CN113126816B

CN113126816B - Data processing method and processing circuit of touch screen display

Info

Publication number: CN113126816B
Application number: CN202110268894.2A
Authority: CN
Inventors: 黄思衡; 王文祺
Original assignee: Huiding Technology Private Ltd
Current assignee: Huiding Technology Private Ltd
Priority date: 2021-03-12
Filing date: 2021-03-12
Publication date: 2024-08-27
Anticipated expiration: 2041-03-12
Also published as: CN113126816A

Abstract

The application discloses a data processing method and a processing circuit of a touch screen display. The data processing method comprises the following steps: receiving N channel data respectively output by N receiving channels of the touch screen display when the touch screen display is in a bright screen state, wherein the N receiving channels are respectively coupled with N sensing channels of the touch screen display; dividing the difference between the channel data of each receiving channel and the reference data by a normalization factor to produce first normalized data, the normalization factor indicating the degree to which the receiving channel is interfered by display noise; according to the touch states of the N sensing channels and the weighting functions corresponding to the receiving channels, carrying out weighted average on N first normalization data corresponding to the N receiving channels to generate second normalization data; and correcting the channel data according to the normalization factor and the second normalization data. The data processing method can improve the signal to noise ratio in a high noise scene.

Description

Data processing method and processing circuit of touch screen display

Technical Field

The present application relates to touch data processing technology, and in particular, to a data processing method for a touch screen display and a processing circuit for the touch screen display.

Background

With the development of touch sensing technology, portable electronic products (e.g., cell phones, tablet computers, and vehicle systems) having touch screen displays (touch screens) have become quite popular. However, the design trend of light and thin design reduces the distance between the touch screen module and the display screen module, so that the touch screen is more obviously interfered by the noise of the display screen, and the accuracy of detecting the touch position of the touch screen is reduced. For example, organic Light Emitting Diode (OLED) displays have a thinner thickness compared to Liquid Crystal Displays (LCDs) without using a backlight layer and a liquid crystal layer. Although the thickness of the mobile phone can be reduced by adopting the OLED display screen, the capacitance between the display screen module and the touch screen module is increased. Under the condition that the OLED display screen is in a bright screen state and plays a high-noise picture, display noise can be coupled to a touch sensor of the touch screen through a capacitor with a high capacitance value, so that the signal-to-noise ratio of the touch sensor is reduced, and the possibility of misjudging the touch position is improved.

Disclosure of Invention

One of the objectives of the present application is to disclose a data processing method of a touch screen display and a processing circuit of the touch screen display, which solve the above-mentioned problems in the prior art.

Certain embodiments of the present application disclose a data processing method for a touch screen display. The data processing method comprises the following steps: receiving N pieces of first channel data respectively output by N receiving channels of the touch screen display when the touch screen display is in a bright screen state, wherein N is a positive integer greater than 1, and the N receiving channels are respectively coupled with N sensing channels of the touch screen display; dividing, for each of the N receive channels, a difference between first channel data corresponding to the receive channel and reference data by a normalization factor to produce first normalized data corresponding to the receive channel, wherein the reference data is from the receive channel when the touch screen display is in an off-screen state, and the normalization factor indicates a degree to which the receive channel is interfered by display noise; according to the touch states of the N sensing channels and the weighting functions corresponding to the receiving channels, carrying out weighted average on N first normalization data corresponding to the N receiving channels so as to generate second normalization data corresponding to the receiving channels; and correcting the first channel data according to the normalization factor and the second normalization data.

Certain embodiments of the present application disclose a processing circuit for a touch screen display. The processing circuit includes N receive channels and a controller. The N receiving channels are respectively coupled with the N sensing channels of the touch screen display. N is a positive integer greater than 1. Each receiving channel is used for outputting first channel data according to a sensing result from a corresponding sensing channel when the touch screen display is in a bright screen state. The controller is coupled to the N receiving channels, and is configured to obtain reference data from the receiving channels when the touch screen display is in an off-screen state, and execute the data processing method.

By carrying out weighted average on the normalization data corresponding to each of the different receiving channels so as to correct the sensing result of the touch sensor, the touch sensing scheme disclosed by the application not only can improve the signal-to-noise ratio of the touch sensing system under a high noise scene, but also can reduce the complexity of the touch sensing system, meet the requirement of randomly adjusting the touch refresh rate and improve the accuracy of touch detection.

Drawings

FIG. 1 is a schematic diagram of one embodiment of a touch screen display of the present application.

FIG. 2 is a schematic diagram of one embodiment of the touch screen display shown in FIG. 1.

FIG. 3 is a flow chart of an embodiment of a data processing method of a touch screen display of the present application.

FIG. 4 is a flow chart of an embodiment of a data processing method of a touch screen display of the present application.

FIG. 5 is a schematic diagram of standard deviation of each channel data generated by the touch sensing system shown in FIG. 2 in a high noise scenario using the data processing method shown in FIG. 4.

Detailed Description

The following provides various embodiments or examples for implementing different features of the application. Specific examples of elements and configurations will be described below to simplify the present disclosure. Of course, these descriptions are merely examples and are not intended to limit the application in any way. In addition, the present application may repeat reference numerals and/or letters in the various examples. Such reuse is for brevity and clarity purposes and does not itself represent a relationship between the different embodiments and/or configurations discussed. Furthermore, it will be understood that if an element is described herein as being "connected to" or "coupled to" another element, the element may be directly connected or coupled to the other element or indirectly connected or coupled to the other element through other elements.

The touch sensing system may receive a sensing result of a touch event from the touch sensor using the receiving channel, thereby detecting the touch event. In order to reduce the interference of display noise on touch detection, the connection between a touch sensor (touch sensor) and a receiving channel (RECEIVING CHANNEL) is usually disconnected when the display noise is large, so that the display noise cannot enter the receiving channel from the touch sensor.

For example, a switch may be provided between the touch sensor and the receive channel, which may be selectively turned on according to a horizontal synchronization signal (horizontal synchronization signal, hsync). The horizontal synchronization signal is an indication signal of screen refresh, wherein the magnitude of display noise is related to the screen refresh rate. When the horizontal synchronization signal has a high signal level, display noise is large. When the horizontal synchronization signal has a low signal level, display noise is small. Thus, the switch may be turned off when the horizontal synchronization signal has a high signal level, so that large display noise is not (or hardly) coupled from the touch sensor to the receiving channel. When the horizontal synchronization signal transitions from a high signal level to a low signal level and is at the low signal level for a period of time, the display noise has been reduced significantly. Accordingly, the switch may be turned on to connect the receiving channel to the touch sensor so that the receiving channel may receive the sensing result from the touch sensor in an attempt to improve the signal-to-noise ratio of the touch sensor.

However, since the above touch detection method needs to use a horizontal synchronization signal, the master (host) end needs to output the horizontal synchronization signal to the touch chip, which increases the complexity of the touch sensing system. In addition, the above touch detection method is difficult to meet the requirement of arbitrarily adjusting the touch refresh rate, subject to the limitation of the screen refresh rate (or horizontal synchronization signal). Moreover, the above touch detection method is not applicable to different screens. For example, for a screen with a long duration of display noise, the above touch detection method may cause the receiving channel to be disconnected from the touch sensor for too long, which greatly reduces the time for outputting the sensing result of the touch sensor to the receiving channel, but rather reduces the signal-to-noise ratio.

The touch sensing scheme disclosed by the application can generate normalized data (normalized data) corresponding to different receiving channels respectively according to the similarity of display noise coupled to different receiving channels at the same time without using a horizontal synchronizing signal, wherein the components related to the display noise in the normalized data corresponding to each receiving channel are approximately the same. By carrying out weighted average on the normalization data corresponding to each of the different receiving channels so as to correct the sensing result of the touch sensor, the touch sensing scheme disclosed by the application not only can improve the signal-to-noise ratio of the touch sensing system under a high noise scene, but also can reduce the complexity of the touch sensing system, meet the requirement of randomly adjusting the touch refresh rate and improve the accuracy of touch detection. Further description is as follows.

FIG. 1 is a schematic diagram of one embodiment of a touch screen display of the present application. In this embodiment, the touch screen display 100 includes a display screen module 102 and a touch sensing system 104. The touch sensing system 104 is configured to detect a touch event TE, such as a touch or contactless operation of the touch sensing system 104 by a finger or stylus. The touch sensing system 104 can be implemented as, but is not limited to, a capacitive touch screen and can include a touch sensor 110 and a processing circuit 120.

Touch sensor 110 includes N sense channels SE ₁-SE_N, where N is a positive integer greater than 1. In embodiments where the touch sensor 110 employs a self-capacitance (self-capacitance) sensing scheme, each sensing channel may generate a sensing result (i.e., one of the N sensing results SR ₁-SR_N) according to the corresponding self-capacitance. In embodiments where the touch sensor 110 employs a mutual-capacitance (dual-capacitance) sensing scheme, each sensing channel can generate a sensing result (i.e., one of the N sensing results SR ₁-SR_N) according to the mutual capacitance between it and the corresponding driving channel (not shown in fig. 1). In addition, since the display screen module 102 may couple the display noise to the N sensing channels SE ₁-SE_N through the N coupling capacitors Cg ₁-Cg_N, respectively, the N sensing results SR ₁-SR_N may carry the display noise from the display screen module 102, respectively.

The processing circuit 120 is coupled to the touch sensor 110 for detecting a touch event TE according to the N sensing results SR ₁-SR_N. It is noted that at the same time (or substantially the same time), the signal components generated by the N sensing channels SE ₁-SE_N in response to the display noise of the display module 102 may have a certain degree of similarity with each other. The processing circuit 120 may generate corresponding N first normalized data according to the N sensing results SR ₁-SR_N, where components related to display noise in the N first normalized data are substantially the same.

Since a sensing channel near a sensing channel is interfered by the noise of the display module 102 and may be coupled to the sensing channel, the processing circuit 120 may perform weighted average on the N first normalized data to generate second normalized data corresponding to the sensing channel. In addition to the signal component generated by the sensing channel in response to the display noise, the second normalization data may further include a signal component coupled to the sensing channel by the signal component generated by the sensing channel in response to the display noise. The processing circuit 120 can more accurately obtain the signal component generated in response to the touch event TE in the sensing result according to the second normalization data.

In this embodiment, the processing circuit 120 includes N receive channels 122.1-122.N and a controller 124.N receiving channels 122.1-122.N are coupled to N sense channels SE ₁-SE_N, respectively. Each receiving channel is configured to output first channel data (i.e. one of the N first channel data CH ₁-CH_N) according to a sensing result from the corresponding sensing channel when the touch screen display 100 is in the bright screen state. The controller 124 is coupled to the N receiving channels 122.1-122.N for obtaining reference data (i.e., one of the N reference data CH _1B-CH_NB) from the receiving channels when the touch screen display 100 is in the off-screen state, and generating N first normalized data corresponding to the N receiving channels 122.1-122.N according to the first channel data and the reference data corresponding to the N receiving channels 122.1-122. N. For example, the controller 124 may subtract the first channel data corresponding to each receive channel from the reference data and divide the difference between the first channel data and the reference data by a normalization factor to generate first normalized data corresponding to the receive channel. Since the normalization factor indicates the extent to which the receive channel is disturbed by display noise. Thus, the display noise-related components of the N first normalized data may be identical (or substantially identical) to each other.

In addition, the controller 124 may perform weighted average on the N first normalized data according to the influence degree of the N sensing channels SE ₁-SE_N on the sensing result received by the receiving channel, so as to generate second normalized data corresponding to the receiving channel, thereby correcting the first channel data. For example, the controller 124 may perform weighted average on the N first normalized data according to the touch states of the N sensing channels SE ₁-SE_N and the weighting function corresponding to the receiving channel, so as to generate the second normalized data. The controller 124 may correct the first channel data based on the normalization factor and the second normalization data.

For ease of understanding, an exemplary circuit configuration is used below to illustrate the disclosed touch sensing scheme. However, this is for illustration purposes. The touch sensing scheme disclosed in the present application can be applied to other embodiments employing a circuit structure based on that shown in fig. 1. Please refer to fig. 2, which is a schematic diagram of an embodiment of the touch screen display 100 shown in fig. 1. Touch screen display 200 includes touch sensing system 204 and display module 102 shown in FIG. 1. Touch sensing system 204 includes a touch sensor 210 and processing circuitry 220, which may be embodiments of touch sensor 110 and processing circuitry 120, respectively, shown in FIG. 1.

The touch sensor 210 includes N sensing channels 212.1-212.N for sensing touch events TE and generating N sensing results SR ₁-SR_N accordingly. Taking the sense channel 212.1 as an example, the sense channel 212.1 can sense the touch event TE according to a driving signal TX to generate a sensing result SR ₁, wherein the driving signal TX is provided by a driving circuit (not shown in fig. 2) included in the touch sensing system 204. In this embodiment, each of the N sense channels 212.1-212.N may be represented by a sense capacitance and may be coupled to the display module 102 by a coupling capacitance. For example, the sense channel 212.1 may be represented by a sense capacitance C1, where the sense capacitance C1 may be a self or mutual capacitance corresponding to the sense channel 212.1 and coupled to the display module 102 through a coupling capacitance Cg ₁. It is noted that since display noise from the display module 102 can be coupled to the sense channel 212.1 through the coupling capacitance Cg ₁, the sensing result SR ₁ (e.g., the charge of the capacitive node N ₁) can be changed according to the driving signal TX, the touch event TE, and the coupling capacitance Cg ₁.

The processing circuit 220 includes N receive channels 222.1-222.N and a controller 224.N receive channels 222.1-222.N may be used as embodiments of N receive channels 122.1-122.N, respectively, as shown in fig. 1. The N receive channels 222.1-222.N may have the same (or substantially the same) circuit structure. For example, the driving signal for driving the touch sensor 210 may be a frequency modulated vector signal. Thus, each receive channel may output first channel data by in-phase quadrature demodulation (in-phase and quadrature demodulation, IQ demodulation) of the corresponding sensing result, which may indicate corresponding amplitude and phase information of the sensing result. In this embodiment, receive path 222.1 includes, but is not limited to, a charge amplifier 232, a low pass filter 234, an analog-to-digital converter (ADC) 236, an in-phase-to-quadrature demodulation unit 238, a plurality of digital filters 242.1 and 242.2, and a plurality of downsampling units 244.1 and 244.2.

The charge amplifier 232 is used for amplifying the sensing result SR ₁ to generate an amplified signal SA. The low-pass filter 234 is used for filtering the amplified signal SA to generate a filtered signal SF. The analog-to-digital converter 236 is used for converting the filtered signal SF into a digital signal SD. The in-phase and quadrature demodulation unit 238 is used for in-phase and quadrature demodulation of the digital signal SD to generate an in-phase signal SI and a quadrature signal SQ. The digital filter 242.1 is configured to filter the in-phase signal SI to generate a filtered signal SFI. The digital filter 242.2 is configured to perform a filtering process on the quadrature signal SQ to generate a filtered signal SFQ. The downsampling unit 244.1 is configured to downsample the filtered signal SFI to generate the in-phase data DI (a portion of the first channel data CH ₁). The downsampling unit 244.2 is configured to downsample the filtered signal SFQ to generate quadrature data DQ (another portion of the first channel data CH ₁). The in-phase data DI and the quadrature data DQ may reflect the capacitance value of the sense capacitor C1 (e.g., the self-capacitance or the mutual capacitance corresponding to the receive channel 222.1).

The controller 224 is coupled to the N receiving channels 222.1-222.N for detecting a touch event TE according to the N first channel data CH ₁-CH_N outputted from the N receiving channels 222.1-222. N. It is noted that the controller 224 may perform weighted average on the N first channel data CH ₁-CH_N according to the influence degree of the N sensing channels SE ₁-SE_N on a certain first channel data, so as to correct the first channel data. By correcting the N first channel data CH ₁-CH_N, the controller 224 can more accurately detect the touch event TE.

For example, the controller 224 may primarily determine the touch position of the touch event TE on the touch sensor 210 based on the in-phase data and the quadrature data output by each receiving channel. The controller 224 may further perform weighted average on the N first channel data CH ₁-CH_N to correct the in-phase data and the quadrature data output by at least one receiving channel, so as to obtain a more accurate sensing result of the sensing capacitance value. The corrected channel data may reflect the force of pressing the touch location. In this embodiment, the N first channel data CH ₁-CH_N and the N reference data CH _1B-CH_NB may be implemented as digital data. Thus, the controller 224 may be implemented as a digital controller.

Please refer to fig. 3 in conjunction with fig. 2. FIG. 3 is a flow chart of an embodiment of a data processing method of a touch screen display of the present application. If the results are substantially the same, the steps do not have to be performed in the order shown in FIG. 3. For example, the data processing method 300 shown in FIG. 3 may also include other steps. The disclosed touch sensing scheme may employ alternative embodiments based on the data processing method 300 without departing from the spirit and scope of the present application. For purposes of illustration, the data processing method 300 shown in FIG. 3 is described below in conjunction with the touch screen display 200 shown in FIG. 2. However, the application is not limited thereto. It is also possible to apply the data processing method 300 to the touch screen display 100 shown in fig. 1.

In step 302, N first channel data respectively output by N receiving channels of the touch screen display when the touch screen display is in a bright screen state are received, where the N receiving channels are respectively coupled to N sensing channels of the touch screen display.

In step 304, for each of the N receiving channels, a difference between the first channel data corresponding to the receiving channel and reference data is divided by a normalization factor to generate first normalized data corresponding to the receiving channel, wherein the reference data is from the receiving channel when the touch screen display is in an off-screen state, and the normalization factor indicates a degree to which the receiving channel is interfered by display noise.

For example, display noise coupled from the display screen module 102 to the touch sensor 210 may differ due to different coupling paths having different resistances and different coupling capacitances, such that the display noise coupled to the N sense channels 212.1-212.N has different magnitudes and phases. However, since the display noise coupled to the N sense channels 212.1-212.N at the same time (or at substantially the same time) is common mode noise generated by coupling the touch sensor 210 from the display module 102 (e.g., from the display cathode), the display noise coupled to the N sense channels 212.1-212.N at the same time (or at substantially the same time) may have some degree of similarity. That is, the display noise related components of the N first channel data CH ₁-CH_N output from the N receiving channels 222.1-222.N may have some degree of similarity.

For example, the first channel data CH _i output by the receiving channel 222.I can be represented by equation (1):

CH_i＝S_i+N_i+k_i×N_c

(1)

Where i is any integer between 1 and N, S _i corresponds to the signal component produced by sense channel 212.I in response to a touch event TE, and N _i is random noise associated with receive channel 222.I (e.g., noise caused by circuitry included in receive channel 222. I). Further, k _i×N_c may represent a display noise related component of the first channel data CH _i, where N _c is an inherent component of display noise of the display screen module 102 coupled to the touch sensor 210 and k _i is a scaling factor of display noise of the display screen module 102 coupled to the receive channel 222. I. k _i may be used as a normalization factor that indicates how much the receive channel 222.I is disturbed by display noise.

For the receiving channel 222.I, the controller 224 may subtract the first channel data CH _i from the reference data CH _iB and divide the result of the subtraction by the normalization factor k _i to generate the first normalized data NC _i corresponding to the receiving channel 222. I. in the case where the reference data CH _iB is taken while the touch screen display 200 is in the off-screen state, the reference data CH _1B carries almost no component related to display noise. Further, the reference data CH _iB may be data having a component of a small amount of random noise. Taking the reference data CH _1B as an example, the controller 224 can receive a plurality of second channel data { CH ₁₂ }, which are respectively outputted from the receiving channel 222.1 at a plurality of time points when the touch screen display 200 is in the off-screen state. The controller 224 may use the average of the plurality of second channel data { CH ₁₂ } as the reference data CH _1B, so that the component related to random noise in the reference data CH _1B is substantially reduced or almost absent. Furthermore, the reference data CH _iB may be data that is not generated in response to the touch event TE. For example, the controller 224 may retrieve the reference data CH _iB from the receive channel 222.I before the touch event TE occurs, or before no touch event has occurred. Thus, the first normalized data NC _i can be expressed based on equation (2):

NC_i＝(CH_i-CH_iB)/k_i＝ΔS_i+(N_i/k_i)+N_c

(2)

where ΔS _i may correspond to the amount of signal change that the sense channel 212.I produces due to the touch event TE.

Furthermore, based on equation (1), the controller 224 may calculate the normalization factor k _i corresponding to the receiving channel 222.I by measuring the reference data CH _iB in advance and measuring the plurality of channel data output by the receiving channel 222.I when the touch screen display 200 is in the high noise scene before the touch event TE occurs (or before the touch event does not occur).

In step 306, according to the touch states of the N sensing channels and the weighting functions corresponding to the receiving channels, weighted average is performed on the N first normalized data corresponding to the N receiving channels, so as to generate second normalized data corresponding to the receiving channels. Taking the receiving channel 222.I as an example, the controller 224 can perform weighted average on the N first normalized data NC ₁-NC_N according to the touch states of the N sensing channels 212.1-212.N and the weighting function corresponding to the receiving channel 222.I, so as to generate the second normalized data NC _iC corresponding to the receiving channel 222. I. Since each of the first normalized data includes noise interference received by the sensing channel, the second normalized data NC _iC generated by weighted averaging the N first normalized data NC ₁-NC_N may include signal components generated by coupling noise interference received by other sensing channels to the sensing channel 212.

In step 308, the first channel data is corrected according to the normalization factor and the second normalization data. Taking the receiving channel 222.I as an example, the controller 224 may correct the first channel data CH _i according to the normalization factor k _i and the second normalization data NC _iC. In this embodiment, the second normalized data NC _iC may be used as a corrected version of the first normalized data NC _i corresponding to the receive channel 222. I. Accordingly, the controller 224 may correct the first channel data CH _i based on equation (1). For example, in a high noise scenario, the display noise related component (k _i×N_c) in the first channel data CH _i may be much larger than the random noise related component (N _i). The controller 224 may subtract the product of the normalization factor k _i from the first channel data CH _i and the second normalization data NC _iC as a corrected version of the first channel data CH _i.

FIG. 4 is a flow chart of an embodiment of a data processing method of a touch screen display of the present application. Method 400 may be used as an embodiment of method 300 shown in fig. 3. For purposes of illustration, the method 400 illustrated in FIG. 4 is described below in conjunction with the touch screen display 200 illustrated in FIG. 2. However, the application is not limited thereto. It is also possible to apply the method 400 to the touch screen display 100 shown in fig. 1. If the results are substantially the same, the steps are not necessarily performed in the order shown in fig. 4.

First, in step 402, the touch sensing system 204 can measure N first channel data CH ₁-CH_N output by N receiving channels 222.1-222.N at a certain time. Step 402 may be implemented as step 302 shown in fig. 3. For example, when the touch screen display 200 is in the bright screen state, the N receiving channels 222.1-222.N may respectively receive the N sensing results SR ₁-SR_N at the same time (or substantially the same time), so as to generate N first channel data CH ₁-CH_N. The controller 224 may receive N first channel data CH ₁-CH_N from N receive channels 222.1-222.N at the same time (or substantially the same time).

In step 404, the controller 224 may calculate the first normalized data corresponding to each receiving channel. Step 404 may be implemented as step 304 shown in fig. 3. For example, the controller 224 may calculate the first normalized data of each receiving channel using equation (2) above. Further, in the embodiment shown in fig. 2, the channel data output by each reception channel is vector data including in-phase data and quadrature data. Thus, the N first normalization data NC ₁-NC_N may be represented as a vector NC _V shown below.

NC_V＝[NC₁,NC₂,…,NC_N]

＝[(CH₁-CH_1B)/k₁,(CH₂-CH_2B)/k₂,…,(CH_N-CH_NB)/k_N]

(3)

In step 406, the controller 224 may pre-determine the touch status of the N sense channels 212.1-212.N at the time of the touch event TE. For example, the controller 224 can determine which sensing channels 212.1-212.N are not touched according to at least the N first channel data CH ₁-CH_N, and generate a1×n matrix isNoTouch according to the above, which can be expressed as follows:

isNoTouch＝[B₁,B₂,…,B_i,…,B_N]

(4)

Element B _i is used to indicate whether the sensing channel 212.I is touched. In this embodiment, the controller 224 may set the element B _i to 0 when it is determined that the sensing channel 212.I is touched. When it is determined that the sensing channel 212.I is not touched, the controller 224 may set the element B _i to 1.

In step 408, the controller 224 may determine the weighting functions corresponding to the N receive channels 222.1-222.N, respectively. Taking the receiving channel 222.I as an example, the controller 224 can determine the weighting function Wi corresponding to the receiving channel 222.I, which can include N weighting coefficients wx _i1-wx_iN corresponding to the N sensing channels 212.1-212.N, respectively. In this embodiment, the weighting function Wi can be expressed as a1×n matrix:

Wi＝[wx_i1,wx_i2,…,wx_ii,…,wx_iN]

(5)

Where N weighting coefficients wx _i1-wx_iN may be 0 or any positive real number. The weighting factor for each sense channel may be determined based on the distance between the sense channel and the sense channel 212.I (the number of sense channels). For example, a sense channel that is closer to sense channel 212.I may have a greater impact on sense channel 212.I than a sense channel that is farther from sense channel 212. I. In the case where the number of sensing channels between sensing channel 212.I and one of the N sensing channels 212.1-212.N is smaller than the number of sensing channels between sensing channel 212.I and another of the N sensing channels 212.1-212.N, the weighting coefficient corresponding to the sensing channel may be greater than the weighting coefficient corresponding to the another sensing channel.

For example, for a weighting function Wi corresponding to a sense channel 212.I, the weighting coefficient corresponding to one of the N sense channels 212.1-212.N may be proportional to the inverse of the number of sense channels between the sense channel 212.I and the sense channel. In the case where the weighting coefficient wx _ii corresponding to the sense channel 212.I is equal to (but not limited to) 1, the weighting function Wi can be expressed by equation (6):

Wi＝[…,1/3,1/2,1,1/2,1/3,…,1/|j-i+1|,…]

(6)

where 1/|j-i+1| is the weighting coefficient wx _ij corresponding to sense channel 212. J.

For another example, the weighting factor for one of the N sense channels 212.1-212.N may be proportional to the inverse square of the number of sense channels between sense channel 212.I and the sense channel. In the case where the weighting coefficient wx _ii corresponding to the sense channel 212.I is equal to (but not limited to) 1, the weighting function Wi can be expressed by equation (7): wi= [ …,1/9,1/4, 1/9, …,1/|j-i+1| ², … ]

(7)

Where 1/|j-i+1| ² is the corresponding weighting coefficient wx _ij for sense channel 212. J.

In step 410, the controller 224 determines N weight factors corresponding to the N first normalized data NC ₁-NC_N according to the touch states of the N sensing channels 212.1-212.N and the N weight coefficients wx _i1-wx_iN of the weight function Wi, and performs a weighted average on the N first normalized data NC ₁-NC_N accordingly. Steps 406 through 410 may be implemented as an embodiment of step 306 shown in fig. 3. In this embodiment, the N weight factors may be determined according to the matrix isNoTouch and the N weight coefficients wx _i1-wx_iN. The weighted average result of the N first normalized data NC ₁-NC_N (i.e., the second normalized data NC _iC corresponding to the receive channel 222. I) can be expressed as:

Where B _j is an element in matrix isNoTouch shown in equation (4) to indicate the touch state of sense channel 212.J (j is any integer between 1 and N).

When the touch state of one of the N sensing channels 212.1-212.N indicates that the sensing channel is touched, the controller 224 may set the weight factor of the first normalized data corresponding to the sensing channel to 0. When the touch state of the sensing channel indicates that the sensing channel is not touched, the controller 224 may set the weighting factor of the first normalized data corresponding to the sensing channel according to the weighting factor corresponding to the sensing channel. For example, when it is determined that the sensing channel 212.J is touched, the controller 224 may set the element B _j to 0, so that the weight factor of the first normalized data NC _j corresponding to the sensing channel 212.J is equal to 0. When it is determined that the sensing channel 212.J is not touched, the controller 224 may set the element B _j to 1, so that the weight factor of the first normalized data NC _j corresponding to the sensing channel 212.J is equal to "wx _ij/(B₁×wx_i1+B₂×wx_i2+…+B_N×wx_iN".

In step 412, the controller 224 may subtract the product of the normalization factor k _i and the second normalization data NC _iC from the first channel data CH _i to generate the corrected channel data CH _iC (i.e., the corrected version of the first channel data CH _i), as shown in equation (9):

CH_iC＝CH_i-NC_iC

(9)

. Step 412 may be implemented as step 308 shown in fig. 3.

By repeating steps 406 to 412, the controller 224 may correct the N first channel data CH ₁-CH_N, thereby controlling the operation of the touch display 200 according to the corrected channel data.

It should be noted that the details of the data processing method 400 are for illustrative purposes and are not intended to limit the scope of the present application. In some embodiments, matrix isNoTouch may take other forms. For example, in step 406, the controller 224 may set the value of the element B _i when the sensing channel 212.I is not touched to be a positive real number different from 1 as long as the value of the element B _i when the sensing channel 212.I is not touched may be greater than or much greater than the value of the element B _i when the sensing channel 212.I is touched.

In some embodiments, the weighting function Wi corresponding to the receiving channel 222.I may be implemented by other forms of weighting functions. For example, since the sensing channel 212.I corresponding to the first channel data CH _i to be corrected may be the touched sensing channel, the weighting factor wx _ii of the sensing channel 212.I may be set to 0. For another example, since the sensing channel 212.I corresponding to the first channel data CH _i to be corrected and the sensing channels adjacent thereto may be the touched sensing channels, the weighting coefficient wx _ii of the sensing channel 212.I may be set to 0, and the weighting coefficients corresponding to the M sensing channels adjacent to the sensing channel 212.I may be set to 0, where M is a positive integer less than N. Taking the example that the weighting coefficient of the sensing channel is determined according to the inverse square of the distance between two sensing channels, the weighting function Wi can be expressed by (but not limited to) the equation (10):

Wi＝[…,1/9,0,0,0,1/9,…,1/|j-i+1|²,…]

(10)

As long as the touch sensing scheme can perform weighted averaging on the N first normalized data CH ₁-CH_N to correct the first normalized data CH ₁ according to the influence degree of the N sensing channels 212.1-212.N on the sensing result received by the receiving channel 222.I, the related alternative embodiments still fall within the spirit and scope of the present application.

FIG. 5 is a schematic diagram of the standard deviation of each channel data generated by the touch sensing system 204 shown in FIG. 2 in a high noise scenario using the data processing method 400 shown in FIG. 4. Fig. 5 also shows the standard deviation of the data of each channel that is not generated using the data processing method 400 shown in fig. 4. Please refer to fig. 5 in conjunction with fig. 2. For purposes of illustration, in this embodiment, the touch sensor 210 shown in FIG. 2 may include 29 sense channels 212.1-212.29 (i.e., N is equal to 29). The measurement result DR1 corresponds to the standard deviation of the first-channel data that has not passed the correction processing. The measurement result DR2 corresponds to a standard deviation obtained by correcting the channel data corresponding to all the reception channels using the channel data corresponding to the same reception channel. The measurement result DR3 corresponds to the standard deviation obtained by performing correction processing using the data processing method 400 shown in fig. 4.

The measurement result DR1 is generated as follows. The processing circuit 220 may perform 100 measurements on the sensing result of each sensing channel to generate 100 first channel data received by the corresponding receiving channel, thereby generating a standard deviation of the 100 first channel data. For example, the standard deviation corresponding to the reception channel 222.1 is the standard deviation of the first channel data CH ₁ outputted 100 times from the reception channel 222.1.

The measurement result DR2 is generated as follows. The processing circuit 220 may perform 100 measurements on the sensing result of each sensing channel, wherein the processing circuit 220 may correct the first channel data output by each receiving channel during each measurement by using the first normalized data corresponding to one sensing channel that is not touched. In this embodiment, it is assumed that the sensing channel 212.29 is an untouched sensing channel. The processing circuit 220 may correct the result generated by the first channel data of each receiving channel according to the first normalization data NC ₂₉ corresponding to the sensing channel 212.29. For example, each time the first channel data CH ₁ is output by the receive channel 222.1, it can be corrected by the corresponding first normalized data NC ₂₉. The processing circuit 220 may generate the standard deviation corresponding to the receiving channel 222.1 according to the correction result of the 100 first channel data CH ₁ corresponding to the 100 measurements. Similarly, the processing circuit 220 may correct the first channel data corresponding to the other receiving channels according to the first normalized data NC ₂₉ corresponding to the sensing channel 212.29 at each measurement, so as to generate a standard deviation corresponding to each receiving channel. As can be seen from fig. 5, the standard deviation of the measurement result DR2 is reduced much compared with the measurement result DR 1. However, the standard deviation of the channel data increases with increasing distance from the sense channel 212.29. The signal to noise ratio of touch sensing systems remains to be improved.

Compared with the measurement results DR1 and DR2, the standard deviation corresponding to the measurement result DR3 is not only greatly reduced, but also has good correction effect when correcting channel data corresponding to the sensing channels 212.29 with a longer distance. That is, through the weighted average correction process disclosed by the application, the touch sensing system can still have a good signal-to-noise ratio in a high noise scene.

Please refer to fig. 1 again. In this embodiment, the controller 124 may include, but is not limited to, a memory 126 and a processor 128. Memory 126 may be used to store program instructions. The processor 128 is coupled to the memory 126 and is operable to invoke the program instructions stored in the memory 126 to cause the controller 124 to perform at least one of the data processing method 300 shown in fig. 3 and the data processing method 400 shown in fig. 4, in accordance with the touch sensing scheme disclosed herein. Similarly, in some embodiments, the controller 224 shown in FIG. 2 may include a memory and a processor (not shown), wherein the processor may invoke program instructions stored in the memory to cause the controller 224 to perform the touch sensing schemes disclosed herein. Since those skilled in the art will appreciate the details of the operation of the controller 124/224 including the memory and the processor to perform the touch sensing scheme disclosed in the present application after reading the above paragraphs with reference to fig. 1 to 5, further description is omitted here.

The foregoing description briefly sets forth features of certain embodiments of the application so that those skilled in the art may more fully understand the several aspects of the application. Those skilled in the art should appreciate that they can readily use the present application as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments described herein. It will be understood by those skilled in the art that such equivalent embodiments are within the spirit and scope of the present application and that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the present application.

Claims

1. A method for processing data of a touch screen display, comprising:

Receiving N pieces of first channel data respectively output by N receiving channels of the touch screen display when the touch screen display is in a bright screen state, wherein N is a positive integer greater than 1, and the N receiving channels are respectively coupled with N sensing channels of the touch screen display;

Dividing, for each of the N receive channels, a difference between first channel data corresponding to the receive channel and reference data by a normalization factor to produce first normalized data corresponding to the receive channel, wherein the reference data is from the receive channel when the touch screen display is in an off-screen state, and the normalization factor indicates a degree to which the receive channel is interfered by display noise;

According to the touch states of the N sensing channels and the weighting functions corresponding to the receiving channels, carrying out weighted average on N first normalization data corresponding to the N receiving channels so as to generate second normalization data corresponding to the receiving channels; and

And correcting the first channel data according to the normalization factor and the second normalization data.

2. The data processing method of claim 1, wherein the weighting function includes N weighting coefficients corresponding to the N sensing channels, respectively, and the step of weighted averaging the N first normalized data to generate the second normalized data includes:

According to the touch states of the N sensing channels and the N weighting coefficients, N weighting factors corresponding to the N first normalization data respectively are determined; and

And carrying out weighted average on the N first normalized data according to the N weight factors to generate the second normalized data.

3. The data processing method of claim 2, wherein the N sensing channels include a first sensing channel, a second sensing channel, and a third sensing channel, the first sensing channel is coupled to the receiving channel, a number of sensing channels between the first sensing channel and the second sensing channel is smaller than a number of sensing channels between the first sensing channel and the third sensing channel, and a weighting coefficient corresponding to the second sensing channel is greater than a weighting coefficient corresponding to the third sensing channel.

4. The data processing method of claim 2, wherein the N sensing channels comprise a first sensing channel and a second sensing channel, the first sensing channel being coupled to the receiving channel, the second sensing channel having a weighting factor proportional to a reciprocal of a number of sensing channels between the first sensing channel and the second sensing channel.

5. The data processing method of claim 2, wherein the N sensing channels comprise a first sensing channel and a second sensing channel, the first sensing channel being coupled to the receiving channel, the second sensing channel corresponding to a weighting factor proportional to a reciprocal of a square of a number of sensing channels between the first sensing channel and the second sensing channel.

6. A data processing method according to any one of claims 3 to 5, wherein the weighting factor corresponding to the first sensing channel is equal to 1.

7. The data processing method according to any one of claims 3 to 5, wherein the weighting coefficient corresponding to the first sensing channel is equal to 0, and M weighting coefficients corresponding to M sensing channels adjacent to the first sensing channel are equal to 0, where M is a natural number smaller than N.

8. The data processing method according to any one of claims 2 to 5, wherein the step of determining the N weight factors to which the N first normalized data respectively correspond includes:

When the touch state of one sensing channel in the N sensing channels indicates that the sensing channel is touched, setting a weight factor of first normalization data corresponding to the sensing channel to be 0; and

When the touch state of the sensing channel indicates that the sensing channel is not touched, setting a weight factor of first normalization data corresponding to the sensing channel according to a weight coefficient corresponding to the sensing channel.

9. The data processing method of claim 1, wherein the step of correcting the first channel data based on the normalization factor and the second normalization data comprises:

subtracting the product of the normalization factor and the second normalization data from the first channel data as a corrected version of the first channel data.

10. The data processing method of claim 1, further comprising:

Before the touch event occurs, the reference data from the receiving channel is retrieved while the touch screen display is in an off-screen state.

11. The method of any of claims 1, 2, 3, 4, 5, 9, or 10, wherein the N first channel data are received at a same time when the touch screen display is in the bright screen state.

12. The method of any one of claims 1, 2,3, 4, 5, 9, or 10, further comprising:

Receiving a plurality of second channel data respectively output by the receiving channel at a plurality of time points when the touch screen display is in the off-screen state; and

And taking the average of the plurality of second channel data as the reference data.

13. A processing circuit for a touch screen display, comprising:

N receiving channels respectively coupled with N sensing channels of the touch screen display, wherein N is a positive integer greater than 1; each receiving channel is used for outputting first channel data according to a sensing result from a corresponding sensing channel when the touch screen display is in a bright screen state; and

A controller, coupled to the N receiving channels, for obtaining the reference data from the receiving channels when the touch screen display is in the off-screen state, and executing the data processing method of any one of the claims 1 to 12.

14. The processing circuit of claim 13, wherein the controller comprises: a memory for storing program instructions; and

A processor, coupled to the memory, for invoking program instructions stored in the memory, to cause the controller to perform the data processing method of any of claims 1-12.