WO2022188325A1 - Procédé et appareil pour la détection tactile de multiples canaux dans un écran tactile - Google Patents

Procédé et appareil pour la détection tactile de multiples canaux dans un écran tactile Download PDF

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Publication number
WO2022188325A1
WO2022188325A1 PCT/CN2021/106281 CN2021106281W WO2022188325A1 WO 2022188325 A1 WO2022188325 A1 WO 2022188325A1 CN 2021106281 W CN2021106281 W CN 2021106281W WO 2022188325 A1 WO2022188325 A1 WO 2022188325A1
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channel
target
noise
channels
output signal
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PCT/CN2021/106281
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English (en)
Chinese (zh)
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孔晨阳
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深圳市汇顶科技股份有限公司
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Priority claimed from CN202110272060.9A external-priority patent/CN112860121A/zh
Priority claimed from CN202110272072.1A external-priority patent/CN112947791B/zh
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
Publication of WO2022188325A1 publication Critical patent/WO2022188325A1/fr

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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

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  • the embodiments of the present application relate to the field of electronic devices, and more particularly, to a method and apparatus for touch detection of multiple channels in a touch screen.
  • Capacitive sensors are widely used in electronic products for touch detection.
  • a conductor such as a finger touches or approaches the detection electrode in the touch screen of the electronic device
  • the capacitance corresponding to the detection electrode will change.
  • the user's operation is touch detection or touch detection.
  • the noise generated by the touch screen of the electronic device will affect the above detection result. Therefore, how to reduce the influence of touch screen noise on capacitance detection has become an urgent problem to be solved.
  • the present application provides a method and device for touch detection of multiple channels in a touch screen, which can improve the efficiency of touch detection.
  • a first aspect provides a method for touch detection of multiple channels in a touch screen, the method comprising: according to a first reference channel, when the touch screen is in a screen-on state and in a screen-off state, respectively. outputting a signal, and determining a noise signal of the first reference channel, where the first reference channel is an untouched channel among the multiple channels; according to the displayed noise figure of the target channel among the multiple channels and the The noise signal of the first reference channel is used to determine the noise signal of the target channel, wherein the display noise figure of the target channel represents the ratio of the display noise signal of the target channel to the reference display noise signal, and the display noise signal is generated when the touch screen is in the bright screen state; the noise signal of the target channel is removed from the original output signal of the target channel to obtain the target output signal of the target channel, and the The target output signal is used for touch detection of the target channel, and the original output signal of the target channel is the output signal when the target channel does not remove the noise signal when the touch screen is in a bright screen state.
  • the display noise coefficient of each channel in the multiple channels relative to the reference display noise is determined by using the similarity of display noise. It can be completed in the mass production test stage, so that the multi-channel touch detection chip can flexibly adapt to different mounted screens; further, the touch detection chip can noise the output signal according to the display noise figure of each channel obtained in the mass production test stage.
  • the removal operation removes the display noise part in the output signal, thereby greatly improving the signal-to-noise ratio of the touch detection system, thereby improving the efficiency of touch detection.
  • the method further includes: when the touch screen is not touched, determining, according to multiple frames of display images, a A display noise figure, the display noise figure for each channel, represents a ratio of the display noise signal for each channel relative to a reference display noise signal.
  • the touch screen when the touch screen is not touched, determine each of the multiple channels according to multiple frames of display images.
  • the display noise figure of the channel includes: determining the basic output signal of each channel according to the output signal of each channel when the touch screen is not touched and the touch screen is in an off-screen state; When the touch screen is not touched and the touch screen is in a bright screen state, determine the sampling output signal of each channel corresponding to each frame of display image in the multi-frame display images; The difference between the sampled output signal of the channel and the basic output signal of each channel determines the display noise figure of each channel.
  • each of the The output signal of the channel includes: when the touch screen is not touched and the touch screen is in an off-screen state, setting each channel within a preset time The average value of the output signal is determined as the base output signal for each channel.
  • determining the The display noise figure of each channel includes: determining a second reference channel among the plurality of channels, and determining the noise figure of the second reference channel to be 1; according to the following formula (a), and the For the sampled output signal of each channel corresponding to each frame of image, the least squares method is used to determine the display noise coefficient km of the target channel:
  • CH m is the sampling output signal of the target channel corresponding to each frame of image
  • CH m,b is the basic output signal of the target channel
  • CH n is the second reference corresponding to each frame of image
  • CH n,b is the basic output signal of the second reference channel
  • the reference display noise signal is CH n -CH n,b .
  • Determining the noise signal of the first reference channel includes: taking the difference between the output signal of the first reference channel when the touch screen is in the bright screen state and the basic output signal of the first reference channel, Determined as the noise signal of the first reference channel.
  • the determination of the The noise signal includes: determining the noise signal N m of the target channel according to the following formula (b):
  • k m is the display noise figure of the target channel
  • k l is the display noise figure of the first reference channel
  • ⁇ CH l is the noise signal of the first reference channel.
  • the display noise figure of the first reference channel is a maximum value of the display noise figures of the multiple channels.
  • the first reference channel is different from the target channel.
  • the method further includes: determining an untouched channel among the plurality of channels as the first reference channel.
  • the determining that an untouched channel among the multiple channels is the first reference channel includes: according to the first The output signals of the channels when the touch screen is in the bright screen state and the screen off state respectively, determine the noise signal of the first channel, and the first channel is any channel among the plurality of channels; according to The displayed noise figure of each of the at least two target channels and the noise signal of the first channel are determined, and the noise signal of each target channel is determined, and the at least two target channels are the phase in the plurality of channels.
  • the display noise figure of each target channel represents the ratio of the display noise signal of each target channel to the reference display noise signal, and the display noise signal is in the touch screen at the touch screen.
  • the display noise coefficient of each channel in the multiple channels relative to the reference display noise is determined by using the similarity of display noise. It can be completed in the mass production testing stage, so that the multi-channel touch detection chip can be flexibly adapted to different mounted screens; further, the first channel is selected as the first reference channel among the multiple channels, and the display noise figure based on the first channel is displayed. , to remove noise from the output signals of other channels. When the selected first channel is touched, if touch detection is performed on the output signals of the other determined channels, misjudgment will occur, so the selected channel can be determined according to the noise-removed output signals of the other channels.
  • the first channel can be used as the first reference channel, and touch detection can be performed based on the noise-removed output signals of other channels; but if the selected first channel is touched , then you can re-select the new channel as the first reference channel to re-determine the output signals of other channels after noise removal, until it is determined that the selected new channel is not touched, you can use it as the first reference channel, And based on the untouched first reference channel, noise is removed from the remaining channels, so as to perform touch detection on the output signal after the noise is removed.
  • the above calculation process is relatively simple, and can avoid the misjudgment of touch detection when the selected first reference channel is touched, and greatly improves the feasibility of practical use on the premise of improving the accuracy of touch detection.
  • the method further includes: if it is determined that the first channel is touched, determining, among the plurality of channels, whether the second channel is touched If it is touched, the first channel is different from the second channel; if it is determined that the second channel is not touched, the second channel is determined as the first reference channel.
  • the second The displayed noise figure of the channel is the maximum value.
  • the at least two target channels include adjacent first target channels and second target channels, and the at least two target channels
  • the target output signals of the at least two target channels, the basic output signals of the at least two target channels, and the display noise figures of the at least two target channels, and determining whether the first channel is touched includes: if the first target channel is touched The channel satisfies the following formula (c), and it is determined that the first target channel satisfies the preset condition,
  • CH m,ca is the target output signal of the first target channel
  • CH m,b is the basic output signal of the first target channel
  • CH m-1,ca is the target output of the second target channel signal
  • CH m-1,b is the basic output signal of the second target channel
  • km is the displayed noise figure of the first target channel
  • km -1 is the displayed noise figure of the second target channel
  • Slope_th1 and Slope_th2 are two preset thresholds; determine the number of channels that satisfy the preset condition in the other channels except the first channel among the multiple channels; if the other channels satisfy the preset condition
  • the ratio of the number of conditional channels to the total number of the plurality of channels is greater than or equal to a preset value, and it is determined that the first channel is touched, or, if the channel that satisfies the preset condition among the other channels
  • the ratio of the number to the total number of the multiple channels is less than the preset value, and it is determined that the first channel is not touched.
  • the preset value is 1/2 or 2/3.
  • the determining is determined according to the output signals of the first channel when the touch screen is in a screen-on state and a screen-off state, respectively.
  • the noise signal of the first channel includes: when the touch screen is not touched and the touch screen is in an off-screen state, determining the basis of the first channel according to the output signal of the first channel Output signal; determine the difference between the output signal of the first channel when the touch screen is in the bright screen state and the basic output signal of the first channel as the noise signal of the first channel.
  • the determination is based on the displayed noise figure of each of the at least two target channels and the noise signal of the first channel.
  • the noise signal of each target channel includes: according to the following formula (d), determining the noise signal N m of the mth target channel in the at least two target channels:
  • k m is the display noise figure of the mth target channel
  • k l is the display noise figure of the first channel
  • ⁇ CH l is the noise signal of the first channel.
  • the display noise figure of the first channel is the maximum value of the display noise figures of the multiple channels.
  • the first channel is different from the at least two target channels.
  • an apparatus for touch detection of multiple channels in a touch screen which is used to execute the method in the first aspect or any possible implementation manner of the first aspect.
  • the apparatus includes a unit for performing the method in the above-mentioned first aspect or any possible implementation manner of the first aspect.
  • a device for touch detection of multiple channels in a touch screen including: a storage unit and a processor, where the storage unit is used for storing instructions, and the processor is used for executing the instructions stored in the memory, And when the processor executes the instructions stored in the memory, the execution causes the processor to perform the method of the first aspect or any possible implementation of the first aspect.
  • a computer-readable medium for storing a computer program, the computer program comprising instructions for performing the method of the first aspect or any possible implementation of the first aspect.
  • a fifth aspect provides a computer program product comprising instructions, when a computer runs the instructions of the computer program product, the computer executes the above-mentioned first aspect or any possible implementation of the first aspect.
  • FIG. 1 is a schematic diagram of a conventional multi-channel touch detection system.
  • FIG. 2 is a schematic diagram of any channel in the improved multi-channel touch detection system.
  • FIG. 3 is a schematic diagram of periodic changes of different signals.
  • FIG. 4 is a schematic flowchart of a method for touch detection of multiple channels in a touch screen according to an embodiment of the present application.
  • FIG. 5 is a schematic diagram of a touch detection system according to an embodiment of the present application.
  • FIG. 6 is a schematic diagram of a touch detection system according to an embodiment of the present application.
  • FIG. 7 is a schematic diagram of touch amounts of multiple channels according to an embodiment of the present application.
  • FIG. 8 is another schematic diagram of a touch amount of a plurality of channels according to an embodiment of the present application.
  • FIG. 9 is another schematic flowchart of a method for touch detection of multiple channels in a touch screen according to an embodiment of the present application.
  • FIG. 10 is still another schematic diagram of touch amounts of multiple channels according to an embodiment of the present application.
  • a touch screen of an electronic device is usually provided with two layers of channels, horizontal and vertical, for example, they may be referred to as RX channels and TX channels, respectively, for touch detection.
  • Touch detection usually includes self-capacitance detection and mutual capacitance detection. Specifically, when performing self-capacitance detection, the touch-control chip scans the variation of the self-capacitance to ground of each horizontal channel and vertical channel. When a finger approaches or touches, the self-capacitance of the channel near the finger becomes larger.
  • the driving channel such as the TX channel
  • the other layer of the channel is used as the sensing channel (such as the RX channel).
  • the touch chip detects the mutual capacitance between the TX channel and the RX channel. Changes.
  • the touch chip can calculate the touch position of the finger according to the detected change of the self-capacitance or mutual capacitance.
  • Figure 1 shows a schematic diagram of a traditional multi-channel touch detection system.
  • the output signal of each RX channel can be detected to determine whether the channel is touched.
  • the multi-channel touch detection system may include a driving circuit (not shown in the figure) for generating a driving signal.
  • the driving signal may also be called a coding signal, and the coding signal may be input to the touch panel TX channel in .
  • the multi-channel touch detection system may further include a capacitance detection circuit, for example, the capacitance detection circuit may include a charge amplifier (Charge amplifier, CA) and a programmable gain amplifier (Programmable Gain Amplifier, PGA), for example, may also include a Low-pass characteristics of the analog anti-aliasing filter (Analog Antialiasing Filter, AAF) and analog-to-digital conversion circuit (Analog to Digital Conversion Circuit, ADC) and so on.
  • a capacitance detection circuit may include a charge amplifier (Charge amplifier, CA) and a programmable gain amplifier (Programmable Gain Amplifier, PGA), for example, may also include a Low-pass characteristics of the analog anti-aliasing filter (Analog Antialiasing Filter, AAF) and analog-to-digital conversion circuit (Analog to Digital Conversion Circuit, ADC) and so on.
  • AAF Analog Antialiasing Filter
  • ADC Analog to Digital Conversion Circuit
  • the PGA circuit can be used to receive the signals transmitted from each RX channel in the touch panel, and after amplifying it, output signals CH 1 to CH n ; in addition, the AAF circuit can be connected to the PGA circuit for filtering out The interference signal carried in the received electrical signal; the ADC circuit can be connected with the AAF circuit to convert the analog signal into a digital signal, and the digital signal can be used for touch detection.
  • FIG. 2 shows a schematic diagram of any channel in an improved touch detection system. After testing, it is found that the amplitude of the display noise is related to the display refresh cycle of the screen. Therefore, the system shown in Figure 2 utilizes the time-domain characteristics of the screen noise.
  • Fig. 3 shows a schematic diagram of periodic changes of different signals, wherein the synchronization (Hsync) signal in Fig.
  • the Hsync signal can be used for isolation control of the RX input.
  • a switch S1 is added to the RX input end, and when the Hsync signal is at a high level, S1 is disconnected to disconnect the analog front end (Active Front End, AFE) and the RX connection, So that the display noise with a large amplitude does not enter the AFE part, and when the level of the Hsync signal is pulled down, the control switch S1 remains off for a period of time, and then the switch S1 is turned on, so as to ensure that when it is connected to RX, the display The noise is small in magnitude.
  • This improved solution can indeed optimize the signal-to-noise ratio of the touch detection system, but there are two problems in this solution.
  • the refresh rate of touch detection is limited by the refresh rate of the screen, which cannot meet the needs of arbitrary detection refresh rates.
  • an embodiment of the present application proposes a method for touch detection of multiple channels in a touch screen, which can solve the above problems based on the similarity of display noise.
  • FIG. 4 shows a schematic flowchart of a method 100 for touch detection of multiple channels in a touch screen according to an embodiment of the present application
  • FIG. 5 shows a multi-channel touch detection system according to an embodiment of the present application.
  • the apparatus may include a processing unit, and the processing unit is configured to execute the method 100;
  • the apparatus may include a processor, and the processor may call and run a computer program from a memory to implement the method in the embodiments of the present application 100, wherein the memory may be a separate device independent of the processor, or may be integrated in the processor.
  • the method can be applied to the touch detection system shown in FIG. 5 .
  • the touch detection system can include a touch chip
  • the The touch chip includes the device 200 .
  • the apparatus 200 may include a processor or a processing unit to perform the method 100 .
  • the digital signal output by the ADC of each channel will undergo demodulation processing, and the output in-phase/quadrature (I/Q) demodulated data is input to the device 200 , to perform the method 100 .
  • the method 100 may include: S110 , acquiring the display noise figure of each channel in the multiple channels, wherein the display noise figure of each channel indicates that the display noise signal of each channel is relative to the display noise signal of each channel.
  • the reference shows the ratio of the noise signal.
  • the S110 may specifically include: when the touch screen is not touched, according to multiple frames of display images, determining The display noise figure of the target channel among the multiple channels, wherein the display noise figure of the target channel represents the ratio of the display noise signal of the target channel to the reference display noise signal. Generated when the screen is on.
  • FIG. 6 shows a schematic diagram of a simplified model of the displayed noise coupled to the RX terminal in the embodiment of the present application.
  • the The display noise is approximately considered to be common mode noise, but due to the difference in the trace resistance and coupling capacitance from the cathode to the touch screen at different positions, the amplitude and phase of the display pixels coupled to each RX terminal are different. Therefore, Figure 1 or The output signal of the system shown in Figure 5 is represented by the following equation (1):
  • the multiple channels are n channels as an example for description, and n is a positive integer greater than 1; CH 1 to CH n represent the output signals of each channel, and S 1 to Sn represent the output signals of each channel except for Signal components other than various noise signals, N 1 to N n represent the random noise of each channel, for example, N 1 represents the random noise of the first channel, the random noise is mainly caused by the AFE itself; N c is the source display noise amount , k 1 to k n are the proportional coefficients of the display noise coupled to each channel, for example, k 1 represents the display noise figure of the first channel, or k 1 represents the relative display noise signal of the first channel In reference to the ratio of the display noise signal, and k 1 to k n are vectors, k 1 to k n indicate that the amplitude and phase of the display noise coupled to different RX channels are different.
  • the display noise figure k 1 of the first channel can be expressed as 0.5*e ⁇ (j30°).
  • the display noise figures k 1 to k n of the plurality of channels can be determined.
  • S110 in the method 100 may specifically include: when the touch screen is not touched and the touch screen is in an off-screen state, according to the output signal of each channel in the plurality of channels, determining the output signal of each channel in the plurality of channels.
  • Basic output signal when the touch screen is not touched and the touch screen is on, determine the sampling output signal of each channel corresponding to each frame of the display image in the multi-frame display image; according to the sampling output signal of each channel and the The difference between the underlying output signals for each channel determines the displayed noise figure for each channel.
  • N c in formula (1) is equal to zero, wherein the touch screen is in the screen-off state.
  • No image is displayed during the preset time; and, within the preset time, taking the target channel among the multiple channels as an example, the average value of the multiple output signals of the target channel is measured, and the average value can be determined as the basic output signal of the target channel , that is, the basic output signal of each channel can be obtained.
  • the basic output signals of 1 to n channels are represented as CH 1,b , CH 2,b , CH 3,b , . . . , CH n,b respectively here.
  • the duration of the preset time may be set according to actual applications.
  • the preset time may be set as a relatively long time, and for the basic output signal of each signal obtained within the preset time, it may be considered that the amount of random noise is not included therein.
  • a second reference channel may be determined from multiple channels, and the noise figure of the second reference channel is determined to be 1, that is, the noise signal of the second reference channel is determined as the reference display noise signal, wherein the second reference channel
  • the reference channel can be any one of multiple channels.
  • k n 1 is used as an example for description in the embodiments of the present application.
  • formula (3) can be obtained according to formula (2):
  • the output signal of each RX channel corresponding to the multi-frame image is collected to obtain the display of each frame in the multi-frame display image.
  • the sampling output signals CH 1 to CH n of the multiple channels corresponding to the image that is, to obtain multiple sets of the output signals CH 1 to CH n corresponding to the multiple frames of images.
  • the multiple frames of images may be 200 frames of images in the same environment, but the embodiment of the present application is not limited thereto.
  • the process of determining the display noise figure of each channel can be carried out in the mass production test stage of the touch chip, and the test is carried out according to the actual mounted touch screen, and stored in the touch chip. Since the display noise figure of each channel is only related to the characteristics of the touch screen itself, it basically does not change with the change of the used screen and the use time, so it can be used in the subsequent noise removal process.
  • the method 100 includes: S120 , determining a noise signal of the first reference channel according to the output signals of the first reference channel when the touch screen is in the bright screen state and the screen off state, respectively, wherein the first reference channel is A reference channel is any one of the channels that is not touched.
  • the method 100 may further include: determining a first reference channel in an untouched channel among the multiple channels, that is, the first reference channel may be any untouched channel among the multiple channels.
  • the embodiment of the present application is described by taking the selection of the 1 th channel among the multiple channels as the first reference channel as an example. According to formula (2), formula (5) satisfied by the lth channel can be obtained:
  • the difference between the output signal CH1 of the first reference channel when the touch screen is in the bright screen state and the basic output signals CH1 ,b of the first reference channel can be determined as the first
  • the noise signal ⁇ CH l of the reference channel that is, the noise signal ⁇ CH l of the first reference channel, satisfies formula (6):
  • the method 100 further includes: S130, determining the noise signal of the target channel according to the displayed noise figure of the target channel and the noise signal of the first reference channel; S140, removing the target channel from the original output signal of the target channel
  • the noise signal of the target channel can be obtained to obtain the target output signal of the target channel.
  • the target output signal of the target channel is used for touch detection of the target channel.
  • the original output signal of the target channel is that the target channel does not remove noise when the touch screen is in the bright state. signal output signal.
  • the noise signal N m of the target channel can be determined according to the following formula (7):
  • N m km * ⁇ CH l / k l (7)
  • the target channel may be each channel in the plurality of channels, or the target channel may also be another channel in the plurality of channels except the first reference channel.
  • the target output signal CH m ,ca of the target channel can be obtained.
  • the output signal CH m,ca can be used for touch detection of the target channel.
  • the random noise amount of each channel is the same as an example, the root mean square value is ⁇ , and the residual noise is ⁇ *(1+km 2 / k l 2 ) 1/2 . It can be seen that, in order to make The residual noise is the smallest, and the first reference channel in this embodiment of the present application can select the channel showing the largest noise figure.
  • the nth channel can be selected as the first reference channel, then the residual noise is ⁇ *(1+ km 2 ) 1/2 , which is greatly reduced compared to the display noise, which can significantly improve the The signal-to-noise ratio of the touch detection system.
  • the display noise coefficient of each channel in the multiple channels relative to the reference display noise is determined by using the similarity of display noise. It can be completed in the mass production test stage, so that the multi-channel touch detection chip can flexibly adapt to different mounted screens; further, the touch detection chip can be based on the display noise figure of each channel obtained in the mass production test stage.
  • the I/Q demodulation data performs noise removal operation to remove the display noise in the AFE output signal, thereby greatly improving the signal-to-noise ratio of the touch detection system. Compared with the traditional detection system, it solves the problem of touch under the bright screen. In addition to the problem of poor signal-to-noise ratio in detection, a synchronization signal for display refresh of the touch screen is not required, so that the data refresh rate of touch detection is not limited by the display refresh rate, and is more flexible and accurate.
  • the first reference channel in the method 100 is an untouched channel among the multiple channels, and the above formula (9) is: A formula that is satisfied when the target channel is not touched.
  • the target output signal CH m,ca of the target channel can satisfy the following formula (10 ):
  • the m can be a positive integer from 1 to n in turn;
  • the following formula (11) can be used to determine whether the target channel is touched:
  • VTH1 and VTH2 are two preset thresholds, and According to practical applications, VTH1 can be set to any positive number, and VTH2 can be set to any negative number. For example, VTH1 and VTH2 can be opposite numbers to each other.
  • the target output signal CH m,ca of the target channel satisfies any one of the two inequalities included in the above formula (11), it can be determined that the target channel is touched.
  • the channel is touched; on the contrary, if the target output signal CH m,ca of the target channel does not satisfy the above formula (11), the target channel can be determined Not touched, for example, the other channels except the mth channel in FIG. 7 do not satisfy the two formulas in the formula (11), therefore, the other channels are not touched.
  • the premise of the above-mentioned touch detection of the target channel is that the first reference channel is not touched, but on the contrary, if the first reference channel is the touched channel, it may cause a misjudgment of touch detection.
  • , k n 1 as an example, and use the nth channel as the first reference channel.
  • the touch amount of the nth channel is expressed as ⁇ S n , then with reference to formula (5), the The nth channel satisfies the following formula (12):
  • FIG. 8 shows a schematic diagram of possible misjudgments in multi-channel touch detection according to an embodiment of the present application. In the case shown in FIG.
  • the two dots in the dotted circle represent the mth The channel and the nth channel, the mth channel and the nth channel are actually the touched channel, but since the touched nth channel is selected as the first reference channel, according to formula (14), the target output signal CH An additional touch amount of the first reference channel is added to m,ca . If the calculation is still performed by formula (11), the mth channel will be misjudged as an untouched channel, and the others are not actually touched. channel, but it will be misjudged as a touch channel.
  • an embodiment of the present application proposes a method for touch detection of multiple channels in a touch screen, which can solve this problem.
  • FIG. 9 shows a schematic flowchart of a method 300 for touch detection of multiple channels in a touch screen according to an embodiment of the present application.
  • the method 100 is similar, and all or part of the steps included in the method 300 in this embodiment of the present application may be performed by an apparatus for touch detection of multiple channels in a touch screen.
  • the apparatus may include a processing unit, and the processing unit is configured to execute the method 300; for another example, the apparatus may include a processor, and the processor may call and run a computer program from a memory to implement the method in the embodiments of the present application 300, wherein the memory may be a separate device independent of the processor, or may be integrated in the processor.
  • the method can be applied to the touch detection system shown in FIG. 5 .
  • the touch detection system can include a touch chip
  • the The touch chip includes the device 200 .
  • the apparatus 200 may include a processor or a processing unit to perform the method 300 .
  • the digital signals output by the ADCs of each channel are subjected to demodulation processing, and the output I/Q demodulated data is input to the device 200 to execute the method 300 .
  • the method 300 includes: S310 , acquiring the display noise figure of each channel in the multiple channels.
  • the S310 may specifically include: when the touch screen is not touched, according to the multi-frame display images, determine the target channel of each of the at least two target channels.
  • the noise figure is displayed, wherein the at least two target channels are any adjacent at least two channels among the plurality of channels, that is, the at least two target channels are at least two adjacent or consecutive channels in the plurality of channels in position,
  • the display noise figure of each target channel represents the ratio of the display noise signal of each target channel to the reference display noise signal, and the display noise signal is generated when the touch screen is in a bright screen state.
  • S310 may correspond to S110 in the foregoing method 100, and is applicable to the relevant descriptions in S110, and for brevity, details are not repeated here.
  • the method 300 further includes: S320 : Determine the noise signal of the first reference channel according to the output signals of the first reference channel when the touch screen is in the bright screen state and the screen off state, respectively, and the first reference channel
  • the channel is the first channel of the plurality of channels.
  • S320 may correspond to S120 in the foregoing method 100, and is applicable to the relevant descriptions in S120, and for the sake of brevity, details are not repeated here.
  • the difference between S320 and S120 is that the first reference channel in S320 can be any one of the plurality of channels.
  • the first reference channel is the first channel of the plurality of channels as an example, that is,
  • the first reference channel in S320 is the first channel
  • the first channel may be the touched channel, or may also be the untouched channel
  • the first reference channel in S120 is the untouched channel.
  • the method 300 further includes: S330 , determining the noise signal of each target channel according to the displayed noise figure of each target channel and the noise signal of the first reference channel.
  • S330 may correspond to S130 in the foregoing method 100, and is applicable to the relevant description in S130, and for the sake of brevity, details are not repeated here.
  • the method 300 further includes: S340 , remove the noise signal of each target channel from the original output signal of each target channel, so as to obtain the target output signal of each target channel, the original output signal of each target channel
  • the output signal is the output signal when the noise signal is not removed from each target channel when the touch screen is in the bright state. It should be understood that the process of determining the target output signal of the target channel in S340 may correspond to S140 in the above-mentioned method 100, and is applicable to the relevant description in S140, which is not repeated here for brevity.
  • the difference between S340 and S140 is that since the first reference channel determined in the method 300 may be touched, the target output signal of the target channel determined in S340 may not be directly used for touch detection, but continue to execute Other steps in the method 300, such as S350 or other steps.
  • the method 300 further includes: S350, according to the target output signals of the at least two target channels, the basic output signals of the at least two target channels, and the display noise figures of the at least two target channels, determine the first Whether a reference channel is touched, the basic output signal of each target channel is the output signal of each target channel when the touch screen is in an off-screen state and not touched.
  • S350 according to the target output signals of the at least two target channels, the basic output signals of the at least two target channels, and the display noise figures of the at least two target channels, determine the first Whether a reference channel is touched, the basic output signal of each target channel is the output signal of each target channel when the touch screen is in an off-screen state and not touched.
  • the first target channel Satisfying the following formula (15) it can be determined that the first target channel satisfies the preset condition
  • CH m,ca is the target output signal of the first target channel, that is, the output signal after noise removal based on the first reference channel
  • CH m,b is the basic output signal of the first target channel
  • CH m-1,ca is the target output signal of the second target channel adjacent to the first target channel, that is, the output signal of the second target channel after removing noise based on the first reference channel
  • CH m-1,b is the basis of the second target channel Output signal
  • km is the displayed noise figure of the first target channel
  • km -1 is the displayed noise figure of the second target channel
  • Slope_th1 and Slope_th2 are two preset thresholds, and these two preset thresholds can be applied according to actual applications It is set to any value, and the embodiment of the present application is not limited to this.
  • can be further determined, correspondingly, Slope_th2 ⁇ Slope in the formula (15) m ⁇ Slope_th1 can be used to indicate whether the value of sign(real(Slope m )*
  • the two preset thresholds can be based on actual The application is set to a real number, but the embodiment of the present application is not limited to this.
  • m can be sequentially taken as a positive integer from 1 to n, and because the random noise N is much smaller than the touch amount ⁇ S of each channel, where ⁇ S m-1 represents the touch amount of the m-1th channel , so the random noise term can be ignored first.
  • Slope m of the mth channel it can be determined whether the channel is touched.
  • FIG. 10 shows a schematic diagram of whether multiple channels meet the preset conditions in the embodiment of the present application, wherein “S” on the ordinate in FIG. 10 represents the sign(real(Slope m )*
  • Touch detection can be performed by using the above formula (15) to determine whether each channel in the multiple channels is touched, and the process may not be limited by whether the first reference channel is touched. However, considering that there may be accidental interference, some channels still satisfy the above formula (15) when they are touched, or some channels do not satisfy the above formula (15) when they are not touched, so this formula ( 15) Determine whether the channel is touched, but further determine whether the selected first reference channel is touched.
  • the ratio of the number of channels that meet the preset conditions in the other channels to the total number of multiple channels is greater than or equal to the preset value, it is determined that the first reference channel is touched; on the contrary, if the channels that meet the preset conditions in the other channels are touched The ratio of the number to the total number of multiple channels is less than the preset value, and it is determined that the first reference channel is not touched.
  • the ratio of the touched channel to the total number of channels is relatively small, so the ratio of 1/2 or 1/3 can be used to determine whether the first reference channel is touched, that is, the preset value. It may be 1/2 or 2/3; or, the preset value may also be determined as other values according to practical applications, but the embodiment of the present application is not limited to this.
  • the method 300 further includes: S360, if it is determined that the first reference channel is not touched, perform touch detection on at least two target channels according to the target output signals of the at least two target channels; on the contrary, if It is determined that the first reference channel is touched, and the first reference channel is updated to a second channel among the plurality of channels, and the first channel is different from the second channel.
  • the first channel among the multiple channels is selected as the first reference channel, for example, the first channel may be the nth channel TX n , if it is determined that the first reference channel is not touched, Then, the target output signal of the determined target channel can be subjected to touch detection.
  • touch detection can be performed according to the above formula (11), and the target output signal of the target channel has been removed from the noise signal.
  • the first reference channel may be re-determined among the multiple channels, for example, the second channel among the multiple channels is determined as the new first reference channel, and the above method is used. 300 Redetermines whether the new first reference channel is touched. By analogy, until the determined first reference channel is not touched, the target output signal of the target channel determined according to the untouched first reference channel can be used for touch detection.
  • the first reference channel in this embodiment of the present application should be selected to display the noise figure
  • the largest channel that is, the displayed noise coefficient of each channel can be arranged from large to small, and the channel corresponding to the largest value can be selected as the first reference channel.
  • the displayed noise coefficient of each channel can be determined when the chip is mass-produced.
  • the displayed noise figure of each channel is also sorted.
  • the display noise coefficient of each channel in the multiple channels relative to the reference display noise is determined by using the similarity of display noise. It can be completed in the mass production test stage, so that the multi-channel touch detection chip can be flexibly adapted to different mounted screens; further, one channel is selected as the first reference channel among the multiple channels, and the display noise figure based on the first reference channel is displayed. , to remove noise from the output signals of other channels. When the selected first reference channel is touched, if touch detection is performed on the output signals of the other determined channels, misjudgment will occur, so the selection can be determined according to the noise-removed output signals of the other channels.
  • the output signals of other channels after noise removal are re-determined until it is determined that the selected new first reference channel is not touched, and noise can be removed from the remaining channels based on the untouched first reference channel.
  • touch detection can be performed based on the noise-removed output signals of other channels; but if the selected first reference channel is touched, then a new By means of a reference channel, the output signals of other channels after noise removal are re-determined until it is determined that the selected new first reference channel is not touched, and noise can be removed from the remaining channels based on the untouched first reference channel.
  • the above calculation process is relatively simple, and can avoid the misjudgment of touch detection when the selected first reference channel is touched, and greatly improves the feasibility of practical use on the premise of improving the accuracy of touch detection.
  • the processor in this embodiment of the present application may be an integrated circuit chip, which has a signal processing capability.
  • each step of the above method embodiments may be completed by a hardware integrated logic circuit in a processor or an instruction in the form of software.
  • the above-mentioned processor can be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), an off-the-shelf programmable gate array (Field Programmable Gate Array, FPGA) or other available Programming logic devices, discrete gate or transistor logic devices, discrete hardware components.
  • DSP Digital Signal Processor
  • ASIC Application Specific Integrated Circuit
  • FPGA Field Programmable Gate Array
  • a general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
  • the steps of the method disclosed in conjunction with the embodiments of the present application may be directly embodied as executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor.
  • the software modules may be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other storage media mature in the art.
  • the storage medium is located in the memory, and the processor reads the information in the memory, and completes the steps of the above method in combination with its hardware.
  • the memory in this embodiment of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory.
  • the non-volatile memory may be a read-only memory (Read-Only Memory, ROM), a programmable read-only memory (Programmable ROM, PROM), an erasable programmable read-only memory (Erasable PROM, EPROM), an electrically programmable read-only memory (Erasable PROM, EPROM). Erase programmable read-only memory (Electrically EPROM, EEPROM) or flash memory.
  • Volatile memory may be Random Access Memory (RAM), which acts as an external cache.
  • RAM Static RAM
  • DRAM Dynamic RAM
  • SDRAM Synchronous DRAM
  • SDRAM double data rate synchronous dynamic random access memory
  • Double Data Rate SDRAM DDR SDRAM
  • enhanced SDRAM ESDRAM
  • synchronous link dynamic random access memory Synchlink DRAM, SLDRAM
  • Direct Rambus RAM Direct Rambus RAM
  • the memory in the embodiment of the present application may also be a static random access memory (static RAM, SRAM), a dynamic random access memory (dynamic RAM, DRAM), Synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous connection Dynamic random access memory (synch link DRAM, SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DR RAM) and so on. That is, the memory in the embodiments of the present application is intended to include but not limited to these and any other suitable types of memory.
  • Embodiments of the present application further provide a computer-readable storage medium for storing a computer program.
  • the computer-readable storage medium can be applied to the apparatus for touch detection of multiple channels in the touch screen in the embodiments of the present application, and the computer program enables the computer to execute the corresponding methods of the methods in the embodiments of the present application.
  • the process, for the sake of brevity, will not be repeated here.
  • Embodiments of the present application also provide a computer program product, including computer program instructions.
  • the computer program product can be applied to the apparatus for touch detection of multiple channels in the touch screen in the embodiments of the present application, and the computer program instructions cause the computer to execute the corresponding processes of the methods in the embodiments of the present application. , and are not repeated here for brevity.
  • the embodiments of the present application also provide a computer program.
  • the computer program can be applied to the apparatus for touch detection of multiple channels in the touch screen in the embodiment of the present application, and when the computer program is run on the computer, the computer is made to execute each of the embodiments of the present application.
  • the corresponding processes in the method will not be repeated here.
  • the disclosed system, apparatus and method may be implemented in other manners.
  • the apparatus embodiments described above are only illustrative.
  • the division of the units is only a logical function division. In actual implementation, there may be other division methods.
  • multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented.
  • the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.
  • each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit.
  • the functions, if implemented in the form of software functional units and sold or used as independent products, may be stored in a computer-readable storage medium.
  • the technical solution of the present application can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution.
  • the computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application.
  • the aforementioned storage medium includes: U disk, mobile hard disk, Read-Only Memory (ROM, Read-Only Memory), Random Access Memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program codes .

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Abstract

Des modes de réalisation de la présente invention concernent un procédé et un appareil destinés à la détection tactile de multiples canaux dans un écran tactile. Le procédé comprend les étapes suivantes : en fonction de signaux de sortie respectifs d'un premier canal de référence non touché parmi de multiples canaux lorsqu'un écran tactile est dans un état d'écran allumé et un état d'écran éteint, déterminer un signal de bruit du premier canal de référence ; en fonction d'un coefficient de bruit d'affichage d'un canal cible et du signal de bruit du premier canal de référence, déterminer un signal de bruit du canal cible ; et éliminer d'un signal de sortie d'origine du canal cible le signal de bruit du canal cible pour obtenir un signal de sortie cible du canal cible pour une détection tactile. Le procédé et l'appareil destinés à la détection tactile de multiples canaux dans un écran tactile que fournit la présente invention peuvent améliorer l'efficacité de la détection tactile.
PCT/CN2021/106281 2021-03-12 2021-07-14 Procédé et appareil pour la détection tactile de multiples canaux dans un écran tactile WO2022188325A1 (fr)

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CN202110272060.9A CN112860121A (zh) 2021-03-12 2021-03-12 用于触控屏中多个通道触控检测的方法和装置
CN202110272072.1A CN112947791B (zh) 2021-03-12 2021-03-12 用于触控屏中多个通道触控检测的方法和装置

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