Touch controller, touch control chip and electronic equipment

Abstract

The embodiment of the invention provides a touch controller, a touch control chip and electronic equipment. The touch controller includes a first digital oscillator configured to generate, based on a received clock signal, at least two carrier signals to be provided to the plurality of modulation modules, where the at least two carrier signals include a first carrier signal and a second carrier signal, a first phase difference exists between the first carrier signal and the second carrier signal; the modulation module is configured to perform code division multiplexing modulation by using the first carrier signal and the second carrier signal based on the code word corresponding to the coupled driving electrode to obtain a driving signal. According to the touch controller, code division multiplexing modulation is performed by using at least two carrier signals, so that the length of a code word required by a driving electrode can be shortened, the transmission power is further reduced, and the time required by touch detection is shortened.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a touch controller, a touch control chip, and an electronic device. Background Art

[0002] Projected Capacitive Touch (PCAP) sensors are widely used in display screens of various devices, such as smartphones. PCAP sensors implement touch functions by designing a set of orthogonally arranged drive electrodes and sense electrodes, forming mutual capacitance at the intersection of the drive electrodes and the sense electrodes. When the touch controller measures the magnitude of the mutual capacitance at these intersections, it can capture the capacitance difference that changes over time, and then determine whether there is a detected object (such as a human finger or a stylus) close to the sensor surface and determine the position of the object. This technology uses the effect of the detected object (for example, a finger) on the capacitance to achieve precise touch operations. Summary of the invention

[0003] At least one embodiment of the present disclosure provides a touch controller for a touch panel, wherein the touch panel includes a plurality of drive electrodes and a plurality of sensing electrodes arranged crosswise, and the touch controller includes: a first digital oscillator and a plurality of modulation modules, wherein the first digital oscillator is coupled to input ends of the plurality of modulation modules, and output ends of the plurality of modulation modules are respectively coupled to the plurality of drive electrodes, and the first digital oscillator is configured to generate at least two carrier signals based on a received clock signal to provide to the plurality of modulation modules, wherein the at least two carrier signals include a first carrier signal and a second carrier signal, and there is a first phase difference between the first carrier signal and the second carrier signal; and the modulation module is configured to perform code division multiplexing modulation using the first carrier signal and the second carrier signal respectively based on code words corresponding to the coupled drive electrodes to obtain drive signals.

[0004] For example, in a touch controller provided in at least one embodiment of the present disclosure, the first phase difference is 90°.

[0005] For example, in the touch controller provided in at least one embodiment of the present disclosure, the touch panel includes a first touch area and a second touch area, the multiple driving electrodes include a first driving electrode and a second driving electrode, the multiple sensing electrodes include a first sensing electrode and a second sensing driving electrode, the first driving electrode crosses the first sensing electrode and both belong to the first touch area, the second driving electrode crosses the second sensing electrode and both belong to the second touch area, and the first sensing electrode and the second sensing electrode are connected to the same demodulation module.

[0006] For example, in a touch controller provided in at least one embodiment of the present disclosure, the plurality of driving electrodes are divided into a first driving electrode group and a second driving electrode group, the first driving electrode group includes first driving electrodes, and the second driving electrode group includes second driving electrodes.

[0007] For example, in the touch controller provided in at least one embodiment of the present disclosure, the modulation module includes a first modulation submodule and a second modulation submodule, the first modulation submodule is coupled to the first output end of the first digital oscillator and the first driving electrode, the second modulation submodule is coupled to the second output end of the first digital oscillator and the second driving electrode, the first modulation submodule is configured to receive the first carrier signal, and based on the received first code word corresponding to the first driving electrode, perform code division multiplexing modulation on the first carrier signal to obtain a first driving signal for the first driving electrode; the second modulation submodule is configured to receive the second carrier signal, and based on the received second code word corresponding to the second driving electrode, perform code division multiplexing modulation on the second carrier signal to obtain a second driving signal for the second driving electrode.

[0008] For example, in the touch controller provided in at least one embodiment of the present disclosure, the first codeword and the second codeword respectively include multiple code fields, the first modulation submodule includes a first modulator and a first comparator, the first modulator is configured to perform signal processing on the first carrier signal based on each code field of the first codeword and output the processed first carrier signal, the first comparator is configured to perform signal conversion on the processed first carrier signal to obtain the first drive signal; the second modulation submodule includes a second modulator and a second comparator, the second modulator is configured to perform signal processing on the scheduled second carrier signal based on each code field of the second codeword and output the processed second carrier signal, the second comparator is configured to perform signal conversion on the processed second carrier signal to obtain the second drive signal; wherein, the first comparator and the second comparator do not change the frequencies of the processed first carrier signal and the processed second carrier signal when performing signal conversion.

[0009] For example, in a touch controller provided in at least one embodiment of the present disclosure, the first drive signal and the second drive signal are square wave signals.

[0010] For example, in the touch controller provided by at least one embodiment of the present disclosure, each of the code words includes multiple code fields, each of the code fields includes a first code value and a second code value, the modulation module includes a selection module and a modulation submodule, the selection module is coupled to the first digital oscillator, and is configured to select to output the first carrier signal or the second carrier signal to the modulation submodule based on the received first code value; the modulation submodule is coupled to the first driving electrode corresponding to the first code word, and is configured to perform signal processing on the signal output by the selection module based on the received second code value, and provide the processed signal to the first driving electrode as the first driving signal.

[0011] For example, in the touch controller provided in at least one embodiment of the present disclosure, the modulation submodule includes a modulator and a comparator, and the modulator is configured to perform signal processing on the signal output by the selection module based on the received second code value, and output the processed signal to the comparator; the comparator is configured to perform signal conversion on the processed signal without changing the frequency of the processed signal to obtain the first drive signal.

[0012] For example, the touch controller provided by at least one embodiment of the present disclosure further includes a plurality of demodulation modules and a multiplication operation module, wherein the plurality of demodulation modules are respectively coupled to the plurality of sensing electrodes, and each of the demodulation modules is configured to receive a sensing signal from a correspondingly coupled sensing electrode, and perform a demodulation operation and a sampling operation on the sensing signal to obtain a sampling result matrix; the multiplication operation module is configured to use an inverse matrix of a codeword matrix to multiply a sampling result matrix to obtain a result matrix, wherein the sampling result matrix includes the sampling results of the plurality of demodulation modules.

[0013] For example, the touch controller provided by at least one embodiment of the present disclosure further includes: a second digital oscillator, configured to generate the at least two carrier signals based on the received clock signal to provide them to the multiple demodulation modules for demodulation operations.

[0014] For example, the touch controller provided by at least one embodiment of the present disclosure further includes: a counter, which is configured to receive a clock signal after frequency division processing and start counting from an initial value, output a timing signal after the count value reaches a preset threshold and reset the count value to the initial value.

[0015] For example, the touch controller provided by at least one embodiment of the present disclosure further includes: a codeword memory, coupled to the counter, configured to store a codeword matrix including multiple codewords, and based on the triggering of the timing signal, provide corresponding codewords to the modulation module, wherein each codeword corresponds to a driving electrode, and the corresponding codeword is a codeword corresponding to the driving electrode coupled to the modulation module.

[0016] At least one embodiment of the present disclosure further provides a touch control chip, including the touch controller provided by any embodiment of the present disclosure.

[0017] At least one embodiment of the present disclosure further provides an electronic device, comprising the touch control chip provided by any embodiment of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present disclosure, but are not intended to limit the present disclosure.

[0019] Figure 1 A structural schematic diagram of a touch control device is shown;

[0020] Figure 2 A schematic diagram showing a driving signal waveform corresponding to a Hadamard code matrix;

[0021] Figure 3 A schematic diagram of the structure of a touch controller using code division multiplexing (CDM) technology is shown;

[0022] Figure 4 A schematic structural diagram of a touch controller using code division multiplexing technology provided by at least one embodiment of the present disclosure is shown;

[0023] Figure 5 A schematic diagram of the structure of another touch controller using code division multiplexing technology provided by at least one embodiment of the present disclosure is shown;

[0024] Figure 6 A schematic diagram showing a touch panel provided by at least one embodiment of the present disclosure; and

[0025] Figure 7 A schematic structural diagram of an electronic device provided by at least one embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0027] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0028] Figure 1 A structural schematic diagram of a touch control device is shown.

[0029] like Figure 1 As shown, the touch control device 100 includes a touch controller 101 and a touch panel 102 .

[0030] The touch controller 101 includes a clock signal generator 111 , a driver 121 , a flexible circuit board pad 131 , a flexible circuit board pad 141 , an amplifier 151 , a demodulator 161 , a filter 171 , a memory 181 , and the like.

[0031] The touch panel 102 includes a touch sensor, a plurality of TX lines (driving electrodes) and a plurality of RX lines (sensing electrodes). A capacitor (mutual capacitance) will be formed where the TX line and the RX line intersect, that is, the TX line and the RX line constitute the two poles of the capacitor respectively. The driver 121 is electrically connected to the TX line through the flexible circuit board pad 131 to transmit a drive signal to the TX line. The drive signal can be, for example, a noise-free carrier signal having a predetermined frequency. After the driver 121 transmits a drive signal to the TX line, for example, the same carrier signal can be input to the demodulator 161, and then the amplifier 151, the demodulator 161 and the filter 171 are used to amplify and demodulate the signal from the RX.

[0032] The touch controller can apply drive signals to multiple drive electrodes of the touch panel, receive sense signals from multiple sense electrodes of the touch panel, and process the received sense signals and provide them to a processing device (e.g., a processor, MCU, DSP, ASIC, or a combination thereof), so that the processing device can determine the position of a finger or other object that is in contact with or close to the touch panel. The touch controller can be integrated into one chip. In addition, in the case of a touch display device or a touch display device with a fingerprint recognition function, the processing device can also interact with a display drive circuit and / or a fingerprint recognition control circuit to control display operations and fingerprint recognition operations. At the same time, at least a portion of the touch controller, display drive circuit, and / or fingerprint recognition control circuit can be integrated into one chip, such as a TDDI (touch and display integration) chip and a FTDI (fingerprint recognition, touch and display integration) chip.

[0033] When measuring the mutual capacitance at each intersection during touch detection, a time division multiplexing (TDM) method can be used, that is, the drive electrodes are scanned in sequence with a preset noise-free drive signal (e.g., a carrier signal) at different times, and the electrical signals are read from all the sensing electrodes at each time (e.g., then amplified and demodulated using the same carrier signal), however, such a scheme may result in a longer sensing time because the electrical signal reading needs to be performed for each drive electrode in a time-division manner. In addition, the touch sensor design using the TDM method cannot fully address the noise signals that appear on the sensing electrodes attributable to environmental or other types of interference, which may result in a low signal-to-noise ratio (SNR) of the sensed signal.

[0034] As an improvement to time division multiplexing (TDM), a code division multiplexing (CDM) method can be used. In the CDM method, a group of driving electrodes can be selected at the same time, and a group of driving signals corresponding to a preset CDM code matrix (the matrix size is determined by the number of driving electrodes in the group) can be provided. For example, the reference driving signal is encoded using the preset code matrix to obtain a driving signal corresponding to the preset CDM code matrix for the group of driving electrodes; then, the sensing signals obtained for all sensing electrodes are demodulated, and then the result code is obtained by multiplying with the inverse matrix of the preset CDM code matrix, and the value of the mutual capacitance at the intersection of each driving electrode and the sensing electrode can be obtained, and then it is determined whether a change has occurred.

[0035] For example, the preset CDM code matrix is ​​a 4x4 Hadamard code matrix, and the reference driving signal is encoded to obtain the driving signals of four driving electrodes. In the Hadamard code matrix, the inner product of any different rows (columns) is 0. For example, the 4x4 Hadamard code can be expressed as follows:

[0036]

[0037] Accordingly, the driving waveform corresponding to the Hadamard code matrix can be expressed as Figure 2 shown.

[0038] exist Figure 2 In the code matrix, the horizontal direction is the time axis direction, and four drive signals are applied simultaneously to the drive electrodes TX[N], TX[N+1], TX[N+2] and TX[N+3]. The code value of a row (or a column) in the code matrix is ​​a code word, and each drive electrode corresponds to a code word. Each code word includes 4 code fields, and each code field corresponds to the waveform of the drive signal applied within a preset time period. For example, when the code field is 1, the waveform of the applied drive signal (within the preset time period corresponding to the code field) is the same as the reference drive signal; when the code value is -1, the waveform of the applied drive signal (within the preset time period corresponding to the code field) is a waveform that lags 180° relative to the reference drive signal.

[0039] For example, the corresponding code word of the driving electrode TX[N+1] is [1,-1,1,-1] (i.e., the second column or the second row of the above CDM matrix), and the code word includes 4 code fields, i.e., Code_segment_0=1, Code_segment_1=-1, Code_segment_2=1 and Code_segment_3=-1, and the preset time periods corresponding to these 4 code fields are [T0,T1), [T1,T2), [T2,T3) and [T3,T4) respectively. Figure 2 As shown, for the driving electrode TX[N+1], in the preset time periods [T0, T1) and [T2, T3), Code_segment_0=Code_segment_2=1, then the waveform of the applied driving signal is the same as the reference driving signal; in the preset time periods [T1, T2) and [T3, T4), Code_segment_1=Code_segment_3=-1, then the waveform of the applied driving signal lags 180° relative to the waveform of the reference driving signal, that is, it is inverted with respect to the waveform of the reference driving signal.

[0040] Of course, the Hadamard code matrix is ​​only an example for encoding a drive signal, and other codes may be used to encode the reference drive signal, and the dimension of the matrix may also be selected as needed. For example, a proprietary code matrix may be used, which includes a code that can balance the code value of 1 and -1 for each drive electrode in each code field to be close to zero (i.e., a so-called DC balance code), so that the coupling noise entering the display panel due to the path formed by the parasitic capacitance between the drive electrode and the display electrode (e.g., gate, data line, and / or common electrode) in the display panel can be reduced, thereby reducing visual artifacts and improving display quality.

[0041] The touch controller can use a square wave signal as a driving signal (such as Figure 2 As shown), a triangular wave signal, a sine wave signal or the like may also be used as a driving signal.

[0042] For example, Figure 3 A structural schematic diagram of a touch controller using code division multiplexing (CDM) technology is shown.

[0043] like Figure 3 As shown, the touch controller 301 includes a modulation module and a demodulation module. The modulation module is based on code division multiplexing (CDM) technology, and uses a preset CDM code matrix (also called a "CDM codeword matrix") to perform in-phase orthogonal modulation (IQ modulation, i.e., using 0° and 180°) on the carrier signal generated by the digital oscillator 313 (NCO1) to obtain a drive signal for driving the TX line (driving electrode), and apply the drive signal to the corresponding TX line through the flexible circuit board pad 318. The demodulation module is coupled to the sensing electrode RX through the flexible circuit board pad 319, for example, and the sensing signal from the RX line is sequentially passed through the amplifier 320, the bandpass filter 321, the analog-to-digital converter 322, the demodulator 323, the low-pass filter 324 and the sampler 325 to perform demodulation, filtering, sampling and other operations to obtain the sampling result of the sensing electrode RX. Then, the touch controller 301 combines the sampling results corresponding to all the sensing electrodes on the touch panel into a sampling result matrix, and multiplies the inverse matrix of the preset CDM code matrix by the sampling result matrix to obtain the value of the mutual capacitance at the intersection of each driving electrode and each sensing electrode, and then locates the touch position based on whether the value of the mutual capacitance at the intersection changes.

[0044] The inventors of the present disclosure note that when the touch controller modulates the carrier signal based on the codeword, two phases (e.g., 0° and 180°) are used to represent "+" and "-" to modulate the same carrier signal to generate a drive signal, and in order to ensure that each drive electrode can be independently encoded and maintain good orthogonality and discrimination in the entire system, the length of the codeword corresponding to the drive electrode depends on the number of drive electrodes on the touch panel. For example, if 10 drive electrodes are set on the touch panel, the length of the codeword corresponding to each drive electrode can be 10 bits (or greater than 10 bits). Although longer codewords can better identify and exclude unnecessary signals, longer codewords mean that more information needs to be sent and longer time is required for signal processing (e.g., demodulation and modulation). Therefore, the drive signal generated based on the longer codeword often requires a higher transmission power to ensure reliable transmission of the signal, and also increases the time of touch detection.

[0045] In view of the above shortcomings, one or more embodiments of the present disclosure propose a touch controller for a touch panel. The touch panel includes a plurality of drive electrodes and a plurality of sensing electrodes arranged crosswise, and the touch controller includes a first digital oscillator and a plurality of modulation modules. The first digital oscillator is coupled to the input ends of the plurality of modulation modules, and the output ends of the plurality of modulation modules are respectively coupled to the plurality of drive electrodes. The first digital oscillator is configured to generate at least two carrier signals based on the received clock signal to provide to the plurality of modulation modules, wherein the at least two carrier signals include a first carrier signal and a second carrier signal, and there is a first phase difference between the first carrier signal and the second carrier signal; the modulation module is configured to perform code division multiplexing modulation using the first carrier signal and the second carrier signal based on the code words corresponding to the coupled drive electrodes to obtain the drive signal. The touch controller can shorten the length of the code words required for the drive electrodes by using at least two carrier signals for code division multiplexing modulation, thereby reducing the transmission power and reducing the time required for touch detection.

[0046] The present disclosure is described below through several specific embodiments. In order to keep the following description of the embodiments of the present disclosure clear and concise, detailed descriptions of known functions and known components may be omitted. When any component of the embodiments of the present disclosure appears in more than one figure, the component is represented by the same or similar reference numeral in each figure.

[0047] Figure 4 A schematic structural diagram of a touch controller using code division multiplexing technology provided by at least one embodiment of the present disclosure is shown.

[0048] like Figure 4 As shown, the touch controller 400 is coupled to the touch panel 410, and the touch panel 410 includes a plurality of driving electrodes and a plurality of sensing electrodes arranged crosswise. Figure 4 Only the driving electrode TX1, the driving electrode TX2 and the sensing electrode RX1 are schematically shown. The touch controller 400 includes a first digital oscillator (NCO1) 405 and a plurality of modulation modules 420, wherein the first digital oscillator 405 is coupled to the input ends of the plurality of modulation modules 420, and the output ends of the plurality of modulation modules 420 are respectively coupled to the plurality of driving electrodes, for example, the modulation module 420 is coupled to the driving electrode TX1 via a flexible circuit board pad 423.

[0049] In this embodiment, the first digital oscillator 405 is configured to generate at least two carrier signals based on the received clock signal to provide to the plurality of modulation modules 420, wherein the at least two carrier signals include a first carrier signal and a second carrier signal, and there is a phase difference (hereinafter referred to as "first phase difference") between the first carrier signal and the second carrier signal. Based on the codeword corresponding to the driving electrode coupled to the modulation module 420, the modulation module 420 is configured to perform code division multiplexing modulation using the first carrier signal and the second carrier signal to obtain a driving signal.

[0050] For example, the touch controller 400 also includes a clock signal generator 401 and a clock divider 402, wherein the clock signal generator 401 is used to generate a clock signal, and the clock divider 402 is used to divide the clock signal. The first digital oscillator 405 is coupled to the clock divider 402 to generate at least two carrier signals based on the divided clock signal, such as a sine signal sin(ωt) and a cosine signal cos(ωt) having the same frequency f as carrier signals, wherein t represents time, ω represents angular velocity, and satisfies ω=2πf. The phase difference between the sine signal sin(ωt) and the cosine signal cos(ωt) is 90°.

[0051] For example, the touch controller 400 may further include a counter 403. The counter 403 is coupled to the clock divider 402, and is configured to receive the divided clock signal, count from an initial value, output a timing signal after the count value reaches a preset threshold, and reset the count value to the initial value.

[0052] For example, the touch controller 400 may further include a codeword memory 404, which is coupled to the counter 403 and configured to store a codeword matrix (eg, Figure 2 The CDM code matrix shown in FIG. 4 is used to generate a CDM code matrix and provide corresponding code words to multiple modulation modules 420. The code word memory 404 triggers a data reading operation upon receiving a timing signal and provides corresponding code words to multiple modulation modules 420. Here, the corresponding code word is a code word corresponding to the driving electrode coupled to the modulation module.

[0053] In one embodiment of the present disclosure, the first digital oscillator can generate at least two carrier signals to provide to multiple modulation modules, and accordingly, the multiple driving electrodes in the touch panel can be divided into at least two groups of driving electrodes, each group of driving electrodes corresponds to a carrier signal, for example, the driving signal obtained by code division multiplexing modulation using the first carrier signal is used for the driving electrodes in the first group, and the driving signal obtained by code division multiplexing modulation using the second carrier signal is used for the driving electrodes in the second group. In this case, the codeword length corresponding to the driving electrode is equal to the number of driving electrodes in each group, which can ensure that each driving electrode can be independently encoded while maintaining good orthogonality and discrimination, without being equal to the number of all driving electrodes on the touch panel, thereby solving the problem of increased signal transmission power of the touch controller and increased touch detection time due to excessive codeword length.

[0054] The touch controller provided by the embodiment of the present disclosure is further introduced below by taking the first digital oscillator NCO1 generating two carrier signals with a first phase difference of 90° as an example.

[0055] In this example, the plurality of driving electrodes on the touch panel are divided into a first group of driving electrodes and a second group of driving electrodes having the same number. The first group of driving electrodes includes driving electrodes TX1 , and the second group of driving electrodes includes driving electrodes TX2 .

[0056] like Figure 4 As shown, the driving electrode TX1 and the driving electrode TX2 cross the same sensing electrode RX1. The modulation module 420 includes a first modulation submodule 420_1 and a second modulation submodule 420_2. The first modulation submodule 420_1 is coupled to the first output terminal of the first digital oscillator 405 and the driving electrode TX1. The first modulation submodule 420_1 is configured to receive a first carrier signal (e.g., a sinusoidal signal sin(ωt)), and based on the received first codeword (i.e., the codeword corresponding to the driving electrode TX1), code division multiplexing modulates the first carrier signal, and provides the modulated first carrier signal to the driving electrode TX1 as a first driving signal.

[0057] The first modulation submodule 420_1 includes a modulator 421 and a comparator 422. The modulator 421 is configured to perform signal processing on the first carrier signal based on each code field of the first codeword and output the processed first carrier signal. The comparator 422 is configured to perform signal conversion on the processed first carrier signal received from the modulator 421 to obtain a first drive signal, and the first comparator does not change the frequency of the processed first carrier signal when performing signal conversion.

[0058] For example, the comparator 422 can convert the signal output by the modulator 421 into a square wave signal with the same frequency, or other signals with the same frequency according to the voltage amplitude of the signal output by the modulator 421 (such as sin(ωt) and -sin(ωt)), and the present disclosure is not limited to this.

[0059] For example, the modulator 421 may include a multiplier, for example, to multiply the first carrier signal by 1 or -1, which is not limited in the present disclosure.

[0060] For example, when the code field in the first codeword is 1, the modulator 421 directly outputs the first carrier signal to the comparator 422 (for example, the multiplier in the modulator 421 multiplies the first carrier signal sin(ωt) by 1 and outputs the signal sin(ωt)); when the code field in the first codeword is -1, the modulator 421 outputs the inverted first carrier signal to the comparator 422 (for example, the multiplier in the modulator 421 multiplies the first carrier signal sin(ωt) by -1 to obtain the inverted first carrier signal -sin(ωt), that is, sin(ωt+180°)). Alternatively, when the code field in the first codeword is -1, the modulator 421 directly outputs the first carrier signal to the comparator 422; when the code field in the first codeword is 1, the modulator 421 outputs the inverted first carrier signal to the comparator 422.

[0061] The following takes the first code word [1, -1, 1, -1] as an example to further describe the modulation process of the first modulation submodule 420_1 on the first carrier signal.

[0062] For example, the above-mentioned first codeword includes 4 code fields Code_segment_0 to Code_segment_3, which correspond to 4 consecutive preset time periods, [T0, T1), [T1, T2), [T2, T3) and [T3, T4). For Code_segment_0=1, the modulator 421 outputs a sinusoidal signal (sin(ωt)) to the comparator 422, where t∈[T0, T1). For Code_segment_1=-1, the modulator 421 outputs an inverted sinusoidal signal (-sin(ωt)) to the comparator 422, where t∈[T1, T2). For Code_segment_2=1, the modulator 421 outputs a sinusoidal signal (sin(ωt)) to the comparator 422, where t∈[T2, T3). For Code_segment_3 = -1, the modulator 421 outputs an inverted sinusoidal signal (-sin(ωt)) to the comparator 422, where t∈[T3,T4]. After modulation, the signal corresponding to the first codeword [1,-1,1,-1] is [sin(ωt),-sin(ωt),sin(ωt),-sin(ωt)], that is, [sin(ωt),sin(ωt+180°),sin(ωt),sin(ωt+180°)].

[0063] like Figure 4 As shown, the second modulation submodule 420_2 is coupled to the second output end of the first digital oscillator NCO1 and the driving electrode TX2. The second modulation submodule 420_2 is configured to receive a second carrier signal (for example, a cosine signal cos(ωt)), and based on the received second code word (that is, the code word corresponding to the driving electrode TX2), perform code division multiplexing modulation on the second carrier signal, and provide the modulated second carrier signal to the driving electrode TX2 as a second driving signal.

[0064] The second modulation submodule 420_2 includes a modulator and a comparator, and its function and structure can refer to the modulator 421 and the comparator 422 in the first modulation submodule 420_1. For example, when the code field in the second codeword is 1, the modulator directly outputs a cosine signal (cos(ωt)) to the comparator; when the code field in the second codeword is -1, the modulator outputs an inverted cosine signal (-cos(ωt)) to the comparator. If the second codeword is [1,-1,1,-1], after modulation, the signal corresponding to the second codeword is [cos(ωt,-cos(ωt),cos(ωt),-cos(ωt)], that is, [sin(ωt+90°),sin(ωt+270°),sin(ωt+90°),sin(ωt+270°)].

[0065] In the above embodiment, a plurality of driving electrodes are divided into two groups of driving electrodes, and the two groups of driving electrodes are modulated respectively using a first carrier signal and a second carrier signal with a phase difference of 90°, that is, according to the code word corresponding to the first group of driving electrodes, a carrier signal (for example, a sinusoidal signal sin(ωt)) is modulated with phases of 0° and 180° to obtain a driving signal for the first group of driving electrodes, and according to the code word corresponding to the second group of driving electrodes, the same carrier signal (for example, a sinusoidal signal sin(ωt)) is modulated with phases of 90° and 270° to obtain a driving signal for the second group of driving electrodes, so that when the code word length corresponding to the driving electrode is equal to half of the number of all driving electrodes on the touch panel, it can be ensured that each driving electrode can be independently encoded, thereby solving the problem of increased signal transmission power of the touch controller and increased touch detection time due to excessively long code word length.

[0066] In addition, the corresponding Figure 4 In the touch controller 400 shown, the modulation module 420 can also use the other four phases with a phase difference of 90° to represent the "+" and "-" in the codeword to modulate the same carrier signal. For example, the other four phases with a phase difference of 90° can be carrier signals of 20°, 110°, 200° and 290° respectively, where phases 20° and 200° are used for the first group of driving electrodes, and phases 110° and 290° are used for the second group of driving electrodes.

[0067] In addition, a three-phase carrier signal with a phase difference of 120° or a five-phase carrier signal with a phase difference of 72° may be used for code division multiplexing modulation, and the present disclosure does not impose any limitation on this.

[0068] One or more embodiments of the present disclosure provide a touch controller further comprising a plurality of demodulation modules and a multiplication operation module, wherein the plurality of demodulation modules are respectively coupled to the multiplication operation module and the plurality of sensing electrodes.

[0069] like Figure 4 As shown, the demodulation module 430 is coupled to the sensing electrode RX1, for example, through the flexible circuit board pad 431. The demodulation module 430 is configured to receive a sensing signal from the corresponding coupled sensing electrode RX1, and perform a demodulation operation and a sampling operation on the sensing signal to obtain a sampling result matrix. The multiplication module 407 is configured to use the inverse matrix of the codeword matrix to multiply the sampling result matrix to obtain a result matrix (i.e., a sensing result).

[0070] For example, the touch controller 400 further includes a second digital oscillator 406 (NCO2). The second digital oscillator NCO2 is configured to generate at least two carrier signals based on the received clock signal to provide to multiple demodulation modules for demodulation operations. It should be noted that the second digital oscillator NCO2 is coupled to the clock divider 402, and the at least two carrier signals generated by the second digital oscillator NCO2 according to the divided clock signal are the same as the at least two carrier signals generated by the first digital oscillator NCO1.

[0071] like Figure 4 As shown, the demodulation module 430 may include an amplifier 432, a band-pass filter 433 (Band-pass filter, BPF), an analog-to-digital converter 434 (ADC), a demodulator 435_1, a demodulator 435_2, a low-pass filter 436, and a sampler 437. For example, the demodulator 435_1 and the demodulator 435_2 may include a multiplier, which is not limited in the present disclosure.

[0072] The sensing signal received from the sensing electrode RX1 passes through the amplifier 432 and the bandpass filter 433 in sequence, and then the analog signal is converted into a digital signal through the analog-to-digital converter 434. After that, the demodulator 435_1 (for example, a multiplier) multiplies the digital signal with the first carrier signal (for example, sin (ωt)) to obtain the in-phase component signal I (t), and the demodulator 435_2 (for example, a multiplier) multiplies the digital signal with the second carrier signal (for example, cos (ωt)) to obtain the quadrature component signal Q (t), and then the low-pass filter 436 removes the higher frequency part of the signal I (t) and Q (t), wherein the higher frequency part is generally a noise signal. After that, the sampler 437 samples the signals I (t) and Q (t) respectively to obtain the sampling results on the sensing electrode RX1. Finally, the touch controller combines the sampling results on the plurality of sensing electrodes to obtain a sampling result matrix, and the multiplication operation module 407 multiplies the sampling result matrix by the inverse matrix of the codeword matrix to obtain a result matrix.

[0073] For example, if Figure 4 The touch panel 410 shown includes M driving electrodes and N sensing electrodes (where M and N are integers greater than or equal to 1) arranged crosswise, and the result matrix is ​​an N×M matrix. Each value in the result matrix represents the value of the mutual capacitance at an intersection of the driving electrode and the sensing electrode. For example, the value in the third row and second column of the result matrix represents the value of the mutual capacitance at the intersection of the second driving electrode and the third sensing electrode on the touch panel 410. According to whether the value in the result matrix changes, the position of the touch point on the touch panel 410 can be further located.

[0074] Figure 5 A schematic structural diagram of another touch controller using code division multiplexing technology provided by at least one embodiment of the present disclosure is shown.

[0075] exist Figure 5 In the touch controller 500 shown, the length of the codeword is equal to the number of all driving electrodes on the touch panel, and each code field in the codeword includes a first code value (bit_1) and a second code value (bit_0). For example, a total of 8 driving electrodes TX[N] to TX[N+7] are arranged on the touch panel, which are cross-coupled with the sensing electrode RX. For example, the codeword corresponding to the driving electrode TX[N] can be [(1,-1), (-1,1), (1,1), (-1,-1)], and the codeword length is 8. The codeword includes 4 code fields, Code_segment_0 to Code_segment_3, which correspond to 4 consecutive preset time periods, [T0, T1), [T1, T2), [T2, T3) and [T3, T4] in sequence. Each code field includes 2 code values, for example, the first code value bit_1 of the code field Code_segment_0 is 1, and the second code value bit_0 is -1.

[0076] like Figure 5 As shown, the modulation module 520 in the touch controller 500 is coupled to the driving electrode TX[N] through the flexible circuit board pad 523, for example, and performs code division multiplexing modulation on the first carrier signal (e.g., sin(ωt)) and the second carrier signal (e.g., cos(ωt)) generated by the first digital oscillator 505 (NCO1) based on the code word corresponding to the driving electrode TX[N] to generate a driving signal applied to the driving electrode TX[N].

[0077] For example, the modulation module 520 includes a selection module 524 and a modulation submodule 520_3. The selection module 524 is coupled to the first digital oscillator NCO1, and is configured to select the first carrier signal or the second carrier signal to be output to the modulation submodule 520_3 based on the received first code value bit_1. The modulation submodule 520_3 is coupled to the driving electrode TX[N] corresponding to the first codeword, and is configured to perform signal processing on the signal output by the selection module 524 based on the received second code value bit_0, and provide the processed signal to the driving electrode TX[N] as a driving signal.

[0078] For example, for a code field in the codeword received by the selection module 524, if the first code value bit_1 in the code field is 1, the first carrier signal is output, and if the first code value bit_1 is -1, the second carrier signal is output. Alternatively, if the first code value bit_1 is 1, the second carrier signal is output, and if the first code value bit_1 is -1, the first carrier signal is output.

[0079] For example, the modulation submodule 520_3 includes a modulator 521 and a comparator 522. The modulator 521 is configured to perform signal processing on the signal output by the selection module 524 based on the received second code value bit_0, and output the processed signal to the comparator 522. The comparator 522 is configured to perform signal conversion on the processed signal without changing the frequency of the processed signal to obtain a first driving signal for driving the electrode TX[N].

[0080] For example, the modulator 521 may include a multiplier, and the multiplier performs signal processing on the signal received by the modulator 521, such as multiplying the signal received by the modulator 521 by 1 or -1, which is not limited in the present disclosure.

[0081] For example, for a code field in a code word received by the modulator 521, if the second code value bit_0 in the code field is 1, the signal received from the selection module 524 is directly output (for example, the multiplier in the modulator 521 multiplies the received signal by 1); if the second code value bit_0 is -1, the signal received from the selection module 524 is inverted and output to the comparator 522 (for example, the multiplier in the modulator 521 multiplies the received signal by -1). Alternatively, if the second code value bit_0 is 1, the signal received from the selection module 524 is inverted and output to the comparator 522; if the second code value bit_0 is -1, the signal received from the selection module 524 is directly output.

[0082] In one example, the code word corresponding to the driving electrode TX[N] is [(1,-1), (-1,1), (1,1), (-1,-1)], the first carrier signal is sin(ωt), and the second carrier signal is cos(ωt). For the code field Code_segment_0 = (1,-1), the selection module 524 selects the output signal sin(ωt), the modulator 521 inverts the signal sin(ωt), and outputs the signal -sin(ωt) within the preset time period [T0, T1). For the code field Code_segment_1 = (-1,1), the selection module 524 selects the output signal cos(ωt), and the modulator 521 directly outputs the signal cos(ωt) within the preset time period [T1, T2). Accordingly, after the operation of the selection module 524 and the modulator 521, the signal corresponding to the code word [(1,-1), (-1,1), (1,1), (-1,-1)] is [-sin(ωt), cos(ωt), sin(ωt), -cos(ωt)], that is, [sin(ωt+180°), sin(ωt+90°), sin(ωt), sin(ωt+270°)]. At this time, the waveform of the driving signal within a preset time period represents a 2-bit code value.

[0083] In addition, if Figure 3 The touch controller 301 shown in the figure modulates the same carrier signal (for example, the sinusoidal signal sin(ωt)) based on the codeword [(1,-1),(-1,1),(1,1),(-1,-1)] and uses two phases (0° and 180°). Before passing through the inverter, the signal signal_1 corresponding to the codeword is [sin(ωt),sin(ωt+180°),sin(ωt+180°),sin(ωt),sin(ωt),sin(ωt),sin(ωt+180°),sin(ωt+180°)]. Compared with Figure 5 The touch controller 500 shown uses 4 phases (0°, 90°, 180° and 270°) to modulate the same carrier signal (e.g., sinusoidal signal sin(ωt)) based on the above codeword. Before passing through the inverter, the signal signal_2 corresponding to the codeword is [sin(ωt+180°), sin(ωt+90°), sin(ωt), sin(ωt+270°)]. Obviously, the signal signal_1 consumes more transmission power and more data processing time than the signal signal_2.

[0084] A touch controller provided by an embodiment of the present disclosure uses a 4-phase carrier signal for code division multiplexing modulation. This can solve the problem of increased power consumption of the touch controller and increased delay in touch detection due to excessively long code word length without shortening the code word length corresponding to the driving electrode.

[0085] like Figure 5 As shown, the touch controller 500 also includes a demodulation module 530 and a multiplication calculation module 507, whose functions and structures can refer to the above Figure 4 The demodulation module 430 and the multiplication calculation module 407 are not described in detail here.

[0086] Figure 6 A schematic diagram of a touch panel provided by at least one embodiment of the present disclosure is shown.

[0087] like Figure 6As shown, the touch panel 610 includes a first touch area 611 and a second touch area 612, the driving electrode TX1 crosses with the sensing electrode RX1 and both belong to the first touch area 611, the driving electrode TX2 crosses with the sensing electrode RX2 and both belong to the second touch area 612, and the sensing electrode RX1 and the sensing electrode RX2 are connected to the same demodulation module 630. For example, the first touch area 611 and the second touch area 612 are arranged adjacent to each other or not adjacent to each other in a physical position, for example, in the case of adjacent arrangement, the first touch area 611 and the second touch area 612 belong to different parts of the same display touch screen; in the case of non-adjacent arrangement, the first touch area 611 and the second touch area 612 are respectively located on different display touch screens of the same display device.

[0088] For example, the touch controller 600 can drive the first touch area 611 and the second touch area 612 at the same time. The modulation module of the touch controller 600 includes a first modulation submodule 620_1 and a second modulation submodule 620_2. The first modulation submodule 620_1 is coupled to the driving electrode TX1 to provide a driving signal for the driving electrode TX1, and the second modulation submodule 620_2 is coupled to the driving electrode TX2 to provide a driving signal for the driving electrode TX2. Other structures and functions of the touch controller 600 are similar to those of FIG. Figure 4 The touch controller 400 shown is similar, and reference may be made to the above description of the touch controller 400 , which will not be repeated here.

[0089] At least one embodiment of the present disclosure further provides a touch control chip, which includes the touch controller provided by any embodiment of the present disclosure.

[0090] At least one embodiment of the present disclosure further provides an electronic device, which includes the touch chip provided by any embodiment of the present disclosure. The electronic device can be a display device, such as a smart phone, a laptop, a PAD (tablet computer), a vehicle terminal (such as a vehicle navigation terminal), and other terminals.

[0091] Figure 7 A schematic structural diagram of an electronic device provided by at least one embodiment of the present disclosure is shown.

[0092] like Figure 7 As shown, the electronic device 700 includes a touch panel 710 , a display panel (not shown in the figure), a display driver chip 720 and a touch control chip 730 , and the touch control chip 730 includes a touch controller 731 .

[0093] For example, the functions of the display driver chip 720 and the touch chip 730 can be integrated on the same chip to form a touch display driver chip (Display Driver IC, TDDI), thereby achieving higher integration and better performance, further simplifying the design of electronic devices, saving space and cost, and improving the overall performance of electronic devices.

[0094] For example, the touch panel 710 may be disposed on the surface of the display panel or implemented inside the display panel. The touch panel 710 includes a drive electrode and a sensing electrode, the drive electrode being configured to receive a drive signal provided by the touch controller 731, and the sensing electrode being configured to provide a sensing signal to the touch controller 731. The drive electrode and the sensing electrode may be prepared by a transparent conductive material or by, for example, a metal grid. For another example, the main bodies of the drive electrode and the sensing electrode may be formed in the same layer and in different layers at the intersection. The embodiments of the present disclosure do not limit the structure, size, etc. of the touch panel 710.

[0095] For example, the display panel may be a liquid crystal display panel (LCD panel), an organic light emitting display panel (OLED panel), an electronic paper display panel, etc., and the embodiments of the present disclosure are not limited to this.

[0096] In addition to the above exemplary descriptions, there are a few points that need to be explained:

[0097] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure, and other structures may refer to the general design.

[0098] (2) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to obtain new embodiments.

[0099] The above description is merely an exemplary embodiment of the present disclosure and is not intended to limit the protection scope of the present disclosure. The protection scope of the present disclosure is determined by the appended claims.

Claims

1. A touch controller for a touch panel, wherein: The touch panel includes a plurality of driving electrodes and a plurality of sensing electrodes arranged crosswise. The touch controller comprises: a first digital oscillator and a plurality of modulation modules, wherein the first digital oscillator is coupled to input ends of the plurality of modulation modules, and output ends of the plurality of modulation modules are respectively coupled to the plurality of driving electrodes. The first digital oscillator is configured to generate at least two carrier signals based on a received clock signal to provide to the plurality of modulation modules, wherein the at least two carrier signals include a first carrier signal and a second carrier signal, and a first phase difference exists between the first carrier signal and the second carrier signal; The modulation module is configured to perform code division multiplexing modulation using the first carrier signal and the second carrier signal respectively to obtain a driving signal based on a code word corresponding to the coupled driving electrode.

2. The touch controller according to claim 1, wherein: The first phase difference is 90°.

3. The touch controller according to claim 2, wherein: The touch panel includes a first touch area and a second touch area, the multiple driving electrodes include a first driving electrode and a second driving electrode, the multiple sensing electrodes include a first sensing electrode and a second sensing driving electrode, the first driving electrode crosses the first sensing electrode and both belong to the first touch area, the second driving electrode crosses the second sensing electrode and both belong to the second touch area, and the first sensing electrode and the second sensing electrode are connected to the same demodulation module.

4. The touch controller according to claim 2, wherein: The plurality of driving electrodes are divided into a first driving electrode group including first driving electrodes and a second driving electrode group including second driving electrodes.

5. The touch controller according to claim 4, wherein: The modulation module includes a first modulation submodule and a second modulation submodule, wherein the first modulation submodule is coupled to a first output terminal of the first digital oscillator and the first driving electrode, and the second modulation submodule is coupled to a second output terminal of the first digital oscillator and the second driving electrode. The first modulation submodule is configured to receive the first carrier signal, and based on the received first codeword corresponding to the first driving electrode, perform code division multiplexing modulation on the first carrier signal to obtain a first driving signal for the first driving electrode; The second modulation submodule is configured to receive the second carrier signal, and based on the received second codeword corresponding to the second driving electrode, perform code division multiplexing modulation on the second carrier signal to obtain a second driving signal for the second driving electrode.

6. The touch controller according to claim 5, wherein: The first codeword and the second codeword respectively include a plurality of code fields, The first modulation submodule includes a first modulator and a first comparator, wherein the first modulator is configured to perform signal processing on the first carrier signal based on each code field of the first codeword and output the processed first carrier signal, and the first comparator is configured to perform signal conversion on the processed first carrier signal to obtain the first driving signal; The second modulation submodule includes a second modulator and a second comparator, the second modulator is configured to perform signal processing on the scheduled second carrier signal based on each code field of the second codeword and output the processed second carrier signal, and the second comparator is configured to perform signal conversion on the processed second carrier signal to obtain the second driving signal; The first comparator and the second comparator do not change the frequencies of the processed first carrier signal and the processed second carrier signal when performing signal conversion.

7. The touch controller according to claim 6, wherein: The first driving signal and the second driving signal are square wave signals.

8. The touch controller according to claim 2, wherein: Each of the codewords includes a plurality of code fields, each of the code fields includes a first code value and a second code value, the modulation module includes a selection module and a modulation submodule, The selection module is coupled to the first digital oscillator and is configured to select to output the first carrier signal or the second carrier signal to the modulation submodule based on the received first code value; The modulation submodule is coupled to the first driving electrode corresponding to the first codeword, and is configured to perform signal processing on the signal output by the selection module based on the received second code value, and provide the processed signal to the first driving electrode as a first driving signal.

9. The touch controller according to claim 8, wherein: The modulation submodule includes a modulator and a comparator. The modulator is configured to perform signal processing on the signal output by the selection module based on the received second code value, and output the processed signal to the comparator; The comparator is configured to perform signal conversion on the processed signal without changing the frequency of the processed signal to obtain the first driving signal.

10. The touch controller according to claim 1, further comprising a plurality of demodulation modules and multiplication modules, wherein: The plurality of demodulation modules are respectively coupled to the plurality of sensing electrodes. Each of the demodulation modules is configured to receive a sensing signal from a corresponding coupled sensing electrode, and perform a demodulation operation and a sampling operation on the sensing signal to obtain a sampling result matrix; The multiplication operation module is configured to use the inverse matrix of the codeword matrix to multiply the sampling result matrix to obtain a result matrix, wherein the sampling result matrix includes the sampling results of the multiple demodulation modules.

11. The touch controller according to claim 10, further comprising: The second digital oscillator is configured to generate the at least two carrier signals based on the received clock signal to provide the at least two carrier signals to the plurality of demodulation modules for demodulation operation.

12. The touch controller according to claim 1, further comprising: The counter is configured to receive the clock signal after frequency division processing, start counting from an initial value, output a timing signal after the count value reaches a preset threshold value, and reset the count value to the initial value.

13. The touch controller according to claim 12, further comprising: a codeword memory, coupled to the counter, configured to store a codeword matrix including a plurality of codewords, and provide corresponding codewords to the modulation module based on the triggering of the timing signal, Wherein, each code word corresponds to a driving electrode, and the corresponding code word is a code word corresponding to the driving electrode coupled to the modulation module.

14. A touch control chip, comprising the touch controller according to any one of claims 1-13.

15. An electronic device comprising the touch control chip according to claim 14.

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