Signal detection method applied to touch screen, touch screen, device, and storage medium

Abstract

Embodiments of the present application relate to the technical field of touch screens. Disclosed are a signal detection method applied to a touch screen, a touch screen, a device, and a storage medium. The method comprises: setting compensation gains for sensing channels of a touch screen, wherein the compensation gains are used for compensating for noise of the sensing channels, so that the compensated noise levels of the sensing channels are consistent; obtaining second capacitance values output by the sensing channels, and respectively multiplying the second capacitance values by the compensation gains corresponding to the sensing channels to obtain compensation capacitance values; and using the compensation capacitance values of the sensing channels to perform differential processing to obtain differential signals, and performing differential recovery on the differential signals to obtain valid signals of the sensing channels. According to the present application, corresponding compensation gains are set for sensing channels, to compensate for and balance the differences between the sensing channels, thereby completely eliminating noise during differencing and accurately detecting valid signals.

Description

Signal detection method, touch screen, device and storage medium applied to touch screen

[0001] Cross-references

[0002] This application claims priority to the Chinese patent application entitled “Signal detection method, touch screen, device and storage medium for touch screen” filed on December 12, 2023, with application number 202311705095.2, which is incorporated herein by reference in its entirety. Technical Field

[0003] The embodiments of the present application relate to the field of touch screen technology, and in particular to a signal detection method, a touch screen, a device, and a storage medium applied to a touch screen. Background Art

[0004] Capacitive touch screens have been widely used in various electronic products. Common capacitive touch screens use sensing electrodes in two directions to receive touch signals, thereby locating the touch position. Traditional capacitive screens mainly detect finger touches. With the increase in human-computer interaction experience, the application of capacitive active pens has emerged, and its detection principle is similar to the finger touch process. On the other hand, Liquid Crystal Display (LCD, liquid crystal display) or Active Matrix / Organic Light Emitting Diode (Amoled, active matrix organic light emitting diode panel) screens have screen noise when they are turned on, and this noise will interfere with the touch signal. Because the tip of the active pen is very small, the amount of signal that can be sensed is limited. In some specific application scenarios (such as suspension), the signal is even weaker. Therefore, when the active pen is used in the touch screen, it is necessary to reduce the interference caused by the screen noise display as much as possible.

[0005] Some preliminary research has shown that interference in screen displays is primarily common-mode noise. Existing technologies often use differential analysis to remove this type of interference. However, due to channel variability, careful selection of differential channels is necessary for different application scenarios. This increases the workload associated with scenario assessment and still fails to completely address the impact of channel variability.

[0006] Summary of the Invention

[0007] The purpose of the embodiments of the present application is to provide a signal detection method, touch screen, device and storage medium for a touch screen, setting a corresponding compensation gain for each sensing channel to compensate and balance the differences between the sensing channels, and accurately detecting the effective signal transmitted by the active pen.

[0008] An embodiment of the present application provides a signal detection method for a touch screen, comprising: setting a compensation gain for each sensing channel of the touch screen, the compensation gain being used to compensate for noise in each sensing channel so that the noise level of each sensing channel after compensation is consistent; obtaining a second capacitance value output by each sensing channel, multiplying the second capacitance value by the compensation gain corresponding to each sensing channel to obtain a compensation capacitance value; performing differential processing on the compensation capacitance values ​​of each sensing channel to obtain a differential signal, and performing differential recovery on the differential signal to obtain a valid signal for each sensing channel.

[0009] An embodiment of the present application further provides a touch screen, comprising: a glass cover plate, an LCD, and a sensing channel layer located between the glass cover plate and the LCD; the output end of each sensing channel of the sensing channel layer is connected to a multiplier, the multiplier being configured to multiply a compensation gain by a second capacitance value output by each sensing channel to obtain a compensation capacitance value, the compensation capacitance value of each sensing channel being used for differential processing to obtain a differential signal, and the differential signal being used for differential recovery to obtain a valid signal for each sensing channel; wherein the compensation gain satisfies that, after compensating for the noise of each sensing channel, the compensated noise level of each sensing channel is consistent.

[0010] In addition, the sensing channel layer as described above includes a first direction sensing channel layer and a second direction sensing channel layer, and the first direction is perpendicular to the second direction.

[0011] An embodiment of the present application also provides an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the signal detection method applied to a touch screen as described above.

[0012] An embodiment of the present application further provides a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the signal detection method applied to a touch screen as described above is implemented.

[0013] In addition, determining the compensation gain includes: when the entire screen is in a bright screen state, obtaining the first capacitance value output by the sensing channel of each screen area when the screen area is not touched; the compensation gain of each sensing channel is the same as the product obtained by multiplying the normalized first capacitance value of the channel.

[0014] In addition, when each screen area is not touched, obtaining the first capacitance value output by the sensing channel of the screen area includes: when the entire screen is not touched, using a preset pattern as the display pattern of the touch screen, and obtaining the first capacitance value output by all sensing channels at once; obtaining the normalized first capacitance value of the sensing channel includes: using the first capacitance value output by all sensing channels obtained at once as the normalized first capacitance value of the sensing channel. In this way, the first capacitance values ​​of all sensing channels can be obtained at once, and because the first capacitance values ​​of all sensing channels are obtained at once, the step of separate normalization is eliminated, and the normalized first capacitance value is directly obtained.

[0015] In addition, the obtaining of the first capacitance value output by the sensing channel of each screen area when the screen area is not touched includes: when different areas of the entire screen are touched multiple times, obtaining the first capacitance value output by the sensing channel corresponding to the area that is not touched each time; wherein the total set of sensing channels corresponding to each acquisition of the first capacitance value includes all sensing channels corresponding to the entire screen; and at least one sensing channel among the sensing channels corresponding to any acquisition of the first capacitance value is included in the sensing channels corresponding to at least one other acquisition of the first capacitance value; obtaining the normalized first capacitance value of the sensing channel includes: based on the proportional relationship between the first capacitance values ​​output by each sensing channel in the same acquisition among the first capacitance values ​​output by each sensing channel, and based on the proportional relationship between the first capacitance values ​​output by the same sensing channel in at least two acquisitions of the same sensing channel, normalizing the first capacitance value output by each sensing channel to obtain the normalized first capacitance value corresponding to each sensing channel.

[0016] In addition, the first capacitance value mentioned above is used to represent the noise value of each sensing channel; the second capacitance value mentioned above is the sum of the noise value and the effective signal of each sensing channel.

[0017] In addition, before multiplying the second capacitance value by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value, it also includes: when the entire screen is in the off state and is not touched, obtaining the capacitance value output by each sensing channel as a reference compensation value, and adding the reference compensation value to the second capacitance value; multiplying the second capacitance value by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value, includes: multiplying the second capacitance value after adding the reference compensation value by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] One or more embodiments are exemplarily described by the figures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments.

[0019] FIG1 is a schematic structural diagram of a touch screen signal detection system in the prior art;

[0020] FIG2 is a flow chart of a signal detection method applied to a touch screen provided by one embodiment of the present application;

[0021] FIG3 is a schematic diagram of a signal detection process provided by an embodiment of the present application;

[0022] FIG4 is a structural diagram 1 of a touch screen provided by one embodiment of the present application;

[0023] FIG5 is a second structural diagram of a touch screen provided by an embodiment of the present application;

[0024] FIG6 is a schematic structural diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, each embodiment of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that, in each embodiment of the present invention, many technical details are provided in order to enable the reader to better understand the present application. However, even without these technical details and the various changes and modifications based on the following embodiments, the technical solutions claimed in the present application can be implemented. It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described with reference to the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of the present application. In addition, in the context, it should also be understood that when referring to an element being connected to another element "on" or "under", it can not only be directly connected to another element "on" or "under", but can also be indirectly connected to another element "on" or "under" through an intermediate element.

[0026] In a common touch screen detection system, as shown in Figure 1, a touch screen typically consists of two sets of orthogonal sensing electrodes. Other configurations exist, such as a single-layer triangle or a single-layer curve. The most common orthogonal electrodes are used here for illustration. In a common operating mode, such as mutual capacitance sensing mode, touch screen 1 in Figure 1 has electrodes in one direction configured as a driving segment driven by driver circuit 2. The other direction is configured as a receiving end, transmitting the sensing signal to receiving circuit 3. After processing the sensing signal (e.g., filtering and gain), receiving circuit 3 sends it to analog-to-digital converter 4, which then forwards it to digital unit processor 5 for processing. Timing control, gain configuration, and other operations for receiving circuit 3 and driver circuit 2 are also generally performed by digital unit processor 5. In Figure 1, touch event 6 can be initiated by a finger, an active pen, or other capacitive sensing material. When touch event 6 is initiated by an active pen, driver circuit 2 in Figure 1 is also configured as a receiving circuit. In this case, there are receiving circuits in two directions, receiving the sensing signals simultaneously or in a time-sharing manner. Based on the sensing signals received in both directions, the coordinates of the actual touch position of the active pen are calculated.

[0027] When the active pen touches the touch screen, it causes the inductive capacitance (capacitance) of the sensing electrode to change, allowing the receiving circuit to receive the sensing signal. The change in capacitance of the sensing electrode caused by the active pen is primarily generated by the coupling capacitance between the active pen and the sensing electrode. When the active pen is located at different positions on the touch screen, the coupling capacitance between the active pen and the sensing channels of the sensing electrode varies, resulting in different amounts of charge coupled to each electrode by the active pen's excitation power supply. The receiving circuit determines the position of the active pen based on this charge distribution. However, in the process of receiving the sensing signal, the LCD layer of the touch screen will introduce display noise interference to the touch screen due to the influence of the periodic horizontal and vertical synchronization signals when the screen is displayed. This noise is also coupled to the sensing electrode through the coupling capacitance between the active pen and the sensing electrode.

[0028] However, due to process variations, the coupling capacitance between sensing channels and traces cannot be completely consistent. Therefore, the coupling capacitance between sensing channels of sensing electrodes cannot be exactly the same. The greater the process variation, the greater the difference. Generally speaking, the greater the distance between channels, the greater the difference. Therefore, using direct differential subtraction will inevitably introduce errors. If the channel differences are too large, the noise cancellation effect will be too poor, and the differential method will not be able to achieve its intended noise cancellation effect.

[0029] An embodiment of the present application relates to a signal detection method applied to a touch screen. Each step in the method can be executed by an electronic device applying the method. As shown in FIG2 , the signal detection method applied to a touch screen in this embodiment specifically includes the following steps.

[0030] Step 101: setting a compensation gain for each sensing channel of the touch screen. The compensation gain is used to compensate for the noise of each sensing channel so that the noise level of each sensing channel after compensation is consistent.

[0031] Specifically, as can be seen from the aforementioned description of the touch screen detection system shown in FIG1 , the coupled noise of each sensing channel is related to the coupling capacitance. Each sensing channel is essentially the same in area, but their routing patterns vary. The coupling capacitance at the near end (where the routing is shorter) and the coupling capacitance at the far end are often distributed in a certain pattern. This pattern is a physical property of the screen and has nothing to do with the screen display. The pattern often appears as a straight line, a parabola, or other irregular shapes. However, even with a simple linear relationship, due to process variations, it is impossible to obtain a precise relationship between the capacitances using a simple proportional relationship. Considering that the coupled noise of each sensing channel is related to the coupling capacitance, the noise introduced by the LCD layer of the touch screen will have different values ​​after coupling to each sensing channel. Therefore, a corresponding compensation gain is set for each sensing channel. The compensation gain is used to compensate for the noise of each sensing channel so that the noise level of each sensing channel after compensation is consistent, thereby ensuring that the capacitance values ​​coupled to each sensing channel remain consistent after increasing the compensation gain.

[0032] It should be noted that the consistency of the noise levels of each sensing channel after compensation can mean that the noises of each sensing channel are equal after compensation gain compensation, or that the noises of each sensing channel are at the same level after compensation gain compensation, or that the noises of each sensing channel are within a preset range after compensation gain compensation. The specific consistency range of the specific noise levels can be determined according to actual needs, and this application does not make any specific limitations.

[0033] Step 102: obtaining a second capacitance value output by each sensing channel, and multiplying the second capacitance value by a compensation gain corresponding to each sensing channel to obtain a compensation capacitance value.

[0034] Specifically, regardless of whether each area of ​​the touch screen is touched, the second capacitance value output by each sensing channel is directly obtained. At this time, when there is no touch in the area, the effective signal is 0, and the obtained second capacitance value may only represent the noise value, or when there is a touch in the area, the second capacitance value obtained is the sum of the noise value and the effective signal generated by the touch. This application does not impose any specific restrictions on the second capacitance value, and the second capacitance value is multiplied by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value.

[0035] Step 103: performing differential processing using the compensation capacitance value of each sensing channel to obtain a differential signal, and performing differential recovery on the differential signal to obtain a valid signal of each sensing channel.

[0036] Specifically, the second capacitance value is multiplied by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value, which means that the noise contained in the second capacitance value is also multiplied by the compensation gain. Because the compensation gain compensates for the noise of each sensing channel, the noise level of each sensing channel after compensation is consistent. Therefore, when using the compensation capacitance value for differentiation, the noise level of the second capacitance with the same noise level after compensation gain can be completely suppressed during differentiation, thereby obtaining a differential signal. The differential signal can then be differentially restored to obtain the effective signal of each sensing channel.

[0037] The above-mentioned embodiment of the present application sets a corresponding compensation gain for each sensing channel. Taking into account the differences between each channel, the amount of coupled noise in each channel will be different. However, by setting a compensation gain for each channel to compensate for the noise of each sensing channel, the noise level of each sensing channel after compensation is consistent, thereby accurately balancing the noise differences of each sensing channel. The second capacitance value output by each sensing channel is obtained, and the second capacitance value is multiplied by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value. The compensation capacitance value of each sensing channel is used to directly select the sensing channel that is farther apart for differential processing, thereby ensuring signal sensitivity. Moreover, since the noise level of each sensing channel after compensation is consistent, the differential result obtained by differential processing can completely suppress the common-mode noise of each channel, further recovering and detecting accurate and effective signals.

[0038] Another embodiment of the present application relates to a signal detection method applied to a touch screen. The signal detection method applied to a touch screen in this embodiment supplements and refines the above-mentioned embodiment, and specifically includes the following contents.

[0039] In one example, the process of determining the compensation gain may be as follows: when the entire screen is in a bright screen state, obtaining the first capacitance value output by the sensing channel of each screen area when the screen area is not touched; the compensation gain of each sensing channel is the same as the product obtained by multiplying the normalized first capacitance value of the channel.

[0040] Specifically, when the entire touch screen is in a bright state, the first capacitance value output by the sensing channel of each screen area when the screen area is not touched is obtained. The untouched screen areas can occur simultaneously, that is, the screen areas are untouched within the same time period; or partial areas of the screen are touched, and the first capacitance value output by the sensing channel of each screen area when the screen area is not touched can be obtained by accumulating multiple times. This application does not limit whether the first capacitance value output by the sensing channel of each screen area when the screen area is not touched is obtained once or multiple times.

[0041] When each screen area is not touched, the first capacitance value output by the sensing channel of the screen area is obtained. The first capacitance value is measured without external signal transmission. At this time, the first capacitance value of each sensing channel is the noise caused by the LCD layer of the touch screen. When the screen is displayed, due to the influence of the periodic horizontal and vertical synchronization signals, the touch screen will be affected by display noise interference. This noise will be coupled to each sensing channel through the coupling capacitance between the active pen and the sensing electrode. It should be noted that the touch in each embodiment of the present application refers to the touch performed by the active pen unless otherwise specified.

[0042] Specifically, there may be multiple sets of compensation gains that can all satisfy the requirement that the product obtained by multiplying the compensation gain of each sensing channel by the normalized first capacitance value of the channel is the same, and there is a multiple relationship between the multiple sets of compensation gains. Any set of compensation gains can be selected for subsequent calculations, and this application does not impose any restrictions on this. When the first capacitance value of each sensing channel is obtained after multiple acquisitions, the capacitance values ​​obtained multiple times for the same channel may be different. Therefore, the multiple acquired capacitance values ​​are normalized to obtain the normalized first capacitance value of each sensing channel, so that the compensation gain can be set according to the normalized first capacitance value, and the compensation standard is more unified.

[0043] In one example, obtaining the first capacitance value output by the sensing channel of each screen area when the screen area is not touched includes: when the entire screen is not touched, using a preset graphic as a display graphic of the touch screen, and obtaining the first capacitance values ​​output by all the sensing channels at once; obtaining the normalized first capacitance value of the sensing channel includes: using the first capacitance values ​​output by all the sensing channels obtained at once as the normalized first capacitance value of the sensing channel.

[0044] Specifically, the entire screen is untouched, the screen is in a lit state, and a preset graphic is used as the display graphic of the touch screen. The preset graphic can be a graphic with obvious noise, such as zebra stripes, checkerboard, etc., and the first capacitance value output by each sensing channel is read at one time. Since the first capacitance value output by each sensing channel is obtained at one time, no additional normalization is required. Therefore, the first capacitance value output by all sensing channels obtained at one time can be used as the normalized first capacitance value of the sensing channel. At the same time, since the entire screen is not touched at this time, the effective signal received by each sensing channel is 0, and the output is completely a noise value, that is, the first capacitance value is used to represent the noise value of each sensing channel.

[0045] In another example, obtaining the first capacitance value output by the sensing channel of each screen area when the screen area is not touched includes: when different areas of the entire screen are touched multiple times, obtaining the first capacitance value output by the sensing channel corresponding to the untouched area each time; wherein the total set of sensing channels corresponding to each first capacitance value obtained includes all sensing channels corresponding to the entire screen; and there is at least one sensing channel among the sensing channels corresponding to any first capacitance value obtained at any time that is included in the sensing channels corresponding to at least one other first capacitance value obtained at least once.

[0046] Obtaining a normalized first capacitance value of the sensing channel includes normalizing the first capacitance values ​​output by each sensing channel based on a proportional relationship between the first capacitance values ​​output by each sensing channel obtained at the same time, among the first capacitance values ​​output by the sensing channel obtained at each time, and based on a proportional relationship between the first capacitance values ​​output by the same sensing channel obtained at least twice, to obtain a normalized first capacitance value corresponding to each sensing channel.

[0047] Specifically, when it is not possible to provide an environment where the entire screen is touch-free, the output value of each sensing channel can be obtained multiple times in the presence of touch to obtain the normalized first capacitance value corresponding to each sensing channel. Considering that even if there is a touch, the touch area generally does not cover the entire screen, it is possible to select the untouched area in real time to obtain the first capacitance value corresponding to its sensing channel, and repeat the acquisition multiple times until the total set of sensing channels corresponding to each first capacitance value obtained contains all sensing channels corresponding to the entire screen. Moreover, in any sensing channel corresponding to the first capacitance value obtained at least once, there is at least one sensing channel included in the sensing channel corresponding to the first capacitance value obtained at least once in other acquisitions, so that the first capacitance values ​​corresponding to all sensing channels obtained twice are normalized by the two first capacitance values ​​corresponding to the sensing channels repeatedly obtained in the two acquisitions.

[0048] Specifically, the normalization process is to adjust the first capacitance values ​​obtained in multiple times to a unified evaluation index, based on the proportional relationship between the first capacitance values ​​output by each sensing channel in the first capacitance values ​​obtained in each sensing channel, and based on the proportional relationship between the first capacitance values ​​obtained by the same sensing channel in at least two acquisitions of the same sensing channel, the first capacitance values ​​output by each sensing channel are normalized to obtain the normalized first capacitance value corresponding to each sensing channel. For example, if there are sensing channels A, B, C, D, and E, when sensing channels C, D, and E are not touched, first capacitance values ​​D3, D4, and D5 of sensing channels C, D, and E are obtained; if sensing channels A, B, and C are not touched in another time, first capacitance values ​​D1, D2, and D3' of sensing channels A, B, and C are obtained. If sensing channel C overlaps in the sensing channels corresponding to the two first capacitance values, the first capacitance values ​​of sensing channels A, B, C, D, and E are normalized with sensing channel C as the connection. Specifically, normalization can be performed from sensing channels C, D, and E to sensing channels A, B, and C, or from sensing channels A, B, and C to sensing channels C, D, and E. This application does not limit the direction of normalization. Here, taking the normalization of sensing channels A, B, and C to sensing channels C, D, and E as an example, the first capacitance values ​​D1, D2, and D3' of sensing channels A, B, and C are multiplied by D3 / D3' to obtain the first capacitance value normalized with sensing channels C, D, and E.

[0049] In another example, before multiplying the second capacitance value by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value in step 102, the method further includes: when the entire screen is in an off state and is not touched, obtaining the capacitance value output by each sensing channel as a reference compensation value, and adding the reference compensation value to the second capacitance value; multiplying the second capacitance value by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value, including: multiplying the second capacitance value after adding the reference compensation value by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value.

[0050] Specifically, considering that the amount of noise coupling in each channel may have different gains and different reference values ​​due to process and structural problems, this embodiment obtains the capacitance value output by each sensing channel when the touch screen is off and the entire screen is not touched as a reference compensation value, and adds the reference compensation value to the second capacitance value. Specifically, the second capacitance value is the sum of the noise value and the effective signal of each sensing channel. The second capacitance value after adding the reference compensation value is multiplied by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value.

[0051] Furthermore, after obtaining the compensation capacitance value, the compensation capacitance value of each sensing channel can be used to perform differential processing to obtain a differential signal, and the differential signal can be differentially restored to obtain the effective signal of each sensing channel. For example, as shown in Figure 3, the process of obtaining the effective signal of the sensing channel is as follows: Assuming that the touch occurs near Y2, the sensing channels Y1 to Y7 receive effective signals S1 to S7 respectively, and noise (normalized first capacitance value) N1 to N7, and the compensation gain of each sensing channel is g1 to g7 respectively. At this time, the second capacitance values ​​of the sensing channels Y1 to Y7 are S1+N1, S2+N2, ..., S7+N7 respectively. Due to the characteristics of the touch signal itself, the farther Y6 channel basically does not contain a valid signal. The effective signal can be considered to be 0, and the amplitude of the common-mode noise N1 to N7 is not completely equal. To eliminate noise, conventional means directly use Y2 and Y6 for differential when no compensation gain is set, that is, Y2-Y6=(S2+N2) (0+N6)=S2+(N2-N6). The obtained differential signal contains noise that is not completely eliminated, and the effective signal detected by the differential signal is not accurate. However, by performing differential processing through the solution of the above embodiment of the present application, it is first necessary to obtain the compensation capacitance values ​​g2*(S2+N2) and g6*(0+N6) of Y2 and Y6, and perform differential processing: Y2-Y6=g2*(S2+N2) g6*(0+N6)=g2*S2. The obtained differential signal can completely eliminate noise, and since the compensation gain g2 in the differential signal g2*S2 is known, an accurate effective signal S2 can be obtained. In addition, the present application does not limit the selection of the sensing channel by introducing the compensation gain and performing differential processing. Whether the sensing channel is close or far, the signal sensitivity advantage can be maintained without reducing the noise suppression effect.

[0052] The above embodiment of the present application is to obtain the first capacitance value of each sensing channel once or multiple times, so that the first capacitance value of each sensing channel can be obtained in various environments, and the obtained capacitance value is normalized, and the first capacitance value obtained multiple times is adjusted to a unified evaluation index, so that the noise can be completely offset when the difference is subsequently combined with the compensation gain. By introducing the compensation gain and then performing differential processing, the selection of the sensing channel is not restricted. Regardless of whether the sensing channel is close or far away, the signal sensitivity advantage can be maintained without reducing the noise suppression effect. At the same time, considering that each channel may have different reference values ​​due to process and structural problems, a reference compensation value is introduced. Before obtaining the compensation capacitance value, the reference compensation value is added to the second capacitance value of each sensing channel to update the second capacitance value, so as to obtain a more accurate effective signal value after subsequent differentiation.

[0053] Yet another embodiment of the present application relates to a touch screen, as shown in Figures 4 and 5, comprising: a glass cover plate 7, an LCD 9, and a sensing channel layer 8 located between the glass cover plate 7 and the LCD 9; the output end of each sensing channel of the sensing channel layer 8 is connected to a multiplier 10, and the multiplier 10 is used to multiply a compensation gain by a second capacitance value output by each sensing channel to obtain a compensation capacitance value. The compensation capacitance value of each sensing channel is used for differential processing to obtain a differential signal, and the differential signal is used for differential recovery to obtain a valid signal of each sensing channel; wherein the compensation gain satisfies that after compensating for the noise of each sensing channel, the compensated noise level of each sensing channel is consistent.

[0054] Specifically, as shown in FIG4 , the glass cover plate 7, the LCD 9, and the sensing channel layer 8 located between the glass cover plate 7 and the LCD 9, wherein the sensing channel layer 8 can be a single layer or multiple layers, and this application does not impose any specific restrictions thereto. The active pen can transmit an effective signal to the sensing channel layer 8 by touching the glass cover plate 7.

[0055] As shown in FIG5 , the output end of each sensing channel of the sensing channel layer 8 is connected to a multiplier 10, which multiplies each compensation gain (g1, g2, g3, g4, g5) by the second capacitance value output by each sensing channel to obtain a compensation capacitance value. The compensation capacitance values ​​of two or two groups of sensing channels are processed by an operational amplifier 11, such as a differential operation, to ultimately obtain a valid signal. The valid signal value can be used to determine the coordinates of the active pen. The above process can be implemented in an analog circuit or a digital circuit, and this application does not specifically limit the implementation environment of the solution.

[0056] Specifically, the detailed steps for compensating the capacitance value have been recorded in the aforementioned embodiments of the signal detection method applied to the touch screen, and will not be repeated herein.

[0057] In one example, the sensing channel layer 8 includes a first direction sensing channel layer 81 and a second direction sensing channel layer 82 , and the first direction is perpendicular to the second direction.

[0058] Specifically, the first direction sensing channel layer 81 and the second direction sensing channel layer 82 can be orthogonal X-direction sensing channel layers and Y-direction sensing channel layers, respectively. When the first direction sensing channel layer is the X-direction sensing channel layer, the second direction sensing channel layer is the Y-direction sensing channel layer; and when the first direction sensing channel layer is the Y-direction sensing channel layer, the second direction sensing channel layer is the X-direction sensing channel layer. It should be noted that the signal detection method in this application is applicable to the sensing channels of the first direction sensing channel layer and the sensing channels of the second direction sensing channel layer.

[0059] In another example, in the analog circuit, there may be an adder between the output end of each sensing channel of the sensing channel layer and the multiplier 10 connected thereto. The adder is used to add the reference compensation value to the second capacitance value, so that the second capacitance value after adding the reference compensation value is input into the multiplier 10 and multiplied by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value. It should be noted that the above-mentioned process of adding the reference compensation value to the second capacitance value and obtaining the compensation capacitance value with the compensation gain corresponding to each sensing channel can also be implemented in a digital circuit. The specific process of obtaining the reference compensation value has been recorded in the above embodiment and will not be repeated in this application.

[0060] Another embodiment of the present application relates to an electronic device, as shown in Figure 6, including at least one processor 202; and a memory 201 communicatively connected to the at least one processor 202; wherein the memory 201 stores instructions that can be executed by the at least one processor 202, and the instructions are executed by the at least one processor 202 to enable the at least one processor 202 to execute any of the above-mentioned signal detection method embodiments applied to a touch screen.

[0061] The memory 201 and processor 202 are connected using a bus. The bus can include any number of interconnected buses and bridges, connecting one or more processors 202 and various circuits of the memory 201. The bus can also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits. These are all well known in the art and are therefore not described further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single component or multiple components, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by the processor 202 is transmitted over a wireless medium via an antenna. Furthermore, the antenna receives data and transmits it to the processor 202.

[0062] The processor 202 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. The memory 201 can be used to store data used by the processor 202 when performing operations.

[0063] Another embodiment of the present invention relates to a computer-readable storage medium storing a computer program, which, when executed by a processor, implements any of the above-mentioned signal detection method embodiments for a touch screen.

[0064] That is, those skilled in the art will understand that all or part of the steps in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a program, which is stored in a storage medium and includes a number of instructions for causing a device (which may be a single-chip microcomputer, chip, etc.) or a processor 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: a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc., various media that can store program code.

[0065] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present application, and that in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.

Claims

1. A signal detection method applied to a touch screen, comprising: Setting a compensation gain for each sensing channel of the touch screen, wherein the compensation gain is used to compensate for the noise of each sensing channel so that the noise level of each sensing channel after compensation is consistent; Acquire a second capacitance value output by each sensing channel, and multiply the second capacitance value by the compensation gain corresponding to each sensing channel to obtain a compensation capacitance value; The differential signal is obtained by performing differential processing using the compensation capacitance value of each sensing channel, and the differential signal is differentially restored to obtain the effective signal of each sensing channel.

2. The signal detection method applied to a touch screen according to claim 1, wherein: Determining the compensation gain includes: In a full screen on state, when each screen area is not touched, obtaining a first capacitance value output by a sensing channel of the screen area; The compensation gain of each sensing channel is the same as a product obtained by multiplying the normalized first capacitance value of the channel.

3. The signal detection method applied to a touch screen according to claim 2, wherein: The step of obtaining a first capacitance value output by a sensing channel of each screen area when the screen area is not touched includes: When the entire screen is not touched, a preset pattern is used as a display pattern of the touch screen, and the first capacitance values ​​output by all sensing channels are obtained at one time; Acquiring the normalized first capacitance value of the sensing channel includes: The first capacitance value outputted by all sensing channels acquired at one time is used as the normalized first capacitance value of the sensing channel.

4. The signal detection method applied to a touch screen according to claim 2, wherein: The step of obtaining a first capacitance value output by a sensing channel of each screen area when the screen area is not touched includes: When touching different areas of the entire screen for multiple times, a first capacitance value output by a sensing channel corresponding to an area that is not touched is obtained for each time; wherein the total set of sensing channels corresponding to the first capacitance values ​​obtained each time includes all sensing channels corresponding to the entire screen; and at least one sensing channel among the sensing channels corresponding to any one time of obtaining the first capacitance value is included in the sensing channels corresponding to at least one other time of obtaining the first capacitance value; Acquiring the normalized first capacitance value of the sensing channel includes: Based on the first capacitance values ​​output by the sensing channels obtained at each time, the proportional relationship between the first capacitance values ​​output by the sensing channels obtained at the same time, and the proportional relationship between the first capacitance values ​​of the sensing channel obtained at least twice for the same sensing channel, the first capacitance values ​​output by the sensing channels are normalized to obtain The normalized first capacitance value corresponding to each sensing channel.

5. The signal detection method applied to a touch screen according to claim 2, wherein: The first capacitance value is used to characterize the noise value of each sensing channel; the second capacitance value is the sum of the noise value of each sensing channel and the effective signal.

6. The method according to claim 1, wherein: Before multiplying the second capacitance value by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value, the method further includes: When the entire screen is in an off state and is not touched, obtaining a capacitance value output by each sensing channel as a reference compensation value, and adding the reference compensation value to the second capacitance value; The step of multiplying the second capacitance value by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value includes: multiplying the second capacitance value after adding the reference compensation value by the compensation gain corresponding to each sensing channel to obtain the compensation capacitance value.

7. A touch screen, wherein: include: A glass cover plate, an LCD, and a sensing channel layer located between the glass cover plate and the LCD; The output end of each sensing channel of the sensing channel layer is connected to a multiplier, and the multiplier is used to multiply the compensation gain with the second capacitance value output by each sensing channel to obtain a compensation capacitance value, and the compensation capacitance value of each sensing channel is used to perform differential processing to obtain a differential signal, and the differential signal is used to perform differential recovery to obtain a valid signal of each sensing channel; wherein, the compensation gain satisfies that after compensating for the noise of each sensing channel, the noise level of each sensing channel after compensation is consistent.

8. The touch screen according to claim 7, wherein: The sensing channel layer includes a first direction sensing channel layer and a second direction sensing channel layer, and the first direction is perpendicular to the second direction.

9. An electronic device, comprising: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can perform the signal detection method applied to a touch screen according to any one of claims 1 to 6. 10 . A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the signal detection method for a touch screen according to claim 1 .

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