CN119356547A

CN119356547A - Touch controller, signal acquisition method, chip and electronic device

Info

Publication number: CN119356547A
Application number: CN202411449215.1A
Authority: CN
Inventors: 基思·布雷迪; 大卫·拜伊
Original assignee: Beijing Eswin Computing Technology Co Ltd
Current assignee: Beijing Eswin Computing Technology Co Ltd
Priority date: 2024-10-16
Filing date: 2024-10-16
Publication date: 2025-01-24

Abstract

A touch controller, a signal acquisition method, a chip and an electronic device are disclosed, and relate to the field of touch control technology. The touch controller includes: a driving module, which is used to obtain a first driving signal based on a reference code, and transmit the first driving signal to the transmitting electrode of the touch sensor, 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 receiving electrode of the touch sensor; a sensing module, which is used to receive the sensing signal from the receiving electrode, filter the sensing signal, and the filtered sensing signal is used to determine the touch position. Since multiple code chips correspond to the same code segment, the sensing signal corresponds to the same code segment, and the signal corresponding to the starting part of the code segment accounts for a small proportion in the sensing signal. Therefore, when the sensing signal is filtered according to the code segment, the proportion of the signal that cannot be used to determine the touch position is small, and the power consumption is less.

Description

Touch controller, signal acquisition method, chip and electronic equipment

Technical Field

The present application relates to the field of touch technologies, and in particular, to a touch controller, a signal acquisition method, a chip, and an electronic device.

Background

With the development of touch technology, many devices are equipped with touch sensors. Touch sensors use orthogonal transmit and receive electrodes to create capacitance at the location where the transmit and receive electrodes intersect. A touch controller connected to the touch sensor transmits a driving signal to the transmitting electrode, receives a sensing signal transmitted by the receiving electrode, filters the sensing signal, measures a capacitance generated at a position where the transmitting electrode and the receiving electrode intersect based on the filtered sensing signal, and determines a touch position based on the measured capacitance.

Disclosure of Invention

The application provides a touch controller, a signal acquisition method, a chip and electronic equipment, which are used for transmitting a driving signal to a transmitting electrode of a touch sensor, receiving a sensing signal transmitted by a receiving electrode and processing the sensing signal. The technical proposal is as follows:

In a first aspect, a touch controller is provided, the touch controller including a driving module connected to a transmitting electrode of a touch sensor for obtaining a first driving signal based on a reference code, the reference code including a plurality of chips corresponding to a same code segment, the first driving signal for causing a sensing signal to be generated on the transmitting electrode, and a sensing module connected to a receiving electrode for receiving the sensing signal from the receiving electrode, filtering the sensing signal, the filtered sensing signal for determining a touch location.

The driving module comprises a shift register for serializing the reference code based on the reference clock frequency to obtain the first driving signal.

The touch controller is located in a display device, the display device further comprises a display driver and a display screen, the display driver is connected with the display screen, the display driver is used for acquiring a second driving signal, the second driving signal is transmitted to the display screen to drive the display screen to display images, and the cross-correlation value of the first driving signal and the second driving signal is smaller than a first reference threshold value.

The method includes the steps of receiving a plurality of first drive signals, receiving a plurality of second drive signals, and obtaining a plurality of first drive signals based on a plurality of reference codes, wherein any one of the reference codes comprises a plurality of chips corresponding to the same code segment, and cross correlation values of the plurality of first drive signals are smaller than a second reference threshold value.

The plurality of first driving signals are not identical, and the sensing module is further configured to demodulate the sensing signal based on the plurality of first driving signals, where the demodulated sensing signal is used to perform a filtering operation.

The touch controller further comprises an equalization filter, wherein the equalization filter is respectively connected with the driving module and the sensing module, and is used for receiving a first driving signal transmitted by the driving module, performing equalization filtering on the first driving signal, transmitting the first driving signal subjected to equalization filtering to the sensing module, demodulating the sensing signal by the sensing module by the first driving signal subjected to equalization filtering, and performing filtering operation on the demodulated sensing signal.

In a second aspect, a signal acquisition method is provided, and the method is applied to the touch controller in any one of the first aspects, and the method comprises the steps of obtaining a first driving signal through a driving module based on a reference code, transmitting the first driving signal to a transmitting electrode, wherein the reference code comprises a plurality of chips corresponding to the same code segment, the first driving signal is used for enabling a receiving electrode to generate a sensing signal, receiving the sensing signal from the receiving electrode through a sensing module, filtering the sensing signal, and determining a touch position through the filtered sensing signal.

The driving module comprises a shift register, and the first driving signal is obtained by the driving module based on the reference code, and the first driving signal is obtained by the shift register by serializing the reference code based on the reference clock frequency.

The method includes the steps of obtaining, by a driving module, a plurality of first driving signals based on a plurality of reference codes, any one of the reference codes including a plurality of chips corresponding to a same code segment, cross correlation values of the plurality of first driving signals being smaller than a second reference threshold, and driving, by the driving module, the plurality of transmitting electrodes in a one-to-one correspondence with the plurality of first driving signals.

The plurality of first drive signals are illustratively not identical, and the method further includes demodulating, by the sensing module, the sense signal based on the plurality of first drive signals, the demodulated sense signal for performing a filtering operation.

The touch controller further comprises an equalization filter, wherein the equalization filter is connected with the driving module and the sensing module, the equalization filter is used for receiving a first driving signal transmitted by the driving module, performing equalization filtering on the first driving signal, transmitting the first driving signal subjected to equalization filtering to the sensing module, demodulating the sensing signal by the sensing module, and performing filtering operation on the demodulated sensing signal.

In a third aspect, a chip is provided, the chip comprising the touch controller of any one of the first aspects.

In a fourth aspect, there is provided an electronic device comprising a touch sensor and the chip of the third aspect, the chip being connected to the touch sensor.

The technical scheme provided by the application has at least the following beneficial effects:

In the technical scheme provided by the application, a plurality of code slices included in the reference code correspond to the same code segment. Since the plurality of chips correspond to the same code segment, the first driving signal corresponds to the same code segment, and the sensing signal corresponds to the same code segment. The signal corresponding to the code segment start portion occupies less space in the sense signal than in the case where the sense signal corresponds to a plurality of code segments. Therefore, when the sensing signal is filtered according to the code segment, compared with a mode of respectively filtering a plurality of parts of the sensing signal according to a plurality of code segments, the signal corresponding to the initial part of the code segment has fewer occupied in the sensing signal, and the filtered sensing signal has fewer signals with lower signal-to-noise ratio, namely fewer signals which cannot be used for determining the touch position and less power consumption waste.

Drawings

FIG. 1 is a schematic diagram of a touch sensor and a touch controller according to the related art;

fig. 2 is a waveform diagram of a driving signal transmitted to a transmitting electrode in the related art;

FIG. 3 is a schematic diagram of another touch sensor and touch controller in the related art;

FIG. 4 is a schematic diagram of a demodulation response in the related art;

FIG. 5 is a schematic diagram of an overlapping demodulation response in the related art;

FIG. 6 is a schematic diagram of an implementation environment provided by an embodiment of the present application;

FIG. 7 is a schematic diagram of a touch sensor and a touch controller according to an embodiment of the present application;

FIG. 8 is a schematic diagram of another touch sensor and touch controller according to an embodiment of the application;

Fig. 9 is a flowchart of a signal acquisition method according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the embodiments of the present application will be described in further detail with reference to the accompanying drawings.

With the development of touch technology, many devices are equipped with touch sensors. Touch sensors use orthogonal transmit and receive electrodes to create capacitance at the location where the transmit and receive electrodes intersect. For example, there is a mutual capacitance (mutual capacitance) at the point in space where the orthogonally disposed transmit and receive electrodes intersect. There is a self-capacitance (self-capacitance) between the transmitting electrode and the system reference, and there is also a self-capacitance between the receiving electrode and the system reference, which may be Ground (GND). By measuring the capacitance at the position where the transmitting electrode and the receiving electrode intersect, in the case where the touch sensor is touched, the touch position can be determined based on the capacitance difference between the two measurements. The touch sensor may be a projected capacitive touch (project capacitive touch, PCAP) sensor.

In the related art, the mutual capacitance of the crossing position of the transmitting electrode and the receiving electrode can be calculated based on the acquired sensing signal by transmitting the driving signal to the transmitting electrode of the touch sensor, measuring the sensing signal on the receiving electrode. 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, then the sensing signal is amplified, the sensing signal is demodulated with the same signal as the carrier signal transmitted to the transmitting electrode, the demodulated signal is filtered, the filtered signal is proportional to the mutual capacitance, and the mutual capacitance is calculated based on the filtered signal. The above-described operation of calculating the mutual capacitance may be implemented based on the touch sensor and the touch controller shown in fig. 1.

Fig. 1 is a schematic diagram of a touch sensor and a touch controller in the related art. As shown in fig. 1, the touch controller includes a signal generator, a driver, a first pad, a second pad, an amplifier, a demodulator, a low-pass filter (LPF-PASS FILTER), and a memory. The connection relation of the components included in the touch controller is shown in fig. 1. The touch sensor includes orthogonally disposed transmit and receive electrodes coupled. Mutual capacitance exists at the intersection of the transmitting electrode and the receiving electrode. The signal generator generates a driving signal, transmits the driving signal to the driver, and the driver is connected with the emitter electrode through the first bonding pad and transmits the driving signal to the emitter electrode.

In the case of transmitting a drive signal to the transmitting electrode, a sense signal is generated on the receiving electrode. The amplifier amplifies the sensing signal and the amplified sensing signal is transmitted to the demodulator. The drive signal may also be transmitted to a demodulator, so that the demodulator demodulates the amplified sense signal using the same drive signal as transmitted to the transmit electrode. The LPF filters the demodulated signal, and the filtered signal may be stored in a memory. The processor may retrieve the stored filtered signals from the memory and calculate the mutual capacitance based on the retrieved signals.

The second pad, the amplifier, the demodulator, and the LPF corresponding to the one receiving electrode may be referred to as one receiver channel. The touch controller may include a plurality of receiver channels, and the touch controller may receive the sensing signals on the plurality of receiving electrodes simultaneously, and may obtain the filtered signals according to the sensing signals.

In one scheme 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, which is called a time division multiplexing (time division multiplexing, TDM) scheme. In another scheme of the related art, the touch controller transmits driving signals to a plurality of transmitting electrodes at the same time, and the driving signals transmitted to the plurality of transmitting electrodes are modulated using carrier coding modes of 0 and 180 °, which is called a code division multiplexing (code division multiplexing, CDM) scheme.

In the CDM scheme, a signal proportional to a mutual capacitance is obtained by multiplying a matrix formed by sampling the filtered signal by an inverse matrix of a coding matrix. The carrier coding modes of 0 and 180 ° may be implemented based on Hadamard (Hadamard) codes, which provide a set of orthogonal codes, as shown below.

Corresponding to the matrix, the related art adopts each element in the matrix to encode the same chip (chip) to obtain an encoding result, wherein the encoding result comprises a plurality of code segments, and one code segment corresponds to one element. And then, modulating the carrier wave by using the coding result to obtain a driving signal, wherein the driving signal comprises a plurality of parts corresponding to the code segments. The waveform of the driving signal is shown in fig. 2. Referring to fig. 2, four waveforms are simultaneously transmitted to the transmitting electrode N to the transmitting electrode n+3, each waveform including portions corresponding to code segment 0, code segment 1, code segment 2, and code segment 3, N being a positive integer. Wherein, a row of elements of the Hadamard code respectively corresponds to a code segment 0, a code segment 1, a code segment 2 and a code segment 3 according to the sequence from left to right. In the case where the element of the Hadamard code is changed from 1 to-1 or from-1 to 1, there is a large phase change at the boundary of the corresponding portions of the two code segments acquired based on the element.

In the Hadamard code described above, the sum of 1 and-1 corresponding to each code segment is equal to 0, and thus the manner of encoding the chips based on the Hadamard code is referred to as direct current balance encoding. Other proprietary codes (codes) may also be employed in the related art to implement dc-balanced coding. In the case where a plurality of driving signals are acquired based on the encoding result obtained by the direct current balance encoding, coupling noise between the driving signals is small. Thus, in the case of transmitting a driving signal to the transmitting electrode of the touch sensor, there is less coupling in the display screen where the touch sensor is located. Wherein the coupling noise may appear as visual artifacts.

In the related art, measurement of mutual capacitance may be achieved by using a mixture of analog circuits and digital circuits, and using one common clock. Fig. 3 is a schematic diagram of another touch sensor and touch controller in the related art. As shown in fig. 3, the touch controller includes a clock signal generator, a frequency divider, a digitally controlled oscillator (numerically 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-to-digital converter (analog digital converter, ADC), a demodulator, LPF, a sampler, a multiplier, and a memory. The connection relationship of the components included in the touch controller is shown in fig. 3. The touch sensor includes orthogonally disposed transmit and receive electrodes coupled. Mutual capacitance exists 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.

Step 1, generating a common clock through a clock signal generator, dividing the common clock through a frequency divider to obtain a reference frequency, and generating a carrier signal based on the reference frequency through an NCO.

Step 2, the obtained count is used to track the index of the CDM code by incrementing the code segment counter by a multiple of the common clock, so that the modulator modulates the carrier signal in each code segment by determining the code segment based on the CDM code according to the index of the CDM code. The CDM code may have a code length similar to the number of transmitting electrodes of the touch sensor.

And 3, transmitting the modulated carrier signal to a transmitting electrode of the touch sensor through a buffer.

And 4, enabling the modulated carrier signal transmitted on the transmitting electrode to pass through the touch sensor and reach the receiving electrode, wherein the sensing signal on the receiving electrode is different from the modulated carrier signal under the condition that a user performs touch operation. The sensing signal is an analog signal.

And 5, amplifying the sensing signal from the receiving electrode by using an amplifier, filtering the amplified sensing signal by using a BPF, and sampling the filtered sensing signal by using an ADC to obtain a digital signal, wherein the ADC works according to the frequency division of the common clock.

And 6, generating a carrier signal by using NCO based on frequency division of a common clock, and demodulating the digital signal output by the ADC by using a demodulator based on the carrier signal generated by the NCO, wherein the frequency of the NCO is matched with the carrier signal so as to transfer signal components corresponding to code segments of CDM codes in the digital signal to a baseband signal.

And 7, performing low-pass filtering on the baseband signal by using an LPF, and sampling the filtered baseband signal before code segment conversion by using a sampler. The sampler is controlled by a frequency divider that matches the code segment counter, but there may be a phase offset whose value is adapted to the system delay.

And 8, the signal sampled by the sampler is a matrix, and each sampling value in the matrix corresponds to the difference value of each receiving electrode on each code segment. The matrix is multiplied by the inverse of the CDM code to generate a resulting matrix comprising signal components corresponding to each of the intersecting transmit and receive electrodes, and the resulting matrix is stored in memory. The process of obtaining the result matrix is called code segment conversion. The processor may then calculate the touch location based on the result matrix.

Since the frequency of the CDM code is low, the above-described manner of acquiring the driving signal may be referred to as a two-stage modulation scheme using a main carrier and a low frequency code. The above steps 6 and 7 may be implemented by means of in-phase quadrature (IQ) demodulation, for example, in step 6, NCO provides carriers at 0 ° and 90 °, and the provided carriers are used for demodulating the digital signal.

In the case where the driving signal includes portions corresponding to the respective code segments, the sensing signal also includes portions corresponding to the respective code segments, and the demodulated sensing signal also includes portions corresponding to the respective code segments. The corresponding parts of each code segment are independent of each other, and filtering is needed to be carried out respectively so as to ensure the accuracy of a filtering result.

However, phase variations at the boundary of the corresponding portions of the two code segments may result in unnecessary energy injection. Fig. 4 is a schematic diagram of a demodulation response in the related art, where the demodulation response represents a demodulated sensing signal. As shown in fig. 4, the demodulation response includes demodulation responses corresponding to code segment 0 through code segment 3. If the demodulation response corresponding to each code segment is filtered, the ratio of the filtering result of the signal corresponding to the initial part of the code segment to the noise is smaller, that is, the signal-to-noise ratio (signal to noise rate, SNR) is lower, and the filtering result cannot be used for calculating the object position, which will cause power consumption waste.

If enough filtering results satisfying the SNR requirement are to be obtained, a longer measurement time is required, i.e. a longer time for transmitting the driving signal to the transmitting electrode and a longer time for receiving the sensing signal from the receiving electrode. In this case, the power consumption of the measurement operation is high, and the maximum reporting rate (maximum report rate) that can be achieved by the touch controller will also be limited.

In the related art, a filter spanning multiple code segments may be used to improve the signal-to-noise ratio, but this is done at the cost of adding additional code segment corresponding signals and if the touch position changes during the measurement, spatial smearing artifacts may occur. Fig. 5 is a schematic diagram of an overlapping demodulation response in the related art. As shown in fig. 5, a virtual code segment 1 is added before a code segment 0, a virtual code segment 2 is added after a code segment 3, and signals are corresponding to the virtual code segment 1 and the virtual code segment 2. The demodulation response for code segment 0 is filtered using a filter that spans virtual code segment 1, code segment 0, and code segment 1. The demodulation response for code segment 1 is filtered using a filter that spans code segment 0, code segment 1, and code segment 2. The demodulation response for code segment 2 is filtered using a filter that spans code segment 1, code segment 2, and code segment 3. The demodulation response for code segment 3 is filtered using a filter that spans code segment 2, code segment 3, and virtual code segment 2.

The structure and the workflow of the touch controller in the related art are described above. Next, noise interference received by the touch controller will be described. The main noise source of the touch controller is the display driver of the display screen, which may be an Organic LIGHT EMITTING Diode (OLED), that is glued together with the touch controller. The display driver is used for updating the display screen according to the clock, and the clock for updating the display screen is usually similar to the operating frequency of the touch controller. Due to electrical characteristics such as frequency response, the touch controller cannot operate at significantly higher or lower frequencies to avoid interference by the display driver.

The clock for updating the display screen usually has an operating frequency of 120 Hertz (Hz) or more, and a time gap cannot be obtained due to the higher operating frequency, so that the touch controller can avoid noise in a time division multiplexing manner. The profile of noise caused by the display driver may vary with at least one of display image changes, display update rate changes, or screen brightness changes, where the display update rate may be dynamically altered based on the display content and the running application.

The touch controller needs to perform filtering on the signals corresponding to each code segment with less influence from the signals corresponding to other code segments. Since the touch controller is also disturbed by the display driver, the touch controller in the related art generates the driving signal using a narrow band (narrow band) that is substantially noise-free in the operating range of the display driver.

In general, the touch controller and the display driver use separate clocks, and thus it is difficult to coordinate the clocks used by the touch controller and the display driver to avoid interference of the operating frequency of the clocks of the display driver to the touch controller. Further, since the touch controller and the display driver use separate clocks, an accuracy error occurs in the operating frequency of either clock, which increases the difficulty of spectrally aligning the two clocks to reduce noise.

In the related art, by phase locking the touch controller with the display driver, the influence of an occurrence of an accuracy error in the operating frequency of the clock of the touch controller or the display driver is reduced. However, this approach is difficult to achieve in practical applications due to the following three factors.

Factor 1, the touch controller may need to avoid other sources of environmental noise. Common mode noise generated by, for example, a direct current to direct current (direct current to direct current, DCDC) switch for cell phone charging cannot be avoided if the common mode noise coincides with the operating frequency at which the touch controller is locked.

Factor 2, the display update rate change may result in a large change in the display drive clock.

Factor 3, the clock of the display driver is turned on or off without alerting the touch controller, e.g., when the screen is black, the clock of the display driver is turned off without alerting the touch controller.

In addition, the signal power of the touch controller needs to be limited to avoid that the radiation value of the device where the touch controller is located exceeds the allowable value.

The embodiment of the application provides a touch controller which is used 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. FIG. 6 is a schematic diagram of an implementation environment provided by an embodiment of the present application. As shown in fig. 6, 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 with the touch controller 102, the display device 10 may include a display screen, and the touch sensor 101 may be disposed in the display screen. The touch sensor 101 and the touch controller 102 may be located on the same or different electronic devices. That is, the display apparatus 10 may be located in the same or different electronic devices. In an embodiment of the present application, the display apparatus 10 may be a display device.

The electronic device may be any electronic product that can perform man-machine interaction with a user through one or more modes of a keyboard, a touch pad, a touch screen, a remote controller, a voice interaction or handwriting device, for example, a personal computer (personal computer, a PC), a mobile phone, a smart phone, a Personal Digital Assistant (PDA), a wearable device, a pocket PC, a tablet PC, a smart car machine, a smart television, a smart sound box, a smart voice interaction device, a smart home appliance, a vehicle terminal, an aircraft, and the like. It will be appreciated by those skilled in the art that the above-described electronic devices are merely examples, and that other electronic devices now known or hereafter may be present as appropriate for use with the present application, and are intended to be within the scope of the present application and are incorporated herein by reference.

Fig. 7 is a schematic structural diagram of a touch sensor and a touch controller according to an embodiment of the present application. As shown in fig. 7, the touch sensor 101 includes a transmitting electrode 1011 and a receiving electrode 1012 coupled, and the touch controller 102 includes a driving module 1021 and a sensing module 1022, the driving module 1021 being connected to the transmitting electrode 1011, and the sensing module 1022 being connected to the receiving electrode 1012.

The driving module 1021 is configured to obtain a first driving signal based on a reference code, and transmit the first driving signal to the transmitting electrode 1011, where the reference code includes a plurality of chips corresponding to a same code segment, the first driving signal is configured to enable the receiving electrode 1012 to generate a sensing signal, and the sensing module 1022 is configured to receive the sensing signal from the receiving electrode 1012, filter the sensing signal, and use the filtered sensing signal to determine a touch position. The embodiment of the application is not limited to the manner in which the touch operation is performed, for example, the user performs the touch operation by a finger or the user performs the touch operation by an active stylus. The touch position may be any position of the device where the touch sensor 101 is located, that is, in the case where the touch sensor 101 is located in the display device 10, the touch position may be any position of the display device 10.

In the touch controller 102 provided in the embodiment of the present application, since the plurality of chips correspond to the same code segment, the first driving signal corresponds to the same code segment, and the sensing signal corresponds to the same code segment. The signal corresponding to the code segment start portion occupies less space in the sense signal than in the case where the sense signal corresponds to a plurality of code segments. Thus, in the case of filtering the sensing signal according to the code segments, compared with the manner of filtering the plurality of portions of the sensing signal according to the plurality of code segments, the signal corresponding to the start portion of the code segment has a smaller proportion of the sensing signal, and the filtered sensing signal has a smaller proportion of the signal having a lower signal-to-noise ratio, i.e., the signal which is wasted and cannot be used for determining the touch position has a smaller proportion of the signal having a lower power consumption.

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 signal with higher signal-to-noise ratio acquired by the touch controller 102 occupies a higher ratio. Or the touch controller 102 can achieve a balance between power consumption and signal-to-noise ratio, and under the condition of lower power consumption, the signal with higher signal-to-noise ratio occupies higher space.

Illustratively, the reference code includes a number of chips that is determined based on the measurement duration and carrier frequency of the touch sensor. For example, in the case of a measurement duration of 1 millisecond (millisecond, ms) to 2ms, a carrier frequency of 100 kilohertz (kHz) to 500kHz, the reference code comprises 100 to 1000 chips. The measurement duration refers to the time from acquisition of the first drive signal to obtaining a filtered sense signal for determining the position of the object. The reference code may be referred to as a single code because the reference code includes a plurality of chips corresponding to the same code segment. On this basis, in the case where the reference code includes a large number of chips, the reference code may be referred to as a long single code.

In one possible implementation, the touch controller 102 is located in the display device 10, and as shown in fig. 6, the display device 10 further 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 may be disposed in the display screen 104 or bonded to the display screen 104. The display driver 105 is configured to acquire a second driving signal, transmit the second driving signal to the display screen 104 to drive the display screen 104 to display an image, and a cross-correlation value of the first driving signal and the second driving signal is smaller than a first reference threshold. The value of the first reference threshold is determined according to experience or actual requirements, which is not limited in the embodiment of the present application. In the case that the cross-correlation value of the first drive signal and the second drive signal is smaller than the first reference threshold value, the cross-correlation of the first drive signal and the second drive signal is considered smaller. Thus, the coupling noise of the first driving signal and the second driving signal is less, the effect of displaying the image on the display screen 104 is better, and the noise in the sensing signal acquired by the touch controller 102 is also less.

In one possible implementation, the number of the transmitting electrodes 1011 coupled with the receiving electrode 1012 is plural, a driving module 1021 for obtaining plural first driving signals based on plural reference codes, any one of which includes plural chips corresponding to the same code segment, the cross correlation value of the plural first driving signals being smaller than the second reference threshold, and a driving module 1021 for driving the plural transmitting electrodes 1011 in a one-to-one correspondence manner according to the plural first driving signals. That is, one first driving signal is used to drive one emitter electrode 1011.

The value of the second reference threshold is determined according to experience or actual requirements, which is not limited in the embodiment of the present application. For example, the second reference threshold is less than or equal to the set signal-to-noise ratio of the display device 10. In the case where the cross-correlation value of the plurality of first drive signals is smaller than the second reference threshold value, the cross-correlation of the plurality of first drive signals is considered smaller. Thus, the coupling noise of the plurality of first driving signals is less, the interference received when the first driving signals are transmitted to the transmitting electrode 1011 is less, and the noise in the sensing signal acquired by the touch controller 102 is also less.

Illustratively, the number of reference codes is the same as the number of the transmission electrodes 1011 included in the touch sensor 101, and one first driving signal obtained based on one reference code is used for transmission to one transmission electrode 1011. By acquiring the same number of the plurality of reference codes as the number of the transmission electrodes 1011, it is possible to ensure that the cross correlation of the first driving signals transmitted to the plurality of transmission electrodes 1011 is low as much as possible.

The reference code may be selected from a set of orthogonal codes. For example, the reference code is selected from a 512-chip Hadamard code set. Since the orthogonal code set includes orthogonal codes, the cross correlation of the reference codes selected from the orthogonal code set is small, and the efficiency of acquiring the reference codes is high. The code space corresponding to the 512-chip Hadamard code set comprises 2 ⁵¹² combinations. In the case where the reference code is selected from the code set and the first driving signals are acquired based on the reference code, the first driving signals may have other characteristics capable of optimizing the system performance in addition to the small cross-correlation between the plurality of first driving signals and the small cross-correlation between the first driving signals and the second driving signals, which is not limited in the embodiment of the present application.

Illustratively, the touch controller 102 is configured to measure the self capacitance, in which case the plurality of reference codes are identical, and thus the first drive signals derived based on the plurality of reference codes are also identical. By transmitting the same first driving signal to the plurality of transmitting electrodes 1011, the measurement process of the self capacitance can be prevented from being affected by the mutual capacitance as much as possible. The touch controller 102 may also be used to measure mutual capacitance, in which case the plurality of reference codes may be different, and thus the first drive signals derived based on the plurality of reference codes may be different. By transmitting different first driving signals to the plurality of transmitting electrodes 1011, cross-correlation between the plurality of first driving signals can be reduced as much as possible.

In one possible implementation, the driving module 1021 includes a shift register 10211, where the shift register 10211 is configured to code the reference sequence based on the reference clock frequency to obtain the first driving signal. By acquiring the first driving signal using the shift register 10211, the manner of acquiring the first driving signal is simpler and more efficient. Illustratively, the driving module 1021 further includes a clock signal generator 10215 and a frequency divider 10212, the frequency divider 10212 being respectively connected to the clock signal generator 10215 and the shift register 10211, the clock signal generator 10215 being configured to generate a common clock, and the frequency divider 10212 being configured to divide the common clock to obtain a reference clock frequency.

Illustratively, the driving module 1021 further includes an amplifier 10213 and a third pad 10214, the amplifier 10213 being connected to the shift register 10211 and the third pad 10214, respectively, the third pad 10214 being further connected to the transmitting electrode 1011. The amplifier 10213 is configured to amplify the first driving signal output from the shift register 10211, and transmit the amplified first driving signal to the transmitting electrode 1011 through the third pad 10214.

In one possible implementation, in the case that the plurality of first driving signals are not all the same, the sensing module 1022 is further configured to demodulate the sensing signal based on the plurality of first driving signals, and the demodulated sensing signal is used to perform the filtering operation. For example, a coding matrix is constructed using a reference code that generates a plurality of first drive signals, and the sense signals are multiplied by an inverse of the coding matrix to demodulate the sense signals. In the case of transmitting the plurality of first driving signals to the plurality of transmitting electrodes 1011, since the plurality of first driving signals are not identical, the sensing module 1022 demodulates the sensing signal based on the plurality of first driving signals, so that the influence of the first driving signals transmitted to the respective transmitting electrodes 1011 on the sensing signal can be determined.

Illustratively, in the case where the plurality of first driving signals are the same, the sensing module 1022 is further configured to demodulate based on the plurality of first driving signals, and the demodulated sensing signals are used to perform the filtering operation. For example, a coding matrix is constructed using a reference code that generates a plurality of first drive signals, and the sense signals are multiplied by an inverse of the coding matrix to demodulate the sense signals.

In one 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 connected to the receiving electrode 1022 and the amplifier 10222, the BPF 10223 is connected to the amplifier 10222 and the ADC 10224, the demodulator 10225 is connected to the ADC 10224 and the accumulation filter 10226, the accumulation filter 10226 is further connected to the memory 10227, and the ADC 10224 is further connected to the frequency divider 103.

The fourth pad 10221 is used to transmit the sensing signal transmitted by the receiving electrode 1012 to the amplifier 10222. The amplifier 10222 amplifies the sense signal and transmits the amplified sense signal to the BPF 10223. Wherein the amplified sensing signal transmitted to the BPF 10223 is an analog signal. The BPF 10223 is configured to filter the amplified sensing signal and transmit the filtered sensing signal to the ADC 10224. The frequency divider 103 is further connected to the clock signal generator 10215, and the frequency divider 103 is configured to divide the common clock to obtain a reference frequency, and transmit the reference frequency to the ADC 10224. The ADC 10224 is configured to sample the filtered sensing signal according to the reference frequency, obtain a sampled sensing signal, and transmit the sampled sensing signal to the demodulator 10225. Wherein the sampled sensing signal is a digital signal. According to the nyquist theorem, the reference frequency may be 4 to 5 times the frequency of the common clock.

The demodulator 10225 demodulates the sampled sensing signal, and transmits the demodulated sensing signal to the accumulation filter 10226. The accumulation filter 10226 is used to filter the demodulated sensing signals, and to transfer the filtered sensing signals to the memory 10227, which are used to determine touch locations. A processor coupled to memory 10227 can retrieve the filtered sense signals from memory 10227 and determine a touch location based on the filtered sense signals.

In one possible implementation, the touch controller 102 further includes an equalization filter (equalization filter) 1023, where the equalization filter 1023 is connected to the driving module 1021 and the sensing module 1022 respectively, and the equalization filter 1023 is configured to receive the first driving signal transmitted by the driving module 1021, perform equalization filtering on the first driving signal, transmit the first driving signal after equalization filtering to the sensing module 1022, and demodulate the sensing signal by the sensing module 1022, where the demodulated sensing signal is used to perform filtering operation. By providing an equalization filter 1023 between the drive module 1021 and the sense module 1022, the first drive signal can be equalization filtered during transfer to the sense module 1022, reducing noise. The operation of equalization filtering may be regarded as compensation of the signal transmission response. Equalization filter 1023 may be a finite impulse response (finite impulse response, FIR) filter or an infinite impulse response (infinite impulse response, IIR) filter.

Illustratively, the equalization filter 1023 is coupled to the shift register 10211 and the demodulator 10225, respectively. The equalization filter 1023 is configured to receive the first driving signal transmitted by the shift register 10211, perform equalization filtering on the first driving signal, and connect the first driving signal after equalization filtering to the demodulator 10225, where the demodulator 10225 is configured to receive the first driving signal after equalization filtering transmitted by the equalization filter 1023, and demodulate the sampled sensing signal based on the first driving signal after equalization.

Fig. 8 is a schematic structural diagram of another touch sensor and touch controller according to an embodiment of the application. The connection relationship of 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 accumulation filter 10226, the memory 10227, the equalization filter 1023, and the frequency divider 103 is as shown in fig. 8. Based on the structure shown in fig. 8, the operation of acquiring the sensing signal for determining the touch position includes, but is not limited to, the following steps 801 to 805.

Step 801, a common clock is generated by using a clock signal generator 10215, the common clock is divided by using a frequency divider 10212 to obtain a reference clock frequency, the reference code is serialized by using a shift register 10211, wherein the shift register 10211 is driven by the reference clock frequency, and the output of the shift register 10211 is amplified by an amplifier 10213 and then transmitted to a transmitting electrode 1011. Each transmit electrode 1011 requires a shift register 10211 and an amplifier 10213.

The contents of generating the common clock using the clock signal generator 10215 and dividing the common clock using the frequency divider 10212 are referred to the description in the related art, and will not be repeated here.

Illustratively, the reference code is input to the shift register 10211, i.e., a plurality of chips comprised by the reference code are input to the shift register 10211. Each chip includes a plurality of bits, one bit corresponding to each bit of the shift register 10211. For example, the reference code includes chips 1 through 100, and the 100 chips are arranged in the order of chips 1 through 100. Each of the chips 1 to 100 includes 8 bits, the 8 bits included in the chip 1 are input to the shift register 10211 in the arrangement order of the 8 bits, and then the 8 bits included in the chip 2 are input to the shift register 10211 in the arrangement order of the 8 bits included in the chip 2.

The shift register 10211 shifts by one bit on each rising edge of the reference clock frequency, and outputs a waveform corresponding to one bit of one chip included in the reference code. Or the reference code is input to the shift register 10211, and the shift register 10211 shifts by one bit on each falling edge of the reference clock frequency, outputting a waveform corresponding to one bit of one chip included in the reference code.

In step 802, the first driving signal transmitted to the transmitting electrode 1011 is transmitted to the receiving electrode 1012 through the display screen, and the sensing signal generated on the receiving electrode 1012 is different from the first driving signal in case the display screen is touched.

Step 802 may refer to the description in the related art, and will not be described herein.

In 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, where the sensing signal transmitted from the receiving electrode 1012 is an analog signal, and the ADC 10224 operates on the frequency division of the same common clock, and the frequency division is obtained by dividing the common clock by the frequency divider 103.

Step 803 may refer to the description in the related art, and will not be described herein.

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

Illustratively, as previously explained, the encoding matrix is constructed using the reference codes that generate the plurality of first drive signals, and the sense signals are multiplied by an inverse of the encoding matrix to demodulate the sense signals.

In step 805, the demodulated sensing signal is filtered by accumulating the previous samples combined with the transmit electrode 1011/receive electrode 1012, the filtering operation being performed by an accumulation filter 10226, and the filtered sensing signal is stored in a memory 10227. A transmit electrode 1011/receive electrode 1012 combination refers to a transmit electrode and a receive electrode in a coupled relationship.

The process of performing the accumulation filter using the accumulation filter 10226 can be referred to the description of the accumulation filter using the accumulation filter in the related art, and will not be further described herein.

In the configuration shown in fig. 8, an equalization filter 1023 is required for each transmit electrode 1011, but an equalization filter 1023 may be employed at each transmit electrode/receive electrode node if the response of a given transmit electrode 1011 varies sufficiently for each receive electrode 1012. Wherein, a transmitting electrode/receiving electrode node refers to a node where a transmitting electrode and a receiving electrode intersect.

In the touch controller provided by the embodiment of the application, since the plurality of chips correspond to the same code segment, the first driving signal corresponds to the same code segment, and the sensing signal corresponds to the same code segment. The signal corresponding to the code segment start portion occupies less space in the sense signal than in the case where the sense signal corresponds to a plurality of code segments. Thus, in the case of filtering the sensing signal according to the code segments, compared with the manner of filtering the plurality of portions of the sensing signal according to the plurality of code segments, the signal corresponding to the start portion of the code segment has a smaller proportion of the sensing signal, and the filtered sensing signal has a smaller proportion of the signal having a lower signal-to-noise ratio, i.e., the signal which is wasted and cannot be used for determining the position of the object has a smaller proportion of the signal having a lower power consumption.

In addition, compared with a mode of measuring capacitance by using a narrow band in a noise spectrum, the touch controller provided by the embodiment of the application can acquire the first driving signal by using a plurality of parts of the spectrum, and then demodulate the sensing signal in a plurality of parts of the spectrum to realize the measurement of the capacitance, so that the robustness is higher. Furthermore, the energy of the reference code is relatively distributed, and the first drive signal may be designed to be broadband rather than narrowband. In this case, the electromagnetic radiation range of the touch controller provided by the embodiment of the application is wider.

The embodiment of the application also provides a signal acquisition method. Fig. 9 is a flowchart of a signal acquisition method according to an embodiment of the present application, which is performed by the touch controller 102 shown in fig. 6 to 8. As shown in fig. 9, the method includes, but is not limited to, steps 901 to 902.

Step 901, obtaining, by a driving module, a first driving signal based on a reference code, and transmitting the first driving signal to a transmitting electrode, where the reference code includes a plurality of chips corresponding to a same code segment, and the first driving signal is used to generate a sensing signal on a receiving electrode.

In step 902, a sensing module receives a sensing signal from a receiving electrode, filters the sensing signal, and the filtered sensing signal is used to determine a touch location.

In the method provided by the embodiment of the application, since the plurality of chips correspond to the same code segment, the first driving signal corresponds to the same code segment, and the sensing signal corresponds to the same code segment. The signal corresponding to the code segment start portion occupies less space in the sense signal than in the case where the sense signal corresponds to a plurality of code segments. Thus, in the case of filtering the sensing signal according to the code segments, compared with the manner of filtering the plurality of portions of the sensing signal according to the plurality of code segments, the signal corresponding to the start portion of the code segment has a smaller proportion of the sensing signal, and the filtered sensing signal has a smaller proportion of the signal having a lower signal-to-noise ratio, i.e., the signal which is wasted and cannot be used for determining the touch position has a smaller proportion of the signal having a lower power consumption.

In an exemplary embodiment, a chip is also provided, the chip including any of the touch controllers described above.

In an exemplary embodiment, an electronic device is also provided, which may include a touch sensor and the chip described above, the chip being connected to the touch sensor. Electronic devices may vary considerably in configuration or performance. For example, the electronic device may further include one or more processors, which may be a central processing unit (central processing unit, CPU), for determining a user performing a touch operation based on a signal component corresponding to the first drive signal. The electronic device may also have a memory, a wired or wireless network interface, a keyboard, an input/output interface, etc. to store and input/output, and may further include other components for implementing the functions of the device, which are not described herein.

It should be noted that, the information (including but not limited to user equipment information, user personal information, etc.), data (including but not limited to data for analysis, stored data, presented data, etc.), and signals related to the present application are all authorized by the user or are fully authorized by the parties, and the collection, use, and processing of the related data is required to comply with the relevant laws and regulations and standards of the relevant countries and regions.

It should be understood that references herein to "a plurality" are to two or more. It should be noted that the terms "first," "second," and the like in the description and in the claims are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein.

The implementations described in the above exemplary embodiments do not represent all implementations consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with aspects of the application as detailed in the accompanying claims.

The above embodiments are merely exemplary embodiments of the present application and are not intended to limit the present application, any modifications, equivalents, improvements, etc. within the principles of the present application should be included in the 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 , wherein the driving module comprises 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 is characterized in that the touch controller is located in a display device, the display device also includes a display driver and a display screen, the display driver is connected to the display screen, the display driver is used to obtain a second drive signal, transmit the second drive signal to the display screen to drive the display screen to display an image, and 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 there are multiple transmitting electrodes coupled to the receiving electrode;

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 is characterized in that 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.

6. The touch controller according to any one of claims 1, 2 or 5, characterized in that the touch controller further comprises an equalization filter, and the equalization 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, wherein the driving module comprises a shift register, and obtaining the first driving signal based on the reference code through the driving module comprises:

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; the step of obtaining a first driving signal based on a reference code by the driving module and transmitting the first driving signal to the transmitting electrode comprises:

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, wherein 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 comprises an equalizing filter, and the equalizing filter is connected to the driving module and the sensing module; the method further comprises:

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 comprises the touch controller according to any one of claims 1-6.

13. An electronic device, characterized in that the electronic device comprises a touch sensor and the chip according to claim 12, wherein the chip is connected to the touch sensor.