Touch controller, signal acquisition method, chip and electronic equipment

Abstract

The invention discloses a touch controller, a signal acquisition method, a chip and electronic equipment, and relates to the technical field of touch control. The touch controller comprises a driving module used for obtaining a first driving signal based on a reference code and transmitting the first driving signal to a transmitting electrode of the touch sensor, the reference code comprises a plurality of chips corresponding to the same code segment, and the first driving signal is used for enabling a receiving electrode of the touch sensor to generate a sensing signal; and the sensing module is used for receiving the sensing signal from the receiving electrode and filtering the sensing signal, and the filtered sensing signal is used for determining the touch position. The plurality of chips correspond to the same code segment, and the sensing signals correspond to the same code segment, so that the signal corresponding to the initial part of the code segment accounts for less in the sensing signals. Therefore, under the condition that the sensing signal is filtered according to the code segment, the signal which cannot be used for determining the touch position occupies less, and the power consumption waste is less.

Description

Technical Field

[0001] The present application relates to the field of touch control technology, and in particular to a touch controller, a signal acquisition method, a chip and an electronic device. Background Art

[0002] With the development of touch technology, many devices are equipped with touch sensors. The touch sensor uses orthogonal transmitting electrodes and receiving electrodes to generate capacitance at the intersection of the transmitting electrode and the receiving electrode. The touch controller connected to the touch sensor transmits a drive signal to the transmitting electrode, receives a sensing signal transmitted by the receiving electrode, filters the sensing signal, measures the capacitance generated at the intersection of the transmitting electrode and the receiving electrode based on the filtered sensing signal, and determines the touch position based on the measured capacitance. Summary of the invention

[0003] The present application provides a touch controller, a signal acquisition method, a chip and an electronic device, which are used to transmit a driving signal to a transmitting electrode of a touch sensor, receive a sensing signal transmitted by a receiving electrode, and process the sensing signal. The technical solution is as follows:

[0004] In a first aspect, a touch controller is provided, which includes: a driving module, connected to a transmitting electrode of a touch sensor, and used to obtain a first driving signal based on a reference code, and transmit the first driving signal to the transmitting electrode, wherein the reference code includes multiple code chips corresponding to the same code segment, and the first driving signal is used to generate a sensing signal on the transmitting electrode; a sensing module, connected to a receiving electrode, and used to receive a sensing signal from the receiving electrode, and filter the sensing signal, and the filtered sensing signal is used to determine a touch position.

[0005] Exemplarily, the driving module includes a shift register, and the shift register is used to serialize the reference code based on the reference clock frequency to obtain the first driving signal.

[0006] Exemplarily, the touch controller is located in a display device, which also includes a display driver and a display screen. The display driver is connected to the display screen, and the display driver is used to obtain a second drive signal and transmit the second drive signal to the display screen to drive the display screen to display an image. The cross-correlation value between the first drive signal and the second drive signal is less than a first reference threshold.

[0007] Exemplarily, there are multiple transmitting electrodes coupled to the receiving electrode; a driving module is used to obtain multiple first driving signals based on multiple reference codes, any reference code includes multiple code bits corresponding to the same code segment, and the cross-correlation values ​​of the multiple first driving signals are less than the second reference threshold; the driving module is used to drive the multiple transmitting electrodes in a one-to-one correspondence manner according to the multiple first driving signals.

[0008] Exemplarily, the multiple first driving signals are not all the same, and the sensing module is further used to demodulate the sensing signal based on the multiple first driving signals, and the demodulated sensing signal is used to perform a filtering operation.

[0009] Exemplarily, the touch controller also includes an equalizing filter, which is respectively connected to the driving module and the sensing module; the equalizing filter is used to receive a first driving signal transmitted by the driving module, perform equalizing filtering on the first driving signal, and transmit the first driving signal after equalizing filtering to the sensing module. The first driving signal after equalizing filtering is used by the sensing module to demodulate the sensing signal, and the demodulated sensing signal is used to perform a filtering operation.

[0010] In a second aspect, a signal acquisition method is provided, which is applied to any touch controller in the first aspect, and the method includes: obtaining a first drive signal based on a reference code through a drive module, transmitting the first drive signal to a transmitting electrode, the reference code includes multiple code bits corresponding to the same code segment, and the first drive signal is used to generate a sensing signal on a receiving electrode; receiving a sensing signal from the receiving electrode through a sensing module, filtering the sensing signal, and using the filtered sensing signal to determine a touch position.

[0011] Exemplarily, the driving module includes a shift register, and obtaining the first driving signal based on the reference code through the driving module includes: serializing the reference code based on a reference clock frequency through the shift register to obtain the first driving signal.

[0012] Exemplarily, there are multiple transmitting electrodes coupled to the receiving electrode; a first driving signal is obtained based on a reference code by a driving module, and the first driving signal is transmitted to the transmitting electrode, including: obtaining multiple first driving signals based on multiple reference codes by the driving module, any reference code includes multiple code bits corresponding to the same code segment, and the mutual correlation values ​​of the multiple first driving signals are less than a second reference threshold; and driving the multiple transmitting electrodes in a one-to-one correspondence manner according to the multiple first driving signals by the driving module.

[0013] Exemplarily, the multiple first driving signals are not all the same, and the method further includes: demodulating the sensing signal based on the multiple first driving signals by the sensing module, and using the demodulated sensing signal to perform a filtering operation.

[0014] Exemplarily, the touch controller also includes an equalizing filter, which is connected to the driving module and the sensing module; the method also includes: receiving a first driving signal transmitted by the driving module through the equalizing filter, performing equalizing filtering on the first driving signal, transmitting the first driving signal after equalizing filtering to the sensing module, the first driving signal after equalizing filtering is used by the sensing module to demodulate the sensing signal, and the demodulated sensing signal is used to perform a filtering operation.

[0015] In a third aspect, a chip is provided, the chip comprising any touch controller in the first aspect.

[0016] In a fourth aspect, an electronic device is provided. The electronic device includes a touch sensor and the chip in the third aspect, and the chip is connected to the touch sensor.

[0017] The technical solution provided by this application brings at least the following beneficial effects:

[0018] In the technical solution provided in the present application, the reference code includes multiple code chips corresponding to the same code segment. Since the multiple code chips correspond to the same code segment, the first drive signal corresponds to the same code segment, and the sensing signal corresponds to the same code segment. Compared with the case where the sensing signal corresponds to multiple code segments, the signal corresponding to the starting part of the code segment accounts for a smaller proportion in the sensing signal. Therefore, in the case of filtering the sensing signal according to the code segment, compared with the method of filtering multiple parts of the sensing signal separately according to multiple code segments, since the signal corresponding to the starting part of the code segment accounts for a smaller proportion in the sensing signal, the filtered sensing signal includes fewer signals with a low signal-to-noise ratio, that is, the proportion of signals that cannot be used to determine the touch position is smaller, and less power consumption is wasted. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a touch sensor and a touch controller in the related art;

[0020] Figure 2 is a waveform diagram of a driving signal transmitted to an emitting electrode in the related art;

[0021] Figure 3 is a structural schematic diagram of another touch sensor and touch controller in the related art;

[0022] Figure 4 is a schematic diagram of a demodulation response in the related art;

[0023] Figure 5 is a schematic diagram of an overlapping demodulation response in the related art;

[0024] Figure 6 It is a schematic diagram of an implementation environment provided by an embodiment of the present application;

[0025] Figure 7 is a structural schematic diagram of a touch sensor and a touch controller provided in an embodiment of the present application;

[0026] Figure 8 is a schematic diagram of the structure of another touch sensor and touch controller provided in an embodiment of the present application;

[0027] Fig. 9It is a flow chart of a signal acquisition method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0029] With the development of touch technology, many devices are equipped with touch sensors. The touch sensor uses orthogonal transmitting electrodes and receiving electrodes to generate capacitance at the intersection of the transmitting electrode and the receiving electrode. For example, there is mutual capacitance at the spatial point where the orthogonally arranged transmitting electrodes and receiving electrodes intersect. There is self-capacitance between the transmitting electrode and the system reference, and there is also self-capacitance between the receiving electrode and the system reference, and the system reference can be ground (GND). By measuring the capacitance at the intersection of the transmitting electrode and the receiving electrode, when the touch sensor is touched, the touch position can be determined based on the capacitance difference between the two measurements. The touch sensor can be a projected capacitive touch (PCAP) sensor.

[0030] In the related art, a driving signal can be transmitted to the transmitting electrode of the touch sensor, a sensing signal on the receiving electrode can be measured, and the mutual capacitance at the intersection of the transmitting electrode and the receiving electrode can be calculated based on the acquired sensing signal. For example, a carrier signal of a predetermined noise-free frequency is transmitted to the transmitting electrode, a sensing signal on the receiving electrode is acquired, and then the sensing signal is amplified, and the sensing signal is demodulated using the same signal as the carrier signal transmitted to the transmitting electrode, and the demodulated signal is filtered, and the signal obtained by filtering is proportional to the mutual capacitance, and the mutual capacitance is calculated based on the signal obtained by filtering. The above operation of calculating mutual capacitance can be based on Figure 1 A touch sensor and touch controller implementation are shown.

[0031] Figure 1 1 is a schematic diagram of the structure of a touch sensor and a touch controller in the related art. Figure 1 As shown, the touch controller includes a signal generator, a driver, a first pad, a second pad, an amplifier, a demodulator, a low-pass filter (LPF) and a memory. The connection relationship of the components included in the touch controller is as follows Figure 1 As shown. The touch sensor includes an orthogonally arranged transmitting electrode and a receiving electrode, and the transmitting electrode and the receiving electrode are coupled. There is a mutual capacitance at the intersection of the transmitting electrode and the receiving electrode. The signal generator generates a driving signal and transmits the driving signal to the driver. The driver is connected to the transmitting electrode through the first pad and transmits the driving signal to the transmitting electrode.

[0032] When a driving signal is transmitted to the transmitting electrode, a sensing signal is generated on the receiving electrode. The amplifier amplifies the sensing signal, and the amplified sensing signal is transmitted to the demodulator. The driving signal can also be transmitted to the demodulator, so that the demodulator uses the same driving signal as that transmitted to the transmitting electrode to demodulate the amplified sensing signal. The LPF filters the demodulated signal, and the filtered signal can be stored in the memory. The processor can obtain the stored filtered signal from the memory and calculate the mutual capacitance based on the obtained signal.

[0033] The second pad, amplifier, demodulator and LPF corresponding to the above-mentioned receiving electrode can be called a receiver channel. The touch controller can include multiple receiver channels, so that the touch controller can simultaneously receive sensing signals on multiple receiving electrodes, and then obtain filtered signals according to the sensing signals.

[0034] In one solution of the related art, the touch controller transmits a driving signal to one transmitting electrode at a time and measures all receiver channels coupled to the transmitting electrode. This solution is called a time division multiplexing (TDM) solution. In another solution of the related art, the touch controller transmits a driving signal to multiple transmitting electrodes at the same time, and the driving signals transmitted to the multiple transmitting electrodes are modulated using a carrier coding mode of 0 and 180 degrees. This solution is called a code division multiplexing (CDM) solution.

[0035] In the CDM scheme, the filtered signal is sampled and the matrix formed by the sampling result is multiplied by the inverse matrix of the coding matrix to obtain a signal proportional to the mutual capacitance. The carrier coding mode of 0 and 180° can be implemented based on Hadamard code, which provides a set of orthogonal codes. Hadamard code can be shown as follows.

[0036]

[0037] Corresponding to this matrix, the related technology uses each element in the matrix to encode the same chip to obtain the encoding result, which includes multiple code segments, and one code segment corresponds to one element. Then, the encoding result is used to modulate the carrier to obtain a driving signal, which includes parts corresponding to multiple code segments. The waveform of the driving signal is as follows Figure 2 See Figure 2, four waveforms are transmitted to transmitting electrode N to transmitting electrode N+3 at the same time, each waveform includes parts corresponding to code segment 0, code segment 1, code segment 2 and code segment 3, and N is a positive integer. Among them, a row of elements of the Hadamard code corresponds to code segment 0, code segment 1, code segment 2 and code segment 3 from left to right. When the element of the Hadamard code changes from 1 to -1 or from -1 to 1, there will be a large phase change at the boundary of the parts corresponding to the two code segments obtained based on the element.

[0038] In the above Hadamard code, the sum of 1 and -1 corresponding to each code segment is equal to 0, so the method of encoding the code piece based on the Hadamard code is called DC balanced coding. The related technology can also use other proprietary codes to achieve DC balanced coding. In the case of obtaining multiple drive signals based on the coding result obtained by DC balanced coding, the coupling noise between the drive signals is less. Therefore, in the case of transmitting the drive signal to the transmitting electrode of the touch sensor, the coupling in the display screen where the touch sensor is located is less. Among them, the coupling noise may appear as a visual artifact.

[0039] In the related art, mutual capacitance measurement can be achieved by mixing analog circuits and digital circuits and using a common clock. Figure 3 FIG. 1 is a schematic diagram of another structure of a touch sensor and a touch controller in the related art. Figure 3 As shown, the touch controller includes a clock signal generator, a frequency divider, a digitally controlled oscillator (NCO), a code segment counter, a CDM code memory, a modulator, a buffer, a first pad, a second pad, an amplifier, a band-pass filter (BPF), an analog digital converter (ADC), a demodulator, an LPF, a sampler, a multiplier and a memory. The connection relationship of the components included in the touch controller is as follows Figure 3 As shown. The touch sensor includes an orthogonally arranged transmitting electrode and a receiving electrode, and the transmitting electrode and the receiving electrode are coupled. There is a mutual capacitance at the intersection of the transmitting electrode and the receiving electrode. The step of measuring the mutual capacitance includes the following steps 1 to 8.

[0040] Step 1, generate a common clock through a clock signal generator; divide the common clock through a frequency divider to obtain a reference frequency; generate a carrier signal based on the reference frequency through an NCO.

[0041] Step 2, the code segment counter is incremented by multiples of the common clock, and the count obtained is used to track the index of the CDM code, so that the modulator determines the code segment based on the CDM code according to the index of the CDM code, and then modulates the carrier signal in each code segment. The code length of the CDM code can be close to the number of transmitting electrodes of the touch sensor.

[0042] Step 3: The modulated carrier signal is transmitted to the transmitting electrode of the touch sensor through the buffer.

[0043] Step 4: The modulated carrier signal transmitted on the transmitting electrode passes through the touch sensor to reach the receiving electrode, wherein when the user performs a touch operation, the sensing signal on the receiving electrode is different from the modulated carrier signal. The sensing signal is an analog signal.

[0044] Step 5, using an amplifier to amplify the sensing signal from the receiving electrode, using a BPF to filter the amplified sensing signal, and using an ADC to sample the filtered sensing signal to obtain a digital signal; wherein the ADC works according to the frequency division of the common clock.

[0045] Step 6, using NCO to generate a carrier signal based on the frequency division of the common clock, and using a demodulator to demodulate the digital signal output by the ADC based on the carrier signal generated by the NCO, wherein the frequency of the NCO matches the carrier signal to transfer the signal component in the digital signal corresponding to the code segment of the CDM code to the baseband signal.

[0046] Step 7, use LPF to low-pass filter the baseband signal, and use a sampler to sample the filtered baseband signal before code segment conversion. The sampler is controlled by a frequency divider that matches the code segment counter, but there may be a phase offset, and the value of the phase offset is adapted to the system delay.

[0047] Step 8: The signal sampled by the sampler is a matrix, and each sampled value in the matrix corresponds to the difference between each receiving electrode on each code segment. The matrix is ​​multiplied by the inverse matrix of the CDM code to generate a result matrix, which includes the signal components corresponding to each intersecting transmitting electrode and receiving electrode, and the result matrix is ​​stored in the memory. The process of obtaining the result matrix is ​​called the process of code segment conversion. The processor can subsequently calculate the touch position based on the result matrix.

[0048] Since the frequency of the CDM code is relatively low, the above method of obtaining the driving signal can be referred to as a two-level modulation scheme using a main carrier and a low-frequency code. The above steps 6 and 7 can be implemented by in-phase quadrature (IQ) demodulation. For example, in step 6, the NCO provides a carrier at 0° and 90°, and the provided carrier is used to demodulate the digital signal.

[0049] Furthermore, when the driving signal includes the parts corresponding to each code segment, the sensing signal also includes the parts corresponding to each code segment, and the demodulated sensing signal also includes the parts corresponding to each code segment. The parts corresponding to each code segment are independent of each other and need to be filtered separately to ensure the accuracy of the filtering result.

[0050] However, the phase change at the boundary of the portion corresponding to two code segments may cause unnecessary energy injection. Figure 4 is a schematic diagram of a demodulation response in the related art, and the demodulation response represents the demodulated sensing signal. Figure 4 As shown, the demodulation response includes demodulation responses corresponding to code segments 0 to 3. If the demodulation response corresponding to each code segment is filtered, since the ratio of the filtering result of the signal corresponding to the beginning of the code segment to the noise is small, that is, the signal to noise ratio (SNR) is low, this part of the filtering result cannot be used to calculate the position of the object, which will cause power consumption waste.

[0051] If you need to obtain enough filtering results that meet the SNR requirements, a longer measurement time is required, that is, a longer time is required to transmit the drive signal to the transmitting electrode and a longer time is required to receive the sensing signal from the receiving electrode. In this case, the power consumption of the measurement operation is high, and the maximum report rate that the touch controller can achieve will also be limited.

[0052] In the related art, a filter spanning multiple code segments can be used to improve the signal-to-noise ratio, but this comes at the cost of adding signals corresponding to the additional code segments, and if the touch position changes during the measurement process, spatial smearing artifacts may be generated. Figure 5 FIG. 1 is a schematic diagram of an overlapping demodulation response in the related art. Figure 5 As shown in FIG. 1 , a virtual code segment 1 is added before code segment 0, and a virtual code segment 2 is added after code segment 3. Both virtual code segment 1 and virtual code segment 2 have corresponding signals. The demodulation response of code segment 0 is filtered using a filter spanning virtual code segment 1, code segment 0, and code segment 1. The demodulation response of code segment 1 is filtered using a filter spanning code segment 0, code segment 1, and code segment 2. The demodulation response of code segment 2 is filtered using a filter spanning code segment 1, code segment 2, and code segment 3. The demodulation response of code segment 3 is filtered using a filter spanning code segment 2, code segment 3, and virtual code segment 2.

[0053] The previous article describes the structure and working process of the touch controller in the related art. Next, the noise interference to the touch controller is described. The main noise source of the touch controller is the display driver of the display screen bonded to the touch controller, and the display screen can be an organic light emitting diode (OLED). The display driver is used to update the display screen according to the clock, and the operating frequency of the clock that updates the display screen is usually close to the operating frequency of the touch controller. Due to electrical characteristics such as frequency response, the touch controller cannot operate at a significantly higher or lower frequency to avoid interference from the display driver.

[0054] The operating frequency of the clock that updates the display is usually 120 Hertz (Hz) or above. Due to the high operating frequency, a time gap cannot be obtained, allowing the touch controller to avoid noise through time division multiplexing. The curve of the noise caused by the display driver can change with at least one of the following factors: display image changes, display update rate changes, or screen brightness changes, where the display update rate can be dynamically changed according to the display content and the running application.

[0055] When the touch controller performs filtering on the signal corresponding to each code segment, it needs to be performed under the condition that the signal corresponding to other code segments is less affected. Since the touch controller is also interfered by the display driver, the touch controller in the related art uses a narrow band that is basically noise-free within the working range of the display driver to generate a driving signal.

[0056] Typically, the touch controller and display driver use independent clocks, so it is difficult to coordinate the clocks used by the touch controller and the display driver to avoid interference from the operating frequency of the display driver's clock to the touch controller. In addition, since the touch controller and the display driver use independent clocks, any precision error in the operating frequency of the clock of either party will increase the difficulty of aligning the two clocks on the spectrum to reduce noise.

[0057] In the related art, the touch controller and the display driver are phase-locked to reduce the impact of the precision error in the operating frequency of the clock of the touch controller or the display driver. However, due to the following three factors, this method is difficult to implement in actual applications.

[0058] Factor 1: The touch controller may need to avoid other environmental noise sources, such as the common-mode noise generated by the direct current to direct current (DCDC) switch used to charge the mobile phone. If the common-mode noise coincides with the operating frequency locked by the touch controller, it cannot be avoided.

[0059] Factor 2: Changes in the display update rate will cause large changes in the display driver clock.

[0060] Factor 3, the display driver's clock is turned on or off without warning the touch controller. For example, when the screen is black, the display driver's clock is turned off without warning the touch controller.

[0061] In addition, the signal power of the touch controller needs to be limited to prevent the radiation value of the device where the touch controller is located from exceeding the allowed value.

[0062] An embodiment of the present application provides a touch controller for transmitting a driving signal to a transmitting electrode of a touch sensor, receiving a sensing signal from a receiving electrode, and processing the sensing signal. Figure 6 Schematic diagram of an implementation environment provided by the embodiment of the present application. Figure 6 As shown, the implementation environment includes a display device 10, the display device 10 includes a touch sensor 101 and a touch controller 102, the touch sensor 101 is connected to the touch controller 102, the display device 10 may include a display screen, and the touch sensor 101 may be set in the display screen. The touch sensor 101 and the touch controller 102 may be located in the same or different electronic devices. In other words, the display device 10 may be located in the same or different electronic devices. In the embodiment of the present application, the display device 10 may be a display device.

[0063] An electronic device may be any electronic product that can interact with a user through one or more methods such as a keyboard, a touchpad, a touch screen, a remote control, voice interaction, or a handwriting device, for example, a personal computer (PC), a mobile phone, a smart phone, a personal digital assistant (PDA), a wearable device, a pocket PC (PPC), a tablet computer, a smart car machine, a smart TV, a smart speaker, a smart voice interaction device, a smart home appliance, a vehicle terminal, an aircraft, etc. Those skilled in the art should understand that the above electronic devices are only examples, and other existing or future electronic devices that may appear should also be included in the scope of protection of this application if they are applicable to this application, and are hereby included by reference.

[0064] Figure 7 1 is a schematic diagram of the structure of a touch sensor and a touch controller provided in an embodiment of the present application. Figure 7 As shown, the touch sensor 101 includes: a coupled transmitting electrode 1011 and a receiving electrode 1012 , and the touch controller 102 includes: a driving module 1021 and a sensing module 1022 , the driving module 1021 is connected to the transmitting electrode 1011 , and the sensing module 1022 is connected to the receiving electrode 1012 .

[0065] Among them, the driving module 1021 is used to obtain a first driving signal based on a reference code, and transmit the first driving signal to the transmitting electrode 1011. The reference code includes multiple code chips corresponding to the same code segment. The first driving signal is used to generate a sensing signal on the receiving electrode 1012; the sensing module 1022 is used to receive the sensing signal from the receiving electrode 1012, filter the sensing signal, and the filtered sensing signal is used to determine the touch position. The embodiment of the present application does not limit the way of performing the touch operation. For example, the user performs the touch operation through a finger, or the user performs the touch operation through an active stylus. The touch position can be any position of the device where the touch sensor 101 is located. That is, when the touch sensor 101 is located in the display device 10, the touch position can be any position of the display device 10.

[0066] In the touch controller 102 provided in the embodiment of the present application, since multiple code chips correspond to the same code segment, the first drive signal corresponds to the same code segment, and the sensing signal corresponds to the same code segment. Compared with the case where the sensing signal corresponds to multiple code segments, the signal corresponding to the starting part of the code segment accounts for a smaller proportion in the sensing signal. Therefore, in the case where the sensing signal is filtered according to the code segment, compared with the method of filtering multiple parts of the sensing signal separately according to multiple code segments, since the signal corresponding to the starting part of the code segment accounts for a smaller proportion in the sensing signal, the filtered sensing signal includes fewer signals with a low signal-to-noise ratio, that is, the proportion of wasted signals that cannot be used to determine the touch position is smaller, and power consumption is less wasted.

[0067] In the case of a preset signal-to-noise ratio, the touch controller 102 consumes less power to achieve the preset signal-to-noise ratio. In the case of preset power consumption, the touch controller 102 acquires a higher proportion of signals with a higher signal-to-noise ratio. Alternatively, the touch controller 102 can achieve a balance between power consumption and signal-to-noise ratio, so that in the case of low power consumption, the proportion of signals with a higher signal-to-noise ratio is higher.

[0068] Exemplarily, the number of chips included in the reference code is determined according to the measurement duration and carrier frequency of the touch sensor. For example, when the measurement duration is 1 millisecond (ms) to 2 ms and the carrier frequency is 100 kiloHertz (kHz) to 500kHz, the reference code includes 100 to 1000 chips. The measurement duration refers to the time from obtaining the first drive signal to obtaining the filtered sensing signal for determining the position of the object. Since the multiple chips included in the reference code correspond to the same code segment, the reference code can be called a single code. On this basis, when the number of chips included in the reference code is large, the reference code can be called a long single code.

[0069] In a possible implementation, the touch controller 102 is located in the display device 10. Figure 6 As shown, the display device 10 also includes a display screen 104 and a display driver 105, the display screen 104 is connected to the display driver 105, and the touch sensor 101 can be set in the display screen 104 or bonded to the display screen 104. The display driver 105 is used to obtain a second drive signal, transmit the second drive signal to the display screen 104 to drive the display screen 104 to display an image, and the cross-correlation value between the first drive signal and the second drive signal is less than the first reference threshold. The value of the first reference threshold is determined based on experience or actual needs, and the embodiment of the present application does not limit this. When the cross-correlation value of the first drive signal and the second drive signal is less than the first reference threshold, it is considered that the cross-correlation between the first drive signal and the second drive signal is small. As a result, the coupling noise of the first drive signal and the second drive signal is less, the display screen 104 has a better effect of displaying an image, and the noise in the sensing signal acquired by the touch controller 102 is also less.

[0070] In a possible implementation, there are multiple transmitting electrodes 1011 coupled to the receiving electrode 1012; the driving module 1021 is used to obtain multiple first driving signals based on multiple reference codes, any one of the reference codes includes multiple chips corresponding to the same code segment, and the cross-correlation values ​​of the multiple first driving signals are less than the second reference threshold; the driving module 1021 is used to drive the multiple transmitting electrodes 1011 in a one-to-one correspondence manner according to the multiple first driving signals. That is, one first driving signal is used to drive one transmitting electrode 1011.

[0071] The value of the second reference threshold is determined based on experience or actual needs, and the embodiment of the present application does not limit this. For example, the second reference threshold is less than or equal to the set signal-to-noise ratio of the display device 10. When the cross-correlation value of the multiple first drive signals is less than the second reference threshold, it is considered that the cross-correlation of the multiple first drive signals is small. As a result, the coupling noise of the multiple first drive signals is less, the interference when transmitting the first drive signal to the transmitting electrode 1011 is less, and the noise in the sensing signal obtained by the touch controller 102 is also less.

[0072] Exemplarily, the number of reference codes is the same as the number of transmitting electrodes 1011 included in the touch sensor 101, and a first driving signal obtained based on one reference code is used for transmission to one transmitting electrode 1011. By obtaining a plurality of reference codes which is the same as the number of transmitting electrodes 1011, the cross-correlation of the first driving signals transmitted to the plurality of transmitting electrodes 1011 can be ensured to be as low as possible.

[0073] The reference code can be selected from an orthogonal code set. For example, the reference code is selected from a 512-chip Hadamard code set. Since the codes included in the orthogonal code set are orthogonal, the cross-correlation of the reference code selected from the orthogonal code set is small, and the efficiency of obtaining the reference code is high. The code space corresponding to the 512-chip Hadamard code set includes 2 512 When a reference code is selected from the code set and the first drive signal is obtained based on the reference code, in addition to the small mutual correlation between the multiple first drive signals and the small mutual correlation between the first drive signal and the second drive signal, the first drive signal may also have other characteristics that can optimize system performance, which is not limited in the embodiments of the present application.

[0074] Exemplarily, the touch controller 102 is used to measure self-capacitance, in which case the multiple reference codes are the same, so that the first drive signals obtained based on the multiple reference codes are also the same. By transmitting the same first drive signal to multiple transmitting electrodes 1011, the self-capacitance measurement process can be avoided as much as possible from being affected by mutual capacitance. The touch controller 102 can also be used to measure mutual capacitance, in which case the multiple reference codes may be different, so that the first drive signals obtained based on the multiple reference codes are also different. By transmitting different first drive signals to multiple transmitting electrodes 1011, the mutual correlation between the multiple first drive signals can be reduced as much as possible.

[0075] In a possible implementation, the driving module 1021 includes a shift register 10211, and the shift register 10211 is used to serialize the reference code based on the reference clock frequency to obtain a first driving signal. By using the shift register 10211 to obtain the first driving signal, the method of obtaining the first driving signal is relatively simple and efficient. Exemplarily, the driving module 1021 also includes a clock signal generator 10215 and a frequency divider 10212, and the frequency divider 10212 is connected to the clock signal generator 10215 and the shift register 10211 respectively, the clock signal generator 10215 is used to generate a common clock, and the frequency divider 10212 is used to divide the common clock to obtain a reference clock frequency.

[0076] Exemplarily, the driving module 1021 further includes an amplifier 10213 and a third pad 10214, wherein the amplifier 10213 is connected to the shift register 10211 and the third pad 10214, respectively, and the third pad 10214 is also connected to the transmitting electrode 1011. The amplifier 10213 is used to amplify the first driving signal output by the shift register 10211, and transmit the amplified first driving signal to the transmitting electrode 1011 through the third pad 10214.

[0077] In a possible implementation, when the multiple first drive signals are not all the same, the sensing module 1022 is further used to demodulate the sensing signal based on the multiple first drive signals, and the demodulated sensing signal is used to perform a filtering operation. For example, a coding matrix is ​​constructed using a reference code that generates multiple first drive signals, and the sensing signal is multiplied by the inverse matrix of the coding matrix to demodulate the sensing signal. In the case of transmitting multiple first drive signals to multiple transmitting electrodes 1011, since the multiple first drive signals are not all the same, the sensing module 1022 demodulates the sensing signal based on the multiple first drive signals, so that the influence of the first drive signal transmitted to each transmitting electrode 1011 on the sensing signal can be determined.

[0078] Exemplarily, when the multiple first drive signals are the same, the sensing module 1022 is further used to perform demodulation based on the multiple first drive signals, and the demodulated sensing signal is used to perform a filtering operation. For example, a coding matrix is ​​constructed using a reference code that generates the multiple first drive signals, and the sensing signal is multiplied by an inverse matrix of the coding matrix to demodulate the sensing signal.

[0079] In a possible implementation, the sensing module 1022 includes a fourth pad 10221, an amplifier 10222, a BPF 10223, an ADC 10224, a demodulator 10225, an accumulation filter 10226, and a memory 10227. The touch controller 102 also includes a frequency divider 103. The fourth pad 10221 is respectively connected to the receiving electrode 1022 and the amplifier 10222, the BPF 10223 is respectively connected to the amplifier 10222 and the ADC 10224, the demodulator 10225 is respectively connected to the ADC 10224 and the accumulation filter 10226, the accumulation filter 10226 is also connected to the memory 10227, and the ADC 10224 is also connected to the frequency divider 103.

[0080] The fourth pad 10221 is used to transmit the sensing signal transmitted by the receiving electrode 1012 to the amplifier 10222. The amplifier 10222 is used to amplify the sensing signal and transmit the amplified sensing signal to the BPF 10223. The amplified sensing signal transmitted to the BPF 10223 is an analog signal. The BPF 10223 is used to filter the amplified sensing signal and transmit the filtered sensing signal to the ADC 10224. The frequency divider 103 is also connected to the clock signal generator 10215. The frequency divider 103 is used to divide the common clock to obtain a reference frequency and transmit the reference frequency to the ADC 10224. The ADC 10224 is used to sample the filtered sensing signal according to the reference frequency to obtain a sampled sensing signal and transmit the sampled sensing signal to the demodulator 10225. The sampled sensing signal is a digital signal. According to the Nyquist theorem, the reference frequency can be 4 to 5 times the frequency of the common clock.

[0081] The demodulator 10225 is used to demodulate the sampled sensing signal and transmit the demodulated sensing signal to the accumulator filter 10226. The accumulator filter 10226 is used to filter the demodulated sensing signal and transmit the filtered sensing signal to the memory 10227. The filtered sensing signal is used to determine the touch position. The processor connected to the memory 10227 can obtain the filtered sensing signal from the memory 10227 and determine the touch position based on the filtered sensing signal.

[0082] In a possible implementation, the touch controller 102 further includes an equalization filter 1023, which is connected to the driving module 1021 and the sensing module 1022 respectively; the equalization filter 1023 is used to receive the first driving signal transmitted by the driving module 1021, perform equalization filtering on the first driving signal, and transmit the first driving signal after equalization filtering to the sensing module 1022, and the first driving signal after equalization filtering is used for the sensing module 1022 to demodulate the sensing signal, and the demodulated sensing signal is used to perform a filtering operation. By setting the equalization filter 1023 between the driving module 1021 and the sensing module 1022, the first driving signal can be equalized and filtered in the process of being transmitted to the sensing module 1022, thereby reducing noise. The operation of equalization filtering can be regarded as compensation for the signal transmission response. The equalization filter 1023 can be a finite impulse response (FIR) filter or an infinite impulse response (IIR) filter.

[0083] Exemplarily, the equalizing filter 1023 is respectively connected to the shift register 10211 and the demodulator 10225. The equalizing filter 1023 is used to receive the first driving signal transmitted by the shift register 10211, perform equalizing filtering on the first driving signal, and connect the first driving signal after equalizing filtering to the demodulator 10225; the demodulator 10225 is used to receive the first driving signal after equalizing filtering transmitted by the equalizing filter 1023, and demodulate the sampled sensing signal based on the equalized first driving signal.

[0084] Figure 8 1 is a schematic diagram of the structure of another touch sensor and touch controller provided by an embodiment of the present application. The connection relationship between the shift register 10211, the frequency divider 10212, the amplifier 10213, the third pad 10214, the fourth pad 10221, the amplifier 10222, the BPF 10223, the ADC 10224, the demodulator 10225, the accumulator filter 10226, the memory 10227, the equalizer filter 1023 and the frequency divider 103 is as shown in FIG. Figure 8 Based on Figure 8 In the structure shown, the operation of obtaining the sensing signal for determining the touch position includes but is not limited to the following steps 801 to 805.

[0085] Step 801, using a clock signal generator 10215 to generate a common clock; using a frequency divider 10212 to divide the common clock to obtain a reference clock frequency; serializing the reference code through a shift register 10211, wherein the shift register 10211 is driven by the reference clock frequency; the output of the shift register 10211 is amplified by an amplifier 10213 and then transmitted to the transmitting electrode 1011. Each transmitting electrode 1011 requires a shift register 10211 and an amplifier 10213.

[0086] For details on using the clock signal generator 10215 to generate a common clock and using the frequency divider 10212 to divide the common clock, please refer to the description in the relevant technology and will not be repeated here.

[0087] Exemplarily, the reference code is input into the shift register 10211, that is, the multiple chips included in the reference code are input into the shift register 10211. Each chip includes multiple bits, and one bit corresponds to one bit of the shift register 10211. For example, the reference code includes chips 1 to 100, and the 100 chips are arranged in the order of chips 1 to 100. Chips 1 to 100 each include 8 bits, then the 8 bits included in chip 1 are input into the shift register 10211 in the order of the 8 bits, and then the 8 bits included in chip 2 are input into the shift register 10211 in the order of the 8 bits included in chip 2.

[0088] The shift register 10211 shifts one bit at each rising edge of the reference clock frequency, and outputs a waveform corresponding to one bit of one chip included in the reference code. Alternatively, the reference code is input into the shift register 10211, and the shift register 10211 shifts one bit at each falling edge of the reference clock frequency, and outputs a waveform corresponding to one bit of one chip included in the reference code.

[0089] Step 802: The first driving signal transmitted to the transmitting electrode 1011 is transmitted to the receiving electrode 1012 through the display screen. When the display screen is touched, the sensing signal generated on the receiving electrode 1012 will be different from the first driving signal.

[0090] For step 802, reference may be made to the description in the related art and will not be repeated here.

[0091] Step 803, the sensing signal transmitted from the receiving electrode 1012 is amplified by the amplifier 10222 and filtered by the BPF 10223, and then sampled by the ADC 10224 to obtain a digital signal; wherein, the sensing signal transmitted by the receiving electrode 1012 is an analog signal, and the ADC 10224 runs on the divided frequency of the same common clock, which is obtained by dividing the common clock by the divider 103.

[0092] For step 803, reference may be made to the description in the related art and will not be repeated here.

[0093] In step 804, the digital signal from ADC 10224 is demodulated using the first drive signal passed through equalization filter 1023 so that the frequencies of the sensing signal and the first drive signal can match. The demodulation operation is performed by demodulator 10225. The sensing signal transmitted by each receiving electrode 1012 is demodulated using all the first drive signals.

[0094] Exemplarily, as described above, a coding matrix is ​​constructed using a reference code for generating a plurality of first driving signals, and the sensing signal is multiplied by an inverse matrix of the coding matrix to demodulate the sensing signal.

[0095] In step 805, the demodulated sensing signal is filtered by accumulating the previous samples of the transmitting electrode 1011 / receiving electrode 1012 combination, and the filtering operation is performed by the accumulator filter 10226. The filtered sensing signal is stored in the memory 10227. A transmitting electrode 1011 / receiving electrode 1012 combination refers to a transmitting electrode and a receiving electrode having a coupling relationship.

[0096] The process of using the accumulation filter 10226 for accumulation filtering can be found in the description of using the accumulation filter for accumulation filtering in the related art, which will not be further described here.

[0097] exist Figure 8 In the illustrated structure, each transmit electrode 1011 requires an equalization filter 1023, but if the response of a given transmit electrode 1011 is sufficiently different for each receive electrode 1012, an equalization filter 1023 may also be used at each transmit electrode / receive electrode node, where a transmit electrode / receive electrode node refers to a node where a transmit electrode intersects with a receive electrode.

[0098] In the touch controller provided in the embodiment of the present application, since multiple code chips correspond to the same code segment, the first drive signal corresponds to the same code segment, and the sensing signal corresponds to the same code segment. Compared with the case where the sensing signal corresponds to multiple code segments, the signal corresponding to the starting part of the code segment accounts for a smaller proportion in the sensing signal. Therefore, in the case where the sensing signal is filtered according to the code segment, compared with the method of filtering multiple parts of the sensing signal separately according to multiple code segments, since the signal corresponding to the starting part of the code segment accounts for a smaller proportion in the sensing signal, the filtered sensing signal includes fewer signals with a low signal-to-noise ratio, that is, the proportion of wasted signals that cannot be used to determine the position of the object is smaller, and power consumption is less wasted.

[0099] In addition, compared with the method of measuring capacitance using a narrow band in the noise spectrum, the touch controller provided in the embodiment of the present application can use multiple parts of the spectrum to obtain the first drive signal, and then demodulate the sensing signal in multiple parts of the spectrum to measure the capacitance, thereby achieving higher robustness. In addition, the energy of the reference code is relatively dispersed, and the first drive signal can be designed to be broadband rather than narrowband. In this case, the electromagnetic radiation range of the touch controller provided in the embodiment of the present application is wider.

[0100] The embodiment of the present application also provides a signal acquisition method. Fig. 9 is a flow chart of a signal acquisition method provided by an embodiment of the present application, the method comprises Figures 6 to 8 The touch controller 102 shown performs. Fig. 9 As shown, the method includes but is not limited to step 901 to step 902.

[0101] Step 901: A driving module obtains a first driving signal based on a reference code and transmits the first driving signal to a transmitting electrode. The reference code includes multiple code chips corresponding to the same code segment. The first driving signal is used to generate a sensing signal on a receiving electrode.

[0102] Exemplarily, the driving module includes a shift register, and obtaining the first driving signal based on the reference code through the driving module includes: serializing the reference code based on a reference clock frequency through the shift register to obtain the first driving signal.

[0103] Exemplarily, there are multiple transmitting electrodes coupled to the receiving electrode; a first driving signal is obtained based on a reference code by a driving module, and the first driving signal is transmitted to the transmitting electrode, including: obtaining multiple first driving signals based on multiple reference codes by the driving module, any reference code includes multiple code bits corresponding to the same code segment, and the mutual correlation values ​​of the multiple first driving signals are less than a second reference threshold; and driving the multiple transmitting electrodes in a one-to-one correspondence manner according to the multiple first driving signals by the driving module.

[0104] Step 902: Receive a sensing signal from a receiving electrode through a sensing module, filter the sensing signal, and use the filtered sensing signal to determine a touch position.

[0105] Exemplarily, the multiple first driving signals are not all the same, and the method further includes: demodulating the sensing signal based on the multiple first driving signals by the sensing module, and using the demodulated sensing signal to perform a filtering operation.

[0106] Exemplarily, the touch controller also includes an equalizing filter, which is connected to the driving module and the sensing module; the method also includes: receiving a first driving signal transmitted by the driving module through the equalizing filter, performing equalizing filtering on the first driving signal, transmitting the first driving signal after equalizing filtering to the sensing module, the first driving signal after equalizing filtering is used by the sensing module to demodulate the sensing signal, and the demodulated sensing signal is used to perform a filtering operation.

[0107] In the method provided in the embodiment of the present application, since multiple code chips correspond to the same code segment, the first drive signal corresponds to the same code segment, and the sensing signal corresponds to the same code segment. Compared with the case where the sensing signal corresponds to multiple code segments, the signal corresponding to the starting part of the code segment accounts for a smaller proportion in the sensing signal. Therefore, in the case of filtering the sensing signal according to the code segment, compared with the method of filtering multiple parts of the sensing signal separately according to multiple code segments, since the signal corresponding to the starting part of the code segment accounts for a smaller proportion in the sensing signal, the filtered sensing signal includes fewer signals with a low signal-to-noise ratio, that is, the proportion of wasted signals that cannot be used to determine the touch position is smaller, and power consumption is less wasted.

[0108] In an exemplary embodiment, a chip is further provided, and the chip includes any one of the above touch controllers.

[0109] In an exemplary embodiment, an electronic device is also provided, and the electronic device may include a touch sensor and the above-mentioned chip, and the chip is connected to the touch sensor. Electronic devices may have relatively large differences due to different configurations or performances. For example, the electronic device may also include one or more processors, and the processor may be a central processing unit (CPU), and the processor is used to determine the user who performs the touch operation based on the signal component corresponding to the first drive signal. The electronic device may also have components such as a memory, a wired or wireless network interface, a keyboard, and an input and output interface for storage and input and output. The electronic device may also include other components for realizing the functions of the device, which will not be repeated here.

[0110] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, stored data, displayed data, etc.) and signals involved in this application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant laws, regulations and standards of relevant countries and regions.

[0111] It should be understood that the "plurality" mentioned in this article refers to two or more. It should be noted that the terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein.

[0112] The embodiments described in the above exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0113] The above are merely exemplary embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A touch controller, characterized in that: The touch controller comprises: a driving module connected to the transmitting electrode of the touch sensor, configured to obtain a first driving signal based on a reference code, and transmit the first driving signal to the transmitting electrode, wherein the reference code includes a plurality of chips corresponding to the same code segment, and the first driving signal is used to generate a sensing signal on the receiving electrode of the touch sensor; The sensing module is connected to the receiving electrode and is used to receive a sensing signal from the receiving electrode and filter the sensing signal. The filtered sensing signal is used to determine the touch position.

2. The touch controller according to claim 1, characterized in that: The driving module includes a shift register, and the shift register is used to serialize the reference code based on a reference clock frequency to obtain the first driving signal.

3. The touch controller according to claim 1 or 2, characterized in that: The touch controller is located in a display device, which also includes a display driver and a display screen. The display driver is connected to the display screen, and is used to obtain a second drive signal and transmit the second drive signal to the display screen to drive the display screen to display an image. The cross-correlation value between the first drive signal and the second drive signal is less than a first reference threshold.

4. The touch controller according to claim 1 or 2, characterized in that: The number of transmitting electrodes coupled to the receiving electrode is multiple; The driving module is used to obtain a plurality of first driving signals based on a plurality of reference codes, any one of the reference codes includes a plurality of chips corresponding to a same code segment, and a mutual correlation value of the plurality of first driving signals is less than a second reference threshold; The driving module is used to drive the plurality of transmitting electrodes in a one-to-one correspondence manner according to the plurality of first driving signals.

5. The touch controller according to claim 4, characterized in that: The multiple first driving signals are not all the same. The sensing module is further used to demodulate the sensing signal based on the multiple first driving signals, and the demodulated sensing signal is used to perform a filtering operation.

6. The touch controller according to any one of claims 1, 2 or 5, characterized in that: The touch controller further includes an equalizing filter, and the equalizing filter is connected to the driving module and the sensing module respectively; The equalizing filter is used to receive the first driving signal transmitted by the driving module, perform equalizing filtering on the first driving signal, and transmit the first driving signal after equalizing filtering to the sensing module. The first driving signal after equalizing filtering is used by the sensing module to demodulate the sensing signal, and the demodulated sensing signal is used to perform filtering operation.

7. A signal acquisition method, characterized in that: The method is applied to the touch controller according to any one of claims 1 to 6, and the method comprises: Obtaining a first driving signal based on a reference code by the driving module, transmitting the first driving signal to the transmitting electrode, wherein the reference code includes a plurality of chips corresponding to the same code segment, and the first driving signal is used to generate a sensing signal on the receiving electrode; The sensing module receives a sensing signal from the receiving electrode, filters the sensing signal, and uses the filtered sensing signal to determine a touch position.

8. The method according to claim 7, characterized in that The driving module includes a shift register, and obtaining a first driving signal based on a reference code through the driving module includes: The reference code is serialized by the shift register based on a reference clock frequency to obtain the first driving signal.

9. The method according to claim 7 or 8, characterized in that: There are multiple transmitting electrodes coupled to the receiving electrode; obtaining a first driving signal based on a reference code by the driving module and transmitting the first driving signal to the transmitting electrode includes: Obtaining a plurality of first driving signals based on a plurality of reference codes by the driving module, any one of the reference codes includes a plurality of chips corresponding to the same code segment, and a mutual correlation value of the plurality of first driving signals is less than a second reference threshold; The plurality of transmitting electrodes are driven in a one-to-one correspondence manner according to the plurality of first driving signals by the driving module.

10. The method according to claim 9, characterized in that The plurality of first driving signals are not all the same, and the method further comprises: The sensing signal is demodulated by the sensing module based on the plurality of first driving signals, and the demodulated sensing signal is used to perform a filtering operation.

11. The method according to any one of claims 7, 8 and 10, characterized in that: The touch controller further includes an equalizing filter, and the equalizing filter is connected to the driving module and the sensing module; the method further includes: The first driving signal transmitted by the driving module is received through the equalizing filter, the first driving signal is equalized and filtered, and the first driving signal after the equalization filtering is transmitted to the sensing module. The first driving signal after the equalization filtering is used by the sensing module to demodulate the sensing signal, and the demodulated sensing signal is used to perform a filtering operation.

12. A chip, characterized in that: The chip includes the touch controller according to any one of claims 1-6.

13. An electronic device, characterized in that: The electronic device includes a touch sensor and the chip as claimed in claim 12, wherein the chip is connected to the touch sensor.

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