providing a display panel as in the above step S1001.

Step S1102: Providing a capacitive sensor. In the first axis direction, the capacitive sensor is configured with a plurality of sensing electrodes corresponding to the plurality of sensing coordinate values, wherein the capacitive sensor has a maximum sensing coordinate value and the distance capacitive sensor a coordinate value corresponding to a first specific sensing electrode of a first edge is an initial value, and a coordinate value corresponding to a second specific sensing electrode closest to a second edge of the capacitive sensor and a maximum sensing coordinate value the same.

Step S1103: adding a preset coordinate value corresponding to the sensing coordinate value of each sensing electrode to replace the original sensing coordinate value. According to the above embodiment, it can be known that since the sensing electrodes have a certain width, and since there are 64 sensing coordinates between the two adjacent sensing electrodes, the center of the sensing electrodes closest to the edge should be different from each other by 32. Inductive coordinates. Therefore, in this embodiment, the inductive coordinate value corresponding to each sensing electrode is added with a preset coordinate value 32 to replace the original inductive coordinate value.

Step S1104: Substituting the maximum sensing coordinate value by twice the preset coordinate value instead of the maximum sensing coordinate value. By the same token, the original maximum coordinate value plus 64 replaces the original maximum inductive coordinate value.

Step S1105: Determine whether the capacitive sensor is touched. When the capacitive sensor is not touched, it returns to step S1106 to continue the determination. When the determination is YES, the process goes to step S1107.

Step S1106: It is judged whether only the sensing electrodes of the edge are touched. When the determination is no, the process goes to step S1108. When it is judged as YES, it progresses to step S1109.

Step S1107: Perform steps S1004 to S1007 described above to obtain calibration coordinates. If the embodiment of Figure 3A above is used, the above steps are equivalent. After adding 32 to the above-mentioned interpolated value 369.76, it is multiplied by the maximum X coordinate 240 of the display panel, and then divided by the corrected maximum coordinate 768 of the capacitive sensor. Thus, the X-axis calibration coordinates 134 as described above can be obtained.

Step S1108: It is judged that the first edge is touched or the second edge is touched. In this embodiment, the first edge refers to the edge closest to the X-axis coordinate 0 of the display panel; the second edge refers to the edge that is closest to the X-axis coordinate 239 of the display panel. When the first edge is touched, step S1110 is performed; when the second edge is touched, step S1114 is performed.

Step S1109: Determine whether the digital value corresponding to the first specific sensing electrode is greater than a reference digital value. As described above, since the contact area of the sensing line X01 is larger, the equivalent capacitance of the sensing line X01 is larger, and as a result, the digital value is larger. Therefore, the above embodiment is preset 160 as a reference digit value. This value is usually set by the experience of an experiment or an engineer.

Step S1110: When the determination is YES, it is determined that the calibration coordinate is a coordinate corresponding to the first specific sensing electrode. As in the above embodiment, when the digit value is greater than 160, the decision coordinate is 32.

Step S1111: When the digit value corresponding to the first specific sensing electrode is smaller than the reference digit value, determining a first edge sensing coordinate value according to a ratio of the digit value corresponding to the first specific sensing electrode to the reference digit value. It can be known from the above embodiment that the larger the contact area of the sensing line X01 is, the larger the equivalent capacitance of the sensing line X01 will be, and the larger the digital value will be. Therefore, as long as the digital value corresponding to the first specific sensing electrode is known, the digital value and the reference digital value (160) can be used according to the digital value. A proportional relationship, such as the lookup table described above, to obtain a first edge-sensing coordinate value. In general, this proportional relationship is based on a lookup table. Of course, those skilled in the art can implement the built-in mathematical or software.

Step S1112: After dividing the first edge sensing coordinate value by the maximum sensing coordinate value, multiplying the first axis display coordinate number to obtain a calibration coordinate.

Step S1113: Determine whether the digital value corresponding to the second specific sensing electrode is greater than a reference digital value. Similarly, when it is detected that only a second specific sensing electrode closest to the second edge is touched, it is first determined whether the corresponding digit value is greater than the reference digit value.

Step S1114: When the determination is YES, it is determined that the calibration coordinate is a coordinate corresponding to the second specific sensing electrode. As in the above embodiment, when the digit value is greater than 160, the decision coordinate is 736.

Step S1115: When the digital value corresponding to the second specific sensing electrode is smaller than the reference digital value, determining a second edge sensing coordinate value according to a ratio of the digital value corresponding to the second specific sensing electrode to the reference digital value, where The second edge sensing coordinate value falls between the maximum sensing coordinate value and the sensing coordinate value corresponding to the first specific sensing electrode.

Step S1116: After dividing the second edge sensing coordinate value by the maximum sensing coordinate value, multiplying the first axis display coordinate number to obtain a calibration coordinate.

One aspect of the present invention is to use an interpolation method to calibrate the coordinate mismatch between the capacitive sensor and the display panel. On the other hand, since the capacitive sensor has a plurality of sensing electrodes, each of the sensing electrodes has a predetermined width. When only the edge of the sensing electrode is touched, only the coordinates corresponding to the edge sensing electrode can be calculated by interpolation, which may cause the display panel. The edge of the invention cannot be touched. Therefore, in another aspect of the present invention, the coordinate value corresponding to the equivalent capacitance sensed by the sensing electrode of the edge is used to determine the coordinates of the edge, thereby also solving the capacitive type. The configuration of the coordinates of the touchpad does not match the configuration of the coordinates of the display.

The specific embodiments of the present invention are intended to be illustrative only and not to limit the invention to the above embodiments, without departing from the spirit of the invention and the following claims. The scope of the invention and the various changes made are within the scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

40‧‧‧Display module

41‧‧‧Capacitive sensor

X01~X12‧‧‧Induction electrode

C10‧‧‧Control circuit

1 is a cross-sectional view showing the structure of a capacitive touch screen according to an embodiment of the invention.

FIG. 2 is a structural top view of the capacitive sensor 41 according to an embodiment of the invention.

3A and 3B are respectively schematic views for explaining a method of positioning the coordinates of the capacitive sensor 41 according to the embodiment of the present invention.

Figure 4 is a schematic diagram of the configuration of the coordinates of the capacitive touch panel, which does not match the configuration of the coordinates of the display.

Fig. 5 is a schematic view showing a linear region of a non-differential sensing type capacitive sensor according to an embodiment of the present invention.

Fig. 6 is a schematic diagram showing the coordinate translation of the non-differential sensing type capacitive sensor according to the embodiment of the present invention.

7A to 7C are diagrams showing a comparison relationship of corresponding digital values when the conductor presses the X-axis sensing line on the capacitive sensor 41.

Fig. 8 is a view showing a linear region of a differential sensing type capacitive sensor according to an embodiment of the present invention.

FIG. 9 is a schematic diagram showing the coordinate translation of the differential sensing type capacitive sensor according to the embodiment of the present invention.

FIG. 10 is a flow chart of a coordinate calibration method of a touch screen according to an embodiment of the invention.

11 is a flow chart of a coordinate calibration method of a touch screen according to an embodiment of the invention.

S1000~S1008‧‧‧ steps of the embodiment of the present invention

Claims (17)

A coordinate calibration method for a touch screen includes: providing a display panel, wherein the display panel includes a plurality of display coordinates in a first axis direction, wherein the display coordinates include a first axis display coordinate number; and providing a capacitive sensor In the first axis direction, the capacitive sensor is configured with a plurality of sensing electrodes respectively corresponding to a plurality of sensing coordinate values, wherein the capacitive sensor has a maximum sensing coordinate value; when the capacitive sensor is touched, the detecting Measure a plurality of digit values corresponding to the sensing electrodes; multiplying the digit values by the inductive coordinate values corresponding to the sensing electrodes to obtain an additive value; dividing the addition value by the sum of the digit values Obtaining an interpolated value; and multiplying the interpolated value by the first axis display coordinate number to obtain a calibration coordinate. The coordinate calibration method of the touch screen as described in claim 1, wherein when the capacitive sensor is touched, detecting a plurality of digit values corresponding to the sensing electrodes includes: when the capacitive sensor is When touched, detecting a plurality of equivalent capacitances corresponding to the sensing electrodes; and converting the equivalent capacitances into a plurality of digital values. The coordinate calibration method of the touch screen as described in claim 1, wherein each of the sensing electrodes includes a fixed width. The coordinate calibration method of the touch screen as described in claim 1, wherein a coordinate value corresponding to a first specific sensing electrode closest to a first edge of the capacitive sensor is an initial value, and the distance is a coordinate value corresponding to a second specific sensing electrode of a second edge of the capacitive sensor and the maximum The sensing coordinates are the same. The coordinate calibration method of the touch screen according to the fourth aspect of the invention, wherein the first edge is disposed on the minimum display coordinate of the display panel, and the second edge is disposed on the maximum display coordinate of the display panel. Substituting the inductive coordinate values corresponding to each of the sensing electrodes with a preset coordinate value instead of the inductive coordinate values; and replacing the maximum inductive coordinate value by twice the preset coordinate value The maximum inductive coordinate value. The coordinate calibration method of the touch screen as described in claim 5, wherein when only the digital value corresponding to the second specific sensing electrode is detected; determining the digital value corresponding to the second specific sensing electrode Whether it is greater than a reference digit value; when the digit value corresponding to the second specific sensing electrode is greater than or equal to the reference digit value, the interpolation value is set to a coordinate value corresponding to the second specific sensing electrode; and when the second When the digital value corresponding to the specific sensing electrode is smaller than the reference digital value, the interpolation value is determined according to the ratio of the digital value corresponding to the second specific sensing electrode to the reference digital value, wherein the interpolation value falls on the maximum sensing coordinate The value is between the coordinate value corresponding to the second specific sensing electrode. The coordinate calibration method of the touch screen as described in claim 5, wherein when only the digital value corresponding to the second specific sensing electrode is detected; determining the digital value corresponding to the second specific sensing electrode Whether it is greater than a reference digit value; when the digit value corresponding to the second specific sensing electrode is greater than or equal to the reference digit value, setting the interpolation value to the seat corresponding to the second specific sensing electrode a value; and when the digit value corresponding to the second specific sensing electrode is less than the reference digit value, determining the interpolation value according to a lookup table, wherein the interpolation value falls between the maximum sensing coordinate value and the second specific sensing Between the coordinate values corresponding to the electrodes. The coordinate calibration method of the touch screen as described in claim 5, wherein when only the digital value corresponding to the first specific sensing electrode is detected; determining the digital value corresponding to the first specific sensing electrode Whether it is greater than a reference digit value; when the digit value corresponding to the first specific sensing electrode is greater than or equal to the reference digit value, setting the interpolation value as a coordinate value corresponding to the first specific sensing electrode; and when the first When the digital value corresponding to the specific sensing electrode is smaller than the reference digital value, the interpolation value is determined according to the ratio of the digital value corresponding to the first specific sensing electrode to the reference digital value, wherein the interpolation value falls on the minimum sensing coordinate value. Between the coordinate values corresponding to the first specific sensing electrode. The coordinate calibration method of the touch screen as described in claim 5, wherein when only the digital value corresponding to the first specific sensing electrode is detected; determining the digital value corresponding to the first specific sensing electrode Whether it is greater than a reference digit value; when the digit value corresponding to the first specific sensing electrode is greater than or equal to the reference digit value, setting the interpolation value as a coordinate value corresponding to the first specific sensing electrode; and when the first When the digital value corresponding to the specific sensing electrode is less than the reference digital value, the interpolation value is determined according to a lookup table, wherein the interpolation value falls in the most The small sensing coordinate value is between the coordinate value corresponding to the first specific sensing electrode. A coordinate calibration method for a touch screen, comprising: providing a display panel, wherein the display panel includes a plurality of display coordinates and a first axis display coordinate number in a first axis direction; providing a capacitive sensor on a first axis In the direction, the capacitive sensor is configured with a plurality of sensing electrodes respectively corresponding to a plurality of sensing coordinate values, wherein the capacitive sensor has a maximum sensing coordinate value and a first closest to a first edge of the capacitive sensor The coordinate value corresponding to the specific sensing electrode is an initial value, and the coordinate value corresponding to a second specific sensing electrode closest to a second edge of the capacitive sensor is the same as the maximum sensing coordinate value; when the first edge is configured In the minimum display coordinate of the display panel, and the second edge is disposed on the maximum display coordinate of the display panel: the preset coordinate values corresponding to each of the sensing electrodes are added with a preset coordinate value instead of the The inductive coordinate value; and the maximum inductive coordinate value is doubled by the preset coordinate value, instead of the maximum inductive coordinate value, wherein The maximum sensing coordinate value is a coordinate value of the second edge; when it is detected that only the first specific sensing electrode closest to the first edge is touched: determining whether the digital value corresponding to the first specific sensing electrode is More than a reference digit value; when the digit value corresponding to the first specific sensing electrode is less than the reference digit value, according to the digit value corresponding to the first specific sensing electrode The ratio of the reference digit value determines a first edge sensing coordinate value, wherein the first edge sensing coordinate value falls between the initial value and the inductive coordinate value corresponding to the first specific sensing electrode; After the edge sensing coordinate value is divided by the maximum sensing coordinate value, multiplying the first axis display coordinate number to obtain a calibration coordinate; and when detecting that only the second specific sensing electrode closest to the second edge is detected When touched: determining whether the digit value corresponding to the second specific sensing electrode is greater than a reference digit value; and when the digit value corresponding to the second specific sensing electrode is less than the reference digit value, according to the second specific sensing electrode a ratio of the corresponding digit value to the reference digit value determines a second edge sensing coordinate value, wherein the second edge sensing coordinate value falls between the maximum sensing coordinate value and the sensing coordinate value corresponding to the first specific sensing electrode And dividing the second edge sensing coordinate value by the maximum sensing coordinate value, multiplying the first axis display coordinate number to obtain the calibration coordinate. The coordinate calibration method of the touch screen as described in claim 10, wherein when the capacitive sensor is touched, the method further comprises: detecting the sensing electrodes when the capacitive sensor is touched Corresponding multiple equivalent capacitors; and converting the equivalent capacitors into a plurality of digit values. The coordinate calibration method of the touch screen as described in claim 10, wherein when the sensing electrodes are touched, the touched sensing electrodes are not the first The specific sensing electrode and the second specific sensing electrode comprise the following steps: detecting a plurality of digit values corresponding to each sensing electrode; multiplying the digit values by an inductive coordinate value corresponding to each sensing electrode to obtain an additive value a value; dividing the addition value by the sum of the digit values to obtain an interpolated value; and multiplying the interpolated value by the first axis display coordinate number to obtain the calibration coordinate. The method for calibrating a touch screen of the touch screen of claim 10, wherein the method for determining a first edge sensing coordinate value comprises: providing a lookup table; and inputting a digital value corresponding to the first specific sensing electrode To obtain the first edge sensing coordinate value. The method for calibrating a touch screen of the touch screen of claim 10, wherein the method for determining a second edge sensing coordinate value comprises: providing a lookup table; and inputting a digital value corresponding to the second specific sensing electrode To obtain the second edge sensing coordinate value. A coordinate calibration method for a touch screen, the touch screen includes a display panel and a capacitive sensor, the method comprising: obtaining, in a first axis direction, a capacitance change caused by the capacitive sensor according to a touch object a touch object coordinate; adding a calibration value to the touch object coordinate to obtain a first coordinate; according to the theoretical total coordinate number of the capacitive sensor in the first axis direction and the analysis of the display panel in the first axis direction The degree determines a conversion ratio; multiplying the first coordinate by the conversion ratio to obtain a second coordinate of the touch object corresponding to the display panel. The coordinate calibration method of the touch screen as described in claim 15 , wherein the step of obtaining the touch object coordinates comprises: detecting each of the sensing electrodes of the capacitive sensor in the first axis direction; The plurality of digit values obtained by the detecting step are multiplied by the inductive coordinate values corresponding to each of the sensing electrodes to obtain an additive value; and the addition value is divided by the sum of the digit values to obtain an interpolated value. A coordinate calibration method for a touch screen, the touch screen includes a display panel and a capacitive sensor, the method comprising: detecting a capacitance change caused by a touch to the capacitive sensor in a first axis direction Obtaining a third coordinate corresponding to the capacitance change according to a lookup table; determining a conversion ratio according to the theoretical total coordinate number of the capacitive sensor in the first axis direction and the resolution of the display panel in the first axial direction Multiplying the third coordinate by the conversion ratio to obtain a fourth coordinate corresponding to the display panel.