TWM505646U - Touch panel - Google Patents

Abstract

The utility model provides a touch panel including a touch unit array, a memory and a processing module executing the commands stored in the memory to perform the following steps. Initial detected voltage values are retrieved by a touch unit group in the touch panel during an initial state to perform a differential calculation to obtain initial differential voltage values stored as baseline values. Detected voltage values are retrieved by the touch unit group during an operation state to perform a differential calculation to obtain differential voltage values. Difference values are generated by subtracting the differential voltage values and the baseline values such that whether the touch unit group includes at least one touch applying point and a touch removing point is determined according to an order of the difference values. When a touch removing point is included, the baseline values are updated to be the differential voltage values.

Description

Touch panel

The present invention relates to a touch technology, and in particular to a touch panel.

The touch panel is combined with the display panel due to the intuition and convenience of the input mode, and is widely used in many handheld electronic devices such as smart phones and tablets. Among the current touch technologies, capacitive touch panels are the most popular touch technology. In some technologies, the capacitive touch panel performs scan detection at the initial stage and continuously scans for detection after obtaining a reference value. The detected value is compared with a fixed set of reference values to determine the actual touch position.

However, when the touch panel is not activated, some objects, such as the user's hand, may have been placed on the surface of the touch panel first. Therefore, after the touch panel is activated, the reference value obtained by scanning will not be able to obtain an accurate value due to the influence of the hand. When the actual touch detection is performed on the touch panel, the judgment cannot be made correctly.

Therefore, how to design a new touch panel and its detection method to solve the above problems is an urgent problem to be solved in the industry.

Therefore, one aspect of the present invention provides a touch detection method for use in a touch panel, wherein the touch panel includes a touch unit array, and the plurality of touch units in the touch unit array are arranged in a plurality of touch Control unit row and multiple touch unit columns. The touch detection method includes: detecting, in an initial mode, a touch unit group of the touch panel, sequentially obtaining a plurality of initial detection voltage values, and sequentially ordering two adjacent initial detection voltage values Performing a differential calculation on the previous subtraction to obtain a complex initial differential voltage value, wherein the touch unit group corresponds to one of the touch unit row and the touch unit column; and the initial differential voltage value is used as the touch a set of reference values of the unit group; in the operation mode, the touch unit group is detected to sequentially obtain the complex detection voltage value, and the adjacent two detected voltage values are sequentially followed by the next pair The previous subtraction performs a differential calculation to obtain a complex differential voltage value; the differential voltage value is sequentially subtracted from the set of reference values, and the complex difference value is sequentially generated to determine the touch according to the positive and negative order relationship of the difference value. Whether the unit group includes at least one touch application point and at least one touch removal point, and updating the reference value to a differential voltage value when the touch unit group includes the touch removal point.

According to an embodiment of the present invention, when one of the touch units is not touched, the corresponding detected voltage value is equivalent to a preset value, and is less than a preset value when touched.

According to another embodiment of the present invention, the touch detection method further includes determining the touch unit when the difference value includes the front negative number and the order of the last positive number. In the group, at least one touch unit corresponding to the front negative number and the rear positive number respectively is a touch application point.

According to still another embodiment of the present invention, the touch detection method further includes: when the difference value is included in the front positive number and the backward negative number, determining that the touch unit group includes the touch removal point.

According to still another embodiment of the present invention, the touch detection method further includes: when the difference value does not appear in the order of the positive number and the negative number, the original reference value is retained.

According to another embodiment of the present invention, the touch unit group further includes a front end virtual touch unit and a back end virtual touch unit, which are located at two ends of the plurality of touch units included in the touch unit group, and the front end is virtualized The initial detection voltage value and the detection voltage value corresponding to the touch unit and the back end virtual touch unit are the preset values.

Therefore, another aspect of the present invention provides a touch panel comprising: a touch unit array, a processing module, and a memory. The plurality of touch units in the touch unit array are arranged in a plurality of touch unit rows and a plurality of touch unit columns. The processing module is coupled to the touch unit array. The memory has a computer-executable plurality of instructions stored therein and coupled to the processing module. When the instruction is executed by the processing module, the following actions are performed: the touch panel group of the touch panel is detected in the initial mode. Measure, sequentially obtain the complex initial detection voltage value, and sequentially calculate the difference between the two adjacent initial detection voltage values by the subsequent one to the previous subtraction to obtain a complex initial differential voltage value, wherein The control unit group corresponds to one of the touch unit row and the touch unit column; the initial differential voltage value is used as a group reference of the touch unit group In the operation mode, the touch unit group is detected to sequentially obtain the complex detection voltage value, and the two adjacent detection voltage values are sequentially calculated by the subsequent subtraction from the previous one. To obtain a complex differential voltage value; the differential voltage value is sequentially subtracted from the set of reference values, and the complex difference value is sequentially generated to determine whether the touch unit group contains at least one touch according to the positive and negative order relationship of the difference value. The control application point and the at least one touch removal point are used to update the reference value to a differential voltage value when the touch unit group includes the touch removal point.

According to an embodiment of the present invention, when one of the touch units is not touched, the corresponding detected voltage value is equivalent to a preset value, and is less than a preset value when touched.

According to another embodiment of the present invention, when the difference value includes the previous negative number and the order of the positive number, the position of the touch unit is determined to correspond to at least one touch unit between the previous negative number and the last positive number. Apply points to the touch separately.

According to still another embodiment of the present invention, when the difference value is included in the order of the front positive number and the negative number, the touch control unit group is included in the touch control unit.

According to still another embodiment of the present invention, wherein the difference value does not appear in the order of the positive number and the subsequent negative number, the original reference value is retained.

According to another embodiment of the present invention, the touch unit group further includes a front end virtual touch unit and a back end virtual touch unit, which are located at two ends of the plurality of touch units included in the touch unit group, and the front end is virtualized Initial detection voltage value and detection corresponding to the touch unit and the back end virtual touch unit The voltage values are all preset values.

The advantage of the present invention is that the touch panel of the present invention determines the touch application point and the touch removal point by calculating the difference between the differential voltage value and the reference value and the positive and negative order relationship between the difference values. Therefore, even if the user has touched the touch panel in the initial mode, the touch panel can determine the new touch application point without being affected, and can update the reference value under the condition that the touch object is removed. The touch panel will avoid the judgment of the touch behavior when the operation mode is affected due to the incorrect reference value caused by the user's prior contact in the initial mode.

1‧‧‧ touch panel

10‧‧‧Touch unit array

100‧‧‧Touch unit

11‧‧‧ directive

12‧‧‧Processing module

14‧‧‧ memory

20, 22‧‧‧ touch action

30, 32‧‧‧ Touch action

1 is a block diagram of a touch panel according to an embodiment of the present invention; FIGS. 2A to 2D are respectively schematic views of a touch unit column in an embodiment of the present invention; and FIG. 3 is a schematic diagram of the present invention; In the embodiment, a schematic diagram of a column of touch units.

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Please refer to Figure 1. FIG. 1 is a block diagram of a touch panel 1 according to an embodiment of the present invention. The touch panel 1 includes a touch unit array 10 , a processing module 12 , and a memory 14 .

The touch unit array 10 includes a plurality of touch units 100 and is arranged For example, the touch unit rows Y1-Y5 and the touch unit rows X1-X5 are shown in FIG. 1 , wherein the touch unit rows Y1-Y5 are depicted in black, and the touch unit columns X1-X5 are in white. Painted. The touch unit 100 can be divided into a plurality of touch unit groups, each corresponding to one touch unit row Y1-Y5 or one touch unit column X1-X5. It should be noted that the number of rows and the number of columns of the touch unit may be adjusted according to actual needs in different embodiments, and is not limited to the embodiment of FIG. 1 .

In an embodiment, the touch panel 1 is, for example, but not limited to, a capacitive touch panel. When the touch unit 100 is not in contact, its voltage value will be a preset value. When the touch action is applied, the voltage value of the touch unit 100 will change and decrease due to the internal capacitance value being affected by the touch object, and become a value smaller than the preset value. In more detail, when the touch unit 100 is not in the touch state to the touched state, the voltage value thereof will change from the preset value to a value smaller than the preset value. When the touch unit 100 returns from the touched state to the untouched state, the voltage value thereof will change from a value smaller than the preset value to a preset value.

In one embodiment, when the touch unit 100 is not in contact, its voltage value is, for example, but not limited to, 1 volt, and when a touch action is applied, the voltage value thereof will be a value less than 1 volt, for example, Not limited to 0.5 volts. In other embodiments, the voltage value of the touch unit 100 when the touch operation is not applied and the touch operation is applied may be different depending on the actual situation, and is not limited by the above numerical values. In one embodiment, the touch panel 1 can be sequentially scanned by the touch unit 100 included in each of the touch unit columns X1-X5 by, for example, but not limited to, a column-by-column cyclic scan. Know each touch The voltage value of the unit 100 is further determined according to the obtained voltage value, and the touch unit 100 is actually subjected to a touch action.

The processing module 12 is coupled to the touch unit array 10 and the memory 14 . The processing module 12 can be a variety of processors with computing power. The memory 14 is in various embodiments such as, but not limited to, a read only memory, a flash memory, a floppy disk, a hard disk, a compact disk, a flash drive, a magnetic tape, a network accessible database, or other types of memory. A plurality of computer executable instructions 11 are stored and coupled to the processing module 12. When the processing is performed by the processing module 12 according to the instruction 11 stored in the memory 14, the touch detection method applied to the touch panel 1 can be performed and provided. The processing operation performed by the processing module 12 will be described below.

Please refer to Figures 2A to 2D. 2A to 2D are schematic views of the touch unit column X1 in the embodiment of the present invention. In the embodiment, five touch units X11-X15 included in the touch unit column X1 are illustrated.

In the initial mode in which the touch panel 1 is just activated, each touch unit group of the touch panel 1 starts to detect. In one embodiment, the touch panel 1 scans the column-by-column cycle, and sequentially scans the touch unit 100 in each touch cell row to sequentially obtain a plurality of initial detection voltage values. . As described above, in an embodiment, when the touch unit 100 is not in contact, its voltage value is 1 volt, and when the touch operation is applied, the voltage value thereof is 0.5 volt.

Taking the touch unit row X1 shown in FIG. 2A as an example, in the initial mode, the user's left hand holds the electronic device equipped with the touch panel 1 When the device touches the touch panel 1 and causes the touch action 20 of the left hand to be applied to, for example, the touch unit X12, the processing module 12 can obtain the initial detection voltage value Vi1- according to the arrangement order of the five touch units X11-X15. Vi5 is 1, 0.5, 1, 1 and 1 volt, respectively.

Then, the processing module 12 performs differential calculation on the adjacent two initial detection voltage values sequentially from the next to the previous subtraction to obtain the complex initial differential voltage values Vid1-Vid4. Taking the values of the initial detection voltage values Vi1-Vi5 as an example, the initial differential voltage values Vid1-Vid4 can be respectively calculated by the following equations: Vid1=Vi2-Vi1=-0.5; Vid2=Vi3-Vi2=0.5; Vid3=Vi4-Vi3=0; Vid4=Vi5-Vi4=0.

The processing module 12 will make the initial differential voltage values Vid1-Vid4 (-0.5, 0.5, 0, 0) as a set of reference values Vb1-Vb4 of the touch unit column X1. In one embodiment, the processing module 12 can store the reference values Vb1 - Vb4 in the memory 14 or other storage modules (not shown) disposed in the touch panel 1 .

In the operation mode after the initial mode, each touch unit group will continue to detect. In one embodiment, the touch panel 1 scans in a column-by-column manner, and sequentially scans the touch units 100 in each touch unit row to obtain a complex detection voltage value Vs1-Vs5. .

Taking the touch unit row X1 shown in FIG. 2B as an example, if the left hand of the user has not been removed, the touch action 20 is maintained, and the right hand is simultaneously touched. For example, in the touch unit X13, the processing module 12 can obtain the detection voltage values Vs1 - Vs5 according to the order of the five touch units X11-X15, which are 1, 0.5, 0.5, 1, and 1 volt, respectively.

Then, the processing module 12 performs differential calculation on the adjacent two detected voltage values sequentially from the next one to the previous subtraction to obtain the complex differential voltage values Vd1 - Vd4. Taking the values of the detected voltage values Vs1 - Vs5 as an example, the differential voltage values Vd1 - Vd4 can be respectively calculated by the following equations: Vd1 = Vs2 - Vs1 = -0.5; Vd2 = Vs3 - Vs2 = 0; Vd3 = Vs4-Vs3 = 0.5; Vd4 = Vs5 - Vs4 = 0.

The processing module 12 further subtracts the differential voltage values Vd1 - Vd4 (-0.5, 0, 0.5, 0) from the reference values Vb1 - Vb4 (-0.5, 0.5, 0, 0) to sequentially generate the complex difference value Ve1- Ve4. Therefore, the difference values Ve1 - Ve4 can be respectively calculated by the following equations: Ve1 = Vd1 - Vb1 = 0; Ve2 = Vd2 - Vb2 = -0.5; Ve3 = Vd3 - Vb3 = 0.5; Ve4 = Vd4 - Vb4 = 0.

The processing module 12 determines the positive and negative order relationship of the difference values Ve1-Ve4. In this embodiment, when the difference values Ve1-Ve4 have a previous negative number and a subsequent positive number, for example, the gap values Ve2 and Ve3 of -0.5 and 0.5, respectively, the processing module 12 determines the touch. In the unit column X1, the position corresponds to the front negative number and the touch unit X13 between the latter positive numbers Apply a point to the touch. That is, the touch unit X13 has not been touched in the previous state (ie, the state of FIG. 2A), but has been touched in the current state (ie, the state of FIG. 2B), and the touch application is formed. point.

It should be noted that since the difference values Ve2 and Ve3 are generated according to the differential voltage values Vd2 and Vd3, the differential voltage values Vd2 and Vd3 are generated based on the detected voltage values Vs2 and Vs3 and the detected voltage values Vs3 and Vs4, respectively. Therefore, the position corresponding to the gap value Ve2 and Ve3 is the touch unit X13 related to the intersection of the two detected voltage values, that is, the detected voltage value Vs3.

Further, when there is no preceding positive number and one subsequent negative number in the gap value, the processing module 12 will retain the original reference value Vb1-Vb4 (-0.5, 0.5, 0, 0) without updating. .

When the touch unit row X1 is as shown in FIG. 2C, the touch action 22 applied by the user's right hand to the touch unit X13 still exists, and the touch action originally applied to the touch unit X12 by the left hand has been removed. The processing module 12 can obtain new detection voltage values Vs1'-Vs5' according to the order of the five touch units X11-X15, which are 1, 1, 0.5, 1, and 1 volt, respectively.

Then, the processing module 12 performs differential calculation on the adjacent two detected voltage values sequentially from the next one to the previous subtraction to obtain the complex differential voltage values Vd1'-Vd4'. Taking the value of the detected voltage value Vs1'-Vs5' as an example, the differential voltage values Vd1'-Vd4' can be calculated by the following equations: Vd1'=Vs2'-Vs1'=0; Vd2'=Vs3 '-Vs2'=-0.5; Vd3'=Vs4'-Vs3'=0.5; Vd4' = Vs5' - Vs4' = 0.

The processing module 12 further subtracts the differential voltage value Vd1'-Vd4' (0, -0.5, 0.5, 0) from the reference value Vb1 - Vb4 (-0.5, 0.5, 0, 0) to sequentially generate a complex difference value. Ve1'-Ve4'. Therefore, the difference values Ve1'-Ve4' can be calculated by the following equations respectively: Ve1'=Vd1'-Vb1=0.5; Ve2'=Vd2'-Vb2=-1; Ve3'=Vd3'-Vb3=0.5; Ve4'=Vd4'-Vb4=0.

The processing module 12 determines the positive and negative order relationship of the difference values Ve1'-Ve4'. In the present embodiment, when the two adjacent gap values of the gap values Ve1'-Ve4' have a preceding positive number and a subsequent negative number, for example, gap values Ve1' and Ve2' of 0.5 and -1, respectively, The processing module 12 will determine that the touched object in the touch unit column X1 is just removed compared to the time point of the previous scan. Therefore, the processing module 12 stores the differential voltage values Vd1'-Vd4' (0, -0.5, 0.5, 0) as the reference values Vb1'-Vb4'. Since the difference values Ve2' and Ve3' are still a previous negative number and a subsequent positive number, the processing module 12 still determines that the touch unit X13 is a touch application point.

When the touch unit row X1 is further removed from the touch action 22 of the touch unit X13 as shown in FIG. 2D, the processing module 12 can be arranged according to the order of the five touch units X11-X15. A new detected voltage value Vs1"-Vs5" is obtained, which is 1, 1, 1, 1 and 1 volt, respectively.

Then, the processing module 12 performs differential calculation on the adjacent two detected voltage values sequentially from the previous one to the previous subtraction to obtain a complex difference. Voltage value Vd1"-Vd4". Taking the value of the detected voltage value Vs1"-Vs5" as an example, the differential voltage values Vd1"-Vd4" can be respectively calculated by the following equation: Vd1"=Vs2"-Vs1"=0; Vd2"=Vs3 "-Vs2" = 0; Vd3" = Vs4" - Vs3" = 0; Vd4" = Vs5" - Vs4" = 0.

The processing module 12 further subtracts the differential voltage values Vd1"-Vd4" (0, 0, 0, 0) from the reference value Vb1'-Vb4' (0, -0.5, 0.5, 0) that has just been updated, in order. A complex difference value Ve1"-Ve4" is generated. Therefore, the difference values Ve1"-Ve4" can be calculated by the following equations respectively: Ve1"=Vd1"-Vb1'=0; Ve2"=Vd2"-Vb2'=0.5; Ve3"=Vd3"-Vb3'= -0.5; Ve4" = Vd4" - Vb4' = 0.

The processing module 12 determines the positive and negative order relationship of the difference values Ve1"-Ve4". In the present embodiment, since the difference values Ve2" and Ve3" of 0.5 and -0.5, respectively, are a preceding positive number and a subsequent negative number, the processing module 12 judges the time point of the previous scan. The touch unit X13 in the touch unit column X1 is a touch removal point. That is, the touch unit X13 has a touch in the previous state (ie, the state of FIG. 2C), and has been removed in the current state (ie, the state of the 2D image) to form a touch removal. point.

Therefore, the processing module 12 will detect that the touch unit column X1 has In the case of the touch removal point, the differential voltage values Vd1"-Vd4" (0, 0, 0, 0) are stored as the reference values Vb1" - Vb4".

Therefore, the touch panel 1 of the present invention determines the touch application point and the touch removal point by calculating the difference between the differential voltage value and the reference value and the positive and negative order relationship between the difference values. Therefore, even if the user has touched the touch panel 1 in the initial mode, the touch panel 1 can determine the new touch application point without being affected, and can update the reference value in the case where the touch object is removed. The touch panel 1 can avoid the judgment of the touch behavior when the operation mode is affected due to the incorrect reference value caused by the user's prior contact in the initial mode.

It should be noted that the above embodiment is an example of the touch unit column X1. In the actual application, all the touch unit rows X1-X5 and the touch unit rows Y1-Y5 in the touch panel 1 can use the above mechanism to determine the touch and whether to update the reference value. Further, in the above-described embodiment, the description is given by the fact that the preceding positive number and the subsequent negative number are adjacent, and the preceding negative number and the subsequent positive number are adjacent. The same mechanism can be used for judgment and processing when the preceding positive number and the negative number or the preceding negative number and the last positive number are not adjacent. Anyone skilled in the art can avoid the spirit and scope of the disclosure. It can be inferred internally, so it will not be described again.

Please refer to Figure 3. FIG. 3 is a schematic diagram of the touch unit column X1 in the embodiment of the present invention.

In an embodiment, the processing module 12 further considers the front-end virtual touch unit X10 and the back-end virtual touch unit X16 included in the touch unit column X1, and is located in the touch unit X11-X15. On both sides. In FIG. 3, the front virtual touch unit X10 and the back virtual touch unit X16 are shown by dashed lines. The voltage values of the front virtual touch unit X10 and the back virtual touch unit X16 are preset values regardless of the initial detection voltage value in the initial mode or the detection voltage value in the operation mode.

For example, if the touch unit column X1 is not previously subjected to any touch action, and after considering the front virtual touch unit X10 and the back virtual touch unit X16, the reference values VB0-VB5 will be (0, 0,0,0,0,0). When the touch unit row X1 is in the state as shown in FIG. 3, touch operations 30 and 32 are applied to the touch units X11 and X15. Therefore, the processing module 12 can obtain the detection voltage values VS0-VS6 according to the arrangement order of the front virtual touch unit X10, the five touch units X11-X15, and the back virtual touch unit X16, which are 1, 0.5, and 1, respectively. 1, 1, 1, 0.5 and 1 volt.

Then, the processing module 12 performs differential calculation on the adjacent two detected voltage values sequentially from the previous one to the previous subtraction to obtain the complex differential voltage values VD0-VD5. Taking the above-mentioned detection voltage values VS0-VS6 as an example, the differential voltage values VD0-VD5 can be calculated by the following equations: VD0=VS1-VS0=-0.5; VD1=VS2-VS1=0.5; VD2= VS3-VS2=0; VD3=VS4-VS3=0; VD4=VS5-VS4=-0.5; VD5=VS6-VS5=0.5.

The processing module 12 further divides the differential voltage values VD0-VD5 (-0.5, 0.5, 0, 0, -0.5, 0.5) is subtracted from the reference value VB0-VB5 (0, 0, 0, 0, 0, 0) to sequentially generate the complex difference values VE0-VE5. Therefore, the difference values VE0-VE5 can be calculated by the following equations: VE0=VD0-VB0=-0.5; VE1=VD1-VB1=0.5; VE2=VD2-VB2=0; VE3=VD3-VB3=0; VE4=VD4-VB4=-0.5; VE5=VD5-VB5=0.5.

Since the gap values VE0 and VE1 appear in the order of the front negative number and the last positive number, and the gap values VE4 and VE5 also appear in the order of the front negative number and the last positive number, the processing module 12 will determine the touch unit column X1. The touch unit X11 corresponding to the gap value VE0 and VE1 and the touch unit X15 corresponding to the gap value VE4 and VE5 are touch application points.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., which are within the spirit and principles of the present invention, should be included in the present invention. Within the scope of protection.

The present disclosure has been disclosed in the above embodiments, but it is not intended to limit the disclosure, and any person skilled in the art can make various changes and refinements without departing from the spirit and scope of the disclosure. The scope of protection of the disclosure is subject to the definition of the scope of the patent application.

1‧‧‧ touch panel

10‧‧‧Touch unit array

100‧‧‧Touch unit

11‧‧‧ directive

12‧‧‧Processing module

14‧‧‧ memory

Claims (6)

A touch panel includes: a touch unit array, wherein the plurality of touch units are arranged in a plurality of touch units and a plurality of touch units; and a processing module coupled to the touch The unit array; and a memory having a computer-executable plurality of instructions stored therein coupled to the processing module, when the instructions are executed by the processing module, performing the following actions: One of the touch panel groups of the touch panel performs detection to sequentially obtain a plurality of initial detection voltage values, and sequentially subtracts each of the two adjacent initial detection voltage values from the next one to the previous one. Performing a differential calculation to obtain a plurality of initial differential voltage values, wherein the touch unit group corresponds to one of the touch unit rows and the touch unit columns; and the initial differential voltage values are used as the touch One set of reference values of the control unit group; one of the operation modes of the initial mode causes the touch unit group to detect, to sequentially obtain the complex detection voltage value, and the two adjacent ones are The detected voltage value is sequentially followed by Performing a differential calculation on the previous subtraction to obtain a complex differential voltage value; and sequentially subtracting the differential voltage values from the set of reference values, and sequentially generating a complex difference value according to one of the difference values The positive or negative sequence relationship determines whether the touch unit group includes at least one touch application point and at least one touch removal point, so that the touch unit group includes the When the touch removal point is touched, the set of reference values is updated to the set of differential voltage values. The touch panel of claim 1, wherein when one of the touch units is not touched, one of the corresponding detection voltage values is equivalent to a preset value, and when touched Less than the preset value. The touch panel of claim 2, wherein the processing module determines that the position in the touch unit group corresponds to the previous one when the difference value includes a front negative number and a rear positive number The negative number and the at least one of the touch units between the negative numbers are respectively applied to the touch. The touch panel of claim 2, wherein the processing module determines that the touch control group includes the touch removal point when the difference value includes a front positive number and a negative negative order . The touch panel of claim 4, wherein the processing module retains the original set of reference values when the difference between the previous positive number and the negative number is not present. The touch panel of claim 2, wherein the touch unit group further includes a front virtual touch unit and a back virtual touch unit, and two of the plurality of touch units included in the touch unit group And the initial detection voltage value and the detection voltage value corresponding to the front-end virtual touch unit and the back-end virtual touch unit are the preset values.