WO2018176197A1

WO2018176197A1 - Method and device for eliminating lcd interference of touch control screen

Info

Publication number: WO2018176197A1
Application number: PCT/CN2017/078297
Authority: WO
Inventors: 杨烊; 方军
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2017-03-27
Filing date: 2017-03-27
Publication date: 2018-10-04
Also published as: CN109219792A; CN109219792B

Abstract

A method and device for eliminating LCD interference of a touch control screen, the touch control screen having a driving line and a sensing line. The method comprises: performing differential calculation on a demodulation signal value with LCD interference on a sensing line at a non-touch control position and a reference demodulation signal value without the LCD interference on the sensing line so as to obtain a first differential value (S1); performing differential calculation on a demodulation signal value on the sensing line at the non-touch control position of a current frame and the first differential value so as to obtain a second differential value (S2); and performing operation according to the second differential value so as to obtain original data of a capacitor node at which the LCD interference is eliminated (S3) so as to eliminate the LCD interference of a touch control screen.

Description

Method and device for eliminating touch screen LCD interference

Technical field

The present application relates to the field of noise interference cancellation technologies, and in particular, to a method and apparatus for eliminating interference from a touch screen LCD.

Background technique

Noise interference directly affects the user experience in consumer electronic devices, so noise immunity is an important performance indicator for measuring consumer electronics. In the field of human-computer interaction, the interference received by terminal equipment (mobile phones, PADs, etc.) mainly comes from the wireless communication system, LCD screen and charger that the device comes with. Since the interaction mode between the human and the terminal device is generally inseparable from the touch screen, the LCD interference from the touch screen will seriously affect the user's interactive experience. Therefore, the ability to improve the resistance to LCD interference has become an important research direction of touch-based interactive products.

Therefore, how to eliminate the LCD interference of the touch screen has become a technical problem that needs to be solved in the prior art.

Summary of the invention

In view of this, one of the technical problems solved by the embodiments of the present application is to provide a method and device for eliminating interference of a touch screen LCD, which is used to eliminate LCD interference of the touch screen.

The embodiment of the present application provides a method for eliminating interference of a touch screen LCD, wherein the touch screen has a driving line and a sensing line, and the method includes:

Performing a difference calculation between a demodulated signal value on the sensing line of the non-touch position where there is LCD interference and a reference demodulated signal value not being interfered by the LCD on the sensing line to obtain a first difference value;

Performing a difference calculation between the demodulated signal value on the sensing line of the non-touch position of the current frame and the first difference value to obtain a second difference value;

Performing an operation according to the second difference value to obtain a capacitor node raw data for eliminating LCD interference.

Corresponding to the above method, the embodiment of the present application further provides a device for eliminating interference of a touch screen LCD, wherein the touch screen has a driving line and a sensing line, and the device includes:

a first difference calculation module, configured to perform differential calculation between a demodulated signal value on the sensing line of the non-touch position where LCD interference exists and a reference demodulated signal value that is not interfered by the LCD on the sensing line, to obtain a first a differential value;

a second difference calculation module, configured to perform a differential calculation between the demodulated signal value on the sensing line of the non-touch position of the current frame and the first difference value to obtain a second difference value;

The original data calculation module is configured to perform operation according to the second differential value to obtain raw data of the capacitor node that eliminates LCD interference.

As can be seen from the above technical solution, since the present application directly calculates the difference between the demodulated signal value on the sensing line of the non-touch position where the LCD interference exists and the reference demodulated signal value that is not interfered by the LCD on the sensing line, A first differential value representative of LCD interference noise is obtained. And performing differential calculation on the sensing signal value on the sensing line of the non-touch position of the current frame and the first differential value to obtain a second differential value, that is, a demodulated signal on the current frame sensing line that eliminates LCD interference noise. value. Thereby, the demodulated signal value on the sensing line for eliminating the LCD interference noise is used to perform calculation, and the raw data of the capacitor node for eliminating the LCD interference is obtained. Therefore, the application eliminates the LCD interference of the touch screen and improves the subsequent digital computing performance, and the application on the touch screen chip can greatly improve the anti-LCD interference capability of the device.

DRAWINGS

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings to be used in the embodiments or the prior art description will be briefly described below. Obviously, the drawings in the following description are only These are some of the embodiments described in this application, and other figures can be obtained from those of ordinary skill in the art in view of these drawings.

1 is a schematic diagram of a touch screen driving line superimposed noise signal;

2 is a flow chart of an example of a method for eliminating interference of a touch screen LCD according to the present application;

3 is a flow chart of an example of step S3 in the method for eliminating interference of a touch screen LCD according to the present application;

4 is a structural diagram of an example of an apparatus for eliminating interference of a touch screen LCD according to the present application;

5 is a structural diagram of an example of a raw data calculation module in an apparatus for eliminating interference of a touch screen LCD according to the present application;

FIG. 6 is a hardware structural diagram of an electronic device applied to a method for eliminating interference of a touch screen LCD according to the present application.

detailed description

Since the LCD driver layer is close to the touch layer, the driving signal of the LCD is easily coupled to the touch layer, which interferes with the normal operation of the touch chip. The form of LCD interference response at the data level is Many, the most common one is to superimpose a fixed value on the entire drive line, as shown in Figure 1 (the vertical direction of the figure 1-16 represents the drive line, the horizontal number 1-10 represents the induction channel).

For the above-mentioned interference phenomenon, the characteristic data of the LCD interference is as follows: 1. The noise interference of the single sensing drive channel at the same time does not change much, and can be considered the same. 2. There is no obvious law in the horizontal direction due to noise interference during driving. 3. There is no obvious law in the time when the same root drive is affected by noise at different times.

Assuming that the touch screen has m driving lines and n sensing lines, the basic process of acquiring data on the touch screen is as follows: simultaneous or group coding on the m driving lines (usually using a sine wave as a coding signal) And a coded signal is coupled to the sensing line on the drive line. At the nodes of the driving line and the sensing line, when there is a touch operation, the capacitance at the touch node is changed. Therefore, the capacitance value at each node can be obtained by solving the equation or the equation group. According to the change of the front and back capacitance values, the position of the touch operation can be determined. The solution process is as shown in equation (1).

Simplified to A·C=B, where A is a coding matrix, C is a matrix of capacitance nodes to be obtained (including phase information), and B is a value of a demodulated signal on the sensing line.

The modulation and demodulation process of the signal on the inductive line is as follows:

Assume single node capacitance

1 modulation process of the capacitor node matrix:

2 Co-directional demodulation of the capacitor node matrix (I way):

3 Quadrature demodulation of the capacitor node matrix (Q path):

4 eliminate random phase:

It can be seen from equations (2) and (3) that the demodulated data is filtered to remove high frequency components to obtain a direct current amount, which is related to the phase of the capacitor node. Although the phase of each capacitor node is not different, the phase of the same capacitor node is a fixed value.

Therefore, the B matrix in A·C=B is the amount of DC in the I and Q signal components in the capacitance node matrix.

According to the interference data characteristic of the LCD, since the LCD interference on the same driving line is the same at the same time, the data that has not been subjected to the LCD interference can be used as the reference data, and the currently acquired capacitance node data matrix, that is, the C matrix ( The raw data, Rawdata) subtracts the reference matrix to obtain a matrix representing the LCD interference noise.

5 Solving the capacitance node matrix, ie C matrix (raw data, Rawdata):

Wherein, the matrix of the noise is an N matrix, and the elements of each row in the N matrix are the same, that is, N ₁₁ =N ₁₂ =...=N _1n (assuming that the interference of the LCD interference is the same on the same driving line at the same time) .

6 The I/Q two-way signal component of the capacitor node matrix decomposed into the same sensing line is:

I Road:

Q Road:

7 performing nonlinear operations using the signal components of the I and Q channels to obtain the capacitance node matrix:

Where S is a coded signal and N is a noise signal.

8 The capacitor node matrix performs processing for eliminating LCD interference, and obtains the raw data of the capacitor node matrix to eliminate LCD interference:

After the matrix of capacitance nodes is found, the matrix of capacitance nodes is subtracted from the matrix of capacitive nodes (ie, reference signals) that are not subject to noise interference.

Reference signal:

Difference processing:

When it is assumed that the interference of the LCD noise on the same driving line Tx at the same time is the same, the noise values of the nodes on the same driving line Tx are the same, both are:

However, the diff obtained after the differential processing is not a simple noise interference component, but also a mixture with the coding signal, because the nonlinear operation is performed when the original data of the capacitance node matrix is acquired, resulting in signal and noise. The amount of mixing appears.

In order to eliminate the mixed noise caused by the non-linear operation, the present application directly determines the demodulated signal value on the sensing line of the non-touch position where there is LCD interference and the reference demodulated signal that is not interfered by the LCD on the sensing line. The values are differentially calculated to obtain a first difference value representative of the LCD interference noise. And performing differential calculation on the sensing signal value on the sensing line of the non-touch position of the current frame and the first differential value to obtain a second differential value, that is, a demodulated signal on the current frame sensing line that eliminates LCD interference noise. value. Thereby, the demodulated signal value on the sensing line for eliminating the LCD interference noise is used to perform calculation, and the raw data of the capacitor node for eliminating the LCD interference is obtained. Therefore, the application eliminates the LCD interference of the touch screen and improves the subsequent digital computing performance, and the application on the touch screen chip can greatly improve the anti-LCD interference capability of the device.

Of course, any technical solution of implementing the embodiments of the present application necessarily does not necessarily need to achieve all the above advantages at the same time.

For a better understanding of the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present application. The embodiment is only a part of the embodiment of the application, not all An embodiment. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by those skilled in the art should be within the scope of protection of the embodiments of the present application.

The specific implementation of the embodiments of the present application is further described below with reference to the accompanying drawings.

The following description of the exemplary embodiments refers to the accompanying drawings, It is to be understood that changes may be made in the various embodiments and may be made without departing from the scope of the various embodiments.

The touch input device of the present application may illustratively be a stylus, and other input devices and/or pointing devices may be used in various embodiments of the present application.

The present application provides a method for eliminating interference from a touch screen LCD having a driving line and a sensing line.

Referring to Figure 2, the method includes:

S1: Perform differential calculation between the demodulated signal value on the sensing line of the non-touch position where LCD interference exists and the reference demodulated signal value that is not interfered by the LCD on the sensing line to obtain a first difference value.

In the specific implementation of the present application, due to the presence of LCD interference, the demodulated signal value on the sensing line includes noise data. The interference of the LCD noise on the same driving line Tx at the same time is the same. Therefore, the present application obtains the matrix of the demodulated signal value of the LCD interference at the same time on the sensing line minus the time of the sensing line. A matrix of reference demodulated signal values that are not subjected to LCD interference at a time, thereby obtaining a noise matrix N.

Wherein, the matrix N in the formula (10) represents a noise matrix, the matrix B+N represents a matrix of demodulated signal values in which LCD interference exists, and the matrix B represents a matrix of demodulated signal values not subjected to LCD interference.

Therefore, the present application directly performs differential processing on the demodulated signal value on the sensing line including noise interference and the demodulated signal value on the sensing line that is not interfered, that is, directly obtains a noise signal in the B matrix ( First difference value).

Specifically, the step S1 further includes:

The first difference value is averaged to obtain an average first difference value.

Specifically, each row of the first difference value matrix is averaged to obtain an average first difference value matrix.

Among them, the matrix N in the formula (11) represents a noise matrix.

The present application performs an average calculation on each row of the first difference value matrix to obtain an average noise condition, thereby eliminating noise errors generated during calculation and signal processing.

Specifically, the reference demodulation signal value on the sensing line that is not interfered by the LCD may be a pre-stored reference demodulated signal value on the sensing line that is not interfered by the LCD, or the sensing line is detected. The reference demodulated signal value on the sensing line that is not subjected to LCD interference.

The pre-stored reference demodulated signal value on the sensing line that is not subjected to LCD interference can be obtained by testing when the LCD screen is not attached before leaving the factory.

In a specific implementation of the application, the step S1 is specifically:

The demodulated signal value on the sensing line of the non-touch position where there is LCD interference is differentially calculated from the reference demodulated signal value on the sensing line that is not interfered by the LCD at the current moment, to obtain the first difference. value.

The reference demodulated signal value on the sensing line that is not subjected to LCD interference is acquired at a previous moment of the demodulated signal value on the sensing line of the non-touch position where LCD interference exists, so Calculating the first difference value can more accurately reflect the noise condition on the same driving line Tx at the same time.

In another specific implementation of the application, the step S1 is specifically:

Comparing the demodulated signal value of all or part of the sensing lines of the touch screen with the non-touch position of the LCD interference with the reference demodulated signal value of the sensing line that is not interfered by the LCD, The first difference value.

In the present application, the difference between the demodulated signal value on the partial sensing line and the reference demodulated signal value on the sensing line that is not interfered by the LCD is used to obtain a first difference value, which can reduce the amount of calculation for performing the difference calculation.

S2. The demodulated signal value on the sensing line of the current frame is differentially calculated from the first difference value to obtain a second difference value.

Specifically, the step S2 is specifically:

The demodulated signal value on the sensing line of the current frame is differentially calculated from the average first difference value to obtain a second difference value.

Wherein, the matrix D in the formula (12) represents a matrix of demodulated signal values on the sensing line of the current frame from which the noise signal is removed, and the matrix B+N represents the value of the demodulated signal on the sensing line of the current frame containing the noise, The matrix N/n represents the average first difference value.

S3. Perform operation according to the second difference value to obtain raw data of the capacitor node that eliminates LCD interference.

In the specific implementation of the present application, referring to FIG. 3, the step S3 includes:

S31. Perform calculation according to the second difference value to obtain signal components of the capacitor node I and Q channels.

The step S31 is specifically:

The signal components of the I and Q paths of the capacitance node matrix are obtained by using the second difference value matrix and the coding matrix.

It can be seen from the above formula (1) and the formulas (6) and (7) that the I and Q paths of the capacitor node matrix C can be obtained by using the coding matrix A and the demodulated signal value matrix B on the sensing line. Signal component.

I Road:

Q Road:

S32. Using the signal components of the I and Q channels, obtain the original data of the capacitor node to eliminate LCD interference.

The step S32 is specifically:

The non-linear operation is performed by using the signal components of the I and Q channels to obtain the raw data of the capacitance node matrix to eliminate LCD interference.

The specific nonlinear operation method is shown in formula (15).

The present invention directly calculates the difference between the demodulated signal value on the sensing line of the non-touch position where the LCD interference exists at one moment and the reference demodulated signal value that is not interfered by the LCD at the previous moment on the sensing line. Obtain a first differential value representative of LCD interference noise. And performing differential calculation on the sensing line according to the current frame and the first differential value to obtain a second differential value, that is, a demodulated signal value on the current frame sensing line that eliminates LCD interference noise. Thereby, the demodulated signal value on the sensing line for eliminating the LCD interference noise is used to perform calculation, and the raw data of the capacitor node for eliminating the LCD interference is obtained. Therefore, the application eliminates the LCD interference of the touch screen and improves the subsequent digital computing performance, and the application on the touch screen chip can greatly improve the anti-LCD interference capability of the device.

The application also provides a device for eliminating interference from a touch screen LCD, the touch screen having a driving line and a sensing line.

Referring to Figure 4, the apparatus includes:

The first difference calculation module 41 is configured to perform differential calculation between the demodulated signal value on the sensing line of the non-touch position where LCD interference exists and the reference demodulated signal value that is not interfered by the LCD on the sensing line, to obtain The first difference value.

The second difference calculation module 42 is configured to perform a difference calculation between the demodulated signal value on the sensing line of the non-touch position of the current frame and the first difference value to obtain a second difference value.

The original data calculation module 43 is configured to perform operation according to the second differential value to obtain raw data of the capacitor node that eliminates LCD interference.

In the specific implementation of the present application, due to the presence of LCD interference, the demodulated signal value on the sensing line includes noise data. The interference of the LCD noise on the same driving line Tx at the same time is the same. Therefore, the present application obtains the demodulated signal value matrix of the LCD interference at the same time on the sensing line minus the reference demodulated signal value that is not interfered by the LCD. Matrix, thereby obtaining a noise matrix N.

Specifically, the first difference calculation module 41 is further configured to perform an average calculation on the first difference value to obtain an average first difference value.

Among them, the matrix N in the formula (11) represents a noise matrix.

In a specific implementation of the present application, the first differential calculation module is specifically configured to: the demodulated signal value on the sensing line of the non-touch position where the LCD interference exists is not interfered by the LCD at a previous moment of the current time. The reference demodulated signal value on the sensing line is differentially calculated to obtain a first difference value.

The reference demodulated signal value on the sensing line that is not affected by the LCD is acquired at a previous moment of the demodulated signal value on the sensing line of the non-touch position where the LCD interference exists. The first difference value obtained by the differential calculation can more accurately reflect the noise condition on the same driving line Tx at the same time.

In another specific implementation of the present application, the first differential calculation module is specifically configured to use a demodulated signal value of all or part of the sensing lines of the touch screen that has a non-touch position with LCD interference. Performing differential calculation on the reference demodulated signal value that is not interfered by the LCD on the sensing line to obtain a first difference value.

Specifically, the second difference calculation module 42 is specifically configured to specifically:

In the specific implementation of the present application, referring to FIG. 5, the original data calculation module 43 includes:

The IQ component obtaining unit 431 is configured to perform an operation according to the second differential value to obtain signal components of the capacitive node I and Q paths.

The IQ component calculation unit 432 is configured to obtain the original data of the capacitance node to eliminate LCD interference by using the signal components of the I and Q paths.

The IQ component obtaining unit 431 is specifically configured to obtain the signal components of the I and Q paths of the capacitor node matrix by using the second difference value matrix and the coding matrix.

I Road:

Q Road:

The IQ component calculation unit 432 is specifically configured to perform nonlinear operations by using signal components of the I and Q channels to obtain original data of the capacitance node matrix to eliminate LCD interference.

The specific nonlinear operation method is shown in formula (15).

FIG. 6 is a schematic diagram showing the hardware structure of an electronic device for eliminating interference from a touch screen LCD according to the present application. According to Figure 6, the device comprises:

One or more processors 610 and memory 620, one processor 610 is taken as an example in FIG.

The device for eliminating touch screen LCD interference may further include: an input device 630 and an output device 630.

The processor 610, the memory 620, the input device 630, and the output device 630 may be connected by a bus or other means, as exemplified by a bus connection in FIG.

The memory 620 is a non-volatile computer readable storage medium, and can be used for storing a non-volatile software program, a non-volatile computer-executable program, and a module, such as a program corresponding to the method for searching for a topic in the embodiment of the present application. An instruction/module (for example, the first difference calculation module 41, the second difference calculation module 42, and the raw data calculation module 43 shown in FIG. 4). The processor 610 performs various functional applications and data processing of the server by running non-volatile software programs, instructions, and modules stored in the memory 620, that is, a method for eliminating the interference of the touch screen LCD by the above method embodiments.

The memory 620 can include a storage program area and a storage data area, wherein the storage program area can store an operating system, an application required for at least one function; and the storage data area can be stored according to the use of the device for eliminating touch screen LCD interference. Data, etc. Moreover, memory 620 can include high speed random access memory 620, and can also include non-volatile memory 620, such as at least one disk storage device 620, flash memory device, or other non-volatile solid state memory 620 device. In some embodiments, the memory 620 can optionally include a memory 620 remotely located relative to the processor 610, which can be connected to the sound mode selection device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

Input device 630 can receive input numeric or character information and generate key signal inputs related to user settings and function control of the device for topic search. Output device 630 can include a device such as a speaker.

The one or more modules are stored in the memory 620, and when executed by the one or more processors 610, perform the method of canceling touch screen LCD interference in any of the above method embodiments.

The above products can perform the methods provided by the embodiments of the present application, and have the corresponding functional modules and beneficial effects of the execution method. For technical details that are not described in detail in this embodiment, reference may be made to the method provided by the embodiments of the present application.

The electronic device of the embodiment of the present application exists in various forms, including but not limited to:

(1) Mobile communication devices: These devices are characterized by mobile communication functions and are mainly aimed at providing voice and data communication. Such terminals include: smart phones (such as iPhone), multimedia phones, functional phones, and low-end phones.

(2) Ultra-mobile personal computer equipment: This type of equipment belongs to the category of personal computers, has computing and processing functions, and generally has mobile Internet access. Such terminals include: PDAs, MIDs, and UMPC devices, such as the iPad.

(3) Portable entertainment devices: These devices can display and play multimedia content. Such devices include: audio, video players (such as iPod), handheld game consoles, e-books, and smart toys and portable car navigation devices.

(4) Server: A device that provides computing services. The server consists of a processor, a hard disk, a memory, a system bus, etc. The server is similar to a general-purpose computer architecture, but because of the need to provide highly reliable services, processing power and stability High reliability in terms of reliability, security, scalability, and manageability.

(6) Other electronic devices with data interaction functions.

Those skilled in the art will appreciate that embodiments of the embodiments of the present application can be provided as a method, apparatus (device), or computer program product. Therefore, the embodiments of the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Moreover, embodiments of the present application may employ a computer usable memory in one or more of the computer usable program code. A form of computer program product embodied on a storage medium, including but not limited to disk storage, CD-ROM, optical storage, and the like.

Embodiments of the present application are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus, and computer program products according to embodiments of the present application. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

While the preferred embodiment of the embodiments of the present invention has been described, those skilled in the art can make further changes and modifications to the embodiments. Therefore, the appended claims are intended to be interpreted as including all the modifications and the modifications It is apparent that those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. Thus, the present embodiments are intended to cover such modifications and variations as the modifications and variations of the embodiments of the present invention are intended to be included within the scope of the appended claims.

Claims

A method for eliminating interference from a touch screen LCD, the touch screen having a driving line and a sensing line, wherein the method comprises:

Performing a difference calculation between a demodulated signal value on the sensing line of the non-touch position where there is LCD interference and a reference demodulated signal value not being interfered by the LCD on the sensing line to obtain a first difference value;

Performing a difference calculation between the demodulated signal value on the sensing line of the non-touch position of the current frame and the first difference value to obtain a second difference value;

Performing an operation according to the second difference value to obtain a capacitor node raw data for eliminating LCD interference.
The method according to claim 1, wherein the demodulated signal value on the sensing line of the non-touch position where there is LCD interference and the reference demodulated signal not interfered by the LCD on the sensing line are The value is calculated by difference, and the first difference value is obtained as follows:

The demodulated signal value on the sensing line of the non-touch position where there is LCD interference is differentially calculated from the reference demodulated signal value on the sensing line that is not interfered by the LCD at the current moment, to obtain the first difference. value.
The method according to claim 1, wherein the demodulated signal value on the sensing line of the non-touch position where there is LCD interference and the reference demodulated signal not interfered by the LCD on the sensing line are The value is differentially calculated, and the first difference value is specifically: a demodulated signal value of all or part of the sensing lines of the touch screen having the non-touch position of the LCD interference and the corresponding sensing line. The reference demodulated signal value that is not subjected to LCD interference is differentially calculated to obtain a first difference value.
The method according to claim 1, wherein the demodulated signal value on the sensing line of the non-touch position where LCD interference exists at a moment and the time before the moment on the sensing line are not Performing differential calculation on the reference demodulated signal value of the LCD interference, and obtaining the first differential value further includes:

Performing an average calculation on the first difference value to obtain an average first difference value;

Performing a difference calculation between the demodulated signal value on the sensing line of the current frame and the first difference value, to obtain a second difference value, specifically:

And decomposing the demodulated signal value on the sensing line of the current frame and the average first difference value to obtain a second difference value.
The method according to claim 1, wherein the calculating, according to the second difference value, the capacitance node raw data for eliminating LCD interference comprises:

Performing an operation according to the second difference value to obtain signal components of the capacitor node I and Q paths;

Using the signal components of the I and Q channels, the raw data of the capacitance node to eliminate LCD interference is obtained.
The method according to claim 5, wherein the calculating the signal according to the second difference value to obtain the signal components of the capacitive node I and the Q channel is specifically:

The signal components of the I and Q paths of the capacitance node matrix are obtained by using the second difference value matrix and the coding matrix.
The method according to claim 5, wherein the using the signal components of the I and Q paths to obtain the raw data of the capacitor node to eliminate LCD interference is specifically:

The non-linear operation is performed by using the signal components of the I and Q channels to obtain the raw data of the capacitance node matrix to eliminate LCD interference.
A device for eliminating interference from a touch screen LCD, the touch screen having a driving line and a sensing line, wherein the device comprises:

a first difference calculation module, configured to perform differential calculation between a demodulated signal value on the sensing line of the non-touch position where LCD interference exists and a reference demodulated signal value that is not interfered by the LCD on the sensing line, to obtain a first a differential value;

a second difference calculation module, configured to perform differential calculation between the demodulated signal value on the sensing line of the non-touch position of the current frame and the first difference value to obtain a second difference value;

The original data calculation module is configured to perform operation according to the second differential value to obtain raw data of the capacitor node that eliminates LCD interference.
The device according to claim 8, wherein the first difference calculation module is specifically configured to: use a demodulated signal value on the sensing line of a non-touch position where LCD interference exists, and a previous moment of a current time The reference demodulated signal value on the sensing line that is not subjected to LCD interference is differentially calculated to obtain a first difference value.
The device according to claim 8, wherein the first difference calculation module is specifically configured to demodulate all or part of the sensing lines of the touch screen having a non-touch position with LCD interference. The signal value is differentially calculated with the corresponding reference demodulated signal value of the sensing line that is not interfered by the LCD to obtain a first difference value.
The apparatus according to claim 8, wherein the first difference calculation module is further configured to perform an average calculation on the first difference value to obtain an average first difference value;

The second difference calculation module is specifically configured to perform differential calculation between the demodulated signal value on the sensing line of the current frame and the average first difference value to obtain a second difference value.
The device according to claim 8, wherein the original data calculation module comprises:

An IQ component obtaining unit, configured to perform an operation according to the second differential value, to obtain signal components of the capacitive node I and Q paths;

An IQ component calculation unit is configured to obtain raw data of the capacitance node to eliminate LCD interference by using signal components of the I and Q paths.
The apparatus according to claim 12, wherein said IQ component obtaining unit is configured to obtain signal components of said capacitive node matrix I and Q paths by using said second difference value matrix and a coding matrix.
The apparatus according to claim 12, wherein the IQ component calculation unit is configured to perform nonlinear operations using signal components of the I and Q channels to obtain raw data of the capacitance node matrix to eliminate LCD interference.