CN117389434B - Signal detection method applied to touch screen, device and storage medium - Google Patents
Signal detection method applied to touch screen, device and storage medium Download PDFInfo
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- 230000006698 induction Effects 0.000 claims abstract description 139
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/0416—Control or interface arrangements specially adapted for digitisers
- G06F3/0418—Control or interface arrangements specially adapted for digitisers for error correction or compensation, e.g. based on parallax, calibration or alignment
- G06F3/04182—Filtering of noise external to the device and not generated by digitiser components
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
Abstract
The embodiment of the application relates to the technical field of touch screens, and discloses a signal detection method applied to a touch screen, the touch screen, equipment and a storage medium. The method comprises the following steps: setting compensation gains for all induction channels of the touch screen, wherein the compensation gains are used for compensating noise of all induction channels so as to enable the noise levels of all induction channels after compensation to be consistent; obtaining a second capacitance value output by each induction channel, and multiplying the second capacitance value by a compensation gain corresponding to each induction channel to obtain a compensation capacitance value; and carrying out differential processing by using the compensation capacitance value of each induction channel to obtain differential signals, and carrying out differential recovery on the differential signals to obtain effective signals of each induction channel. According to the method and the device, the corresponding compensation gain is set for each induction channel, so that the difference between the induction channels is compensated and balanced, the noise is completely eliminated when the difference is achieved, and the effective signals are accurately detected.
Description
Technical Field
The embodiment of the application relates to the technical field of touch screens, in particular to a signal detection method applied to a touch screen, the touch screen, equipment and a storage medium.
Background
Capacitive touch screens have been widely used in various electronic products, and are commonly used to receive a touch signal by using two sensing electrodes in two directions, so as to locate a touch position. The traditional capacitive screen mainly detects finger touch, and along with the increase of human-computer interaction experience modes, the application of a capacitive active pen appears, and the detection principle is similar to the finger touch process. On the other hand, LCD (liquid crystal display)/Amoled (active matrix organic light emitting diode) screens have screen noise when they are lit, and this noise interferes with the touch signal. Because the tip of the active pen is very small, the amount of signal that can be sensed is inherently limited, and is weaker in certain application scenarios (such as suspension). Therefore, when the active pen is applied to a touch screen, the interference caused by screen noise display needs to be reduced as much as possible.
Some previous studies have shown that the interference in the screen display is essentially common mode noise interference, and the prior art often uses the difference between the signals of different sensing channels to remove such interference. However, because of the differences among the channels, the differential channels must be carefully selected according to different application scenes, but the scene judgment brings additional workload, and the influence caused by the channel differences still cannot be thoroughly solved.
Disclosure of Invention
An object of the embodiment of the present application is to provide a signal detection method, a touch screen, a device and a storage medium applied to the touch screen, in which a corresponding compensation gain is set for each sensing channel so as to compensate and balance the difference between the sensing channels, so as to achieve the purpose of completely eliminating noise during the difference, and realize accurate detection of an effective signal transmitted by an active pen.
In order to solve the above technical problems, an embodiment of the present application provides a signal detection method applied to a touch screen, including:
setting compensation gains for all induction channels of the touch screen, wherein the compensation gains are used for compensating noise of all induction channels so as to enable the noise levels of all induction channels after compensation to be consistent;
obtaining a second capacitance value output by each induction channel, and multiplying the second capacitance value by the compensation gain corresponding to each induction channel to obtain a compensation capacitance value;
and carrying out differential processing by using the compensation capacitance value of each induction channel to obtain differential signals, and carrying out differential recovery on the differential signals to obtain effective signals of each induction channel.
The embodiment of the application also provides a touch screen, which comprises: a glass cover plate, an LCD and an induction channel layer positioned between the glass cover plate and the LCD; the output end of each induction channel of the induction channel layer is connected with a multiplier, the multiplier is used for multiplying the compensation gain with a second capacitance value output by each induction channel to obtain a compensation capacitance value, the compensation capacitance value of each induction channel is used for carrying out differential processing to obtain a differential signal, and the differential signal is used for carrying out differential recovery to obtain an effective signal of each induction channel; the compensation gain satisfies that the noise level of each induction channel after compensation is consistent.
In addition, the sense channel layer as described above includes a first direction sense channel layer and a second direction sense channel layer, the first direction being perpendicular to the second direction.
The embodiment of the invention also provides electronic equipment, which comprises:
at least one processor; the method comprises the steps of,
a memory communicatively coupled to the at least one processor; wherein,
the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the signal detection method as described above for a touch screen.
Embodiments of the present invention also provide a computer-readable storage medium storing a computer program which, when executed by a processor, implements a signal detection method as described above applied to a touch screen.
According to the signal detection method applied to the touch screen, the corresponding compensation gains are set for the induction channels, the difference of the noise quantity of the coupling of each channel is considered, but the noise of each induction channel is compensated by setting the compensation gains for each channel, the noise level after compensation of each induction channel is consistent, and therefore the noise difference of each induction channel is accurately balanced. Obtaining a second capacitance value output by each induction channel, multiplying the second capacitance value by compensation gain corresponding to each induction channel to obtain a compensation capacitance value, and directly selecting the induction channels with far intervals to perform differential processing by using the compensation capacitance values of each induction channel, so that the signal sensitivity is ensured; and because the noise levels of the sensing channels after compensation are consistent, the noise of each channel can be completely restrained by the differential result obtained by differential processing, and more accurate original effective signals can be further recovered and detected.
In addition, determining the compensation gain includes: under the full screen bright state, when each screen area is not touched, acquiring a first capacitance value output by an induction channel of the screen area; the compensation gain of each induction channel is the same as the product obtained by multiplying the normalized first capacitance value of the channel.
In addition, when each screen area is not touched, acquiring a first capacitance value output by a sensing channel of the screen area, including: taking a preset graph as a display graph of the touch screen in a state that the whole screen is not touched, and acquiring the first capacitance values output by all the sensing channels at one time; the obtaining the normalized first capacitance value of the sensing channel includes: and taking the first capacitance values output by all the sensing channels obtained at one time as the normalized first capacitance values of the sensing channels. Therefore, the first capacitance values of all the induction channels can be obtained at one time, and because the first capacitance values of all the induction channels are obtained at one time, the step of independently normalizing is omitted, and the normalized first capacitance values are obtained directly.
In addition, the acquiring the first capacitance value output by the sensing channel of each screen area when the screen areas are not touched includes: when different areas of the whole screen are touched for multiple times, acquiring a first capacitance value output by an induction channel corresponding to each area which is not touched; the total set of the induction channels corresponding to the first capacitance value obtained each time comprises all induction channels corresponding to the whole screen; and at least one induction channel in the induction channels corresponding to the first capacitance value obtained at any time is included in the induction channels corresponding to the first capacitance value obtained at least once; the obtaining the normalized first capacitance value of the sensing channel includes: and normalizing the first capacitance value output by each induction channel based on the proportional relation between the first capacitance values output by each induction channel acquired at the same time and the proportional relation between the first capacitance values acquired by the induction channel at least twice based on the same induction channel, so as to obtain the normalized first capacitance value corresponding to each induction channel. Therefore, the normalized first capacitance value of each sensing channel can be acquired for multiple times under the condition of touching, an environment without touching does not need to be prepared independently, and normal use of the touch screen is not affected.
In addition, the first capacitance value is used for representing the noise value of each induction channel; the second capacitance value is the sum of the noise value and the effective signal of each sensing channel as described above.
In addition, before the second capacitance value is multiplied by the compensation gain corresponding to each sensing channel to obtain a compensation capacitance value, the method further includes: when the whole screen is in a screen-off state and is not touched, acquiring capacitance values output by all sensing channels as reference compensation values, and adding the reference compensation values into the second capacitance values; the step of multiplying the second capacitance value by the compensation gain corresponding to each sensing channel to obtain a compensation capacitance value includes: and multiplying the second capacitance value added with the reference compensation value by the compensation gain corresponding to each induction channel to obtain a compensation capacitance value. Further considering the difference of each channel due to the technical problem and the structural problem, the effective signal finally obtained is more accurate by introducing the reference compensation value.
Drawings
One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings.
FIG. 1 is a schematic diagram of a touch screen signal detection structure of the prior art;
fig. 2 is a flowchart of a signal detection method applied to a touch screen according to an embodiment of the present application;
FIG. 3 is a schematic diagram of a signal detection process provided in an embodiment of the present application;
fig. 4 is a schematic structural diagram of a touch screen according to an embodiment of the present application;
fig. 5 is a schematic structural diagram of a touch screen according to a second embodiment of the present disclosure;
fig. 6 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the following detailed description of the embodiments of the present invention will be given with reference to the accompanying drawings. However, those of ordinary skill in the art will understand that in various embodiments of the present invention, numerous technical details have been set forth in order to provide a better understanding of the present application. However, the technical solutions claimed in the present application can be implemented without these technical details and with various changes and modifications based on the following embodiments.
It should be noted that, the terms "upper", "lower", "left", "right", and the like in the embodiments of the present application are described in terms of the angles shown in the drawings, and should not be construed as limiting the embodiments of the present application. In the context of this document, it will also be understood that when an element is referred to as being "on" or "under" another element, it can be directly on the other element or be indirectly on the other element through intervening elements.
In the conventional touch screen detection system, as shown in fig. 1, the touch screen is generally composed of two groups of sensing electrodes orthogonal to each other, and other manners of forming the touch screen, such as a single-layer triangle, a single-layer curve, etc., are described herein by using the most common orthogonal electrodes. In fig. 1, the touch screen 1 is in a common operation mode, such as a mutual capacitance sensing mode, electrodes in one direction are configured as driving segments, and are driven by the driving circuit 2. The other direction is configured as a receiving end, and the sensing amount is supplied to the receiving circuit 3. The receiving circuit 3 processes (e.g. filters, gains, etc.) the sensing signal, sends it to the analog-to-digital converter 4, and then goes to the digital unit processor 5 for processing. Timing control, gain configuration, etc. of the receiving circuit 3 and the driving circuit 2 are also typically performed by the digital unit processor 5. In fig. 1, the touch event 6 may be performed by a finger or by an active pen or other capacitive sensing material. When the touch event 6 is a touch event performed by the active pen, the driving circuit 2 in fig. 1 is also configured as a receiving circuit, and two receiving circuits in two directions exist at this time, and receive the sensing signals simultaneously or in a time-sharing manner, and calculate the coordinates of the touch position of the actual active pen according to the received sensing signals in the two directions.
When the active pen contacts the touch screen, the sensing amount (capacitance) of the sensing electrode is changed, so that the receiving circuit can receive the sensing signal. The capacitance change of the sensing electrode caused by the active pen is mainly generated through the coupling capacitance between the active pen and the sensing electrode, when the active pen is positioned at different positions of the touch screen, the coupling capacitance between the active pen and each sensing channel of the sensing electrode is different, so that the electric charge quantity of the excitation power supply of the active pen coupled to each electrode is also different, and the receiving circuit determines the position of the active pen according to the electric charge distribution. However, in the process of receiving the sensing signal, the LCD layer of the touch screen may cause display noise interference to the touch screen due to the influence of the periodic line field synchronizing signal, and the noise is also coupled to the sensing electrode through the coupling capacitance between the active pen and the sensing electrode.
However, the coupling capacitances between the sensing channels of the sensing electrodes cannot be identical due to the process deviation between the sensing channels and the wirings, and the larger the process deviation is, the larger the difference is. In general, the farther the channel interval is, the larger the difference is, and then the error is inevitably brought by directly using the differential subtraction method, if the channel difference is too large, the noise cancellation effect is too bad, and the differential method cannot exert the due noise cancellation effect.
The embodiment of the application relates to a signal detection method applied to a touch screen, as shown in fig. 2, and the signal detection method applied to the touch screen in the embodiment specifically includes the following steps.
Step 101: and setting compensation gains for all the sensing channels of the touch screen, wherein the compensation gains are used for compensating the noise of all the sensing channels so as to ensure that the noise levels of all the sensing channels after compensation are consistent.
Specifically, as previously described, the noise of the coupling of each inductive channel is related to the coupling capacitance. The area of each sensing channel is basically the same, but the routing is not limited to be different. The coupling capacitance of the near end (with shorter wiring) and the coupling capacitance of the far end are often distributed in a certain rule, and the rule belongs to the physical characteristics of the screen body and is irrelevant to the screen display picture. The law of which tends to present a straight line, or a parabola, or other irregular pattern. However, even with a simple linear relationship, it is not possible to obtain an accurate relationship between the capacitors with a simple proportional relationship due to process variations. The fact that the coupled noise of each sensing channel is related to the coupling capacitance is considered, the values of the noise brought by the LCD layer of the touch screen after being coupled to each sensing channel are different, and therefore corresponding compensation gains are set for each sensing channel and used for compensating the noise of each sensing channel, so that the noise levels after compensation of each sensing channel are consistent, and accordingly the consistency of the capacitance values coupled to each sensing channel after the compensation gains are increased is guaranteed.
It should be noted that, the noise levels after compensation of the sensing channels are identical, that is, the noise of each sensing channel is equal after compensation of the compensation gain, that the noise of each sensing channel is in the same magnitude after compensation of the compensation gain, and that the noise of each sensing channel is in a preset range after compensation of the compensation gain. The specific noise level consistency can determine a specific consistency range according to actual requirements, and the application is not particularly limited.
Step 102: and obtaining a second capacitance value output by each induction channel, and multiplying the second capacitance value by the compensation gain corresponding to each induction channel to obtain a compensation capacitance value.
Specifically, whether each area of the touch screen is touched is not considered, the second capacitance value output by each sensing channel is directly obtained, at this time, under the condition that the area is not touched, the effective signal is 0, the obtained second capacitance value may only represent the noise value, or under the condition that the area is touched, the obtained second capacitance value is the sum of the noise value and the effective signal generated by the touch.
Step 103: and carrying out differential processing by using the compensation capacitance value of each induction channel to obtain differential signals, and carrying out differential recovery on the differential signals to obtain effective signals of each induction channel.
Specifically, the second capacitance value is multiplied by the compensation gain corresponding to each sensing channel to obtain a compensation capacitance value, which means that noise included in the second capacitance value is also multiplied by the compensation gain. Because the compensating gain compensates the noise of each induction channel, the noise levels of the compensated induction channels are consistent, in the process of carrying out difference by using the compensating capacitance value, the noise with consistent levels can be completely restrained when the second capacitance with consistent noise levels is subjected to difference after compensating gain compensation, so as to obtain a differential signal, and the differential signal is subjected to difference recovery, so that the effective signal of each induction channel can be obtained.
Compared with the related art, in the embodiment of the application, the corresponding compensation gain is set for each induction channel, and the noise quantity of the coupling of each channel is different in consideration of the difference between the channels, but the noise of each induction channel is compensated by setting the compensation gain for each channel, so that the noise level after the compensation of each induction channel is consistent, and the noise difference of each induction channel is accurately balanced. Obtaining a second capacitance value output by each induction channel, multiplying the second capacitance value by compensation gain corresponding to each induction channel to obtain a compensation capacitance value, and directly selecting the induction channels with far intervals to perform differential processing by using the compensation capacitance values of each induction channel, so that the signal sensitivity is ensured; and because the noise levels of the sensing channels after compensation are consistent, the differential result obtained by differential processing can completely inhibit common mode noise of the channels, and accurate effective signals can be further recovered and detected.
Another embodiment of the present invention relates to a signal detection method applied to a touch screen, and the signal detection method applied to the touch screen in this embodiment is complementary and refined to the foregoing embodiment, and specifically includes the following matters.
In one example, the process of determining the compensation gain may be: under the full screen bright state, when each screen area is not touched, acquiring a first capacitance value output by an induction channel of the screen area; the compensation gain of each induction channel is the same as the product obtained by multiplying the normalized first capacitance value of the channel.
Specifically, when the whole screen of the touch screen is in a bright screen state, a first capacitance value output by a sensing channel of each screen area is obtained when the screen area is not touched. The screen areas not being touched may occur simultaneously, i.e., the screen areas not being touched within the same time period; or a part of the screen area is touched, and the first capacitance value output by the sensing channel of each screen area can be acquired through multiple times of accumulation.
When each screen area is not touched, a first capacitance value output by the sensing channel of the screen area is obtained, the first capacitance value is measured under the condition that no external signal is transmitted, and at the moment, the first capacitance value of each sensing channel is noise brought by the LCD layer of the touch screen. When the screen is displayed, display noise interference is brought to the touch screen due to the influence of the periodic line field synchronous signals, and the noise is coupled to each sensing channel through the coupling capacitance between the active pen and the sensing electrode. In the present embodiment, the touch is performed by the active pen unless otherwise specified.
Specifically, there may be multiple groups of compensation gains that can all satisfy the product obtained by multiplying the compensation gain of each sensing channel by the normalized first capacitance value of the channel, and multiple relationships exist among the multiple groups of compensation gains, so that any group of compensation gains can be taken to participate in subsequent calculation, which is not limited in the application. When the first capacitance value of each induction channel is obtained through multiple times of acquisition, the capacitance values obtained for multiple times of the same channel may be different, so that the capacitance values obtained for multiple times are normalized to obtain the normalized first capacitance value of each induction channel, so that the compensation gain is set according to the normalized first capacitance value, and the compensation standard is more uniform. In one example, acquiring a first capacitance value output by a sense channel of each screen region when the screen region is not touched includes: in a state that the whole screen is not touched, taking a preset pattern as a display pattern of the touch screen, and acquiring first capacitance values output by all the sensing channels at one time; the obtaining of the normalized first capacitance value of the sensing channel includes: and taking the first capacitance values output by all the induction channels obtained at one time as normalized first capacitance values of the induction channels.
Specifically, the whole screen is enabled to be free of touch, the screen is enabled to be in a lighting state, a preset pattern is used as a display pattern of the touch screen, the preset pattern can be a pattern with obvious noise, such as a zebra stripe pattern, a checkerboard pattern and the like, is used as a display pattern, and the first capacitance value output by each sensing channel is read at one time. Because the first capacitance value output by each induction channel is obtained once without additional normalization, the first capacitance values output by all the induction channels can be obtained once and used as normalized first capacitance values of the induction channels. Meanwhile, as the whole screen is not touched at this time, the effective signal received by each sensing channel is 0, and the output is the noise value completely, namely the first capacitance value is used for representing the noise value of each sensing channel.
In another example, acquiring a first capacitance value output by a sense channel of each screen region when the screen region is not touched includes: when different areas of the whole screen are touched for multiple times, acquiring a first capacitance value output by an induction channel corresponding to each area which is not touched; the total set of induction channels corresponding to the first capacitance value obtained each time comprises all induction channels corresponding to the whole screen; and at least one induction channel exists in the induction channels corresponding to the first capacitance value obtained at any time and is contained in the induction channels corresponding to the first capacitance value obtained at least once;
the obtaining of the normalized first capacitance value of the sensing channel includes: based on the proportional relation between the first capacitance values output by each induction channel obtained at each time and the proportional relation between the first capacitance values output by each induction channel obtained at the same time and the first capacitance values of the induction channel obtained at least twice by the same induction channel, normalizing the first capacitance values output by each induction channel to obtain normalized first capacitance values corresponding to each induction channel.
Specifically, when the whole screen touchless environment cannot be provided, the normalized first capacitance value corresponding to each sensing channel can be obtained by acquiring the output value of each sensing channel for multiple times under the condition of touching. In consideration of the fact that even if a touch exists, the touch area generally does not spread over the whole screen, therefore, the area which is not touched can be selected in real time to acquire the first capacitance value corresponding to the sensing channel, and the acquisition is repeated for a plurality of times until the total set of sensing channels corresponding to the first capacitance value acquired each time contains all sensing channels corresponding to the whole screen. And at least one induction channel corresponding to the first capacitance value obtained at any time is contained in the induction channels corresponding to the other at least one induction channel corresponding to the first capacitance value obtained at least once, so that the normalization processing is carried out on the first capacitance values corresponding to all the induction channels obtained at the two times through the two first capacitance values corresponding to the induction channels repeatedly obtained in the two times of obtaining.
Specifically, the normalization process is to adjust the first capacitance values acquired for multiple times to a uniform evaluation index, normalize the first capacitance values output by each induction channel based on a proportional relationship between the first capacitance values output by each induction channel acquired at the same time and a proportional relationship between the first capacitance values acquired by the induction channel at least twice based on the same induction channel, and obtain normalized first capacitance values corresponding to each induction channel. For example, if there are sense channels A, B, C, D, E, respectively, the first capacitance values D3, D4, D5 of the sense channel C, D, E are obtained when the sense channel C, D, E is not touched; if the sensing channel A, B, C is not touched, the first capacitance values D1, D2 and D3' of the sensing channel A, B, C are obtained, and the sensing channel C corresponding to the first capacitance value is obtained twice, and the first capacitance value of the sensing channel A, B, C, D, E is normalized by taking the sensing channel C as a connection. Specifically, the normalization may be performed by the sense channel C, D, E to the sense channel A, B, C, and may also be performed by the sense channel A, B, C to the sense channel C, D, E, and the direction of normalization is not limited in this application. Taking sense channel A, B, C as an example for normalization to sense channel C, D, E, the first capacitance values D1, D2, D3 'of sense channel A, B, C are each multiplied by D3/D3' to obtain a first capacitance value normalized to sense channel C, D, E.
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 whole screen is in a screen-off state and is not touched, acquiring capacitance values output by all the sensing channels as reference compensation values, and adding the reference compensation values into second capacitance values;
the second capacitance value is multiplied by the compensation gain corresponding to each sensing channel to obtain a compensation capacitance value, which comprises the following steps: and multiplying the second capacitance value added with the reference compensation value by the compensation gain corresponding to each sensing channel to obtain a compensation capacitance value.
Specifically, considering that each channel has a coupling amount to noise due to a process problem and a structure problem, there may be a difference in not only gain but also a reference value. Therefore, in this embodiment, the capacitance value output by each sensing channel is obtained as the reference compensation value when the touch screen is turned off and the whole screen is not touched, and the reference compensation value is added 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. And multiplying the second capacitance value added with the reference compensation value by the compensation gain corresponding to each sensing channel to obtain a compensation capacitance value.
Further, after the compensation capacitance value is obtained, differential processing can be performed by using the compensation capacitance value of each induction channel to obtain a differential signal, and the differential signal is subjected to differential recovery to obtain an effective signal of each induction channel. For example, as shown in fig. 3, the effective signal process for the sensing channel is as follows: assuming that the touch position is near Y2, the sensing channels Y1-Y7 receive effective signals S1-S7 and noise (normalized first capacitance values) N1-N7, and the compensation gains of the sensing channels are g 1-g 7, and at this time, the second capacitance values of the sensing channels Y1-Y7 are S1+N1, S2+N2, … and S7+N7 in sequence. Because of the characteristics of the touch signal, the far Y6 channel basically does not contain an effective signal, and the effective signal can be considered as 0, and the amplitudes of common-mode noises N1-N7 are not completely equal. In order to eliminate noise, the conventional means directly uses Y2 and Y6 to make difference when the compensation gain is not set, that is, Y2-y6= (s2+n2) - (0+n6) =s2+ (N2-N6), the obtained differential signal contains noise which is not completely eliminated, and the effective signal detected by the differential signal is not accurate; by the scheme of the above embodiment of the present application, the differential processing is performed by first obtaining the compensation capacitance values g2 (s2+n2) and g6 (0+n6) of Y2 and Y6, and performing the differential processing: y2—y6=g2 (s2+n2) -g6 (0+n6) =g2×s2, the resulting 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 selection of the induction channels is not limited by the differential processing after the compensation gain is introduced, the advantage of signal sensitivity can be kept no matter the induction channels with short distance or long distance are selected, and the noise suppression effect is not reduced.
Compared with the related art, the first capacitance value of each induction channel can be acquired in various environments by setting the first capacitance value of each induction channel one or more times, the acquired capacitance values are normalized, and the first capacitance values acquired for multiple times are adjusted to be under a unified evaluation index, so that noise can be completely counteracted when the subsequent compensation gain is combined for differentiation. The selection of the induction channels is not limited by the differential processing after the compensation gain is introduced, and the advantage of signal sensitivity can be maintained no matter the induction channels with short distance or long distance are selected, and the noise suppression effect is not reduced. Meanwhile, due to the technical problem and the structural problem of each channel, reference values may be different, reference compensation values are introduced, and the reference compensation values are added into the second capacitance values of each induction channel before the compensation capacitance values are obtained so as to update the second capacitance values, so that more accurate effective signal values are obtained after the subsequent difference.
Yet another embodiment of the present invention relates to a touch screen, as shown in fig. 4 and 5, including: a glass cover 7, an LCD9 and a sense channel layer 8 between the glass cover 7 and the LCD 9; the output end of each induction channel of the induction channel layer 8 is connected with a multiplier 10, the multiplier 10 is used for multiplying the compensation gain with a second capacitance value output by each induction channel to obtain a compensation capacitance value, the compensation capacitance value of each induction channel is used for carrying out differential processing to obtain a differential signal, and the differential signal is used for differential recovery to obtain an effective signal of each induction channel;
the compensation gain satisfies that the noise level of each sensing channel after the noise of each sensing channel is compensated is consistent.
Specifically, as shown in fig. 4, the glass cover plate 7, the LCD9, and the sensing channel layer 8 between the glass cover plate 7 and the LCD9, the sensing channel layer 8 may be one layer or may be multiple layers, which is not particularly limited in this application. The active pen may transmit an active signal to the sense channel layer 8 by touching the glass cover plate 7.
As shown in fig. 5, a multiplier 10 is connected to each output end of each sensing channel of the sensing channel layer 8, and each compensation gain (g 1, g2, g3, g4, g 5) is multiplied by the second capacitance value output by each sensing channel to obtain a compensation capacitance value. The compensation capacitance values of the two or two groups of induction channels are subjected to differential operation and other operation processing by the operational amplifier 11, so that an effective signal is finally obtained, the coordinates of the active pen can be obtained by using the effective signal value, and the process can be realized in an analog circuit or a digital circuit.
Specifically, the detailed steps related to compensating the capacitance value are described in the foregoing embodiments of the signal detection method applied to the touch screen, and are not repeated herein.
In one example, sense channel layer 8 includes a first direction sense channel layer 81 and a second direction sense channel layer 82, the first direction being perpendicular to the second direction.
Specifically, the first direction sensing channel layer 81 and the second direction sensing channel layer 82 may be an orthogonal X-direction sensing channel layer and a Y-direction sensing channel layer, respectively, and 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; when the first direction sensing channel layer is a Y direction sensing channel layer, the second direction sensing channel layer is an X direction sensing channel layer. It should be noted that the signal detection method in the present 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.
In another example, an adder may be further included in the analog circuit between the multipliers 10 connected to the output ends of the sensing channels of the sensing channel layer, where the adder is configured to add the reference compensation value to the second capacitance value, and input the second capacitance value after the reference compensation value is added to the multipliers 10, and multiply the second capacitance value with compensation gains corresponding to the sensing channels respectively to obtain the compensation capacitance value. It should be noted that the above process of adding the reference compensation value to the second capacitance value and obtaining the compensation capacitance value by the compensation gain corresponding to each sensing channel may be implemented in a digital circuit. The specific reference compensation value obtaining process has already been described in the above embodiment, and will not be described in detail herein.
Another embodiment of the invention is directed to an electronic device, as shown in fig. 6, comprising at least one processor 202; and a memory 201 communicatively coupled to the at least one processor 202; wherein the memory 201 stores instructions executable by the at least one processor 202, the instructions being executable by the at least one processor 202 to enable the at least one processor 202 to perform any one of the method embodiments described above.
Where memory 201 and processor 202 are connected by a bus, the bus may comprise any number of interconnected buses and bridges, the buses connecting together various circuits of one or more of the processor 202 and memory 201. The bus may also connect various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver may be one element or may be a plurality of elements, such as a plurality of receivers and transmitters, providing a means for communicating with various other apparatus over a transmission medium. The data processed by the processor 202 is transmitted over a wireless medium via an antenna, which further receives the data and transmits the data to the processor 202.
The processor 202 is responsible for managing the bus and general processing and may also provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. And memory 201 may be used to store data used by processor 202 in performing operations.
Another embodiment of the present invention relates to a computer-readable storage medium storing a computer program. The computer program, when executed by a processor, implements any of the method embodiments described above.
That is, it will be understood by those skilled in the art that all or part of the steps in implementing the methods of the embodiments described above may be implemented by a program stored in a storage medium, where the program includes several instructions for causing a device (which may be a single-chip microcomputer, a chip or the like) or a processor (processor) to perform all or part of the steps in the methods of the embodiments described herein. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples of carrying out the invention and that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
Claims (9)
1. A signal detection method applied to a touch screen, comprising:
setting compensation gains for all induction channels of the touch screen, wherein the compensation gains are used for compensating noise of all induction channels so as to enable the noise levels of all induction channels after compensation to be consistent;
obtaining a second capacitance value output by each induction channel, and multiplying the second capacitance value by the compensation gain corresponding to each induction channel to obtain a compensation capacitance value;
differential processing is carried out by using the compensation capacitance value of each induction channel to obtain differential signals, and differential recovery is carried out on the differential signals to obtain effective signals of each induction channel;
the compensation gain of each induction channel is the same as the product obtained by multiplying the normalized first capacitance value of the channel;
the first capacitance value is used for representing the noise value of each induction channel; the second capacitance value is the sum of the noise value and the effective signal of each sensing channel.
2. The method of claim 1, wherein in the full screen bright state, the first capacitance value output by the sense channel of each screen region is acquired when the screen region is not touched.
3. The method of claim 2, wherein obtaining the first capacitance value output by the sensing channel of each screen area when the screen area is not touched comprises:
taking a preset graph as a display graph of the touch screen in a state that the whole screen is not touched, and acquiring the first capacitance values output by all the sensing channels at one time;
the obtaining the normalized first capacitance value of the sensing channel includes:
and taking the first capacitance values output by all the sensing channels obtained at one time as the normalized first capacitance values of the sensing channels.
4. The method of claim 2, wherein obtaining the first capacitance value output by the sensing channel of each screen area when the screen area is not touched comprises:
when different areas of the whole screen are touched for multiple times, acquiring a first capacitance value output by an induction channel corresponding to each area which is not touched; the total set of the induction channels corresponding to the first capacitance value obtained each time comprises all induction channels corresponding to the whole screen; and at least one induction channel in the induction channels corresponding to the first capacitance value obtained at any time is included in the induction channels corresponding to the first capacitance value obtained at least once;
the obtaining the normalized first capacitance value of the sensing channel includes:
and normalizing the first capacitance value output by each induction channel based on the proportional relation between the first capacitance values output by each induction channel acquired at the same time and the proportional relation between the first capacitance values acquired by the induction channel at least twice based on the same induction channel, so as to obtain the normalized first capacitance value corresponding to each induction channel.
5. The method of claim 1, further comprising, before multiplying the second capacitance value by the compensation gain corresponding to each sensing channel to obtain a compensation capacitance value, respectively:
when the whole screen is in a screen-off state and is not touched, acquiring capacitance values output by all sensing channels as reference compensation values, and adding the reference compensation values into the second capacitance values;
the step of multiplying the second capacitance value by the compensation gain corresponding to each sensing channel to obtain a compensation capacitance value includes:
and multiplying the second capacitance value added with the reference compensation value by the compensation gain corresponding to each induction channel to obtain a compensation capacitance value.
6. A touch screen, comprising: a glass cover plate, an LCD and an induction channel layer positioned between the glass cover plate and the LCD;
the output end of each induction channel of the induction channel layer is connected with a multiplier, the multiplier is used for multiplying the compensation gain with a second capacitance value output by each induction channel to obtain a compensation capacitance value, the compensation capacitance value of each induction channel is used for carrying out differential processing to obtain a differential signal, and the differential signal is used for carrying out differential recovery to obtain an effective signal of each induction channel;
the compensation gain satisfies the condition that the noise level of each induction channel after the compensation is consistent;
the compensation gain of each induction channel is the same as the product obtained by multiplying the normalized first capacitance value of the channel;
the first capacitance value is used for representing the noise value of each induction channel; the second capacitance value is used for representing the sum of the noise value and the effective signal of each sensing channel.
7. The touch screen of claim 6, wherein the sense channel layer comprises a first direction sense channel layer and a second direction sense channel layer, the first direction being perpendicular to the second direction.
8. An electronic device, comprising:
at least one processor; the method comprises the steps of,
a memory communicatively coupled to the at least one processor; wherein,
the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the signal detection method applied to a touch screen as claimed in any one of claims 1 to 5.
9. A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the signal detection method applied to a touch screen as claimed in any one of claims 1 to 5.
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