CN118056177A

CN118056177A - Touch detection method, touch detection circuit, touch chip and electronic equipment

Info

Publication number: CN118056177A
Application number: CN202480000161.2A
Authority: CN
Inventors: 谢浩
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2024-01-09
Filing date: 2024-01-09
Publication date: 2024-05-17

Abstract

The embodiment of the application provides a touch detection method, a touch detection circuit, a touch chip and electronic equipment for a touch display panel. The touch display panel comprises a display layer and a touch layer, wherein the touch layer comprises a plurality of sensing electrodes. The method comprises the following steps: detecting signals on the plurality of induction electrodes respectively to obtain original detection data corresponding to the plurality of induction electrodes, wherein the signals on the plurality of induction electrodes comprise display interference signals; determining a display interference compensation value corresponding to a target sensing electrode in a plurality of sensing electrodes aiming at the target sensing electrode, wherein the target sensing electrode comprises at least one of the sensing electrodes, and the display interference compensation value is used for indicating the interference intensity of the display interference signal on the target sensing electrode; and correcting the original detection data corresponding to the target sensing electrode based on the display interference compensation value corresponding to the target sensing electrode to obtain target detection data corresponding to the target sensing electrode, so as to determine a touch detection result.

Description

Touch detection method, touch detection circuit, touch chip and electronic equipment

Technical Field

The embodiment of the application relates to the technical field of touch control, in particular to a touch control detection method, a touch control detection circuit, a touch control chip and electronic equipment for a touch control display panel.

Background

In recent years, as a screen becomes thinner, the distance between a touch layer and a display layer in the screen becomes closer, so that the influence of various driving waveforms of the display layer on the touch layer due to data refreshing becomes larger, display interference coupled to a touch sensor in the touch layer becomes more serious, and finally, the accuracy of deriving touch detection is reduced.

Disclosure of Invention

In view of the above, one of the technical problems to be solved by the embodiments of the present application is to provide a touch detection method, a touch detection circuit, a touch chip and an electronic device for a touch display panel, which are used for at least partially solving the above technical problems.

In a first aspect, an embodiment of the present application provides a touch detection method for a touch display panel, where the touch display panel includes a display layer and a touch layer, and the touch layer includes a plurality of sensing electrodes, and the method includes:

detecting signals on the plurality of induction electrodes respectively to obtain original detection data corresponding to the plurality of induction electrodes, wherein the signals on the plurality of induction electrodes comprise display interference signals;

Determining a display interference compensation value corresponding to a target sensing electrode of the plurality of sensing electrodes, wherein the target sensing electrode comprises at least one of the plurality of sensing electrodes, and the display interference compensation value is used for indicating the interference intensity of the display interference signal on the target sensing electrode;

And correcting the original detection data corresponding to the target sensing electrode based on the display interference compensation value corresponding to the target sensing electrode to obtain target detection data corresponding to the target sensing electrode, so as to determine a touch detection result.

In a second aspect, an embodiment of the present application further provides a touch detection circuit for a touch display panel, where the touch display panel includes a display layer and a touch layer, the touch layer includes a plurality of sensing electrodes, and the touch detection circuit includes:

The signal detection module is used for respectively detecting signals on the plurality of induction electrodes to obtain original detection data corresponding to the induction electrodes, and the signals on the plurality of induction electrodes comprise display interference signals;

A processing module, configured to determine, for a target sensing electrode of the plurality of sensing electrodes, a display interference compensation value corresponding to the target sensing electrode, where the target sensing electrode includes at least one of the plurality of sensing electrodes, and the display interference compensation value is used to indicate an interference intensity of the display interference signal on the target sensing electrode;

The processing module is further configured to correct the original detection data corresponding to the target sensing electrode based on the display interference compensation value corresponding to the target sensing electrode, so as to obtain target detection data corresponding to the target sensing electrode, and determine a touch detection result.

In a third aspect, an embodiment of the present application further provides a touch chip, including the touch detection circuit provided in the second aspect.

In a fourth aspect, an embodiment of the present application further provides an electronic device, including a touch display panel and a touch chip as provided in the third aspect.

In the technical scheme provided by the embodiment of the application, signals on a plurality of induction electrodes in a touch layer of a touch display panel are detected respectively to obtain original detection data corresponding to the induction electrodes, a display interference compensation value corresponding to a target induction electrode is determined aiming at the target induction electrode in the induction electrodes, and the original detection data corresponding to the target induction electrode is corrected based on the display interference compensation value corresponding to the target induction electrode to obtain target detection data corresponding to the target induction electrode so as to be used for determining a touch detection result. Because the display interference compensation value indicates the interference intensity of the display interference signal on the target induction electrode, the original detection data corresponding to the target induction electrode is corrected by using the display interference compensation coefficient corresponding to the target induction electrode, and the display interference noise corresponding to the target induction electrode can be better removed, so that the touch detection result is determined by using the corrected target detection data, and the accuracy of touch position detection can be ensured.

Drawings

Some specific embodiments of the application will be described in detail hereinafter by way of example and not by way of limitation with reference to the accompanying drawings. The same reference numbers will be used throughout the drawings to refer to the same or like parts or portions. It will be appreciated by those skilled in the art that the drawings are not necessarily drawn to scale. In the accompanying drawings:

fig. 1 is a schematic diagram of a lamination of a touch display panel according to an embodiment of the present application;

fig. 2 is a top view of a touch display panel according to an embodiment of the application;

fig. 3 is a schematic diagram of display interference intensity in an RX direction of a touch display panel according to an embodiment of the present application;

fig. 4 is a schematic diagram of display interference intensity in TX direction of a touch display panel according to an embodiment of the present application;

fig. 5a to fig. 5c are schematic diagrams of a display interference model of a touch display panel according to an embodiment of the application;

fig. 6 is a flowchart of a touch detection method for a touch display panel according to an embodiment of the present application;

Fig. 7 is a schematic structural diagram of a front-end analog circuit according to an embodiment of the present application;

FIG. 8 is a schematic diagram of another front-end analog circuit according to an embodiment of the present application;

FIG. 9 is a flowchart of a method for obtaining a display interference compensation coefficient according to an embodiment of the present application;

Fig. 10 is a schematic circuit diagram of a touch detection circuit according to an embodiment of the present application;

FIG. 11 is a schematic circuit diagram of another touch detection circuit according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of a touch detection circuit according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of another touch detection circuit according to an embodiment of the present application.

Detailed Description

The technical scheme of the application will be described below with reference to the accompanying drawings.

In order to better understand the technical solutions of the embodiments of the present application, the following description will clearly and completely describe the technical solutions of the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, but not all embodiments. All other embodiments, which are derived by a person skilled in the art based on the embodiments of the application, shall fall within the scope of protection of the embodiments of the application.

Referring to fig. 1, fig. 1 is a schematic diagram of stacking touch display panels for electronic devices. The electronic device may be a smart phone, a smart watch, a tablet computer, a laptop computer, a car touch screen, or other suitable electronic device. The touch display panel 10 includes a display layer 110 and a touch electrode layer 120 (also referred to as a touch sensor or touch layer).

Above the display layer 110 is a cathode plate 130 for providing a common voltage (also referred to as a common voltage layer) for all pixels in the display array of the display layer 110 and capacitively coupled to the touch layer via a thin film encapsulation (Thin Film Encapsulation, TFE) layer 140 of an Organic LIGHT EMITTING Diode (OLED). Touch layer 120 is located over TFE layer 140. As shown in fig. 2, the touch electrodes in the touch layer 120 include a plurality of driving electrodes TXi arranged in a first direction (i.e., RX direction) and a plurality of sensing electrodes RXi arranged in a second direction (i.e., TX direction), where i and j are positive integers greater than 1. The first direction is perpendicular to the second direction. A touch is detected via the mutual capacitance between the driving electrode TXi and the sensing electrode RXi.

With continued reference to fig. 1, cathode plate 130 is capacitively coupled to touch layer 120, and display layer 110 is capacitively coupled to cathode plate 130. Accordingly, a first coupling capacitance Cp1 is formed between the touch electrode in the touch layer 120 and the cathode plate 130, and a second coupling capacitance Cp2 is formed between the cathode plate 130 and the display layer 110 (specifically, shown as a trace).

The display layer includes display layer traces of the OLED light emitting cells. These display layer traces have various drive waveforms as the display layer continually refreshes the data. The driving waveform is coupled to the cathode plate 130 through the second coupling capacitor Cp2 between the display layer 110 and the cathode plate 130, and the cathode plate 130 is coupled to the touch electrode through the first coupling capacitor Cp1 between the cathode plate 130 and the touch electrode, so that the touch layer 120 is coupled to the display disturbance. As OLED manufacturing technology advances, the TFE layer 140 becomes thinner, resulting in a larger first coupling capacitance Cp1 between the cathode plate 130 and the touch electrode, which results in a more serious display disturbance to which the touch sensor is coupled, thereby reducing the sensitivity and accuracy of touch detection.

As shown in fig. 2, one end of the cathode plate 130 is grounded, specifically, the cathode plate 130 is connected to the system ground GND at an end near the display driving control chip (DISPLAY DRIVER IC, DDIC), and the longer the path through to the system ground, the greater the impedance due to the existence of the resistivity of the cathode plate 130. That is, the more impedance the farther from the system on the cathode plate. Accordingly, the display disturbance is greater at locations on the cathode plate that are farther from the system. As shown in fig. 2, the impedance of the position on the cathode plate corresponding to the sense electrode RXi becomes larger in the direction indicated by the arrow D1, and the display disturbance of the sense electrode RXi further from the DDIC becomes larger. Fig. 3 shows the display interference characteristics in the RX direction. As shown in fig. 3, the difference in display interference of RX sense electrodes distributed in the downward-upward direction indicated by an arrow D1 shown in fig. 2 is arched.

In addition, due to process variations, the thickness of cathode plate 130 may not be exactly uniform (e.g., may be thick in the middle and thin at both ends), and thus there may be random deviations in the distances between different touch electrodes in touch layer 120 and the cathode plate, resulting in random deviations in the coupling capacitances between the different touch electrodes and the cathode plate. Due to random deviations in coupling capacitance between different sensing electrodes of the touch electrodes and the cathode plate and due to process deviations in amplification of Analog Front End (AFE) connected to different sensing electrodes of the touch electrodes, a morphology of superimposing a saw tooth on the arch is shown as shown in fig. 3.

With continued reference to fig. 2, since the ground of the DDIC is located at both sides on the flexible circuit board (Flexible Printed Circuit, PFC), the cathode plate 130 is connected to the ground of the DDIC through both left and right ends thereof. Likewise, due to the resistivity of the cathode plate 130, the impedance on the middle of the cathode plate is large and the impedance on the both sides is small, and accordingly, the display disturbance for the TX direction, as shown in fig. 4, takes on the case that the middle is large and the both sides are small. It should be understood that fig. 4 only shows the display interference feature of the middle size and the two sides small in the Tx direction. Due to the process variations, there is in fact also a random deviation of the coupling capacitance between the different driving electrodes and the cathode plate, i.e. a saw-tooth pattern (not shown) is superimposed on the display disturbance in the Tx direction as shown in fig. 4.

The reason why the display interference differs in the RX direction and the TX direction is described in further detail below with further reference to the display interference model shown in fig. 5 (a) to (c). As shown in fig. 5, the coupling capacitance Cr1 represents a coupling capacitance between the driving electrode TX and the cathode plate, the coupling capacitance Cr2 represents a coupling capacitance between the sensing electrode RX and the cathode plate, and the capacitance Cm represents a mutual capacitance between the driving electrode TX and the sensing electrode RX, and a touch is detected by detecting a capacitance variation amount of the mutual capacitance Cm. Due to the effect of the process variations mentioned above, there are differences in the coupling capacitances of the different sense and drive electrodes and the cathode plate, and thus the coupling capacitances Cr1 and Cr2 are each represented by a variable capacitance. Furthermore, as mentioned above, the impedance of the different positions of the cathode plate to system ground is different, so the variable impedance Z is used to represent the impedance of the different positions of the cathode plate to system ground. The current source Inoise represents the display interference current, and the input resistance Rin represents the equivalent impedance of the circuit connection between the sense electrode and the touch chip (specifically, the front-end circuit in the touch chip). The display disturbance model shown in fig. 5 (a) is obtained by equivalent change of a current source and a voltage source, where a parallel circuit of the current source Inoise and the impedance Z in the dashed line box of fig. 5 (a) is equivalent converted into a series circuit of the voltage source Vnoise and the impedance Z of fig. 5 (b), where vnoise= Inoise ×z. As can be seen from the display disturbance model shown in fig. 5 (b), the display disturbance voltage Vnoise corresponds to the transfer to the touch chip through the impedance Z and the coupling capacitance Cr 2.

For the sake of more clarity, the display disturbance model shown in fig. 5 (b) is further equivalent, resulting in the display disturbance model shown in fig. 5 (c). Specifically, as shown in fig. 5 (b), since the mutual capacitance Cm is far smaller than the coupling capacitance Cr2, and the impedance corresponding to the mutual capacitance Cm is far greater than the impedance corresponding to the coupling capacitance Cr2, which corresponds to an open circuit, the display disturbance model of fig. 5 (c) is obtained. In fig. 5 (c), the impedance Z' is equivalent to the series value of the impedance Z from the different positions of the cathode plate to the system ground in the dashed box in fig. 5 (b), the impedance corresponding to the coupling capacitance Cr2, and the impedance of the input resistor Rin. As can be seen from fig. 5 (a) and fig. 5 (c), due to the different impedances between the cathode plate and the system ground at different positions and the difference of coupling capacitances between the different sensing electrodes and the cathode plate (i.e., the difference of physical model parameters of the touch display panel), inconsistent display interference noise data is mixed in the original detection data obtained by detecting the different sensing electrodes, which will cause abnormal mutual capacitance data and reflect the abnormal mutual capacitance data to the touch position, and may cause phenomena such as point impersonation or point elimination or coordinate jitter, thereby affecting the accuracy of touch position detection on the touch display panel.

Therefore, the display interference compensation value corresponding to the target sensing electrode in the touch layer of the touch display panel is obtained, and the original detection data corresponding to the target sensing electrode is corrected based on the display interference compensation value corresponding to the target sensing electrode, so that the influence of display interference is removed, and the accuracy of touch detection is improved.

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

Fig. 6 is a flowchart of a touch detection method for a touch display panel according to an embodiment of the application. The touch display panel comprises a display layer and a touch layer, wherein the touch layer comprises a plurality of sensing electrodes.

As shown in fig. 6, the method includes:

S601, detecting signals on a plurality of induction electrodes in a touch layer to obtain original detection data corresponding to the induction electrodes, wherein the signals on the induction electrodes comprise display interference signals;

Specifically, when the display layer is in the driving period, the display driving signal brings signal interference to the sensing electrode, and the display interference signal comprises an interference signal generated by the display layer to the sensing electrode when the display layer is in the driving period. During the touch detection, the touch detection circuit outputs a driving signal to the driving electrode in the touch layer, and the sensing electrode of the touch layer is coupled to the sensing signal due to the mutual capacitance Cm of the coupling between the driving electrode and the sensing electrode. When a touch is present, the capacitance value of the mutual capacitance Cm between the driving electrode and the sensing electrode corresponding to the touch position may change, for example, the capacitance value of the mutual capacitance Cm may decrease. Therefore, the sensing signal coupled to the sensing electrode also changes, and the touch coordinate can be determined by detecting the change amount of the sensing signal on the sensing electrode.

As mentioned above, during the time that the display layer is driven to display an image, the display layer traces have various drive waveforms due to the refresh data, which are coupled to the sense electrodes as display disturbances during touch detection. Thus, the signal on the sense electrode also includes a display disturbance signal coupled to the sense electrode during the period that the display layer is driven. Correspondingly, the original detection data obtained by detecting the signals on the induction electrodes in the touch layer contains display interference noise corresponding to the display interference signals.

In this embodiment, the detection of the signals on the plurality of sensing electrodes in the touch layer is implemented by the signal detection module 21 in the touch detection circuit 20 shown in fig. 12. Specifically, the signal detection module 21 includes a plurality of Analog Front End (AFE) circuits, where the Analog Front End circuits respectively correspond to the plurality of sensing electrodes, so as to respectively detect signals on the plurality of sensing electrodes in the touch layer, and obtain original detection data corresponding to the plurality of sensing electrodes.

In one implementation, the analog front end circuit may be a current input type AFE 210A as shown in fig. 7. The current input AFE 210A includes a first gain amplification circuit 211A, where the first gain amplification circuit 211A may be a transimpedance amplification circuit for converting a current signal variation on the sense electrode RXi into an amplified voltage signal Vout. As shown in fig. 7, the first gain amplifying circuit 211A includes a first operational amplifier, wherein during the touch detection, a non-inverting input terminal of the first operational amplifier is connected to the sensing electrode RXi, an inverting input terminal of the first operational amplifier is connected to the common mode voltage VCMI, the common mode voltage VCMI is half of the power supply voltage, an inverting output terminal of the first operational amplifier is connected to the non-inverting input terminal of the first operational amplifier via the feedback resistor Rf and the feedback capacitor Cf, and a non-inverting output terminal of the first operational amplifier is connected to the inverting input terminal of the first operational amplifier via the feedback resistor Rf and the feedback capacitor Cf. The current input-type AFE 210A may further include an Anti-aliasing filter circuit (Anti-ALIASING FILTER, AAF) 212A and an Analog-to-Digital Converter (ADC) 213A, etc., the AAF 212A being connected to the non-inverting output terminal and the inverting output terminal of the first operational amplifier for filtering the output signal of the first operational amplifier, and the ADC 213A for performing Analog-to-digital conversion on the filtered output signal. It should be appreciated that the current input type AFE may also include other circuits between the AAF 212A and the ADC 213A, such as sample and hold circuits, buffer circuits, and the like. In this embodiment, the original detection data obtained by detecting the signals on the plurality of sensing electrodes in the touch layer may be the signal Vout output by the first operational amplifier, or may be a digital signal obtained by processing the signal Vout output by the first operational amplifier through the AAF 212A and the ADC 213A. Since there is a one-to-one correspondence between the signal Vout output by the first operational amplifier and the digital signal obtained by processing it via the AAF 212A and the ADC 213A, hereinafter, vout also represents the digital signal obtained by processing the signal output by the first operational amplifier via the AAF 212A and the ADC 213A for convenience of description.

The analog front end circuit may also be an AFE210B of voltage input type as shown in fig. 8. The voltage input type AFE210B includes a second gain amplification circuit 211B, where the second gain amplification circuit 211B is configured to amplify the voltage signal variation on the sensing electrode RXi to obtain an amplified voltage signal Vout. The second gain amplification circuit includes a second operational amplifier. During touch detection, the non-inverting input of the second operational amplifier is connected to the sensing electrode RXi, and the non-inverting input of the second operational amplifier is also connected to the common mode voltage VCMI via the pull-up resistor Rb and a capacitor connected in parallel with the pull-up resistor Rb, and the inverting input of the second operational amplifier is connected to the common mode voltage VCMI. The common mode voltage VCMI is equal to half the supply voltage. The non-inverting input of the second operational amplifier is connected to the common mode voltage VCMI via a pull-up resistor, which biases the input signal of the second operational amplifier above 0V, so the AFE can amplify normally under single power supply. The positive output of the second operational amplifier is connected to the inverting input of the second operational amplifier via a feedback resistor Rf and a feedback capacitor Cf. The voltage input type AFE210B may also include an AAF 212B, an ADC 212B, and the like, where the AAF 212B is connected to the positive output terminal and the negative output terminal of the second operational amplifier, and is configured to perform filtering processing on the output signal Vout of the second operational amplifier, and the ADC 212B is configured to perform analog-to-digital conversion on the filtered output signal to obtain a digital signal.

It should be appreciated that the voltage input AFE may also include other circuitry between AAF 212B and ADC 213B, such as sample and hold circuitry, buffer circuitry, and the like. Similarly, in this embodiment, the original detection data obtained by detecting the signals on the plurality of sensing electrodes in the touch layer may refer to the signal Vout output by the second operational amplifier, or may refer to a digital signal obtained by processing the signal Vout output by the second operational amplifier through the AAF 212B and the ADC 213B. Since there is a one-to-one correspondence between the signal Vout output by the first operational amplifier and the digital signal obtained by processing it via the AAF 212B and the ADC 213B, vout also represents the digital signal obtained by processing the signal Vout output by the second operational amplifier via the AAF 212B and the ADC 213B, hereinafter for convenience of description.

It should be appreciated that the analog front end circuits described in fig. 7 and 8 are just one example. In addition, it should be understood that fig. 7 and fig. 8 only show the connection relationship between one analog front-end circuit and the sensing electrode in the signal detection module, and in practical application, the signal detection module includes a plurality of analog front-end circuits, each corresponding to one sensing electrode, for detecting a signal on the sensing electrode, so as to obtain original detection data corresponding to the sensing electrode.

S602, aiming at a target sensing electrode in the sensing electrodes, determining a display interference compensation value corresponding to the target sensing electrode;

Wherein the target sensing electrode comprises at least one of a plurality of sensing electrodes. The display interference compensation value is used for indicating the interference intensity of the display interference signal on the target induction electrode.

In this embodiment, after the raw detection data corresponding to the plurality of sensing electrodes is obtained, the sensing electrodes that are not touched are preliminarily determined based on the raw detection data corresponding to the plurality of sensing electrodes, and the target sensing electrode may include sensing electrodes other than the sensing electrode preliminarily determined to be touched among the plurality of sensing electrodes.

Due to the different impedances of the cathode plate and the system ground at different positions in the touch display panel and the difference of coupling capacitances between different sensing electrodes and the cathode plate (namely, the difference of physical model parameters of the touch display panel), inconsistent display interference noise data is mixed in original detection data obtained by detecting different sensing electrodes. For the target sensing electrode, the obtained original detection data contains components corresponding to the mutual capacitance variation and display interference noise. In order to better remove the display interference noise in the original detection data corresponding to the target sensing electrode, the corresponding display interference compensation value of the target sensing electrode needs to be acquired for the target sensing electrode.

And S603, correcting the original detection data corresponding to the target sensing electrode based on the display interference compensation value corresponding to the target sensing electrode to obtain target detection data corresponding to the target sensing electrode, so as to determine a touch detection result.

In one implementation of the present application, step S603 includes: and subtracting the display interference compensation value corresponding to the target sensing electrode from the original detection data corresponding to the target sensing electrode to obtain target detection data corresponding to the target sensing electrode.

Because the display interference compensation value indicates the interference intensity of the display interference signal on the target induction electrode, the original detection data corresponding to the target induction electrode is corrected by using the display interference compensation value corresponding to the target induction electrode, and the display interference noise corresponding to the target induction electrode can be better removed, so that the touch detection result is determined by using the corrected target detection data, and the accuracy of touch position detection can be ensured.

Based on the embodiment shown in fig. 6, in some embodiments of the application, step S602 includes:

And performing curve fitting based on the display interference gain coefficients corresponding to the sensing electrodes in the touch layer, and determining a display interference compensation value corresponding to the target sensing electrode based on the fitting result.

The display interference gain coefficient corresponding to each sensing electrode is related to the position of the sensing electrode in the touch control layer. Specifically, the corresponding display interference gain coefficient for each sense electrode is indicative of the relative gain value of the display interference signal coupled to each sense electrode. By performing curve fitting on the display interference gain coefficients corresponding to the sensing electrodes in the touch layer, the relation between different sensing electrodes and the corresponding display interference signal intensities can be obtained. Thus, based on the fitting result, the display interference compensation value corresponding to the target sensing electrode can be determined.

Specifically, in one implementation, based on the fitting result, determining the display interference compensation value corresponding to the target sensing electrode includes: and calculating a display interference compensation value corresponding to the target sensing electrode based on the fitting result and the original detection data of the sensing electrode which is preliminarily determined to be not touched by at least one of the sensing electrodes.

Because the original detection data of the sensing electrode which is not touched can reflect the interference intensity of the display interference signal of the sensing electrode under the current display picture and the display brightness, the interference intensity of the display interference signal of the target sensing electrode under the current display picture and the display brightness can be determined based on the fitting result and the original detection data of the sensing electrode which is preliminarily determined to be not touched by at least one of the sensing electrodes, the original detection data corresponding to the target sensing electrode is corrected by using the display interference compensation value, the display interference noise corresponding to the target sensing electrode can be better removed, the touch detection result is determined by using the target detection data obtained by correction, and the accuracy of touch position detection can be ensured.

As shown in fig. 9, in some embodiments of the present application, the display interference gain coefficient is obtained for each sensing electrode by:

s901, when the touch display panel is in a screen-off state, controlling to input a calibration excitation signal to an input end of an analog front-end circuit corresponding to an induction electrode so as to inject the calibration excitation signal into the induction electrode;

S902, detecting signals generated on the induction electrode in response to injection of the calibration excitation signals, and obtaining calibration detection data corresponding to the induction electrode;

s903, calculating a display interference gain coefficient corresponding to the sensing electrode according to the calibration detection data corresponding to the sensing electrode.

In this embodiment, the display interference gain coefficient is obtained when the touch display panel is in a screen-off state during a power-on process of the electronic device where the touch display panel is located, or when the touch display panel is in a screen-off state during a standby process of the electronic device. Since the touch display panel is in the off-screen state, the display layer does not display images, so that no display interference signal coupled to the sensing electrode exists at the moment. At this time, for each sensing electrode, the calibration detection data corresponding to the sensing electrode obtained by controlling the input of the calibration excitation signal to the input end of the analog front-end circuit corresponding to the sensing electrode, so as to inject the calibration excitation signal to the sensing electrode, and detecting the signal generated on the sensing electrode in response to the injection of the calibration excitation signal by the analog front-end circuit corresponding to the sensing electrode may reflect the magnitude of the relevant parameter of the display interference transmission path corresponding to the sensing electrode in the touch layer, that is, the magnitude of the physical model parameter corresponding to the sensing electrode in the touch layer. The calibration detection data corresponding to different sensing electrodes can reflect the difference of physical model parameters corresponding to different sensing electrodes, namely the difference of the impedance Z from the cathode plate corresponding to the position of the different sensing electrodes to the system ground and the difference of the coupling capacitance Cr2 between the different sensing electrodes and the cathode plate, and further, the calibration detection data corresponding to different sensing electrodes can reflect the difference of equivalent impedance Z' in the display interference model shown in FIG. 5. Since the gain values of the display interference signals coupled to different sensing electrodes depend on the equivalent impedance Z', the display interference gain coefficients corresponding to the sensing electrodes can be calculated according to the calibration detection data corresponding to the sensing electrodes.

In the present embodiment, step S901 may be performed by the excitation signal generation module 24 and the control module 23 in the touch detection circuit 20 shown in fig. 13, step S902 may be performed by the analog front end circuit 210 corresponding to the corresponding sensing electrode in the signal detection module 21 in fig. 12 and 13, and step S903 may be performed by the processing module 22 in fig. 12 and 13. For ease of understanding, a specific procedure for obtaining the display interference gain coefficient is described below by two implementations in conjunction with fig. 10 and 11.

In the first implementation of the present application, the analog front-end circuit employs the analog front-end circuit 210A shown in fig. 7, and in this embodiment, for each sensing electrode, the display interference gain coefficient is obtained by:

A1, when the touch display panel is in a screen-off state, controlling a non-inverting input end of a first gain amplifying circuit to be connected to an induction electrode, and controlling a calibration excitation signal to be input to an inverting input end of the first gain amplifying circuit;

And A2, detecting signals generated on the induction electrode in response to injection of the calibration excitation signals, and obtaining calibration detection data corresponding to the induction electrode.

And A3, calculating a display interference gain coefficient corresponding to the sensing electrode according to the calibration detection data corresponding to the sensing electrode.

The above-described process is specifically described below with reference to fig. 10. As shown in fig. 10, the non-inverting input terminal of the first gain amplification circuit 211A of the analog front-end circuit 210A is connected to the sense electrode RXi, and the inverting input terminal of the first gain amplification circuit 211A is connected to the excitation signal generation module 24 and the common mode voltage VCMI through the first switch SW 1. When the touch display panel is in the off-screen state, the control module (not shown) controls the first switch SW1 to be in the first closed state so that the excitation signal generation module 24 inputs the calibration excitation signal Vtest to the inverting input terminal of the first gain amplification circuit 211A. In this embodiment, the calibration excitation signal Vtest may be a sine wave signal having a certain current driving capability. The inverting input terminal of the first gain amplification circuit 211A is connected to the excitation signal generation module 24 when the first switch SW1 is in the first closed state, and the inverting input terminal of the first gain amplification circuit 211A is connected to the common mode voltage VCMI when the first switch SW1 is in the second closed state.

Due to the imaginary short characteristic between the positive input terminal and the negative input terminal of the first gain amplification circuit 211A, it is equivalent to providing the calibration excitation signal Vtest at the positive input terminal of the first gain amplification circuit 211A. The non-inverting input terminal of the first gain amplification circuit 211A is connected to the sense electrode RXi, which causes the calibration stimulus signal Vtest to be injected to the corresponding sense electrode RXi of the analog front-end circuit.

When the touch display panel is in the off-screen state, there is no display interference signal, and no driving signal is applied to the driving electrode. Z' in the dashed box on the left of Rxi represents the impedance Z of the cathode plate corresponding to the position of the sensing electrode to the system ground and the equivalent impedance of the coupling capacitance Cr2 between the sensing electrode and the cathode plate. After the calibration excitation signal Vtest is injected into the sensing electrode RXi, detecting a signal generated on the sensing electrode RXi in response to the injection of the calibration excitation signal Vtest to obtain calibration detection data Vout1 corresponding to the sensing electrode, where the calibration detection data Vout1 and the calibration excitation signal Vtest satisfy the following equation (1), and the equation (1) is:

Vout1＝Vtest*(1+Rf/Z’) (1)。

That is, the amplification transfer function of the calibration detection signal is Vout 1/vtest= (1+rf/Z').

During touch detection, the control module 23 controls the first switch SW1 to be in the second closed state, such that the inverting input terminal of the first gain amplifying circuit is connected to the common mode voltage VCMI. At this time, the amplification transfer function of the signal on the induction electrode is-Rf/Z'. Therefore, assuming that the display disturbance signal included in the signal on the induction electrode is Vnoise, and a component corresponding to the display disturbance signal in the output signal of the first gain amplification circuit 211A is represented by Vout2, the following equation (2) is satisfied between Vout2 and the display disturbance signal Vnoise, where equation (2) is:

Vout2＝-Vnoise*Rf/Z’ (2)。

That is, the amplification transfer function (i.e., gain factor) showing the interference signal is Vout 1/vnoise=rf/Z'. Based on the relationship between the amplification transfer function of the calibration detection signal and the amplification transfer function of the display interference signal, a display interference gain coefficient corresponding to the sensing electrode can be determined. Specifically, the value of Rf/Z ', that is, rf/Z ' = (Vout 1/Vtest-1) is calculated according to equation (1) and equation (2), and the calculated Rf/Z ' value is used as the display interference gain coefficient corresponding to the sensing electrode.

It should be appreciated that since the display interference gain coefficient corresponding to each sensing electrode indicates a relative gain value of the display interference signal coupled to each sensing electrode, rather than an absolute gain value, other values having a preset proportional relationship with the value of-Rf/Z' may also be used as the display interference gain coefficient.

In addition, there are a plurality of analog front end circuits corresponding to a plurality of sensing electrodes in the signal detection module, and due to manufacturing process deviation, a gain value of the first gain amplifying circuit in each analog front end circuit also generally has deviation, so as to further eliminate the process deviation, in one implementation manner of the present application, an initial display interference gain coefficient corresponding to the sensing electrode may be determined based on a relation between an amplifying transfer function of the calibration detection signal and an amplifying transfer function of the display interference signal, and the initial display interference gain coefficient is processed based on original detection data corresponding to the sensing electrode, and a processing result is used as a final display interference gain coefficient.

Specifically, the value of Rf/Z 'is calculated as the initial display interference gain coefficient a _f from Rf/Z' =vout 1/Vtest-1. Thereafter, a _f is processed according to equation (4), and the processing result is taken as a final display interference gain coefficient.

Where Cali denotes a final display interference gain coefficient, cali _t denotes a ratio between the actually acquired calibration detection data and the ideal calibration detection data in the absence of the gain error Δa of the first gain amplifier, specifically,A _f is the initial display interference gain coefficient.

Because the Cali considers the influence of the deviation of the gain value of the first gain amplifying circuit on the display interference signal, the Cali is used as the final display interference gain coefficient to more accurately reflect the relative gain value of the display interference signal, so that the influence of the display interference can be better eliminated based on the display interference gain coefficient, and the accuracy of touch detection is improved.

In addition, in one implementation, as shown in fig. 10, the excitation signal generation module 24 may include a digital-to-analog conversion circuit 241 and a buffer circuit 242 connected to an output of the digital-to-analog conversion circuit 241. The digital-to-analog conversion circuit 241 is used for generating an analog excitation signal, and the buffer circuit 242 is used for improving the current driving capability of the analog excitation signal, so that the calibration detection signal can be input to the first gain amplification circuit 211A corresponding to each sensing electrode through the same excitation signal generation module 24, and errors caused when the calibration detection signal is independently input to the second gain amplification circuit 211A corresponding to each sensing electrode through different excitation signal generation modules are avoided.

In a second implementation of the present application, the analog front end circuit employs analog front end circuit 210B shown in fig. 8. In the present embodiment, for each sensing electrode, the display interference gain coefficient is obtained by:

Step B1: when the touch display panel is in the off-screen state, the inverting input terminal of the second gain amplification circuit 211B is controlled to be connected to the common mode voltage VCMI, the non-inverting input terminal of the second gain amplification circuit 211B is controlled to be connected to the sensing electrode RXi, and the calibration excitation signal Vtest is controlled to be input to the non-inverting input terminal of the second gain amplification circuit 211B so as to be injected to the sensing electrode RXi.

And B2, detecting a signal generated on the sensing electrode Rxi in response to the injection of the calibration excitation signal Vtest to obtain calibration detection data corresponding to the sensing electrode.

And step B3, calculating a display interference gain coefficient corresponding to the sensing electrode according to the calibration detection data corresponding to the sensing electrode.

The above-described process is specifically described below with reference to fig. 11. The inverting input terminal of the second gain amplification circuit 211B of the analog front-end circuit 210B is connected to the common mode voltage VCMI, the non-inverting input terminal of the second gain amplification circuit 211B is connected to the sense electrode RXi via the second switch SW2, and the non-inverting input terminal of the second gain amplification circuit 211B is connected to the excitation signal generation module 24 and the common mode voltage VCMI via the third switch SW 3; when the touch display panel is in the off-screen state, the control module (not shown) controls the second switch SW2 to be in the closed state so that the non-inverting input terminal of the second gain amplifying circuit 211B is electrically connected to the sensing electrode RXi, and controls the third switch SW3 to be in the first closed state so that the excitation signal generating module 24 injects the calibration excitation signal Vtest into the non-inverting input terminal of the second gain amplifying circuit 211B. Specifically, as shown in fig. 11, when the third switch SW3 is in the first closed state, the non-inverting input terminal of the second gain amplifying circuit is connected to the excitation signal generation module 24 via the pull-up resistor Rb and the capacitor Cb connected in parallel to the pull-up resistor. Similar to the first implementation, the calibration excitation signal Vtest may be a sine wave signal having a certain current driving capability.

As shown in fig. 11, since the second switch SW2 is in the closed state and the third switch SW3 is in the first closed state, this causes the calibration excitation signal Vtest input to the non-inverting input terminal of the second gain amplification circuit 211B to be injected to the sense electrode RXi. When the touch display panel is in the off-screen state, there is no display interference signal, and no driving signal is applied to the driving electrode. Z' in the dashed box on the left of RXi represents the impedance Z of the cathode plate corresponding to the location of the sensing electrode RXi to system ground and the equivalent impedance of the coupling capacitance Cr2 between the sensing electrode RXi and the cathode plate. After the calibration excitation signal Vtest is injected into the sensing electrode RXi, detecting a signal generated on the sensing electrode RXi in response to the injection of the calibration excitation signal Vtest, so as to obtain calibration detection data Vout3 corresponding to the sensing electrode and the calibration excitation signal Vtest, where equation (5) is satisfied, where equation (5) is:

Vout3＝Vtest*G1*Z’/(Rb+Z’) (5)

Wherein G1 is the gain value of the second gain amplifying circuit.

From the above relation (5), Z '/(rb+z')=vout 3/(vtest×g1) can be calculated. For convenience of description, Z '/(rb+z') is represented by G2. .

During touch detection, the control module controls the second switch SW2 to be in a closed state so that the non-inverting input terminal of the second gain amplification circuit 211B is electrically connected to the sensing electrode RXi, and controls the third switch SW3 to be in a second closed state, and the non-inverting input terminal of the second gain amplification circuit 211B is connected to the common mode voltage. In the case where the display layer of the touch display panel is driven, there may be display interference. The interference gain factor is shown to be two parts, one part being caused by rb+z ', i.e. g3=rb/(rb+z'), and the other part being the gain value G1 of the second gain amplifying circuit. G3=1 to G2 can be calculated from the relationship between G2 and G3. Thus, since Vout3 and Vtest are known, in the case where the gain value G1 of the second gain amplifying circuit is known, the value of G3 can be calculated as the display interference gain coefficient. It should be appreciated that since the display interference gain coefficient corresponding to each sensing electrode indicates the relative gain value of the display interference signal coupled to each sensing electrode, other values in a preset proportional relationship with the value of G3 may also be used as the display interference gain coefficient.

In addition, each sensing electrode corresponds to an analog front end circuit, and for process reasons, gain values of the second gain amplifying circuits in different analog front end circuits are not identical, so as to more accurately determine the display interference gain coefficient, in one implementation manner of the present application, in the process of obtaining the display interference gain coefficient, the method further includes:

Step B4, when the touch display panel is in the off-screen state, controlling the inverting input end of the second gain amplification circuit 211B to be connected to the common-mode voltage VCMI, controlling the non-inverting input end of the second gain amplification circuit 211B to be disconnected from the sensing electrode, and controlling the injection of a calibration excitation signal to the non-inverting input end of the second gain amplification circuit 211B;

step B5, calculating the gain value of the second gain amplification circuit 211B according to the detection data acquired by the output signal of the second gain amplification circuit 211B.

Wherein step B4 and step B5 may be performed before step B1. Specifically, referring to fig. 11, when the touch display panel is in the off-screen state, the control module controls the second switch SW2 to be in an off-state to disconnect the non-inverting input terminal of the second gain amplification circuit 211B from the sensing electrode RXi, and controls the third switch to be in a first on-state, so that the excitation signal generation module 24 inputs the calibration excitation signal Vtest to the non-inverting input terminal of the second gain amplification circuit 211B. The analog front-end circuit 24 collects the calibration stimulus signal Vtest at the non-inverting input of the second gain amplification circuit 211B. The processing circuit calculates a gain value of the second gain amplification circuit 211B based on the acquired detection data.

As shown in fig. 11, when the first switch SW is turned off and the calibration excitation signal Vtest is input to the non-inverting input terminal of the second gain amplification circuit 211B, the relation (6) is satisfied between the detection data Vout4 collected by the front-end analog circuit 210B and the calibration excitation signal Vtest, and the relation (6) is:

Vout4＝Vtest*G1(6)

Wherein G1 is the gain value of the second gain amplification circuit 211B, and the gain value G1 of the second gain amplification circuit 211B can be calculated according to the relation (6).

Thereafter, the control module controls the second switch SW2 to be in a closed state so that the non-inverting input terminal of the second gain amplifying circuit 211B is electrically connected to the sensing electrode RXi, and controls the third switch SW3 to be in a first closed state so that the excitation signal generating module 24 injects the calibration excitation signal Vtest into the non-inverting input terminal of the second gain amplifying circuit 211B. Therefore, after the calibration excitation signal Vtest is injected into the sensing electrode, a signal generated on the sensing electrode in response to the injection of the calibration excitation signal is detected to obtain calibration detection data Vout3 corresponding to the sensing electrode, and the relationship (5) between Vout3 and the calibration excitation signal Vtest is satisfied. Based on G1 calculated in step B5, a value of g2=z '/(rb+z') can be calculated according to the relation (5).

As mentioned above, the interference gain factor is shown to be two parts, one part being caused by rb+z ', i.e., g3=rb/(rb+z'), and the other part being the gain value G1 of the second gain amplifying circuit. G3=1 to G2 can be calculated from the relationship between G2 and G3. Thereafter, from the product of G3 and G1, the display interference gain coefficient can be determined. It should be appreciated that since the display interference gain coefficient corresponding to each sensing electrode indicates the relative gain value of the display interference signal coupled to each sensing electrode, other values in a preset proportional relationship with the product of G3 x G1 may also be used as the display interference gain coefficient.

In this embodiment, since the influence of the difference of the physical model parameters corresponding to the different sensing electrodes in the touch display panel is considered when determining the display interference gain factor, the influence of the difference of the gain values of the analog front-end circuits corresponding to the different sensing electrodes (i.e., the gain values of the second gain amplifying circuit) is also considered, thereby determining the display interference gain factor more accurately.

In addition, in one implementation, as shown in fig. 11, the excitation signal generation module 214 may include a digital-to-analog conversion circuit 241 and a buffer circuit 242 connected to an output of the digital-to-analog conversion circuit. The digital-to-analog conversion circuit 241 is used for generating an analog excitation signal, and the buffer circuit 242 is used for improving the current driving capability of the analog excitation signal, so that the calibration detection signal can be input to the second gain amplification circuit 211B corresponding to each sensing electrode through the same excitation signal generation module, and errors caused when the calibration detection signal is independently input to the second gain amplification circuit 211B corresponding to each sensing electrode through different excitation signal generation modules are avoided.

Fig. 12 is a schematic structural diagram of a touch detection circuit for a touch display panel according to an embodiment of the present application. The touch display panel comprises a display layer and a touch layer, wherein the touch layer comprises a plurality of sensing electrodes. As shown in fig. 12, the touch detection circuit includes a signal detection module 21 and a processing module 22.

The signal detection module 21 is configured to detect signals on the plurality of sensing electrodes respectively, so as to obtain original detection data corresponding to each of the plurality of sensing electrodes, where the signals on the plurality of sensing electrodes include display interference signals;

The processing module 22 is configured to determine, for a target sensing electrode of a plurality of sensing electrodes, a display interference compensation value corresponding to the target sensing electrode, where the target sensing electrode includes at least one of the plurality of sensing electrodes, and the display interference compensation value is used to indicate an interference intensity of the display interference signal on the target sensing electrode.

The processing module 22 is further configured to correct the original detection data corresponding to the target sensing electrode based on the display interference compensation value corresponding to the target sensing electrode, so as to obtain target detection data corresponding to the target sensing electrode, which is used for determining the touch detection result.

In one implementation of the application, the processing module 22 is further configured to:

And performing curve fitting based on the display interference gain coefficients corresponding to the sensing electrodes, and determining a display interference compensation value corresponding to the target sensing electrode based on a fitting result, wherein the display interference gain coefficient corresponding to each sensing electrode is related to the position of the sensing electrode in the touch layer.

In one implementation of the present application, as shown in fig. 13, the touch detection circuit 20 further includes an excitation signal generation module 24 and a control module 23. The signal detection module 21 includes a plurality of analog front-end circuits 210, and the plurality of analog front-end circuits 210 respectively correspond to the plurality of sensing electrodes RXi. It should be appreciated that for ease of illustration, only one analog front end circuit 210 and a corresponding one of the sense electrodes are shown in fig. 13.

An excitation signal generation module 24 for generating a calibration excitation signal under the control of the control module 23;

a control module 23, configured to control the excitation signal generation module 24 to input calibration excitation signals to the input terminals of the plurality of analog front-end circuits 210 when the touch display panel is in the off-screen state, so as to inject the calibration excitation signals to the plurality of sensing electrodes RXi;

The analog front-end circuits 210 are respectively configured to detect signals generated on the sensing electrodes RXi in response to injection of the calibration excitation signals, so as to obtain calibration detection data corresponding to the sensing electrodes RXi; and

The processing module 22 is configured to calculate display interference gain coefficients corresponding to the plurality of sensing electrodes respectively according to the calibration detection data corresponding to the plurality of sensing electrodes respectively.

In one implementation of the present application, each analog front-end circuit 210 employs an analog front-end circuit 210A shown in fig. 7. As shown in fig. 10, the analog front-end circuit 210A includes a first gain amplification circuit 211A, a non-inverting input terminal of the first gain amplification circuit 211A is connected to the sense electrode RXi, and an inverting input terminal of the first gain amplification circuit 211A is connected to the excitation signal generation module 24 and the common mode voltage VCMI through a first switch SW 1;

The control module 23 is configured to control the first switch SW1 to be in a first closed state when the touch display panel is in an off-screen state, so that the excitation signal generating module 24 inputs the calibration excitation signal Vtest to the inverting input terminal of the first gain amplifying circuit to inject the calibration excitation signal Vtest to the sensing electrode RXi corresponding to the analog front-end circuit 210A.

In this implementation, as shown in fig. 10, the first gain amplification circuit 211A is a transimpedance gain amplification circuit.

In one implementation of the present application, each analog front-end circuit 210 employs an analog front-end circuit 210B shown in fig. 8. As shown in fig. 11, the analog front-end circuit 210B includes a second gain amplification circuit 211B, an inverting input terminal of the second gain amplification circuit 211B is connected to the common mode voltage, a non-inverting input terminal of the second gain amplification circuit 211B is connected to the sense electrode RXi via a second switch SW2, and a non-inverting input terminal of the second gain amplification circuit 211B is connected to the excitation signal generation module 24 and the common mode voltage VCMI via a third switch;

The control module 23 is configured to control the second switch SW2 to be in a closed state when the touch display panel is in an off-screen state, so that the non-inverting input terminal of the second gain amplification circuit 211B is electrically connected to the sensing electrode RXi corresponding to the analog front end circuit 210B, and control the third switch SW3 to be in a first closed state, so that the excitation signal generation module 24 injects the calibration excitation signal Vtest into the non-inverting input terminal of the second gain amplification circuit 211B to inject the calibration excitation signal Vtest into the sensing electrode RXi corresponding to the analog front end circuit 210B.

In a possible implementation manner of the present application, referring to fig. 11, the control module 23 is further configured to, when the touch display panel is in a screen-off state, control the second switch SW22 to be in an off state, so that the non-inverting input terminal of the second gain amplification circuit 211B is disconnected from the sensing electrode RXi corresponding to the analog front-end circuit 210B, and control the third switch SW3 to be in a first on state, so that the excitation signal generation module 24 injects the calibration excitation signal Vtest into the non-inverting input terminal of the second gain amplification circuit 211B;

A processing module for calculating the gain value of the second gain amplification circuit according to the detection data obtained by detecting the calibration excitation signal at the non-inverting input terminal of the second gain amplification circuit 211B

In a possible implementation manner of the present application, for each sensing electrode, the processing module 22 is configured to calculate, according to the calibration detection data corresponding to the sensing electrode and the gain value of the second gain amplifying circuit, a display interference gain coefficient corresponding to the sensing electrode.

In one possible implementation of the present application, the excitation signal generation module 24 includes a digital-to-analog conversion circuit and a buffer circuit connected to the digital-to-analog conversion circuit; the digital-to-analog conversion circuit is used for generating an analog excitation signal; the buffer circuit is used for improving the current driving capability of the analog excitation signal so as to obtain the calibration excitation signal.

The touch detection circuit provided by the embodiment of the present application is used for executing the operations of the foregoing method embodiments, and has the same beneficial effects as the foregoing method embodiments, and will not be described in detail herein.

The embodiment of the application provides a touch chip, which comprises: the touch detection circuit in any embodiment of the application.

The embodiment of the application also provides electronic equipment which comprises a touch display panel and the touch chip in any embodiment of the application.

The touch display panel in the present embodiment includes the touch display panel in the embodiment shown with reference to fig. 1 to 4. The electronic device of the embodiments of the present application exists in a variety of forms including, but not limited to:

(1) Mobile communication devices, which are characterized by mobile communication functionality and are aimed at providing voice, data communication. Such terminals include smart phones (e.g., iPhone), multimedia phones, functional phones, and low-end phones, among others.

(2) Ultra mobile personal computer equipment, which belongs to the category of personal computers, has the functions of calculation and processing and generally has the characteristic of mobile internet surfing. Such terminals include PDA, MID and UMPC devices, etc., such as iPad.

(3) Portable entertainment devices such devices can display and play multimedia content. Such devices include audio, video players (e.g., iPod), palm game consoles, electronic books, and smart toys and portable car navigation devices.

(4) The server, which is a device for providing computing services, is composed of a processor 810, a hard disk, a memory, a system bus, etc., and is similar to a general computer architecture, but is required to provide highly reliable services, and thus has high requirements in terms of processing power, stability, reliability, security, scalability, manageability, etc.

(5) Other electronic devices with data interaction function.

Thus, particular embodiments of the present subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may be advantageous.

In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, as relevant to see a section of the description of method embodiments.

The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and variations of the present application will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the application are to be included in the scope of the claims of the present application.

Claims

1. A touch detection method for a touch display panel, the touch display panel comprising a display layer and a touch layer, the touch layer comprising a plurality of sensing electrodes, the method comprising:

2. The method of claim 1, wherein the determining, for a target sensing electrode of the plurality of sensing electrodes, a display interference compensation value corresponding to the target sensing electrode comprises:

3. The method of claim 2, wherein for each sense electrode, the display interference gain factor is obtained by:

When the touch display panel is in a screen-off state, controlling to input a calibration excitation signal to an input end of an analog front-end circuit corresponding to the sensing electrode so as to inject the calibration excitation signal to the sensing electrode;

Detecting signals generated on the induction electrode in response to the injection of the calibration excitation signals to obtain calibration detection data corresponding to the induction electrode;

And calculating a display interference gain coefficient corresponding to the sensing electrode according to the calibration detection data corresponding to the sensing electrode.

4. A method according to claim 3, wherein the analog front end circuit comprises a first gain amplification circuit;

When the touch display panel is in a screen-off state, the control unit is configured to input a calibration excitation signal to an input end of an analog front-end circuit corresponding to the sensing electrode, so as to inject the calibration excitation signal to the sensing electrode, and the control unit comprises:

When the touch display panel is in a screen-off state, the non-inverting input end of the first gain amplifying circuit is controlled to be connected to the sensing electrode, and the calibration excitation signal is controlled to be input to the inverting input end of the first gain amplifying circuit so as to be injected into the sensing electrode.

5. The method of claim 3, wherein the analog front end circuit comprises a second gain amplification circuit,

When the touch display panel is in a screen-off state, controlling the inverting input end of the second gain amplifying circuit to be connected to a common mode voltage, controlling the non-inverting input end of the second gain amplifying circuit to be connected to the sensing electrode, and controlling the calibration excitation signal to be input to the non-inverting input end of the second gain amplifying circuit so as to be injected into the sensing electrode.

6. The method of claim 5, wherein the calculating the display interference gain factor corresponding to the sensing electrode according to the calibration detection data corresponding to the sensing electrode comprises:

and calculating a display interference gain coefficient corresponding to the sensing electrode according to the calibration detection data and the gain value of the second gain amplifying circuit.

7. The method of claim 6, further comprising:

When the touch display panel is in a screen-off state, controlling the inverting input end of the second gain amplifying circuit to be connected to a common mode voltage, controlling the non-inverting input end of the second gain amplifying circuit to be disconnected with the sensing electrode, and controlling the non-inverting input end of the second gain amplifying circuit to be input with the calibration excitation signal;

And calculating the gain value of the second gain amplifying circuit according to detection data obtained by detecting the calibration excitation signal at the non-phase input end of the second gain amplifying circuit.

8. The method of any of claims 3-7, wherein the calibration stimulus signal input to the analog front-end circuit for each sense electrode is generated by the same stimulus signal generation module.

9. The method of claim 8, wherein the excitation signal generation module comprises a digital-to-analog conversion circuit and a buffer circuit coupled to the digital-to-analog conversion circuit.

10. The method of claim 1, wherein correcting the raw detection data corresponding to the target sensing electrode based on the display interference compensation value corresponding to the target sensing electrode to obtain the target detection data corresponding to the target sensing electrode comprises:

And subtracting the display interference compensation value corresponding to the target sensing electrode from the original detection data corresponding to the target sensing electrode to obtain target detection data corresponding to the target sensing electrode.

11. A touch detection circuit for a touch display panel, the touch display panel including a display layer and a touch layer, the touch layer including a plurality of sensing electrodes, the touch detection circuit comprising:

12. The touch detection circuit of claim 11, wherein the processing module is specifically configured to:

13. The touch detection circuit of claim 12, further comprising: the signal detection module comprises a plurality of analog front-end circuits, and the analog front-end circuits respectively correspond to the sensing electrodes;

The excitation signal generation module is used for generating a calibration excitation signal under the control of the control module;

The control module is used for controlling the excitation signal generation module to input calibration excitation signals to the input ends of the plurality of analog front-end circuits when the touch display panel is in a screen-off state so as to inject the calibration excitation signals into the plurality of sensing electrodes;

The analog front-end circuits are respectively used for detecting signals generated by the induction electrodes in response to the injection of the calibration excitation signals to obtain calibration detection data corresponding to the induction electrodes; and

The processing module is used for respectively calculating display interference gain coefficients corresponding to the sensing electrodes according to the calibration detection data corresponding to the sensing electrodes.

14. The touch detection circuit of claim 13, wherein each analog front-end circuit comprises a first gain amplification circuit, a non-inverting input of the first gain amplification circuit is connected to a corresponding sense electrode of the analog front-end circuit, and an inverting input of the first gain amplification circuit is connected to the excitation signal generation module and a common mode voltage through a first switch;

And the control module is used for controlling the first switch to be in a first closed state when the touch display panel is in a screen-off state, so that the excitation signal generation module inputs the calibration excitation signal to the inverting input end of the first gain amplification circuit, and the calibration excitation signal is injected to the induction electrode corresponding to the analog front-end circuit.

15. The touch detection circuit of claim 13, wherein each of the analog front-end circuits comprises a second gain amplification circuit having an inverting input connected to a common mode voltage, a non-inverting input connected to a corresponding sense electrode of the analog front-end circuit via a second switch, and a non-inverting input connected to the excitation signal generation module and the common mode voltage via a third switch;

The control module is used for controlling the second switch to be in a closed state when the touch display panel is in a screen-off state, so that the normal phase input end of the second gain amplifying circuit is electrically connected to the sensing electrode corresponding to the analog front end circuit, and controlling the third switch to be in a first closed state, so that the excitation signal generating module injects the calibration excitation signal into the normal phase input end of the second gain amplifying circuit, so as to inject the calibration excitation signal into the sensing electrode corresponding to the analog front end circuit.

16. The touch detection circuit of claim 15, wherein, for each sensing electrode, the processing module is configured to calculate a display interference gain coefficient corresponding to the sensing electrode according to calibration detection data corresponding to the sensing electrode and a gain value of the second gain amplification circuit.

17. The touch detection circuit of claim 16, wherein,

The control module is further configured to control, when the touch display panel is in a screen-off state, the second switch to be in an off state, so that a non-inverting input end of the second gain amplification circuit is disconnected from an induction electrode corresponding to the analog front-end circuit, and control the third switch to be in a first on state, so that the excitation signal generation module injects the calibration excitation signal into the non-inverting input end of the second gain amplification circuit;

The processing module is configured to calculate a gain value of the second gain amplification circuit according to detection data obtained by detecting the calibration excitation signal at a non-inverting input end of the second gain amplification circuit.

18. The touch detection circuit according to any one of claims 13-17, wherein the excitation signal generation module comprises a digital-to-analog conversion circuit and a buffer circuit connected to the digital-to-analog conversion circuit,

The digital-to-analog conversion circuit is used for generating an analog excitation signal;

The buffer circuit is used for improving the current driving capability of the analog excitation signal so as to generate the calibration excitation signal.

19. A touch chip, comprising: the touch detection circuit of any of claims 11-18.

20. An electronic device comprising a touch display panel and the touch chip of claim 19.