TWI443571B - Touch sensing apparatus - Google Patents

Description

Touch sensing device

The present invention relates to a liquid crystal display; in particular, the present invention relates to a mutual inductance capacitive touch sensing device capable of improving sensing voltage accuracy and maintaining anti-noise capability.

With the rapid development of technology, thin film transistor liquid crystal display (TFT LCD) has gradually replaced traditional displays, and has been widely used in various electronic products such as televisions, flat panel displays, mobile phones, tablet computers and projectors. For a thin film transistor liquid crystal display with touch function, the touch sensor is one of its important modules, and its performance directly affects the overall performance of the liquid crystal display.

In general, a conventional liquid crystal display having a mutual capacitive touch function includes a display panel, an ITO sensor, and a touch control chip. The conductive film sensor includes a plurality of sensing lines and a plurality of driving lines, and the touch control chip includes a plurality of pins. The sensing lines are respectively coupled to the pins. After the driving line transmits a driving pulse and a small voltage is coupled to the sensing line, the touch control chip senses the coupling voltage and determines whether the conductive film sensor is touched according to the magnitude of the coupling voltage.

Specifically, the performance of the touch sensing device depends on the sensing voltage accuracy of the conductive film sensor. The touch sensing device includes an amplification module, and the input mode of the amplification module can be divided into a differential input mode and a single-ended input mode. The advantage of using the differential input mode is that it has good anti-noise capability, but its disadvantage is that it cannot sense accurate voltage information on the panel boundary. The advantage of using the single-ended input mode is that it can accurately sense the voltage at the panel boundary, but its ability to resist noise is poor. Therefore, regardless of whether the input mode of the conventional touch sensing device is a differential input mode or a single-ended input mode, the above disadvantages exist, so that the performance of the overall touch sensing device cannot be improved.

Therefore, the present invention proposes a mutual-inductance capacitive touch sensing device capable of improving the accuracy of the sensing voltage and maintaining good anti-noise capability to solve the above problem.

One aspect of the present invention is to provide a touch sensing device. In one embodiment, the touch sensing device includes a logic control module and a multiplexer. The multiplexer includes a switching module. The switching module includes a plurality of pairs of differential input switches and a pair of single-ended input switches. The switching module controls the opening and closing of the plurality of differential input switches and the pair of single-ended input switches according to the switching control signal to control an input mode of the plurality of sensing voltages. The sensing voltages are analog data of a plurality of sensing lines respectively sensed from the conductive film inductor, and the plurality of sensing lines respectively correspond to the plurality of channels.

In one embodiment, the touch sensing device further includes an amplification module. The amplification module includes a positive input terminal and a negative input terminal. The amplifying module subtracts and amplifies the two voltages received from the positive input terminal and the negative input terminal according to the amplification control signal in the control signals, and outputs the amplified analog data.

In one embodiment, the pair of single-ended input switches includes a positive single-ended input switch and a negative single-ended input switch. Each pair of differential input switches includes a positive differential input switch and a negative differential input switch. Both the positive differential input switch and the negative differential input switch are coupled to the reference voltage. The positive differential input switches are coupled to the positive input terminal of the amplification module and the positive single-ended input switch, and the negative differential input switches are coupled to the negative input terminal and the negative single-ended input switch of the amplification module.

In an embodiment, the touch sensing device further includes an analog/digital conversion module. The analog/digital conversion module is coupled to the logic control module for converting the amplified analog data into a digital data and outputting the digital data to the logic control module.

In one embodiment, the touch sensing device further includes a storage control module. The storage control module includes a first switch, a second switch, a third switch, and a storage capacitor. The second switch is coupled between the output end of the amplifying module and the analog/digital conversion module; one end of the first switch is coupled between the second switch and the analog/digital conversion module, and the other end is coupled to the ground end One end of the third switch is coupled between the second switch and the analog/digital conversion module and the other end is coupled to the storage capacitor; the storage capacitor is coupled to the ground. The storage capacitor stores the amplified analog data according to the storage control signal in the control signals.

In one embodiment, the touch sensing device further includes a plurality of pins. The multiplexer further includes at least one drive/sense control module. The driving/sensing control module is coupled to the logic control module, the pins, and the switching module for controlling the pins to perform a plurality of pin functions according to the driving/sensing control signals of the control signals. And causing the pins to sense the sensing voltages from the sensing lines of the conductive film inductor.

In an embodiment, in the first single-ended input mode, the switching module controls the positive single-ended input switch to be turned on according to the switching control signal, so that the positive input end of the amplification module is coupled to the reference voltage, and the negative input terminal receives the conductive The first boundary of the thin film sensor senses the voltage.

In an embodiment, in the first differential input mode, the switching module controls the negative difference between the positive differential input switch and the second differential input switch of the adjacent first pair of differential input switches according to the switching control signal. The input switch is turned on, so that the positive input terminal of the amplification module receives the first sensing voltage and the negative input terminal receives the second sensing voltage; in the second differential input mode, the switching module controls the first pair according to the switching control signal The positive differential input switch of the differential input switch and the positive differential input switch of the second pair of differential input switches are turned on, such that the positive input terminal receives the second sense voltage and the negative input terminal receives the third sense voltage.

In an embodiment, in the second single-ended input mode, the switching module controls the negative single-ended input switch to be turned on according to the switching control signal, so that the positive input end of the amplification module receives the second boundary sensing of the conductive film sensor. The voltage and the negative input are coupled to the reference voltage.

In an embodiment, when the multiplexer receives the first boundary sensing voltage or the second boundary sensing voltage of the conductive thin film sensor, the logic control module transmits the switching control signal to the switching module to execute The first single-ended input mode or the second single-ended input mode.

Compared with the prior art, the touch sensing device according to the present invention generates a switching control signal through a logic control module, so that the switching module of the multiplexer controls the opening of the differential pair differential input switch and the pair of single-ended input switches. Or off, thereby enabling the touch sensing device to arbitrarily switch between the differential input mode and the single-ended input mode. In general, the touch sensing device receives the sensing voltage sensed by the boundary sensing pin of the conductive thin film display, and the switching module activates the differential input mode. Once the touch sensing device receives the sensing voltage sensed by the boundary sensing pin of the conductive thin film display, the switching module initiates the single-ended input mode. Therefore, the touch sensing device of the present invention can control the voltage output mode through the switching module, which can not only effectively improve the accuracy of the sensing voltage, but also maintain good anti-noise capability and save the functions required for the above functions. Memory space.

The advantages and spirit of the present invention will be further understood from the following detailed description of the invention.

A touch sensing device according to an embodiment of the invention. In this embodiment, the touch sensing device may be a mutual-capacitive capacitive touch sensing device, but is not limited thereto.

Please refer to FIG. 1 . FIG. 1 is a schematic diagram of the touch sensing device 1 of the present invention performing touch point sensing on a display panel. As shown in FIG. 1 , the liquid crystal display includes a conductive film sensor 100 and a touch sensing device 1 . The liquid crystal display panel is generally attached to the conductive film sensor 100, but is not limited thereto. The touch sensing device 1 includes a logic control module 10 , a plurality of pins 20 , at least one multiplexer 30 , at least one amplification module 40 , at least one storage control module 50 , and an analog/digital conversion module 60 . Each of the multiplexers 30 includes a driving/sensing control module 300 and a switching module 302.

The logic control module 10 is coupled to the driving/sensing control module 300, the switching module 302, the amplifying module 40, and the storage control module 50; the driving/sensing control module 300 is coupled to the interfaces The switch module 302 is coupled to the amplifier module 40; the amplifier module 40 is coupled to the storage control module 50; the storage control module 50 is coupled to the analog/digital converter module 60; The /digital conversion module 60 is coupled to the logic control module 10 .

As shown in FIG. 1, the conductive film sensor 100 includes a plurality of sensing lines 80 and a plurality of driving lines 90 that are vertically distributed with each other. It should be noted that the driving line 90 and the sensing line 80 are interchangeable, that is, the 90 in FIG. 1 can also be used as a sensing line, and the 80 in FIG. 1 can also be used as a driving line. Control device 1 controls.

The pins 20 not only have a single function, but can switch between different functions according to actual needs, such as driving function, sensing function, ground function or floating. Function, but not limited to this. Each of the driving/sensing control modules 300 controls the pins 20 to perform a sensing function according to the sensing control signals in the control signals to sense the sensing lines 80 or 90 of the conductive film sensor 100. To multiple analog data.

Each of the driving/sensing control modules 300 receives the driving/sensing control signals in the control signals from the logic control module 10, and controls the pins according to the driving/sensing control timing of the driving/sensing control signals. The plurality of pin functions are respectively performed by the plurality of pins, such that the pins 20 are capable of sensing a plurality of sensing voltages from the plurality of sensing lines 80 or 90 of the conductive film sensor 100, respectively. In this embodiment, the drive/sense control module 300 includes a complex array drive/sense switch. As shown in FIG. 2, the driving/sensing control module 300 includes a first group of driving/sensing switches SW11~SW13, a first grounding switch SW14, a second group of driving/sensing switches SW21~SW23 and a second grounding switch SW24. . The driving/sensing switches SW11~SW13 are respectively coupled to the pins S1, S3 and S5; the driving/sensing switches SW21~SW23 are respectively coupled to the pins S2, S4 and S6; the first grounding switch SW14 is The grounding switch SW24 is coupled between one end of the driving/sensing switch SW21~SW23 and the grounding end.

Assuming that the first grounding switch SW14 and the second grounding switch SW24 are both in a closed state, when the driving/sensing switches SW11 and SW21 are turned on, the first sensing voltage and the second sensing voltage measured by the pins S1 and S2 are The driving/sensing switches SW11 and SW21 can be respectively output to the switching module 302; when the driving/sensing switches SW12 and SW22 are turned on, the third sensing voltage and the fourth sensing voltage measured by the pins S3 and S4 are respectively The driving/sensing switches SW12 and SW22 can be respectively output to the switching module 302; when the driving/sensing switches SW13 and SW23 are turned on, the fifth sensing voltage and the sixth sensing measured by the pins S5 and S6 are respectively The voltages can be output to the switching module 302 through the drive/sense switches SW13 and SW23, respectively.

In this embodiment, the logic control module 10 generates a plurality of control signals of different control timings, and the control signals include switching control signals. The switching module 302 includes a plurality of pairs of differential input switches and a pair of single-ended input switches. As shown in FIG. 2, the switching module 302 includes a first pair of differential input switches SW31 and SW32, a second pair of differential input switches SW41 and SW42, and a pair of single-ended input switches SW51 and SW52. Wherein, SW31 is a first positive differential input switch and SW32 is a first negative differential input switch; SW41 is a second positive differential input switch and SW42 is a second negative differential input switch; SW51 is a positive single-ended input switch and SW52 is a negative single-ended input switch. The positive single-ended input switch SW51 and the negative single-ended input switch SW52 are both coupled to a reference voltage Vt, and the first positive differential input switch SW31 and the second positive differential input switch SW41 are coupled to the positive input of the amplification module 40. The first negative differential input switch SW32 and the second negative differential input switch SW42 are coupled to the negative input terminal of the amplification module 40 and the negative single-ended input switch SW52.

The switching module 302 controls the first positive differential input switch SW31 and the first negative differential input switch SW32 of the first pair of differential input switches and the second positive of the second pair of differential input switches according to the switching control signal. The differential input switch SW41 and the second negative differential input switch SW42 and the positive single-ended input switch SW51 and the negative single-ended input switch SW52 of the pair of single-ended input switches are turned on or off to control the input of the plurality of sensing voltages. mode. The sensing voltages are analog data of a plurality of sensing lines 80 or 90 respectively sensed from the conductive film sensor 100, and the plurality of sensing lines 80 or 90 respectively correspond to a plurality of channels.

Next, the case where the touch sensing device 1 operates in various single-ended input modes and differential input modes will be described. It should be noted that when the input sensing voltage belongs to the beginning or the last boundary sensing voltage, the touch sensing device 1 will operate in the single-ended input mode to obtain complete information; as for other non-boundaries In the case of sensing voltage, the touch sensing device 1 will operate in the differential input mode to enhance its anti-noise capability. The touch sensing device 1 can be freely switched between the single-ended input mode and the differential input mode according to actual needs, and is not limited to the following embodiments.

As shown in FIG. 2, in this embodiment, since the touch sensing device 1 includes a total of six pins S1 S S6, the first sensing voltages of the first and last input pins S1 and S6 are provided. Both the sixth sensing voltage and the sixth sensing voltage belong to the boundary sensing voltage. First, since the sensing voltage V1 initially input belongs to the boundary sensing voltage, at the first time point, the touch sensing device 1 will operate in the first single-ended input mode, and the driving/sensing switches SW11 and SW21 Open. In the first single-ended input mode, the switching module 302 will control the positive single-ended input switch SW51 to be turned on according to the switching control signal, so that the positive input terminal + of the amplification module 40 is coupled to the reference voltage Vt, and the amplification module 40 Negative input - will receive the first sense voltage of pin S1. At this time, the first sensing voltage of the pin S1 belongs to the boundary sensing voltage.

Then, since the sensing voltage of the subsequent input no longer belongs to the boundary sensing voltage, but belongs to the non-boundary sensing voltage, the touch sensing device 1 will alternately operate in the first differential input mode and the second In differential input mode.

At the second time, the driving/sensing switches SW11 and SW21 are turned on, and the first sensing voltage of the pin S1 and the second sensing voltage of the pin S2 can be output to the switching module through the driving/sensing switches SW11 and SW21. 302. At this time, the touch sensing device 1 operates in the first differential input mode, and the switching module 302 controls the first positive differential input switch SW31 and the second of the first pair of differential input switches according to the switching control signal. The second negative differential input switch SW42 of the differential input switch is turned on, so that the positive input terminal of the amplification module 40 + the first sensing voltage of the receiving pin S1 and the negative input terminal of the amplifying module 40 - the receiving pin The second sense voltage of S2. At this time, both the first sensing voltage of the pin S1 and the second sensing voltage of the pin S2 belong to the non-boundary sensing voltage.

At the third time, the driving/sensing switches SW21 and SW12 are turned on, and the second sensing voltage of the pin S2 and the third sensing voltage of the pin S3 can be output to the switching module through the driving/sensing switches SW21 and SW12. 302. At this time, the touch sensing device 1 operates in the second differential input mode, and the switching module 302 controls the first negative differential input switch SW32 and the second pair of the first pair of differential input switches according to the switching control signal. The second positive differential input switch SW41 of the dynamic input switch is turned on, so that the positive input terminal of the amplification module 40 + the second sensing voltage of the receiving pin S2 and the negative input terminal of the amplifying module 40 - the receiving pin S3 The third sensing voltage. At this time, the second sensing voltage of the pin S2 and the third sensing voltage of the pin S3 belong to the non-boundary sensing voltage.

At the fourth time, the driving/sensing switches SW12 and SW22 are turned on, and the third sensing voltage of the pin S3 and the fourth sensing voltage of the pin S4 can be output to the switching module through the driving/sensing switches SW12 and SW22. 302. At this time, the touch sensing device 1 returns to operate in the first differential input mode, and the switching module 302 controls the first positive differential input switch SW31 of the first pair of differential input switches according to the switching control signal. And opening the second negative differential input switch SW42 of the second pair of differential input switches, so that the positive input terminal of the amplification module 40 + the third sensing voltage of the receiving pin S3 and the negative input terminal of the amplification module 40 - The fourth sensing voltage of the pin S4 is received. At this time, the third sensing voltage of the pin S3 and the fourth sensing voltage of the pin S4 belong to the non-boundary sensing voltage.

At the fifth time point, the driving/sensing switches SW22 and SW13 are turned on, and the fourth sensing voltage of the pin S4 and the fifth sensing voltage of the pin S5 can be output to the switching module through the driving/sensing switches SW22 and SW13. 302. At this time, the touch sensing device 1 will operate in the second differential input mode, and the switching module 302 controls the first negative differential input switch SW32 and the second of the first pair of differential input switches according to the switching control signal. The second positive differential input switch SW41 of the differential input switch is turned on, so that the positive input terminal of the amplification module 40 + the fourth sensing voltage of the receiving pin S4 and the negative input terminal of the amplification module 40 - the receiving pin The fifth sense voltage of S5. At this time, the fourth sensing voltage of the pin S4 and the fifth sensing voltage of the pin S5 belong to the non-boundary sensing voltage.

At the sixth time point, the driving/sensing switches SW13 and SW23 are turned on, and the fifth sensing voltage of the pin S5 and the sixth sensing voltage of the pin S6 can be output to the switching module through the driving/sensing switches SW13 and SW23. 302. At this time, the touch sensing device 1 returns to operate in the first differential input mode, and the switching module 302 controls the first positive differential input switch SW31 of the first pair of differential input switches according to the switching control signal. And the second negative differential input switch SW42 of the second pair of differential input switches is turned on, so that the positive input terminal of the amplification module 40 + the fifth sensing voltage of the receiving pin S5 and the negative input terminal of the amplification module 40 - The sixth sense voltage of the pin S6 is received. At this time, the fifth sensing voltage of the pin S5 and the sixth sensing voltage of the pin S6 belong to the non-boundary sensing voltage.

Finally, at the seventh time point, since the sixth sensing voltage input from the pin S6 belongs to the boundary sensing voltage, the touch sensing device 1 will operate in the second single-ended input mode, driving/sensing The test switches SW13 and SW23 are turned on. In the second single-ended input mode, the switching module 302 will control the negative single-ended input switch SW52 to be turned on according to the switching control signal, so that the positive input terminal of the amplification module 40 receives the sixth sensing voltage of the pin S6. The negative input terminal of the amplification module 40 is coupled to the reference voltage Vt. At this time, the sixth sensing voltage of the last input pin S6 belongs to the boundary sensing voltage.

Regardless of which of the above input modes, when the positive input terminal + and the negative input terminal of the amplification module 40 respectively receive the respective sensing voltages or reference voltages, the amplification control signals transmitted according to the logic control module 10 will be used. After subtracting and amplifying the two sensing voltages or reference voltages received from the positive input terminal + the negative input terminal, an amplified analog data is output to the storage control module 50.

As shown in FIG. 2, the storage control module 50 includes a first switch SW61, a second switch SW62, a third switch SW63, and a storage capacitor C. The second switch SW62 is coupled between the output end of the amplification module 40 and the analog/digital conversion module 60. One end of the first switch SW61 is coupled between the second switch SW62 and the analog/digital conversion module 60. The other end is coupled to the ground end; the third end of the third switch SW63 is coupled between the second switch SW62 and the analog/digital conversion module 60, and the other end is coupled to the storage capacitor C. The storage capacitor C is coupled to the ground. . When the storage control module 50 controls the second switch SW62 and the third switch SW63 to be turned on according to the storage control signal transmitted from the logic control module 10, the amplified analog data outputted from the output end of the amplification module 40 can pass through the second The switch SW62 and the third switch SW63 are transmitted to the storage capacitor C. Then, after the storage control module 50 controls the third switch SW63 to be turned off according to the storage control signal, the storage capacitor C can store the amplified analog data.

Before the analog data is output and stored in the storage capacitor C, the logic control module 10 transmits a ground control signal to the storage control module 50, so that the grounding switch SW61 is turned on, and the voltage stored on the storage capacitor C is discharged first. Increase the accuracy of the sensing. In fact, the structure of the storage control module 50 can be changed according to actual needs, and is not limited to the one shown in FIG.

The analog/digital conversion module 60 is coupled to the storage control module 50 and the logic control module 10 for converting the amplified analog data into digital data and outputting the digital data to the logic control module 10. In fact, the amplification module 40 can be any form of amplifier, and the analog/digital conversion module 60 can be any type of analog/digital converter, and is not particularly limited.

Compared with the prior art, the touch sensing device according to the present invention generates a switching control signal through a logic control module, so that the switching module of the multiplexer controls the opening of the differential pair differential input switch and the pair of single-ended input switches. Or off, thereby enabling the touch sensing device to arbitrarily switch between the differential input mode and the single-ended input mode. In general, the touch sensing device receives the sensing voltage sensed by the boundary sensing pin of the conductive thin film display, and the switching module activates the differential input mode. Once the touch sensing device receives the sensing voltage sensed by the boundary sensing pin of the conductive thin film display, the switching module initiates the single-ended input mode. Therefore, the touch sensing device of the present invention can control the voltage output mode through the switching module, which can not only effectively improve the accuracy of the sensing voltage, but also maintain good anti-noise capability and save the functions required for the above functions. Memory space.

The features and spirit of the present invention will be more apparent from the detailed description of the preferred embodiments. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed.

1. . . Touch sensing device

10. . . Logic control module

20. . . Pin

30. . . Multiplexer

100. . . Conductive film sensor

40. . . Amplification module

50. . . Storage control module

S1~S6. . . Pin

60. . . Analog/digital conversion module

80. . . Sensing line

300. . . Drive/sense control module

90. . . Drive line

302. . . Switching module

SW14, SW24. . . Grounding switch

SW11~SW13, SW21~SW23. . . Drive/sense switch

SW31. . . First positive differential input switch

SW32. . . First negative differential input switch

SW41. . . Second positive differential input switch

SW42. . . Second negative differential input switch

SW51. . . Positive single-ended input switch

SW52. . . Negative single-ended input switch

SW61. . . Grounding switch

SW62. . . Second switch

SW63. . . Third switch

Vt. . . Reference voltage

+. . . Positive input of the amplification module

-. . . Amplifying the negative input of the module

C. . . Storage capacitor

FIG. 1 is a schematic diagram showing touch sensing of a conductive film sensor by a touch sensing device of the present invention.

2 is a schematic view showing an embodiment of a touch sensing device of the present invention.

1. . . Touch sensing device

10. . . Logic control module

20. . . Pin

30. . . Multiplexer

100. . . Conductive film sensor

40. . . Amplification module

50. . . Storage control module

60. . . Analog/digital conversion module

80. . . Sensing line

90. . . Drive line

300. . . Drive/sense control module

302. . . Switching module

Claims (9)

A touch sensing device includes: a logic control module for generating a plurality of control signals of different control timings, the control signals including a switching control signal; and a multiplexer including a switching module, The switching module includes a plurality of pairs of differential input switches and a pair of single-ended input switches, and the switching module controls the opening and closing of the plurality of differential input switches and the pair of single-ended input switches according to the switching control signal to control the plurality of And an input mode of the sensing voltage, wherein the sensing voltages are analog data of sensing a plurality of sensing lines respectively from a conductive film sensor, and the plurality of sensing lines respectively correspond to the plurality of channels. The touch sensing device of claim 1, further comprising: an amplifying module, comprising: a positive input terminal and a negative input terminal, wherein the amplifying module amplifies the control signal according to one of the control signals The two voltages received from the positive input terminal and the negative input terminal are subtracted and amplified, and an amplified analog data is output. The touch sensing device of claim 2, wherein the pair of single-ended input switches comprise a positive single-ended input switch and a negative single-ended input switch, each pair of differential input switches comprising a positive difference a positive input switch and a negative differential input switch, the positive single-ended input switch and the negative single-ended input switch are coupled to a reference voltage, and the positive differential input switches are coupled to the positive The input terminal and the positive single-ended input switch are coupled to the negative input terminal of the amplification module and the negative single-ended input switch. The touch sensing device of claim 2, further comprising: an analog/digital conversion module coupled to the logic control module for converting the amplified analog data into a digital data, And outputting the digital data to the logic control module. The touch sensing device of claim 4, further comprising: a storage control module, including a first switch, a second switch, a third switch, and a storage capacitor, the second switch coupling Between the output end of the amplifying module and the analog/digital conversion module, one end of the first switch is coupled between the second switch and the analog/digital conversion module, and the other end is coupled to The storage terminal is coupled to the storage capacitor, and the storage capacitor is coupled to the ground. The storage capacitor is coupled to the ground. The storage capacitor is coupled to the storage capacitor. One of the control signals stores a control signal to store the amplified analog data. The touch sensing device of claim 1, further comprising a plurality of pins, the multiplexer further comprising: at least one driving/sensing control module coupled to the logic control module, the The pin and the switching module are configured to drive the sensing/sensing control signals according to one of the control signals to control the pins to perform a plurality of pin functions respectively, so that the pins can be from the conductive film sensor The sensing lines sense the sensing voltages. The touch sensing device of claim 3, wherein in the first single-ended input mode, the switching module controls the positive single-ended input switch to be turned on according to the switching control signal, so that the amplification module is The positive input terminal is coupled to the reference voltage, and the negative input terminal receives a first boundary sensing voltage of the conductive film inductor. The touch sensing device according to claim 3, wherein the first difference is In the dynamic input mode, the switching module controls the positive differential input switch of the adjacent first pair of differential input switches and the negative differential input switch of the second pair of differential input switches according to the switching control signal, thereby causing the switching module to open The positive input terminal of the amplifying module receives a first sensing voltage and the negative input terminal receives a second sensing voltage; in a second differential input mode, the switching module controls the switching control signal according to the switching control signal The positive differential input switch of the first pair of differential input switches and the positive differential input switch of the second pair of differential input switches are turned on, such that the positive input terminal receives the second sensing voltage and the negative input terminal receives a first Three sense voltages. The touch sensing device of claim 3, wherein in a second single-ended input mode, the switching module controls the negative single-ended input switch to be turned on according to the switching control signal, so that the amplification module is The positive input terminal receives a second boundary sensing voltage of the conductive film inductor, and the negative input terminal is coupled to the reference voltage.