WO2020124323A1 - 触摸检测方法、触控芯片及电子设备 - Google Patents

触摸检测方法、触控芯片及电子设备 Download PDF

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Publication number
WO2020124323A1
WO2020124323A1 PCT/CN2018/121558 CN2018121558W WO2020124323A1 WO 2020124323 A1 WO2020124323 A1 WO 2020124323A1 CN 2018121558 W CN2018121558 W CN 2018121558W WO 2020124323 A1 WO2020124323 A1 WO 2020124323A1
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WIPO (PCT)
Prior art keywords
signal
touch
periods
driving
sampling period
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PCT/CN2018/121558
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English (en)
French (fr)
Inventor
蒋宏
袁广凯
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深圳市汇顶科技股份有限公司
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Application filed by 深圳市汇顶科技股份有限公司 filed Critical 深圳市汇顶科技股份有限公司
Priority to PCT/CN2018/121558 priority Critical patent/WO2020124323A1/zh
Priority to CN201880002876.6A priority patent/CN111587415B/zh
Priority to CN202410147715.3A priority patent/CN118092702A/zh
Priority to EP18935995.3A priority patent/EP3696654A4/en
Priority to US16/866,409 priority patent/US11086446B2/en
Publication of WO2020124323A1 publication Critical patent/WO2020124323A1/zh

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    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/0416—Control or interface arrangements specially adapted for digitisers
    • G06F3/04166—Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/0416—Control or interface arrangements specially adapted for digitisers
    • G06F3/0418—Control or interface arrangements specially adapted for digitisers for error correction or compensation, e.g. based on parallax, calibration or alignment
    • G06F3/04182—Filtering of noise external to the device and not generated by digitiser components

Definitions

  • the present application relates to the field of touch technology, in particular to a touch detection method, a touch chip and an electronic device.
  • Existing capacitive touch screens usually adopt multi-channel code detection mode or single-channel detection mode for touch detection.
  • the capacitance value on the capacitance sensing node at the corresponding position will change, and the touch chip can determine the corresponding touch position by detecting the change in capacitance in real time, thereby generating a corresponding touch event.
  • the purpose of some embodiments of the present application is to provide a touch detection method, a touch chip and an electronic device, which can improve the ability to resist low-frequency interference in touch detection, thereby improving the signal-to-noise ratio of the system and enhancing touch sensitivity.
  • An embodiment of the present application provides a touch detection method, including: applying a driving signal encoded based on a preset encoding method to a driving channel of a touch screen; wherein the encoding method includes dividing a plurality of signal waveforms of the driving signal Into a waveform with at least one correlated double sampling period, and the same correlated double sampling period includes two sampling periods with a phase difference of 180°; the sensing signal corresponding to the driving signal is received from the sensing channel of the touch screen; The sensing signal and the coding information corresponding to the coding method determine touch position information.
  • An embodiment of the present application further provides a touch control chip, which includes: a driving unit that applies a driving signal encoded based on a preset encoding method to a driving channel of the touch screen; wherein the encoding method includes: multiplying the driving signal Signal waveforms are divided into at least one correlated double sampling period waveform, and the same correlated double sampling period includes two sampling periods with a phase difference of 180°; the receiving unit is used to receive the drive from the sensing channel of the touch screen A sensing signal corresponding to the signal; the processing unit determines touch position information according to the sensing signal and the coding information corresponding to the coding mode.
  • Embodiments of the present invention also provide an electronic device, including: a touch screen and the above touch chip.
  • multiple signal waveforms of the driving signal are divided into at least one waveform with a correlated double sampling period, and the same correlated double sampling period includes two sampling periods with a phase difference of 180° .
  • the time of touch detection is relatively short, and it can be considered that low-frequency interference remains unchanged during the process of touch detection; and those skilled in the art should also know that the sensing signal includes the target signal (that is, the driving signal Coupling signal) and low-frequency interference, the target signal will have a phase shift relative to the drive signal, and the waveform phase of the target signal and the drive signal at the same time always maintain this phase shift difference.
  • the phase difference of the driving signals of two sampling periods in a correlated double sampling period is 180°
  • the phase difference of the target signal is also maintained at 180° in the sensing signal sampled by the two sampling periods.
  • the phase of low-frequency interference is the same, so the low-frequency interference in the two sampling periods of the same correlated double sampling period can be canceled out by calculation; thus the ability to resist low-frequency interference in touch detection can be improved, thereby improving the signal-to-noise ratio of the system and enhancing Touch sensitivity.
  • the number of signal periods included in the two sampling periods in the same related double sampling period is equal; wherein, one of the signal periods corresponds to one of the signal waveforms.
  • the number of signal periods included in the two sampling periods is equal, that is, the waveforms of the two sampling periods are waveforms of the same time length, which can make the low-frequency interference contained in the waveforms of the two sampling periods completely cancel out as much as possible.
  • the plurality of signal waveforms are divided into one waveform of the relevant double sampling period. This embodiment provides a specific implementation manner.
  • the plurality of signal waveforms are divided into several waveforms of the related double sampling periods, and the number of signal periods included in the sampling period in each of the related double sampling periods is equal; and, each of the correlations The number of signal periods included in the sampling period in the double sampling period is all one.
  • This embodiment provides another specific implementation; for the same drive signal (including the same number of signal waveforms), the more related double sampling periods divided into, the more the touch position information calculation process can be Precisely cancel the low-frequency interference in the induced signal; that is, the stronger the ability to resist low-frequency interference.
  • FIG. 1 is a flowchart of a touch detection method according to the first embodiment of the present application.
  • FIG. 2 is a schematic diagram of a touch screen that can perform touch detection using the touch detection method of the first embodiment
  • FIG. 3 is a specific flowchart of the touch detection method according to the first embodiment of the present application.
  • FIG. 4 is a schematic diagram of encoding information when a conventional encoding detection method is applied to the touch screen in FIG. 2;
  • FIG. 5 is a schematic diagram of the waveform of the driving signal corresponding to the encoded information in FIG. 4;
  • FIG. 6 is a schematic diagram of coding information corresponding to the coding manner in the touch detection method according to the first embodiment of the present application.
  • FIG. 7 is a waveform diagram of a driving signal corresponding to the encoded information in FIG. 6;
  • FIG. 8 is a schematic waveform diagram of a drive signal corresponding to the encoded information in the touch detection method according to the second embodiment of the present application.
  • FIG. 9 is a schematic diagram of encoded information when the driving signal is divided into four correlated double sampling periods in the touch detection method according to the second embodiment of the present application.
  • FIG. 10 is a schematic diagram of a waveform of a driving signal corresponding to the encoded information in the touch detection method according to the third embodiment of the present application;
  • FIG. 11 is a block diagram of a touch chip according to a fourth embodiment of the present application.
  • the first embodiment of the present application relates to a touch detection method. As shown in FIG. 1, it includes the following steps:
  • Step S101 applying a driving signal encoded based on a preset encoding method to the driving channel of the touch screen; wherein the encoding method includes dividing a plurality of signal waveforms of the driving signal into waveforms of at least one correlated double sampling period, the same correlated double sampling The period includes two sampling periods with a phase difference of 180°;
  • Step S102 receiving the sensing signal corresponding to the driving signal from the sensing channel of the touch screen;
  • Step S103 Determine the touch position information according to the sensing signal and the encoding information corresponding to the encoding mode.
  • the multiple signal waveforms of the driving signal are divided into at least one waveform with a correlated double sampling period, and the same correlated double sampling period includes two sampling periods with a phase difference of 180°.
  • the time of touch detection is relatively short, and it can be considered that low-frequency interference remains unchanged during the process of touch detection; and those skilled in the art should also know that the sensing signal includes the target signal (that is, the driving signal Coupling signal) and low-frequency interference, the target signal will have a phase shift relative to the drive signal, and the waveform phase of the target signal and the drive signal at the same time always maintain this phase shift difference.
  • the phase difference of the driving signals of two sampling periods in a correlated double sampling period is 180°
  • the phase difference of the target signal is also maintained at 180° in the sensing signal sampled by the two sampling periods.
  • the phase of low-frequency interference is the same, so the low-frequency interference in the two sampling periods of the same correlated double sampling period can be canceled out by calculation; thus the ability to resist low-frequency interference in touch detection can be improved, thereby improving the signal-to-noise ratio of the system and enhancing Touch sensitivity.
  • the touch detection method of this embodiment may be used to perform touch detection on a mutual-capacitance or self-capacitance touch screen.
  • 2 is a schematic diagram of a touch screen that can perform touch detection using the touch detection method of this embodiment.
  • the touch screen in FIG. 2 includes a driving layer and a sensing layer (not shown); the driving layer includes four driving channels arranged in parallel along the first direction, and the sensing layer includes four sensing channels arranged in parallel along the second direction.
  • the first direction is perpendicular to the second direction; the coupling capacitance C ij is formed at the intersection of each driving channel and each sensing channel, where 1 ⁇ i ⁇ 4, 1 ⁇ j ⁇ 4, and i and j are positive numbers; coupling The size of the capacitor C ij can represent the touch situation at the touch position where the intersection is located.
  • the four driving channels and the four sensing channels are respectively connected to the touch chip; the touch chip is used to apply a driving signal to the driving channel and receive the sensing signal from the sensing channel.
  • the embodiments of the present application include The number of driving channels and sensing channels is not limited; and the touch detection method of the embodiment of the present application can also be applied to a self-contained touch screen. When applied to a self-contained touch screen, the driving channel and the sensing channel are the same channel.
  • step S101 the driving signal applied to the driving channel will continue for at least one preset time period, or may also last for multiple preset time periods, and the drive signal within each preset time period includes multiple signal waveforms . That is, the multiple signal waveforms of the driving signal are divided into at least one waveform with a correlated double sampling period, and the same correlated double sampling period includes two sampling periods with a phase difference of 180°, which can be understood as a preset time The multiple signal waveforms of the driving signal in the segment are divided into waveforms of at least one correlated double sampling period, and the same correlated double sampling period includes two sampling periods with a phase difference of 180°.
  • the coding method of the touch detection method may be full-channel coding and correlated double sampling It is formed by the combination of principles; however, this embodiment does not impose any restrictions on it.
  • the encoding method may be a combination of multi-channel encoding and correlated double sampling principles, or it may be a single channel encoding method and correlated double sampling.
  • the driving signals can be sequentially applied to each of the 16 driving channels as a group (that is, a combination of multi-channel encoding and related double sampling principles).
  • step S102 the touch chip receives the sensing signal from the sensing channel during the process of applying the driving signal to the driving channel.
  • the touch chip simultaneously applies driving signals to the four driving channels, and receives sensing signals from the four sensing channels during the application of the driving signals.
  • step S103 includes the following sub-steps:
  • sub-step S103 analog-to-digital conversion is performed on the sensing signal, and the sensing signal in digital form is obtained.
  • the sensing signal and the driving signal have the same signal period; first, the signal waveforms of multiple signal periods of the sensing signal are digitally converted to obtain a digital signal corresponding to the multiple signal waveforms, which is a sensing signal in a digital form.
  • the driving signal includes a signal waveform of 2N signal periods
  • the sensing signal also includes a signal waveform of 2N signal periods.
  • Sub-step S1032 demodulate the induction signal in digital form and obtain demodulation information; wherein, the waveform of each sampling period corresponds to a demodulation value in the demodulation information.
  • the above sampling period is the sampling period of the induction signal.
  • the induction signal is sampled according to the sampling period, so that the waveform of each sampling period can obtain a demodulated value; suppose a sampling period contains x Signal period, then the waveform of x signal periods can be demodulated to obtain a demodulated value; where x is an integer greater than or equal to 1.
  • the waveform of each relevant double sampling period in the received sensing signal can obtain two demodulated values, that is, the sensing signal received by each sensing channel can contain at least two demodulated values; Therefore, the demodulation information includes multiple demodulation values, and the multiple demodulation values may form a demodulation matrix R, that is, the demodulation information may be represented by the demodulation matrix R.
  • orthogonal demodulation is used for demodulation, but it is not limited to this.
  • the touch position information is calculated according to the demodulation information and the coding information corresponding to the coding method.
  • the touch position information can be characterized by the capacitance value of the coupling capacitor Cij (as described above, the coupling capacitance C ij is formed at the intersection of each driving channel and each sensing channel), and the capacitance values of multiple coupling capacitors Cij can form a capacitance matrix C, that is, touch position information can be represented by a capacitance matrix C.
  • the preset encoding information in the touch chip corresponds to the encoding method; specifically, the encoding information includes multiple encoding values, and each encoding value represents a certain driving channel is applied in a certain sampling period The phase of the driving signal; multiple encoding values can form an encoding matrix A, that is, the encoding information can be characterized by the encoding matrix A.
  • FIG. 4 it is a schematic diagram of encoding information when the conventional encoding detection method is used to perform touch detection on the touch screen in FIG. 2; wherein, the encoding information in FIG. 4 embodies the phase change of the driving signal in different time periods.
  • the drive channels TX1 to TX4 are shown in the horizontal direction, and the four preset time periods T0 to T4 are shown in the vertical direction.
  • each group of driving channels is assigned four consecutive time periods T0-T4 to apply driving signals; in this embodiment, the durations of the four time periods T0-T4 are all equal; This is the limit.
  • the signal waveform of the driving signal may be a sine wave, for example, "+” indicates that the initial phase of the sine wave is 0°, which is called a positive code; "-" indicates that the initial phase of the sine wave is 180°, which is called a negative code; each time The drive signal applied to the drive channel in the segment is a positive code or a negative code; and the drive signal applied in each time period contains a sine wave of multiple signal periods, and the initial phase of the sine wave of each signal period is the same (same as Positive code or negative code). It should be noted that “+” here means that the initial phase of the sine wave is 0°, and “-” means that the initial phase of the sine wave is 180°, but it is not limited to this.
  • the signal waveform of the drive signal is not limited to a sine wave, but may also be a square wave, a triangular wave, or the like.
  • FIG. 5 is a schematic diagram of the waveform of the driving signal in FIG. 4, and the waveform of the driving signal in the period T3 is illustrated in FIG. 5.
  • the time period T3 contains 2N signal cycles (Cycle) of sine waves; in this embodiment, the duration of each time period is equal, that is, each time period contains a waveform of 2N signal periods, where N is an integer greater than or equal to 1.
  • the driving signals applied to the driving channels TX1, TX2, TX3, and TX4 during the time period T3 are "+", "+", "+”, and "-", respectively.
  • the signal waveforms above the drive channels TX1, TX2, TX3, and TX4 respectively represent the signal waveforms of the drive signals applied to the drive channels TX1, TX2, TX3, and TX4; it can be seen that for the three drives TX1, TX2, and TX3 In the channel, the start phase of each sine wave in the drive signal is 0°. For the TX4 drive channel, the start phase of each sine wave in the drive signal is 180°.
  • the coding matrix A can represent the coding information of TX1 to TX4 in the above traditional coding detection method;
  • the coding matrix A includes a plurality of coding values Aij (ie, A11, A12, A13, A14, A21, A22).
  • i represents the time period
  • j represents the jth TX channel
  • the value range of i and j in Aij here is 0 ⁇ i ⁇ 3, 1 ⁇ j ⁇ 4;
  • the drive signal is "+”, the corresponding code value is "1"; the drive signal is "-”, the corresponding code value is "-1"; the specific values of A are as follows:
  • Cij in the capacitance matrix C (that is, C11, C12, C13, C14, C21, C227) characterizes the capacitance value of the coupling capacitor C ij formed at the intersection of each driving channel and each sensing channel in FIG. 1, and The value range of i and j is 0 ⁇ i ⁇ 3, 1 ⁇ j ⁇ 4;
  • Demodulation matrix R represents demodulation information
  • the demodulation matrix R contains multiple demodulation values Rij (ie R01, R02, R03, R04, R11, R12, R13, R14...), i in Rij represents the time period, j represents the jth RX drive channel, And the value range of i and j in Rij is 0 ⁇ i ⁇ 3, 1 ⁇ j ⁇ 4; wherein, the sensing signal of each sensing channel in each time period corresponds to a demodulation value; for example, The induction channel RX1 corresponds to R01, R02, R03 and R04 in the time period of T0, T1, T2 and T3 respectively.
  • the capacitance matrix C represents the detected touch position information of the touch screen in FIG. 2.
  • FIG. 6 shows the encoding information corresponding to the encoding method in the touch detection method of this embodiment
  • FIG. 7 shows the waveform diagram of the drive signal corresponding to the encoding information in FIG. 6, where Is the waveform of the drive signal in the period T3.
  • the 2N signal periods in each time period are divided into a correlated double sampling period.
  • the correlated double sampling period includes two sampling periods, and the number of signal periods included in the two sampling periods is equal; that is, The first N signal periods of the 2N signal periods are used as one sampling period, and the last N signal periods are used as another sampling period.
  • the waveform phases of the two sampling periods differ by 180°.
  • the 2N signal periods in the time period T3 form a correlated double sampling period, and the two sampling periods included in the correlated double sampling period respectively correspond to the sub-period 31 and the sub-period 32; It should be emphasized that, since the number of signal periods included in the two sampling periods is equal, the durations of the sub-period 31 and the sub-period 32 are equal; the phase of the waveform in the sub-period 31 and the waveform in the sub-period 32 is 180 different °.
  • the coding information contains multiple coding values, and each coding value represents the phase of the driving signal applied to a certain driving channel in a certain sampling period; since each sampling period corresponds to each sub-time period, it can also be It is understood that each coded value represents the phase of the driving signal applied to a certain driving channel in a certain sub-period.
  • the drive signal of the drive channel TX1 changes from “+” to “+” and “-” (corresponding to time periods 31 and 32, respectively), which corresponds to the code value in the coding matrix, from “1” Change to “1" and “-1” (corresponding to time periods 31 and 32, respectively);
  • the drive signal of drive channel TX2 changes from “+” to “+” and “-” (corresponding to time periods 31 and 32, respectively) ,
  • the driving signal of the driving channel TX3 changes from "+” to "+” , "-” (corresponding to time periods T31 and T32, respectively), corresponding to the code values in the coding matrix, from “1” to "1", “-1” (corresponding to time periods 31, 32, respectively);
  • drive The drive signal of the channel TX4 changes from “-” to "-” and “+” (corresponding to the time periods T
  • the time period T0 is divided into sub-time periods 01, 02
  • the time period T1 is divided into sub-time periods 11, 12
  • the time period T2 is divided into sub-time periods 21, 22
  • the drive signal and the encoding value in the encoding matrix are also used
  • the encoding information in FIG. 6 is changed from the encoding information in FIG. 4, the specific change method is that "+” in FIG. 4 becomes “+”, “-” (corresponding to a Two sampling periods in the correlated double sampling period), "-” in Figure 4 becomes “-” and "+” (corresponding to two sampling periods in a correlated double sampling period).
  • Encoding information in tabular form can be converted into encoding information in matrix form, that is, encoding matrix; the encoding value "1" in the encoding matrix is opposite to the "+” in the encoding information, and the encoding value "-1" in the encoding matrix is the encoding information
  • the "-" in is relative; that is, when the coding information in the form of tables in FIGS. 4 and 6 is converted into a coding matrix, "+” is represented by "1", and "-” is represented by "-1".
  • the coding matrix A′ contains a plurality of coding values A′ij (ie A′011, A′012, A′013, A′014, A′021, A′022...), indicating that the coding mode of this embodiment
  • the capacitance matrix C′ A′ ⁇ 1 R′, and the touch position information is obtained.
  • the received induction signal includes low-frequency interference and the target signal obtained by coupling the drive signal; the signal period of the induction signal is the same as the drive signal, and the target signal will have a phase relative to the drive signal Shift, and the phase of the waveform of the target signal and the waveform of the drive signal at the same time always maintain this phase shift difference.
  • the signal period of the sine wave is 10us (that is, the frequency of the drive signal is 100kHz), the signal period of the induction signal is also 10us; in a related double sampling period, the waveform phase of the two sampling periods of the drive signal 0° and 180° respectively, corresponding to these two sampling periods, the waveform of the target signal, for example, has a phase shift of 30° (Here is just an example, the phase shift is not limited to 30°, and needs to be determined according to the actual situation) , That is, the phases of the waveforms of the target signals corresponding to these two sampling periods are 30° and 210°, respectively, so the phase difference of the waveforms of the target signals within these two sampling periods remains at 180°; Short, it can be considered that the low-frequency interference remains unchanged during the touch detection, that is, the phase of the low-frequency interference is unchanged.
  • the target signal is S and the low-frequency interference is D; then, in the relevant double sampling period, if the drive signals corresponding to the two sampling periods are positive code and negative code respectively, then two sampling periods
  • the demodulated values of the induced signal of can be expressed as S+D and -S+D, respectively.
  • the above-mentioned subtraction method is used to cancel out the low-frequency interference, so the resulting data can be considered to contain only the target signal S.
  • the matrix calculation process here includes the process of canceling out the low frequency interference by the above subtraction method.
  • the number of signal periods included in two sampling periods in the same correlated double sampling period is equal, which can make the low-frequency interference contained in the waveforms of the two sampling periods as complete as possible offset.
  • this embodiment is not limited to this, and the number of signal periods included in two sampling periods in the same correlated double sampling period may not be equal.
  • the touch detection method in this embodiment It can still cancel at least part of the low-frequency interference and improve the signal-to-noise ratio of the system.
  • the second embodiment of the present application relates to a touch detection method.
  • This embodiment is substantially the same as the first embodiment.
  • the main difference is that: in the first embodiment, multiple signal waveforms of a driving signal are divided into a related double Sampling period; in this embodiment, multiple signal waveforms of the driving signal are divided into multiple correlated double sampling periods, and the number of signal periods included in the sampling period in each correlated double sampling period is one.
  • FIG. 8 is a schematic diagram of the waveform of the driving signal corresponding to the encoded information in the touch detection method of the second embodiment.
  • the driving signal also includes 2N signal waveforms (that is, 2N signal periods).
  • the 2N signal waveforms are divided into N correlated double sampling periods, and each correlated double sampling period
  • the number of signal periods included in the two sampling periods of is 1; where the larger the value of N, the greater the number of related double sampling periods.
  • FIG. 9 shows a schematic diagram of the encoded information when N is equal to 4.
  • the time period T0 is equally divided into four sub-time periods 01, 02, 03, and 04; similarly, the time periods T1, T2, and T3 are equally divided into four sub-time periods.
  • This embodiment provides a specific implementation of the touch detection method; for the same drive signal (including the same number of signal waveforms), the more the number of related double sampling periods divided into, the calculation of the touch position information In the process, the more accurately the low-frequency interference in the induced signal can be cancelled; that is, the ability to resist low-frequency interference is stronger.
  • the third embodiment of the present application relates to a touch detection method.
  • This embodiment is substantially the same as the second embodiment.
  • the main difference is that: in the second embodiment, two sampling periods in each relevant double sampling period include The number of signal periods of is 1; in this embodiment, the number of signal periods contained in two sampling periods in each correlated double sampling period is greater than 1.
  • the drive signal also contains 2N signal waveforms (that is, 2N signal periods).
  • the 2N signal waveforms are divided into, for example, four correlated double sampling periods, and two samples in each correlated double sampling period
  • the number of signal cycles included in the cycle is equal and N/4.
  • N is an even number greater than or equal to 8.
  • FIG. 10 only illustrates the driving channel TX1 in the third time period T3. Waveform; Refer to Figure 9 for a schematic diagram of the encoded signal in this example.
  • the number of signal periods included in the two sampling periods in each correlated double sampling period is equal, but it is not limited to this; it may also be that in the same correlated double sampling period
  • the number of signal periods included in the two sampling periods is equal, and the number of signal periods included in the sampling periods in different related double sampling periods is not equal.
  • the touch chip 1 includes:
  • the driving unit 11 applies a driving signal encoded based on a preset encoding method to the driving channel of the touch screen; wherein the encoding method includes dividing a plurality of signal waveforms of the driving signal into at least one waveform with a relevant double sampling period, and the same relevant double The sampling period includes two sampling periods with a phase difference of 180°;
  • the receiving unit 12 is configured to receive the sensing signal corresponding to the driving signal from the sensing channel of the touch screen.
  • the receiving unit 12 may be understood to include a signal conditioning circuit, where the signal conditioning circuit may include functions such as signal amplification and signal filtering; that is, the receiving unit 12 may perform some preprocessing on the sensing signal.
  • the processing unit 13 determines the touch position information according to the sensing signal and the encoding information corresponding to the encoding method.
  • the processing unit 13 specifically includes:
  • the analog-to-digital conversion subunit 131 is used for analog-to-digital conversion of the sensing signal and obtaining the sensing signal in digital form;
  • the demodulation subunit 132 is used to demodulate the digital form of the induction signal and obtain demodulation information; wherein, the waveform of each sampling period corresponds to a demodulation value in the demodulation information;
  • the calculation subunit 133 is used to calculate the touch position information according to the coding information corresponding to the demodulation information and the coding mode;
  • the storage subunit 134 is used to store coding information corresponding to the coding mode.
  • the driving unit 11 is connected to the analog-to-digital conversion sub-unit 131 in the processing unit 13 to synchronize the analog-to-digital conversion sub-unit 131, that is, when the driving unit 11 applies a driving signal to the driving channel,
  • the conversion subunit 131 acquires the sensing signal in digital form synchronously.
  • the driving unit 11 may simultaneously connect the analog-to-digital conversion subunit 131 and the receiving unit 12, that is, the driving unit 11 may synchronize both the analog-to-digital conversion subunit 131 and the receiving unit 12.
  • multiple signal waveforms of the driving signal are divided into at least one waveform with a correlated double sampling period, and the same correlated double sampling period includes two sampling periods with a phase difference of 180° .
  • the time of touch detection is relatively short, and it can be considered that low-frequency interference remains unchanged during the process of touch detection; and those skilled in the art should also know that the sensing signal includes the target signal (that is, the driving signal Coupling signal) and low-frequency interference, the target signal will have a phase shift relative to the drive signal, and the waveform phase of the target signal and the drive signal at the same time always maintain this phase shift difference.
  • the phase difference of the driving signals of two sampling periods in a correlated double sampling period is 180°
  • the phase difference of the target signal is also maintained at 180° in the sensing signal sampled by the two sampling periods.
  • the phase of low-frequency interference is the same, so the low-frequency interference in the two sampling periods of the same correlated double sampling period can be canceled out by calculation; thus the ability to resist low-frequency interference in touch detection can be improved, thereby improving the signal-to-noise ratio of the system and enhancing Touch sensitivity.
  • this embodiment is a device example corresponding to any one of the first to third embodiments, and this embodiment can be implemented in conjunction with any one of the first to third embodiments.
  • the relevant technical details mentioned in any of the first to third embodiments are still valid in this embodiment, and in order to reduce repetition, they will not be repeated here.
  • the relevant technical details mentioned in this embodiment can also be applied to any one of the first to third embodiments.
  • the fifth embodiment of the present application relates to an electronic device, including a touch screen and the touch chip described in the fourth embodiment.

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Abstract

一种触摸检测方法、触控芯片(1)及电子设备。触摸检测方法包括：向触摸屏的驱动通道(TX1, TX2, TX3, TX4)施加基于预设的编码方式编码的驱动信号；其中，所述编码方式包括，将所述驱动信号的多个信号波形划分成至少一个相关双采样周期的波形，同一个所述相关双采样周期包含波形相位相差180°的两个采样周期(101)；从所述触摸屏的感应通道(RX1, RX2, RX3, RX4)接收所述驱动信号对应的感应信号(102)；根据所述感应信号和所述编码方式对应的编码信息确定触摸位置信息(103)。所述的技术方案可以提高触摸检测中抵抗低频干扰的能力，从而提高系统的信噪比，增强触摸灵敏度。

Description

触摸检测方法、触控芯片及电子设备 技术领域
本申请涉及触控技术领域，特别涉及一种触摸检测方法、触控芯片及电子设备。
背景技术
现有的电容式触摸屏通常都采用多通道编码检测方式或单通道检测方式进行触摸检测。当有手指触摸时，相应位置的电容感应节点上的电容值会发生变化，触控芯片通过实时地检测电容的变化，可以确定相应的触摸位置，从而产生相应的触摸事件。
发明人发现现有技术至少存在以下问题：现有的多通道编码检测方式或单通道检测方式，容易受低频干扰影响，导致触摸检测的灵敏度不高。
发明内容
本申请部分实施例的目的在于提供一种触摸检测方法、触控芯片及电子设备，可以提高触摸检测中抵抗低频干扰的能力，从而提高系统的信噪比，增强触摸灵敏度。
本申请实施例提供了一种触摸检测方法，包括：向触摸屏的驱动通道施加基于预设的编码方式编码的驱动信号；其中，所述编码方式包括，将所述驱 动信号的多个信号波形划分成至少一个相关双采样周期的波形，同一个所述相关双采样周期包含波形相位相差180°的两个采样周期；从所述触摸屏的感应通道接收所述驱动信号对应的感应信号；根据所述感应信号和所述编码方式对应的编码信息确定触摸位置信息。
本申请实施例还提供了一种触控芯片，包括：驱动单元，向触摸屏的驱动通道施加基于预设的编码方式编码的驱动信号；其中，所述编码方式包括，将所述驱动信号的多个信号波形划分成至少一个相关双采样周期的波形，同一个所述相关双采样周期包含波形相位相差180°的两个采样周期；接收单元，用于从所述触摸屏的感应通道接收所述驱动信号对应的感应信号；处理单元，根据所述感应信号和所述编码方式对应的编码信息确定触摸位置信息。
本发明的实施方式还提供了一种电子设备，包括：触摸屏以及上述触控芯片。
本申请实施例相对于现有技术而言，驱动信号的多个信号波形被划分成至少一个相关双采样周期的波形，同一个所述相关双采样周期包含波形相位相差180°的两个采样周期。本领域技术人员应当知晓，触摸检测的时间相对较短，可以认为在触摸检测的过程中低频干扰是保持不变的；且本领域技术人员也应当知晓，感应信号包含目标信号(即驱动信号的耦合信号)和低频干扰，目标信号相对于驱动信号会有一个相移，且相同时刻的目标信号的波形相位与驱动信号的波形相位始终保持这个相移差值。本申请实施例中，由于一个相关双采样周期中两个采样周期的驱动信号的相位差为180°，因此两个采样周期采样得到的感应信号中，目标信号的相位差也保持在180°且低频干扰的相位相同，所以通过计算可以将同一个相关双采样周期中两个采样周期中的低频干扰抵消 掉；从而可以提高触摸检测中抵抗低频干扰的能力，从而提高系统的信噪比，增强触摸灵敏度。
另外，同一个所述相关双采样周期中的所述两个采样周期包含的信号周期的数量相等；其中，一个所述信号周期对应于一个所述信号波形。本实施例中，两个采样周期包含的信号周期的数量相等，即两个采样周期的波形是同等时间长度的波形，可以使得两个采样周期波形中包含的低频干扰尽可能完全抵消。
另外，所述多个信号波形被划分成一个所述相关双采样周期的波形。本实施例提供了一种具体的实现方式。
另外，所述多个信号波形被划分成若干个所述相关双采样周期的波形，各所述相关双采样周期中的所述采样周期包含的信号周期的数量均相等；并且，各所述相关双采样周期中的所述采样周期包含的信号周期的数量均为1。本实施例提供了另一种具体的实现方式；对于相同的驱动信号(包含相同数量的信号波形)而言，被划分成的相关双采样周期越多，在触摸位置信息的计算过程中可以越精确地抵消掉感应信号中的低频干扰；即抵抗低频干扰的能力越强。
附图说明
一个或多个实施例通过与之对应的附图中的图片进行示例性说明，这些示例性说明并不构成对实施例的限定，附图中具有相同参考数字标号的元件表示为类似的元件，除非有特别申明，附图中的图不构成比例限制。
图1是根据本申请第一实施例的触摸检测方法的流程图；
图2是可采用第一实施例的触摸检测方法进行触摸检测的触摸屏的示意 图；
图3是根据本申请第一实施例的触摸检测方法的具体流程图；
图4是对图2中的触摸屏采用传统的编码检测方式时的编码信息的示意图；
图5是图4中的编码信息对应的驱动信号的波形示意图；
图6是根据本申请第一实施例的触摸检测方法中的编码方式对应的编码信息的示意图；
图7是图6中的编码信息对应的驱动信号的波形示意图；
图8是根据本申请第二实施例的触摸检测方法中的编码信息对应的驱动信号的波形示意图；
图9是根据本申请第二实施例的触摸检测方法中驱动信号被划分成4个相关双采样周期时的编码信息的示意图；
图10是根据本申请第三实施例的触摸检测方法中的编码信息对应的驱动信号的波形示意图；
图11是根据本申请第四实施例的触控芯片的方框图。
具体实施方式
为了使本申请的目的、技术方案及优点更加清楚明白，以下结合附图及实施例，对本申请部分实施例进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本申请，并不用于限定本申请。
本申请第一实施例涉及一种触摸检测方法，如图1所示，包括以下步骤：
步骤S101，向触摸屏的驱动通道施加基于预设的编码方式编码的驱动信 号；其中，编码方式包括，将驱动信号的多个信号波形划分成至少一个相关双采样周期的波形，同一个相关双采样周期包含波形相位相差180°的两个采样周期；
步骤S102，从触摸屏的感应通道接收驱动信号对应的感应信号；
步骤S103，根据感应信号和编码方式对应的编码信息确定触摸位置信息。
本实施例相对于现有技术而言，驱动信号的多个信号波形被划分成至少一个相关双采样周期的波形，同一个相关双采样周期包含波形相位相差180°的两个采样周期。本领域技术人员应当知晓，触摸检测的时间相对较短，可以认为在触摸检测的过程中低频干扰是保持不变的；且本领域技术人员也应当知晓，感应信号包含目标信号(即驱动信号的耦合信号)和低频干扰，目标信号相对于驱动信号会有一个相移，且相同时刻的目标信号的波形相位与驱动信号的波形相位始终保持这个相移差值。本申请实施例中，由于一个相关双采样周期中两个采样周期的驱动信号的相位差为180°，因此两个采样周期采样得到的感应信号中，目标信号的相位差也保持在180°且低频干扰的相位相同，所以通过计算可以将同一个相关双采样周期中两个采样周期中的低频干扰抵消掉；从而可以提高触摸检测中抵抗低频干扰的能力，从而提高系统的信噪比，增强触摸灵敏度。
下面对本实施例的触摸检测方法的实现细节进行具体的说明，以下内容仅为方便理解提供的实现细节，并非实施本方案的必须。
本实施方式的触摸检测方法可以用于对互容式或自容式的触摸屏进行触摸检测。如图2所示为可采用本实施例的触摸检测方法进行触摸检测的触摸屏的示意图。图2中的触摸屏包括驱动层和感应层(未示出)；驱动层包括沿第 一方向平行设置的4根驱动通道，感应层包含沿第二方向平行设置的4根感应通道，本实施方式中第一方向和第二方向垂直；各驱动通道和各感应通道的交叉处形成耦合电容C ij，其中，1≤i≤4，1≤j≤4，且i、j均为正数；耦合电容C ij的大小可以表示该交叉处所在的触摸位置的触摸情况。4根驱动通道、4根感应通道分别连接于触控芯片；触控芯片用于向驱动通道施加驱动信号，并从感应通道接收感应信号。本实施例及以下实施例均以图2中的触摸屏为例进行说明；然需要说明的是，图2仅示意出了4*4的互容式触摸屏，然本申请实施例对触摸屏中包含的驱动通道和感应通道的数量不作任何限制；并且，本申请实施例的触摸检测方法也可以应用于自容式触摸屏，当应用于自容式触摸屏时，驱动通道和感应通道为同一根通道。
在步骤S101中，对驱动通道施加的驱动信号会至少持续一个预设的时间段，或者也可以持续多个预设的时间段，每个预设的时间段内的驱动信号包括多个信号波形。即，将该驱动信号的多个信号波形划分成至少一个相关双采样周期的波形，同一个相关双采样周期包含波形相位相差180°的两个采样周期，可以理解为，将一个预设的时间段内的驱动信号的多个信号波形划分成至少一个相关双采样周期的波形，同一个相关双采样周期包含波形相位相差180°的两个采样周期。
需要说明的是，图2的例子中由于只有4根驱动通道，所以同时对4根驱动通道施加驱动信号；即基于图2的例子，触摸检测方法的编码方式可以是全通道编码和相关双采样原理相结合而形成的；然本实施例对此不作任何限制，在其他例子中，编码方式可以是多通道编码和相关双采样原理相结合而形成，或者可以是单通道编码方式和相关双采样原理相结合而形成；例如对于一个 16*16的互容式触摸屏，可以将16根驱动通道每4根为一组依次施加驱动信号(即多通道编码和相关双采样原理相结合而形成)。
在步骤S102中，触控芯片在对驱动通道施加驱动信号的过程中，从感应通道接收感应信号。对应于图2中，触控芯片对四根驱动通道同时施加驱动信号，并在施加驱动信号的过程中，从四根感应通道接收感应信号。
如图3所示，步骤S103包括如下子步骤：
子步骤S1031，将感应信号进行模拟数字转换，并得到数字形式的感应信号。
具体的，感应信号和驱动信号具有同样的信号周期；先对感应信号的多个信号周期的信号波形进行数字转换，得到多个信号波形对应的数字信号，即为数字形式的感应信号。例如，驱动信号包含2N个信号周期的信号波形，则感应信号也包含2N个信号周期的信号波形。
子步骤S1032，对数字形式的感应信号进行解调，并得到解调信息；其中，每个采样周期的波形对应于解调信息中的一个解调值。
具体的，上述的采样周期即为感应信号的采样周期，解调过程中，根据采样周期对感应信号进行采样，从而每个采样周期的波形可以得到一个解调值；假设一个采样周期包含x个信号周期，则x个信号周期的波形可以解调得到一个解调值；其中x为大于或等于1的整数。对于每一根感应通道，接收的感应信号中的每一个相关双采样周期的波形即可以得到两个解调值，即每一根感应通道接收的感应信号均可以包含至少两个解调值；所以，解调信息包含多个解调值，多个解调值可以形成一个解调矩阵R，即解调信息可以由解调矩阵R表示。本实施例中采用正交解调方式进行解调，然并不以此为限。
子步骤S1033，根据解调信息和编码方式对应的编码信息，计算触摸位置信息。
具体的，触摸位置信息可以以耦合电容Cij的电容值表征(如上所述，各驱动通道和各感应通道的交叉处形成耦合电容C ij)，多个耦合电容Cij的电容值可以形成一个电容矩阵C，即触摸位置信息可以以电容矩阵C表示。
本实施例中，触控芯片内预设的编码信息与编码方式相对应；具体的，编码信息包含多个编码值，每个编码值表征某一根驱动通道在某一个采样周期内被施加的驱动信号的相位情况；多个编码值可以形成一个编码矩阵A，即编码信息可以以编码矩阵A来表征。本领域技术人员应当知晓，解调矩阵R＝AC，因此，电容矩阵C＝A -1R，从而可以计算出触摸位置信息。
以下是基于图2所示的触摸屏，将本实施实施方式中的触摸检测方法和传统的触摸检测方法进行具体对比，以更直观的体现两者差别。
如图4所示，是对图2中的触摸屏采用传统的编码检测方式进行触摸检测时的编码信息的示意图；其中，图4中的编码信息体现驱动信号在不同时间段内的相位变化。图4中横向上表示驱动通道TX1～TX4，纵向上表示4个预设的时间段T0～T4。如图4所示的编码信息可知，每组驱动通道被分配了连续的四个时间段T0～T4施加驱动信号；本实施例中，四个时间段T0～T4的时长均相等；然并不以此为限。
驱动信号的信号波形例如可以为正弦波，“+”表示正弦波起始相位为0°，称为正码；“-”表示正弦波起始相位为180°，称为负码；每个时间段内向驱动通道施加的驱动信号为正码或者负码；且每个时间段内施加的驱动信号包含多个信号周期的正弦波，且各信号周期的正弦波的起始相位均相同(同为正码或 同为负码)。需要说明的是，这里“+”表示正弦波起始相位为0°，“-”表示正弦波起始相位为180°，然并不以此为限，在其他例子中，也可以以“-”表示正弦波起始相位为0°，“+”表示正弦波起始相位为180°；或者，正码和负码不一定要分为为0°和180°，也可以为其他度数，只要正码和负码的相位差为180°即可。另外，驱动信号的信号波形也不仅限于正弦波，也可也方波、三角波等。
如图5所示为图4中的驱动信号的波形示意图，图5中示意出的是时间段T3内的驱动信号的波形。如图5中，时间段T3内包含2N个信号周期(Cycle)的正弦波；本实施例中，每个时间段的时长相等，即每个时间段内均包含2N个信号周期的波形，其中N为大于或等于1的整数。如图4中的编码信息所示，在时间段T3内，向驱动通道TX1、TX2、TX3、TX4施加的驱动信号分别为“+”、“+”、“+”、“-”，图5中位于驱动通道TX1、TX2、TX3、TX4上方的信号波形，分别表示施加在驱动通道TX1、TX2、TX3、TX4上的驱动信号的信号波形；可以看出，对于TX1、TX2、TX3这三根驱动通道，驱动信号中的每个正弦波的起始相位都为0°，对于TX4这根驱动通道，驱动信号中的每个正弦波的起始相位都为180°。
如下，编码矩阵A可以表示上述传统的编码检测方式中TX1～TX4的编码信息；编码矩阵A包括多个编码值Aij(即A11、A12、A13、A14、A21、A22……)，Aij中的i表示时间段，j表示第j个TX通道，且这里的Aij中的i、j的取值范围是0≤i≤3，1≤j≤4；
Figure PCTCN2018121558-appb-000001
这个例子中，驱动信号为“+”的，对应的编码值为“1”；驱动信号为 “-”的，对应的编码值为“-1”；A的具体值如下：
Figure PCTCN2018121558-appb-000002
电容矩阵C中的Cij(即C11、C12、C13、C14、C21、C22……)表征图1中各驱动通道和各感应通道的交叉处形成的耦合电容C ij的电容值，且Cij中的i、j的取值范围是0≤i≤3，1≤j≤4；
Figure PCTCN2018121558-appb-000003
解调矩阵R表示解调信息：
Figure PCTCN2018121558-appb-000004
解调矩阵R中包含多个解调值Rij(即R01、R02、R03、R04、R11、R12、R13、R14……)，Rij中的i表示时间段，j表示第j个RX驱动通道，且这里的Rij中的i，j的取值范围是0≤i≤3，1≤j≤4；其中，每根感应通道在每个时间段内的感应信号分别对应一个解调值；例如，感应通道RX1在T0、T1、T2、T3时间段内分别对应于R01、R02、R03、R04。
由于，解调矩阵R＝AC，
所以，可得电容矩阵C＝A -1R。
电容矩阵C表示检测到的图2中的触摸屏的触摸位置信息。
如图6所示为本实施例的触摸检测方法中的编码方式对应的编码信息；如图7所示为图6中的编码信息对应的驱动信号的波形示意图，其中，图7中示意出的是时间段T3中的驱动信号的波形。
本实施例中，每个时间段内的2N个信号周期被划分成一个相关双采样周期，该相关双采样周期包含两个采样周期，且两个采样周期中包含的信号周期的数量相等；即，将2N个信号周期中前N个信号周期作为一个采样周期，后N个信号周期作为另一个采样周期，两个采样周期的波形相位相差180°。结合图6和图7所示，时间段T3中的2N个信号周期形成一个相关双采样周期，且该相关双采样周期包含的两个采样周期分别对应于子时间段31、子时间段32；需要强调的是，由于两个采样周期中包含的信号周期数量相等，所以子时间段31和子时间段32的时长相等；子时间段31中的波形与子时间段32中的波形的相位相差180°。
编码信息中包含多个编码值，每个编码值表征某一根驱动通道在某一个采样周期内被施加的驱动信号的相位情况；由于每个采样周期与每一个子时间段对应，因此亦可以理解为，每个编码值表征某一根驱动通道在某一个子时间段内被施加的驱动信号的相位情况。如在时间段T3内，驱动通道TX1的驱动信号由“+”变为“+”、“-”(分别对应于时间段31、32)，对应于编码矩阵中的编码值，由“1”变为“1”、“-1”(分别对应于时间段31、32)；驱动通道TX2的驱动信号由“+”变为“+”、“-”(分别对应于时间段31、32)，对应于编码矩阵中的编码值，由“1”变为“1”、“-1”(分别对应于时间段31、32)；驱动通道TX3的驱动信号由“+”变为“+”、“-”(分别对应于时间段T31、T32)，对应于编码矩阵中的编码值，由“1”变为“1”、“-1”(分别对应于时间段31、32)；驱动通道TX4的驱动信号由“-”变为“-”、“+”(分别对应于时间段T31、T32)，对应于编码矩阵中的编码值，由“1”变为“1”、“-1”(分别对应于时间段31、32)。类似的，时间段T0被划分 成子时间段01、02，时间段T1被划分成子时间段11、12；时间段T2被划分成子时间段21、22；驱动信号以及编码矩阵中的编码值也作相应的变化。亦即，本实施例中，图6中的编码信息是由图4中的编码信息变化而来，具体变化方式为，图4中“+”变为“+”、“-”(对应于一个相关双采样周期中的两个采样周期)，图4中“-”变为“-”、“+”(对应于一个相关双采样周期中的两个采样周期)。
另外需要说明的是，本实施例中，图4和图6的表格形式编码信息中，以“+”、“-”来分别表示驱动信号的相位为0°、180°，而在具体计算中，表格形式编码信息可以转换为矩阵形式的编码信息，即编码矩阵；编码矩阵中的编码值“1”与编码信息中的“+”相对，编码矩阵中的编码值“-1”与编码信息中的“-”相对；即将图4和图6中的表格形式的编码信息转换成编码矩阵时，将“+”用“1”表示，将“-”用“-1”表示。
编码矩阵A′中包含多个编码值A′ij(即A′011、A′012、A′013、A′014、A′021、A′022……)，表示本实施例的编码方式中驱动通道TX1～TX4对应的编码信息；A′ij中的i表示子时间段，j表示第j个TX通道，且这里的取值范围i＝01、02、11、12、21、22、31、32，j＝1、2、3、4；
Figure PCTCN2018121558-appb-000005
这个例子中，A′的具体值如下：
Figure PCTCN2018121558-appb-000006
解调矩阵R’中包含多个解调值R’ij(即R’011、R’012、R’013、R’014、R’021、R’022……)，R’ij中的i表示子时间段，j表示第j个RX通道，且R’ij中的i、j的取值分为是i＝01、02、11、12、21、22、31、32，j＝1、2、3、4，解调矩阵R’表示为：
Figure PCTCN2018121558-appb-000007
电容矩阵C’＝A’ -1R’，得到触摸位置信息。
本实施例中，本领域技术人员应当知晓，接收的感应信号中包括低频干扰和由驱动信号耦合得到的目标信号；感应信号的信号周期与驱动信号相同，目标信号相对于驱动信号会有一个相移，且相同时刻的目标信号的波形相位与驱动信号的波形相位始终保持这个相移差值。例如上述例子中，正弦波的信号周期为10us(即驱动信号的频率为100kHz)，则感应信号的信号周期也为10us；在一个相关双采样周期中，驱动信号的两个采样周期的波形相位分别为0°、180°，则对应于这两个采样周期，目标信号的波形例如发生30°的相移(此处仅为举例，相移并不限于30°，需要根据实际情况而定)，即对应于这两个 采样周期的目标信号的波形相位分别为30°和210°，因此这两个采样周期内的目标信号的波形相位差仍然保持180°；而由于触摸检测的时间相对较短，可以认为在触摸检测的过程中低频干扰是保持不变的，即低频干扰的相位是不变的。假设在感应信号的一个采样周期内，目标信号为S、低频干扰为D；那么，相关双采样周期中，如果两个采样周期对应的驱动信号分别为正码和负码，则两个采样周期的感应信号的解调值分别可以表示为S+D、-S+D。那么，一个相关双采样周期中的感应信号经过相减处理可以得到：(-S+D)-(S+D)＝-2S，从而可以求出目标信号S，即可以通过将低频干扰抵消的方法，较为准确地求得目标信号。在本实施例的解调值的求解过程中，即采用上述相减方式将低频干扰抵消掉，所以最后得到的数据可以认为只包含目标信号S。其中，由于编码矩阵A′中的各编码值的“+”或“-”是根据各子时间段内的驱动信号是正码或负码而定的，解调矩阵中的解调值R’ij即为S+D或者-S+D，因此，电容矩阵C’＝A’ -1R’，这里的矩阵运算过程中即包含了上述相减方式将低频干扰抵消掉的过程。
需要说明的是，本实施例中的具体例子中，同一个相关双采样周期中的两个采样周期包含的信号周期的数量相等，这样可以使得两个采样周期波形中包含的低频干扰尽可能完全抵消。然本实施例并不以此为限，同一个相关双采样周期中的两个采样周期包含的信号周期的数量也可以不相等。另外，实际中由于环境或其他不定因素的影响，不管两个采样周期包含的信号周期是否相等，都可能存在两个采样周期中的低频干扰并非完全相同的情况，但是本实施例的触摸检测方法还是可以抵消至少部分低频干扰，提高系统的信噪比。
本申请第二实施例涉及一种触摸检测方法，本实施例与第一实施例大致 相同，主要区别之处在于：在第一实施例中，将驱动信号的多个信号波形划分成一个相关双采样周期；而在本实施例中，将驱动信号的多个信号波形划分成多个相关双采样周期，且各相关双采样周期中的采样周期包含的信号周期的数量均为1。
如图8所示为第二实施例的触摸检测方法中的编码信息对应的驱动信号的波形示意图。在图8中，与第一实施例中一样，驱动信号也包含2N个信号波形(即2N个信号周期)，2N个信号波形被划分成N个相关双采样周期，每个相关双采样周期中的两个采样周期包含的信号周期的数量均为1；其中，N的取值越大，相关双采样周期的数量越多。
如图9示意出了当N等于4时的编码信息的示意图。其中，时间段T0被均分成子时间段01、02、03、04四个子时间段；同理，时间段T1、T2、T3分别被均分成四个子时间段。
本实施例提供了触摸检测方法的一种具体实现方式；对于相同的驱动信号(包含相同数量的信号波形)而言，被划分成的相关双采样周期的数量越多，在触摸位置信息的计算过程中可以越精确地抵消掉感应信号中的低频干扰；即抵抗低频干扰的能力越强。
本申请第三实施例涉及一种触摸检测方法，本实施例与第二实施例大致相同，主要区别之处在于：在第二实施例中，每个相关双采样周期中的两个采样周期包含的信号周期的数量均为1；而在本实施例中，每个相关双采样周期中的两个采样周期包含的信号周期的数量大于1。
如图10所示为第三实施例的触摸检测方法中的编码信息对应的驱动信号的波形示意图。与第二实施例中一样，驱动信号也包含2N个信号波形(即 2N个信号周期)，2N个信号波形例如被划分成4个相关双采样周期，每个相关双采样周期中的两个采样周期包含的信号周期的数量均相等且为N/4，这个例子中N为大于或等于8的偶数。例如，N＝16，则每个采样周期包含的信号周期的数量为4个(如图10中所示的4Cycle)。需要说明的是，由于每个采样周期的信号周期的数量较多且相关双采样周期，为更清楚地示意出波形，图10中仅示意出了驱动通道TX1在第三个时间段T3中的波形；这个例子中的编码信号的示意图可以参照图9。
需要说明的是，本实施例中每个相关双采样周期中的两个采样周期包含的信号周期的数量均相等，然并不以此为限；也可以是，同一个相关双采样周期中的两个采样周期包含的信号周期的数量相等，不同的相关双采样周期中的采样周期包含的信号周期的数量不相等。
本申请第四实施例涉及一种触控芯片，如图11所示，触控芯片1包括：
驱动单元11，向触摸屏的驱动通道施加基于预设的编码方式编码的驱动信号；其中，编码方式包括，将驱动信号的多个信号波形划分成至少一个相关双采样周期的波形，同一个相关双采样周期包含波形相位相差180°的两个采样周期；
接收单元12，用于从触摸屏的感应通道接收所述驱动信号对应的感应信号。其中，接收单元12可以理解为包含信号调理电路，其中，信号调理电路可以包括信号放大、信号过滤等作用；即，接收单元12可以对感应信号做一些预处理。
处理单元13，根据感应信号和编码方式对应的编码信息确定触摸位置信息。
其中，处理单元13具体包括：
模数转换子单元131，用于将感应信号进行模拟数字转换，并得到数字形式的感应信号；
解调子单元132，用于对数字形式的感应信号进行解调，并得到解调信息；其中，每个采样周期的波形对应于解调信息中的一个解调值；
计算子单元133，用于根据解调信息与编码方式对应的编码信息，计算触摸位置信息；
存储子单元134，用于存储编码方式对应的编码信息。
本实施例中，驱动单元11连接于处理单元13中的模数转换子单元131，用于对模数转换子单元131进行同步，即当驱动单元11向驱动通道施加驱动信号时，控制模数转换子单元131同步获取数字形式的感应信号。在另一个例子中，驱动单元11可以同时连接模数转换子单元131和接收单元12，即驱动单元11可以对模数转换子单元131和接收单元12都进行同步。
本申请实施例相对于现有技术而言，驱动信号的多个信号波形被划分成至少一个相关双采样周期的波形，同一个所述相关双采样周期包含波形相位相差180°的两个采样周期。本领域技术人员应当知晓，触摸检测的时间相对较短，可以认为在触摸检测的过程中低频干扰是保持不变的；且本领域技术人员也应当知晓，感应信号包含目标信号(即驱动信号的耦合信号)和低频干扰，目标信号相对于驱动信号会有一个相移，且相同时刻的目标信号的波形相位与驱动信号的波形相位始终保持这个相移差值。本申请实施例中，由于一个相关双采样周期中两个采样周期的驱动信号的相位差为180°，因此两个采样周期采样得到的感应信号中，目标信号的相位差也保持在180°且低频干扰的相位相同， 所以通过计算可以将同一个相关双采样周期中两个采样周期中的低频干扰抵消掉；从而可以提高触摸检测中抵抗低频干扰的能力，从而提高系统的信噪比，增强触摸灵敏度。
不难发现，本实施方式为与第一至三中任一实施例相对应的装置实施例，本实施方式可与第一至三中任一实施方式互相配合实施。第一至三中任一实施方式中提到的相关技术细节在本实施方式中依然有效，为了减少重复，这里不再赘述。相应地，本实施方式中提到的相关技术细节也可应用在第一至三中任一实施方式中。
本申请第五实施例涉及一种电子设备，包括触摸屏和上述第四实施例所述的触控芯片。
本领域的普通技术人员可以理解，上述各实施例是实现本申请的具体实施例，而在实际应用中，可以在形式上和细节上对其作各种改变，而不偏离本申请的精神和范围。

Claims (14)

  1. 一种触摸检测方法，其特征在于，包括：
    向触摸屏的驱动通道施加基于预设的编码方式编码的驱动信号；其中，所述编码方式包括，将所述驱动信号的多个信号波形划分成至少一个相关双采样周期的波形，同一个所述相关双采样周期包含波形相位相差180°的两个采样周期；
    从所述触摸屏的感应通道接收所述驱动信号对应的感应信号；
    根据所述感应信号和所述编码方式对应的编码信息确定触摸位置信息。
  2. 根据权利要求1所述的触摸检测方法，其特征在于，同一个所述相关双采样周期中的所述两个采样周期包含的信号周期的数量相等；其中，一个所述信号周期对应于一个所述信号波形。
  3. 根据权利要求1或2所述的触摸检测方法，其特征在于，所述多个信号波形被划分成一个所述相关双采样周期的波形。
  4. 根据权利要求2所述的触摸检测方法，其特征在于，所述多个信号波形被划分成若干个所述相关双采样周期的波形，各所述相关双采样周期中的所述采样周期包含的信号周期的数量均相等。
  5. 根据权利要求4所述的触摸检测方法，其特征在于，各所述相关双采样周期中的所述采样周期包含的信号周期的数量均为1。
  6. 根据权利要求1所述的触摸检测方法，其特征在于，所述根据所述感应信号和所述编码方式对应的编码信息确定触摸位置信息，包括：
    将所述感应信号进行模拟数字转换，并得到数字形式的所述感应信号；
    对数字形式的所述感应信号进行解调，并得到解调信息；其中，每个所述采样周期的波形对应于所述解调信息中的一个解调值；
    根据所述解调信息和所述编码方式对应的编码信息，计算所述触摸位置信息。
  7. 根据权利要求1所述的触摸检测方法，其特征在于，所述触摸屏包括驱动层和感应层，所述驱动层包含沿第一方向平行设置的若干根所述驱动通道，所述感应层包含沿第二方向平行设置的若干根所述感应通道。
  8. 一种触控芯片，其特征在于，包括：
    驱动单元，向触摸屏的驱动通道施加基于预设的编码方式编码的驱动信号；其中，所述编码方式包括，将所述驱动信号的多个信号波形划分成至少一个相关双采样周期的波形，同一个所述相关双采样周期包含波形相位相差180°的两个采样周期；
    接收单元，用于从所述触摸屏的感应通道接收所述驱动信号对应的感应信号；
    处理单元，根据所述感应信号和所述编码方式对应的编码信息确定触摸位置信息。
  9. 根据权利要求8所述的触控芯片，其特征在于，同一个所述相关双采样周期中的所述两个采样周期包含的信号周期的数量相等；其中，一个所述信号周期对应于一个所述信号波形。
  10. 根据权利要求8或9所述的触控芯片，其特征在于，所述多个信号波形被划分成一个所述相关双采样周期的波形。
  11. 根据权利要求9所述的触控芯片，其特征在于，所述多个信号波形被划分成若干个所述相关双采样周期的波形，各所述相关双采样周期中的所述采样周期包含的信号周期的数量均相等。
  12. 根据权利要求11所述的触控芯片，其特征在于，各所述相关双采样周期中的所述采样周期包含的信号周期的数量均为1。
  13. 根据权利要求8所述的触控芯片，其特征在于，所述解调单元包括：
    模数转换子单元，用于将所述感应信号进行模拟数字转换，并得到数字形式的所述感应信号；
    解调子单元，用于对数字形式的所述感应信号进行解调，并得到解调信息；其中，每个所述采样周期的波形对应于所述解调信息中的一个解调值；
    计算子单元，用于根据所述解调信息与所述编码方式对应的编码信息，计算所述触摸位置信息；
    存储子单元，用于存储所述编码方式对应的编码信息。
  14. 一种电子设备，其特征在于，包括：触摸屏以及权利要求8至13中任一项所述的触控芯片。
PCT/CN2018/121558 2018-12-17 2018-12-17 触摸检测方法、触控芯片及电子设备 WO2020124323A1 (zh)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109634451A (zh) * 2017-10-06 2019-04-16 联咏科技股份有限公司 信号处理方法及其触控感测系统

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20220141964A (ko) * 2021-04-13 2022-10-21 삼성디스플레이 주식회사 터치 센서 및 이를 포함하는 표시 장치

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110063249A1 (en) * 2009-09-14 2011-03-17 Raydium Semiconductor Corporation Touch sensing apparatus and touch sensing method
CN103257738A (zh) * 2012-02-17 2013-08-21 义隆电子股份有限公司 触控面板的抗噪声干扰驱动方法及其触控面板装置
US20140198053A1 (en) * 2013-01-14 2014-07-17 Sangsic Yoon Method, device and computer-readable recording medium for sensing touch on touch panel
CN104238843A (zh) * 2013-06-11 2014-12-24 广达电脑股份有限公司 触控装置及使用其的触控方法

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI507949B (zh) * 2010-02-08 2015-11-11 Novatek Microelectronics Corp 觸控感測系統、電容感測電路及電容感測方法
CN102467305B (zh) * 2010-11-19 2015-04-29 矽统科技股份有限公司 具有携带相位信息的电容感应电路的电子装置和其方法
TWI433022B (zh) * 2011-02-01 2014-04-01 Orise Technology Co Ltd 低功率差動偵測電容式觸控的解調變方法及系統
US20140204053A1 (en) * 2013-01-22 2014-07-24 Pixart Imaging Inc. Concurrent driving capacitive touch sensing device and transmission system
US20160034080A1 (en) * 2014-08-01 2016-02-04 Jin-chul Lee Semiconductor device and method of operating the same
US9740356B1 (en) * 2016-02-05 2017-08-22 Pixart Imaging Inc. Capacitive touch system using differential sensing and operating method thereof
CN109074200B (zh) * 2017-03-07 2021-11-12 深圳市汇顶科技股份有限公司 触控芯片、电容式触摸屏、电容式主动笔及电容式触摸屏与电容式主动笔的双向通信方法
CN108700963B (zh) * 2017-12-12 2021-07-02 深圳市汇顶科技股份有限公司 触控芯片、触摸检测方法及装置和终端设备
CN108475155B (zh) * 2018-03-30 2020-10-27 深圳市为通博科技有限责任公司 电容检测电路、触摸检测装置和终端设备
EP3640779B1 (en) * 2018-09-07 2022-04-27 Shenzhen Goodix Technology Co., Ltd. Capacitance detection circuit, touch chip and electronic device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110063249A1 (en) * 2009-09-14 2011-03-17 Raydium Semiconductor Corporation Touch sensing apparatus and touch sensing method
CN103257738A (zh) * 2012-02-17 2013-08-21 义隆电子股份有限公司 触控面板的抗噪声干扰驱动方法及其触控面板装置
US20140198053A1 (en) * 2013-01-14 2014-07-17 Sangsic Yoon Method, device and computer-readable recording medium for sensing touch on touch panel
CN104238843A (zh) * 2013-06-11 2014-12-24 广达电脑股份有限公司 触控装置及使用其的触控方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3696654A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109634451A (zh) * 2017-10-06 2019-04-16 联咏科技股份有限公司 信号处理方法及其触控感测系统
CN109634451B (zh) * 2017-10-06 2022-04-08 联咏科技股份有限公司 信号处理方法及其触控感测系统

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