Touch sensing device and touch sensing method for mutual capacitance touch sensor

Abstract

The present invention relates to a touch sensing apparatus and a touch sensing method. The present embodiment applies a two-stage encoding / decoding technique using a spread code and an orthogonal code, whereby the touch sensing can be robust to noise, can reduce touch sensing time, and can improve touch sensitivity.

Description

Technical Field

[0001] The embodiments involve touch sensing technology. Background Technology

[0002] Position sensors are used as input devices in computers, personal digital assistants (PDAs), media players, video game players, home appliances, cordless phones, public telephones, point-of-sale (POS) terminals, ATMs, and the like. One type of position sensor used in this field is the touch sensor, which is readily found in input devices such as laptops and smartphones. Users interact with the touch sensor by moving their fingers, styluses, or other objects around its detection area. The object can generate capacitive, inductive, and other electrical effects in response to a carrier signal applied to the detection area, and the carrier signal can be used to detect the object's position within the detection area or its approach to the detection area. Information related to the position detected by the touch sensor can be used to move a cursor or other indicator on a display screen, scroll text elements on the screen, or for other user interface purposes.

[0003] Touch sensors have been used for several years, but engineers are constantly seeking design alternatives that can reduce costs and improve touch sensor performance. Specifically, there has been considerable focus recently on reducing the impact of noise generated by the display, power supply, wireless frequency interference, and / or other sources external to the sensor. Various types of sampling, filtering, signal processing, shielding, and other noise reduction techniques have been successfully implemented to varying degrees.

[0004] Therefore, there is a need for a system and method for rapidly, effectively and efficiently detecting the location-based attributes of objects in the presence of noise. Summary of the Invention

[0005] In this context, on the one hand, this embodiment provides a touch sensing technology that is robust to noise. On the other hand, this embodiment provides a technique for simultaneously driving multiple touch sensors to reduce touch sensing time and improve touch sensitivity.

[0006] To achieve the objectives described above, this embodiment provides a touch sensing method for a mutual capacitance touch sensor, wherein the mutual capacitance touch sensor is formed by a plurality of intersecting transmission electrodes and receiving electrodes. The method includes: encoding a base signal with a spreading code to generate a spreading signal; encoding the spreading signal with a plurality of orthogonal codes to generate a plurality of drive signals; supplying the drive signals to the transmission electrodes respectively; receiving a response signal for the drive signals from the receiving electrodes; converting the response signal into a digital response signal by analog-to-digital conversion; decoding the digital response signal with the orthogonal codes and the spreading code to generate sensing data for each touch sensor; and determining, by using the sensing data, whether an external object is touching or approaching the touch sensor.

[0007] On the other hand, this embodiment provides a touch sensing device for a mutual capacitance touch sensor, wherein the mutual capacitance touch sensor is formed by a plurality of intersecting transmission electrodes and receiving electrodes. The device includes: a driving circuit configured to: encode a base signal with a spreading code to generate a spreading signal, encode the spreading signal with a plurality of orthogonal codes to generate a plurality of driving signals, and supply the driving signals to the transmission electrodes respectively; and a sensing circuit configured to: receive a response signal to the driving signal from the receiving electrode, convert the response signal into a digital response signal by analog-to-digital conversion, decode the digital response signal with the orthogonal codes and the spreading code to generate sensing data for each touch sensor, and determine the touch or proximity of an external object to the touch sensor by using the sensing data.

[0008] The touch sensing circuit can decode the digital response signal using the spreading code to generate a first decoded signal, sum the first decoded signal at each unit time of the orthogonal code to generate a second decoded signal, and decode the second decoded signal using the orthogonal code to generate the sensing data.

[0009] On the other hand, this embodiment provides a touch sensing device for a mutual capacitance touch sensor, wherein the mutual capacitance touch sensor is formed by intersecting receiving electrodes and transmitting electrodes, the device comprising: a driving circuit configured to supply a pulse signal including a high voltage level interval and a low voltage level interval to the transmitting electrodes; and a sensing circuit configured to: receive a response signal for the pulse signal from the receiving electrodes, invert a portion of the response signal corresponding to the high voltage level interval or the portion corresponding to the low voltage level interval, convert the response signal into a digital response signal by analog-to-digital conversion, and generate sensing data for the touch sensor by using the digital response signal.

[0010] The pulse signal can correspond to a signal encoded with a spread spectrum signal, and the sensing circuit can decode the digital response signal with the spread spectrum code to generate the sensing data.

[0011] According to the embodiments described above, touch sensing can be robust to noise. Furthermore, according to this embodiment, multiple touch sensors can be driven simultaneously, thereby reducing touch sensing time or improving touch sensitivity. Attached Figure Description

[0012] Figure 1 This is a block diagram of a display device according to an embodiment.

[0013] Figure 2 This is a block diagram of an example of a touch system according to an embodiment.

[0014] Figure 3 This is a block diagram of the driving circuit according to an embodiment.

[0015] Figure 4 This is a block diagram of the base signal generation circuit according to an embodiment.

[0016] Figure 5 This is a block diagram of the spread spectrum coding circuit according to an embodiment.

[0017] Figure 6 This is a block diagram of an orthogonal encoding circuit according to an embodiment.

[0018] Figure 7 Show Figure 6 The main signal waveform.

[0019] Figure 8 This is a block diagram of the output circuit according to an embodiment.

[0020] Figure 9 An example of a drive signal according to an embodiment is shown.

[0021] Figure 10This is a block diagram of the sensing circuit according to an embodiment.

[0022] Figure 11 This is a flowchart illustrating a touch sensing method according to an embodiment. Detailed Implementation

[0023] Figure 1 This is a block diagram of a display device according to an embodiment.

[0024] refer to Figure 1 The display device 100 may include a display panel 150, a gate driving device 160, a data driving device 170, a data processing device 180, a host 190, a touch panel 110, and a touch sensing device 120.

[0025] The data driving device 170, the gate driving device 160, and the touch sensing device 120 can drive at least one element included in the display panel 150 or the touch panel 110. The data driving device 170 can drive data lines connected to pixels in the display panel 150, and the gate driving device 160 can drive gate lines connected to pixels. The touch sensing device 120 can drive touch electrodes disposed on the touch panel 110.

[0026] The data driver 170 can supply a data voltage (Vdata) to the data lines to display an image on each pixel of the display panel 150. The data driver 170 may include at least one data driver integrated circuit, which may be connected to the bonding pads of the display panel 150 via tape auto-bonding (TAB) or glass flip-chip (COG), or may be directly disposed on the display panel 150, and in some cases may be integrated into the display panel 150. The data driver 170 may also be implemented using a thin-film flip-chip (COF) method.

[0027] The gate driving device 160 can supply scan signals to the gate lines to turn on or off transistors located in each pixel. Depending on the operating mode, the gate driving device 160 can be as follows: Figure 1 The gate drive device 160 may be positioned only on one side of the display panel 150, or it may be divided into two parts and positioned on opposite sides of the display panel 150. Furthermore, the gate drive device 160 may include at least one gate driver integrated circuit, which may be connected to the bonding pads of the display panel 150 in a TAB or COG manner, or may be implemented as an in-board gate (GIP) type to be directly disposed on the display panel 150, and in some cases may be integrated into the display panel 150. Additionally, the gate drive device 160 may also be implemented in a COF manner.

[0028] The data processing device 180 can receive image data (RGB) from the host 190 and convert the image data into a form that can be recognized by the data driving device 170. The data processing device 180 can transmit the converted image data (RGB') to the data driving device 170.

[0029] The data processing device 180 can control the timing of each drive device 160, 170, or 120 via control signals (GCS, DCS, or TCS). In this respect, the data processing device 180 can be referred to as a timing controller.

[0030] Touch panel 110 may have touch electrodes disposed thereon. Each touch electrode may include a transmitting electrode and a receiving electrode. Touch sensing device 120 may transmit a drive signal (TXS) to the transmitting electrode and receive a response signal (RXS) from the receiving electrode to generate touch data (TDATA). Touch sensing device 120 may transmit the touch data (TDATA) to host 190. The transmitting electrode and the receiving electrode may be the same as each other or different from each other. In the following, an embodiment in which the transmitting electrode and the receiving electrode are two different electrodes coupled to each other by capacitance is described, but this disclosure is not limited thereto.

[0031] The touch sensing device 120 may include a driving circuit 122, a sensing circuit 124, and a control circuit 126. The driving circuit 122 may transmit a driving signal (TXS) to a transmitting electrode. The control circuit 126 may transmit a timing signal to the driving circuit 122 and the sensing circuit 124. The sensing circuit 124 may receive a response signal (RXS) from a receiving electrode and analyze the response signal (RXS) to generate touch data (TDATA).

[0032] The touch sensing device 120 can be coupled to the touch panel 110 to form a touch system.

[0033] Figure 2 This is a block diagram of an example of a touch system according to an embodiment.

[0034] refer to Figure 2 The touch panel 210 may have a transmission electrode (TXE) and a receiving electrode (RXE) disposed thereon. The transmission electrode (TXE) and the receiving electrode (RXE) may intersect each other and may be disposed in both horizontal and vertical directions. The touch panel 210 may have an overall quadrilateral shape, but this embodiment is not limited to this shape.

[0035] The driving circuit 122 can supply a driving signal (TXS) to the transmitting electrode (TXE). The sensing circuit 124 can receive a response signal (RXS) from the receiving electrode (RXE) and modulate the response signal (RXS) to generate touch data (TDATA). The transmitting electrode (TXE) and the receiving electrode (RXE) can be capacitively coupled, wherein the driving signal (TXS) supplied to the transmitting electrode (TXE) can be coupled to the receiving electrode (RXE) to obtain the response signal (RXS).

[0036] The driving circuit 122 can perform multiple driving of multiple transmission electrodes (TXE). Here, multiple driving can mean driving multiple transmission electrodes (TXE) simultaneously. When multiple driving is used in the touch system 200, multiple transmission electrodes (TXE) can be driven simultaneously, thereby reducing the overall touch driving time and increasing the length of the driving signal (TXS) supplied to each transmission electrode (TXE), thereby improving touch sensitivity (signal-to-noise ratio (SNR)).

[0037] The driving circuit 122 can divide all transmission electrodes (TXEs) into multiple groups and can drive multiple transmission electrodes (TXEs) in each group. For example, in the case of a total of 48 transmission electrodes (TXEs) disposed on the touch panel 210, the driving circuit 122 can divide all transmission electrodes (TXEs) into 12 groups and assign four transmission electrodes (TXEs) to each group. The driving circuit 122 can drive the four transmission electrodes (TXEs) assigned to each group simultaneously.

[0038] The driving circuit 122 can simultaneously transmit quadrature-modulated driving signals (TXS) to each of the transmission electrodes (TXE) belonging to a group. Even if multiple quadrature-modulated driving signals (TXS) overlap with a single response signal (RXS), the multiple quadrature-modulated driving signals (TXS) can still be distinguished from each other through the modulation process. The sensing circuit 124 can modulate the response signal (RXS) received through the receiving electrode (RXE) to distinguish the influence of each driving signal (TXS).

[0039] Here, the orthogonally modulated drive signals (TXS) can correspond to drive signals indicating different codes. The modulation scheme can be called a code division multiplexing (CDM) scheme. Each drive signal (TXS) can have codes that are orthogonal to each other, where the value obtained by multiplying two orthogonal codes may be zero.

[0040] The driving circuit 122 can perform time-division driving on each group. The driving circuit 122 can drive the first group multiple times at a first time interval, and can drive the second group multiple times at a second time interval, wherein the second group does not overlap with the first group.

[0041] The sensing circuit 124 may include a readout circuit 222, an analog-to-digital converter (ADC) 224, and a multiplexer (MUX) 226.

[0042] MUX 226 can select one of a plurality of receiving electrodes (RXE) according to the timing signal of the control circuit 126, and can receive a response signal (RXS) from the selected receiving electrode (RXE).

[0043] The readout circuit 222 corresponds to the circuitry that converts the response signal (RXS) in an analog manner, and may include circuitry such as an integrator. The analog-to-digital converter 224 converts the output of the readout circuit 222 into a digital signal (hereinafter referred to as the "digital response signal").

[0044] The processing circuit 228 can process digital response signals to generate sensing data for each touch sensor, and can determine whether an external object is touching or approaching the touch sensor by using the sensing data. Here, the touch sensor can correspond to the intersection (SN) of the transmitting electrode (TXE) and the receiving electrode (RXE).

[0045] The control circuit 126 can transmit timing signals to the drive circuit 122, the sensing circuit 124, and the processing circuit 228. The drive circuit 122 and the sensing circuit 124 can transmit drive signals (TXS) and receive response signals (RXS) according to the timing signals.

[0046] The drive circuit 122 can apply spread spectrum technology to the drive signal (TXS) to avoid noise with a specific frequency or reduce electromagnetic interference (EMI).

[0047] The drive circuit 122 can transmit a signal encoded with a spreading code as a drive signal (TXS). The sensing circuit 124 can decode the response signal (RXS) with the spreading code to generate sensing data.

[0048] The driving circuit 122 can encode the driving signal (TXS) with spreading codes for noise avoidance and EMI reduction and orthogonal codes for multiple drives, and in this respect, the touch system according to the embodiment applies a two-level encoding / decoding technique.

[0049] Figure 3 This is a block diagram of the driving circuit according to an embodiment.

[0050] refer to Figure 3 The driving circuit 122 may include a base signal generation circuit 310, a spread spectrum coding circuit 320, a quadrature coding circuit 330, and an output circuit 340.

[0051] The base signal generation circuit 310 generates a base signal (BS) that forms the basis of the drive signal (TXS). The base signal (BS) can have waveforms such as square waves, triangle waves, and sine waves. The base signal (BS) can be a periodic signal. A periodic signal corresponds to a signal that has the same waveform repeating at a predetermined period. In the following description, for ease of description, the example of a periodic pulse signal as the base signal (BS) will be used.

[0052] The spread spectrum coding circuit 320 can encode the base signal (BS) with spreading codes to generate a spread spectrum signal (RS). The spread spectrum signal (RS) can be understood as a signal with wide bandwidth and low signal strength across all frequency bands during frequency analysis. Because the spread spectrum signal (RS) has wide bandwidth and low signal strength across all frequency bands, EMI can be low, and the effects of noise from specific frequencies can be minimal.

[0053] Spreading codes can be pseudo-noise (PN) codes. Spreading codes, as pseudo-random codes, can include maximum-length sequences, Parker codes, or Gold codes.

[0054] The quadrature encoding circuit 330 can encode the spread spectrum signal (RS) with orthogonal codes to generate orthogonal signals (OS). Here, orthogonal codes are codes that are orthogonal to each other and can correspond to Perfect codes or Hadamard codes. The quadrature encoding circuit 330 can generate multiple orthogonal signals (OS) from a single base signal (BS) through two levels of encoding.

[0055] The output circuit 340 can generate a drive signal (TXS) based on multiple quadrature signals (OS) and supply the drive signal (TXS) to the transmission electrode.

[0056] Figure 4 This is a block diagram of the base signal generation circuit according to an embodiment.

[0057] refer to Figure 4 The base signal generation circuit 310 may include a counter 410, an XOR (exclusive OR) logic circuit, and a DQ flip-flop 420.

[0058] A common clock can be input to counter 410 and DQ flip-flop 420. Counter 410 can count the clock, output a first pulse relative to a first count value to DQ flip-flop 420 through XOR logic circuit, and output a second pulse relative to a second count value to DQ flip-flop 420 through XOR logic circuit.

[0059] The D terminal of the DQ flip-flop 420 can be connected to the output of the XOR logic circuit. One end of the XOR logic circuit can be connected to the output of the counter 410, and the other end of the XOR logic circuit can be connected to the Q terminal of the DQ flip-flop 420.

[0060] Based on the above structure, a pulse signal with a high voltage level interval corresponding to the first count value and a low voltage level interval corresponding to the second count value can be output from the Q terminal of the DQ flip-flop 420. The pulse signal can be used as the base signal (BS).

[0061] The base signal generation circuit 310 can determine the signal period of the base signal (BS) based on the sum of the first count value and the second count value, determine the length of the high voltage level interval based on the first count value, and determine the length of the low voltage level interval based on the second count value.

[0062] Figure 5 This is a block diagram of the spread spectrum coding circuit according to an embodiment.

[0063] refer to Figure 5 The spread spectrum coding circuit 320 may include a spread spectrum code sequence generator 510 and an XOR logic circuit.

[0064] The spreading code sequence generator 510 can generate spreading code sequences (R-CODE). The spreading code sequence generator 510 may include several DQ flip-flops and XOR logic circuits, and can generate maximum length sequences, Parker code sequences, Gold code sequences, etc.

[0065] XOR logic circuits can generate spread spectrum signals (RS) by performing XOR logic operations on the spread spectrum code sequence (R-CODE) and the base signal (BS).

[0066] Figure 6 This is a block diagram of an orthogonal encoding circuit according to an embodiment.

[0067] refer to Figure 6 The orthogonal encoding circuit 330 may include an orthogonal code sequence generator 610 and multiple XOR logic circuits (XOR1 to XORn).

[0068] The orthogonal code sequence generator 610 can generate multiple orthogonal code sequences (O-CODE1 to O-CODEn) generated using mutually orthogonal codes.

[0069] The XOR logic circuits (XOR1 to XORn) can generate quadrature signals (OS1 to OSn) by performing XOR logic operations on the spread spectrum signal (RS) and the quadrature code sequences (O-CODE1 to O-CODEn) respectively.

[0070] Figure 7 Show Figure 6 The main signal waveform.

[0071] refer to Figure 7 The spread spectrum signal (RS) can be repeated at various time units (T1, T2, or T3) of the orthogonal code. The orthogonal signals (OS1 to OS3) can be generated by XOR logic operations on the spread spectrum signal (RS) and the orthogonal code sequence (O-CODE1 to O-CODE3).

[0072] Figure 8 This is a block diagram of the output circuit according to an embodiment.

[0073] refer to Figure 8 The output circuit 340 may include a switching circuit 810 and an output terminal 820.

[0074] The switching circuit 810 can receive a high drive voltage (VH) and a low drive voltage (VL), and output one of the high drive voltage (VH) and the low drive voltage (VL) according to the quadrature signal (OS). A drive signal (TXS) is generated based on the output, and the drive signal (TXS) can be supplied to the transmission electrode (TXE) through the output terminal 820.

[0075] refer to Figures 3 to 8 This section describes detailed examples of the drive circuit, and as shown in the examples, the drive circuit can be easily implemented using XOR logic circuits, DQ flip-flops, counters, etc.

[0076] Drive signals can be implemented in various forms. Drive signals may include unit signals, each indicating 1 or 0, wherein the unit signals can be classified as 1 or 0 according to polarity or phase.

[0077] Figure 9 An example of a drive signal according to an embodiment is shown.

[0078] exist Figure 9 In the diagram, the unit signals constituting the drive signal are separated by dashed lines. Each unit signal can indicate 1 or 0.

[0079] Signals from various units can be formed in various forms. Figure 9 In the first exemplary drive signal (TXSa), each unit signal can be classified as 1 or 0 according to its polarity.

[0080] exist Figure 9 In this context, referring to the second exemplary drive signal (TXSb), the third exemplary drive signal (TXSc), and the fourth exemplary drive signal (TXSd), each unit signal can be classified as 1 or 0.

[0081] When each unit signal is classified as 1 or 0 according to its phase, a dummy signal (DM) can be further inserted into each unit signal. Figure 9 Referring to the second exemplary drive signal (TXSb), a dummy signal (DM) can be further inserted into each unit signal. Figure 9 In the example of the third exemplary drive signal (TXSc), the dummy signal (DM) can be inserted between two unit signals that have different values.

[0082] Response signals can be generated on the falling and rising edges of the drive signal, wherein the dummy signal (DM) has the function of generating falling and rising edges for each unit signal.

[0083] Figure 10 This is a block diagram of the sensing circuit according to an embodiment.

[0084] refer to Figure 10 The sensing circuit 124 may include an analog front-end circuit 1010, an analog-to-digital converter 1020, a spread spectrum code decoding (random decoding) circuit 1030, a summing circuit 1040, and an orthogonal decoding circuit 1050.

[0085] The analog front-end circuit 1010 can generate a sense voltage (VS) by integrating the response signal (RXS).

[0086] Here, the response signal (RXS) corresponds to the response signal of the touch sensor to the drive signal. As mentioned above, the drive signal can be a periodic pulse signal and may include high voltage level intervals and low voltage level intervals.

[0087] The response signal (RXS) may have a portion corresponding to a high voltage level interval and a portion corresponding to a low voltage level interval, wherein the portions corresponding to each interval may have different polarities.

[0088] The analog front-end circuit 1010 can invert the portion of the response signal (RXS) corresponding to the high voltage level interval or the portion corresponding to the low voltage level interval, and then integrate the response signal (RXS).

[0089] A circuit that reverses one of the two polarity portions so that the two polarities are the same is also called a correlated double sampling (CDS) circuit, wherein the analog front-end circuit 1010 can use a CDS circuit to reverse the portion of the response signal (RXS) that corresponds to the high voltage level interval or the portion that corresponds to the low voltage level interval.

[0090] The front end of the analog front end circuit 1010 may have a second MUX circuit arranged therein, wherein the drive circuit can select one of a plurality of TX groups by using the first MUX circuit, and the sensing circuit 124 can select one of a plurality of receiving electrodes by using the second MUX circuit.

[0091] Analog front-end circuit 1010 may be included in the above reference. Figure 2 In the described readout circuit.

[0092] The analog-to-digital converter 1020 converts the sensed voltage (VS) into a digital response signal (DS). Here, the digital response signal (DS) corresponds to a signal with a digital value and can be interpreted as digital data stored in memory.

[0093] The spread spectrum code decoding (random decoding) circuit 1030 can use the spread spectrum code to decode the digital response signal (DS) to generate the first decoded signal (RDS).

[0094] The summing circuit 1040 sums the first decoded signal (RDS) at various unit times of the orthogonal code to generate the second decoded signal (MDS). Here, a unit time of the orthogonal code can mean the time during which a value is present in the orthogonal code. For example, in an orthogonal code, the time for a unit signal with a value of 1 or 0 can be a unit time.

[0095] The quadrature decoding circuit 1050 can use orthogonal codes to decode the second decoded signal (MDS) to generate sense data (SD).

[0096] Figure 11 This is a flowchart illustrating a touch sensing method according to an embodiment.

[0097] refer to Figure 11 The touch sensing device can encode the base signal with a spreading code to generate a spread spectrum signal (S1100).

[0098] The touch sensing device can encode the spread spectrum signal with multiple orthogonal codes that are orthogonal to each other to generate multiple drive signals (S1102).

[0099] The touch sensing device can supply drive signals to each transmission electrode (S1104).

[0100] The touch sensing device can receive a response signal to the drive signal from the receiving electrode (S1106).

[0101] The touch sensing device can convert the response signal into a digital response signal through analog-to-digital conversion (S1108).

[0102] The touch sensing device can decode the digital response signal using orthogonal codes and spreading codes to generate sensing data for each touch sensor (S1110).

[0103] The touch sensing device can determine whether an external object touches or approaches the touch sensor by using the sensing data, and generate touch data including touch coordinates (S1112).

[0104] As described above, according to this embodiment, touch sensing can be robust to noise based on the spreading code. According to this embodiment, multiple touch sensors are driven simultaneously using orthogonal codes, thereby reducing touch sensing time or improving touch sensitivity.

[0105] Cross-reference to related applications

[0106] This application claims priority to Korean Patent Application 10-2020-0174620, filed on December 14, 2021, which is incorporated herein by reference for all purposes as fully set forth herein.

Claims

1. A touch sensing method for a mutual capacitance touch sensor, wherein, The mutual capacitance touch sensor is formed by a plurality of intersecting transmitting and receiving electrodes, and the method includes: The base signal is encoded using spreading codes to generate a spread spectrum signal; The spread spectrum signal is encoded using multiple orthogonal codes to generate multiple drive signals; The drive signal is supplied to the transmission electrode respectively; Receive a response signal in response to the drive signal from the receiving electrode; The response signal is converted into a digital response signal through analog-to-digital conversion; The digital response signal is decoded using the spreading code to generate a first decoded signal; The first decoded signal is summed at each unit time of the orthogonal code to generate the second decoded signal; The second decoded signal is decoded using the orthogonal code to generate sensing data for each of the touch sensors; and The touch sensor is used to determine whether an external object is touching or approaching it.

2. The touch sensing method according to claim 1, wherein, The spreading code corresponds to the pseudo-noise code, i.e., the PN code.

3. The touch sensing method according to claim 1, wherein, The base signal includes a periodic pulse signal.

4. The touch sensing method according to claim 1, wherein, The orthogonal code corresponds to the complete code or Adamant code.

5. The touch sensing method according to claim 1, wherein, The spreading code, as a pseudo-random code, corresponds to the maximum length sequence (MLS), Parker code, or Gold code.

6. A touch sensing device for a mutual capacitance touch sensor, wherein, The mutual capacitance touch sensor is formed by multiple intersecting transmitting and receiving electrodes, and the device includes: A driving circuit configured to: encode a base signal with a spreading code to generate a spreading signal; encode the spreading signal with a plurality of orthogonal codes to generate a plurality of driving signals; and supply the driving signals to the transmission electrodes respectively; and A sensing circuit is configured to: receive a response signal to the driving signal from the receiving electrode; convert the response signal into a digital response signal via analog-to-digital conversion; decode the digital response signal using the orthogonal code and the spreading code to generate sensing data for each touch sensor; and determine, by using the sensing data, whether an external object is touching or approaching the touch sensor. The sensing circuit uses the spreading code to decode the digital response signal to generate a first decoded signal, sums the first decoded signal at each unit time of the orthogonal code to generate a second decoded signal, and uses the orthogonal code to decode the second decoded signal to generate the sensing data.

7. The touch sensing device according to claim 6, wherein, The base signal corresponds to the periodic pulse signal, and the driving circuit configures the high voltage level interval and low voltage level interval of the pulse signal by using a counter.

8. The touch sensing device according to claim 6, wherein, The driving circuit performs an XOR operation on the base signal and the signal corresponding to the spreading code to generate the spreading signal.

9. The touch sensing device according to claim 8, wherein, The driving circuit performs an XOR operation on the spread spectrum signal and each signal corresponding to the orthogonal code to generate the driving signal.

10. The touch sensing device according to claim 6, wherein, The sensing circuit integrates the response signal to generate a sensing voltage, and performs analog-to-digital conversion on the sensing voltage to generate the digital response signal.

11. The touch sensing device according to claim 10, wherein, The drive signals include unit signals, each indicating 1 or 0, and the unit signals are classified as 1 or 0 according to their polarity or phase.

12. The touch sensing device according to claim 11, wherein, The unit signals are classified as 1 or 0 according to their phase, and dummy signals are further inserted into each unit signal.

13. The touch sensing device according to claim 11, wherein, The unit signals are classified as 1 or 0 according to their phase, and a dummy signal is inserted between two unit signals with different values.

14. The touch sensing device according to claim 6, wherein, The driving circuit includes a first MUX circuit, i.e., a first multiplexer circuit, configured to select one of a plurality of TX groups. The sensing circuit includes a second MUX circuit configured to select one of a plurality of receiving electrodes, and Each TX group includes two or more transmission electrodes.

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