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

Abstract

This application provides a touch detection method, touch detection circuit, touch chip, and electronic device for a touch display panel. The touch display panel includes a display layer and a touch layer, the touch layer including multiple sensing electrodes. The method includes: detecting signals on the multiple sensing electrodes respectively to obtain original detection data corresponding to each of the multiple sensing electrodes, wherein the signals on the multiple sensing electrodes include display interference signals; determining a display interference compensation value corresponding to a target sensing electrode among the multiple sensing electrodes, wherein the target sensing electrode includes at least one of the multiple sensing electrodes, and the display interference compensation value is used to indicate 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, for use in determining the touch detection result.

Description

Technical Field

[0001] This application relates to the field of touch technology, and in particular to a touch detection method, touch detection circuit, touch chip and electronic device for touch display panels. Background Technology

[0002] In recent years, as screens have become thinner, the distance between the touch layer and the display layer has become closer. This has led to a greater impact of various driving waveforms in the display layer due to data refresh on the touch layer. Consequently, the display interference coupled to the touch sensors in the touch layer has become more severe, ultimately resulting in a decrease in the accuracy of touch detection. Summary of the Invention

[0003] In view of the above, one of the technical problems solved by the embodiments of this application is to provide a touch detection method, touch detection circuit, touch chip and electronic device for touch display panel, so as to at least partially solve the above-mentioned technical problems.

[0004] In a first aspect, embodiments of this application provide a touch detection method 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 method comprising:

[0005] The signals on the plurality of sensing electrodes are detected respectively to obtain the original detection data corresponding to each of the plurality of sensing electrodes. The signals on the plurality of sensing electrodes include display interference signals.

[0006] For a target sensing electrode among the plurality of sensing electrodes, a display interference compensation value corresponding to the target sensing electrode is determined. The target sensing electrode includes at least one of the plurality of sensing electrodes. The display interference compensation value is used to indicate the interference intensity of the display interference signal on the target sensing electrode.

[0007] Based on the display interference compensation value corresponding to the target sensing electrode, the original detection data corresponding to the target sensing electrode is corrected to obtain the target detection data corresponding to the target sensing electrode, which is used to determine the touch detection result.

[0008] Secondly, embodiments of this application also provide 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, and the touch detection circuit including:

[0009] The signal detection module is used to detect the signals on the plurality of sensing electrodes respectively, and obtain the original detection data corresponding to each of the plurality of sensing electrodes. The signals on the plurality of sensing electrodes include display interference signals.

[0010] The processing module is used to determine a display interference compensation value corresponding to a target sensing electrode among the plurality of sensing electrodes, wherein the target sensing electrode includes at least one of the plurality of sensing electrodes, and the display interference compensation value is used to indicate the interference intensity of the display interference signal on the target sensing electrode;

[0011] 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 the target detection data corresponding to the target sensing electrode for determining the touch detection result.

[0012] Thirdly, embodiments of this application also provide a touch chip, including the touch detection circuit as provided in the second aspect.

[0013] Fourthly, embodiments of this application also provide an electronic device, including a touch display panel and a touch chip as provided in the third aspect.

[0014] In the technical solution provided in this application embodiment, signals on multiple sensing electrodes in the touch layer of a touch display panel are detected respectively to obtain original detection data corresponding to each of the multiple sensing electrodes. For a target sensing electrode among the multiple sensing electrodes, a display interference compensation value corresponding to the target sensing electrode is determined. Based on the display interference compensation value corresponding to the target sensing electrode, the original detection data corresponding to the target sensing electrode is corrected to obtain target detection data corresponding to the target sensing electrode, which is used to determine the touch detection result. Since the display interference compensation value indicates the interference intensity of the display interference signal on the target sensing electrode, using the display interference compensation coefficient corresponding to the target sensing electrode to correct the original detection data corresponding to the target sensing electrode can better remove the display interference noise corresponding to the target sensing electrode. Therefore, using the corrected target detection data to determine the touch detection result can ensure the accuracy of touch position detection. Attached Figure Description

[0015] The following sections will describe some specific embodiments of the present application in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0016] Figure 1 This is a schematic diagram of the stacked layers of the touch display panel provided in the embodiments of this application;

[0017] Figure 2 A top view of the touch display panel provided in the embodiments of this application;

[0018] Figure 3A schematic diagram of the display interference intensity in the RX direction of the touch display panel provided in the embodiments of this application;

[0019] Figure 4 A schematic diagram of the display interference intensity in the TX direction of the touch display panel provided in the embodiments of this application;

[0020] Figure 5 (a) to Figure 5 (c) A schematic diagram of the display interference model of the touch display panel provided in the embodiments of this application;

[0021] Figure 6 A schematic flowchart of a touch detection method for a touch display panel provided in an embodiment of this application;

[0022] Figure 7 This is a schematic diagram of the structure of a front-end analog circuit provided in an embodiment of this application;

[0023] Figure 8 This is a schematic diagram of another front-end analog circuit provided in an embodiment of this application;

[0024] Figure 9 A flowchart illustrating the method for obtaining display interference compensation coefficients provided in an embodiment of this application;

[0025] Figure 10 A schematic circuit diagram of a touch detection circuit provided in an embodiment of this application;

[0026] Figure 11 A schematic circuit diagram of another touch detection circuit provided in an embodiment of this application;

[0027] Figure 12 This is a schematic diagram of the structure of a touch detection circuit provided in an embodiment of this application;

[0028] Figure 13 This is a schematic diagram of another touch detection circuit provided in an embodiment of this application. Detailed Implementation

[0029] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0030] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0031] Reference Figure 1 , Figure 1 This is a schematic diagram of the stacked layers of a touch display panel for an electronic device. The electronic device may be a smartphone, smartwatch, tablet computer, laptop computer, automotive touchscreen, or other suitable electronic device. The touch display panel 10 includes a display layer 110 and a touch electrode layer 120 (also called a touch sensor or touch layer).

[0032] A cathode plate 130 is located above the display layer 110, providing a common voltage (also called a common voltage layer) for all pixels in the display array of the display layer 110, and is capacitively coupled to the touch layer via a thin film encapsulation (TFE) layer 140 of the organic light-emitting diode (OLED). The touch layer 120 is located above the TFE layer 140. Figure 2 As shown, the touch electrodes in the touch layer 120 include a plurality of driving electrodes TXI arranged along a first direction (i.e., the RX direction) and a plurality of sensing electrodes RXI arranged along a second direction (i.e., the TX direction), where i and j are positive integers greater than 1. The first direction is perpendicular to the second direction. Touch is detected via the mutual capacitance between the driving electrodes TXI and the sensing electrodes RXI.

[0033] Continue to refer to Figure 1 The cathode plate 130 is capacitively coupled to the touch layer 120, and the display layer 110 is capacitively coupled to the cathode plate 130. Therefore, a first coupling capacitor Cp1 is formed between the touch electrode in the touch layer 120 and the cathode plate 130, and a second coupling capacitor Cp2 is formed between the cathode plate 130 and the display layer 110 (specifically, displayed as a trace).

[0034] The display layer includes the display layer traces of the OLED light-emitting units. These display layer traces have various driving waveforms due to the continuous data refresh of the display layer. This driving waveform is coupled to the cathode 130 through the second coupling capacitor Cp2 between the display layer 110 and the cathode 130. The cathode 130 is coupled to the touch electrode through the first coupling capacitor Cp1 between it and the touch electrode, thereby causing the touch layer 120 to be coupled to display interference. With the development of OLED manufacturing technology, the thickness of the TFE layer 140 is becoming thinner and thinner, resulting in a larger and larger first coupling capacitor Cp1 between the cathode 130 and the touch electrode. This leads to increasingly severe display interference coupled to the touch sensor, thereby reducing the sensitivity and accuracy of touch detection.

[0035] like Figure 2As shown, one end of the cathode plate 130 is grounded. Specifically, the end of the cathode plate 130 closest to the display driver IC (DDIC) is connected to system ground (GND). Due to the resistivity of the cathode plate 130, the longer the path to system ground, the greater the impedance. That is, the impedance is greater at locations on the cathode plate farther from system ground. Correspondingly, the display interference is greater at locations on the cathode plate farther from system ground. Figure 2 As shown, the impedance at the position corresponding to the sensing electrode RXI on the cathode plate increases along the direction indicated by arrow D1, and the display interference is greater the further away the sensing electrode RXI is from DDIC. Figure 3 The display interference characteristics in the RX direction are shown. For example... Figure 3 As shown, along as Figure 2 The interference differences of the RX sensing electrodes distributed in the upward direction indicated by arrow D1 are arched.

[0036] Furthermore, due to manufacturing process variations, the thickness of the cathode plate 130 may not be entirely consistent (e.g., it may be thicker in the middle and thinner at both ends). Therefore, the distance between different touch electrodes in the touch layer 120 and the cathode plate may have random deviations, resulting in random deviations in the coupling capacitance between the different touch electrodes and the cathode plate. Because of these random deviations in the coupling capacitance between the different sensing electrodes in the touch electrodes and the cathode plate, and because of manufacturing process variations in the amplification factor of the analog front end (AFE) connected to the different sensing electrodes in the touch electrodes, this leads to... Figure 3 As shown, the interference is superimposed on the arch with a jagged shape.

[0037] Continue to refer to Figure 2 Since the grounding of the DDIC on the flexible printed circuit (PFC) is located on both sides, the cathode plate 130 is connected to the grounding of the DDIC through its left and right ends. Similarly, due to the resistivity of the cathode plate 130, the impedance in the middle of the cathode plate is high and the impedance on both sides is low. Correspondingly, for display interference in the TX direction, such as... Figure 4 As shown, the middle is larger than the two sides. This should be understood. Figure 4 Only the display interference characteristics, which are larger in the middle and smaller on both sides, are shown in the Tx direction. Due to differences in manufacturing processes, the coupling capacitance between different driving electrodes and the cathode plate also exhibits random deviations, i.e., in... Figure 4 A jagged pattern (not shown) will also be superimposed on the display interference in the Tx direction.

[0038] The following is further reference Figure 5 The display interference models shown in (a) to (c) further illustrate the reasons for the differences in display interference along the RX and TX directions. Figure 5 As shown, coupling capacitor Cr1 represents the coupling capacitance between the driving electrode TX and the cathode plate, coupling capacitor Cr2 represents the coupling capacitance between the sensing electrode RX and the cathode plate, and capacitance Cm represents the mutual capacitance between the driving electrode TX and the sensing electrode RX. Touch is detected by detecting the change in mutual capacitance Cm. Due to the process differences mentioned above, the coupling capacitances between different sensing electrodes and driving electrodes and the cathode plate vary; therefore, coupling capacitors Cr1 and Cr2 are both represented by variable capacitors. Furthermore, as mentioned above, the impedance from different positions of the cathode plate to system ground is different; therefore, a variable impedance Z is used to represent the impedance from different positions of the cathode plate to system ground. Current source Inoise represents the display interference current, and input resistance Rin represents the equivalent impedance of the circuit connection between the sensing electrode and the touch chip (specifically, the front-end circuitry in the touch chip). Figure 5 The display interference model described in (a) is obtained through equivalent changes in the current source and voltage source. Figure 5 The display interference model shown in (b) is as follows, where, Figure 5 The current source Inoise in the dashed box in (a) is equivalent to the parallel circuit of impedance Z, which is transformed into Figure 5 In diagram (b), the voltage source Vnoise is connected in series with the impedance Z, where Vnoise = Inoise * Z. From... Figure 5 As can be seen from the display interference model shown in (b), the display interference voltage Vnoise is equivalent to being transmitted to the touch chip through the impedance Z and the coupling capacitor Cr2.

[0039] To make it clearer, further... Figure 5 The equivalent model of the display interference shown in (b) is obtained. Figure 5 The display interference model in (c). Specifically, in Figure 5 As shown in (b), since the mutual capacitance Cm is much smaller than the coupling capacitance Cr2, the impedance corresponding to the mutual capacitance Cm is much larger than the impedance corresponding to the coupling capacitance Cr2, which is equivalent to an open circuit. Therefore, we obtain... Figure 5 The interference model shown in (c) is in the middle. Figure 5 In (c), the impedance Z' is equivalent to Figure 5 The series impedance Z from different positions of the cathode plate to system ground, the impedance corresponding to the coupling capacitor Cr2, and the impedance of the input resistance Rin are shown in the dashed box in (b). Figure 5 (a) and Figure 5As can be seen in (c), due to the different impedances of the cathode plates and system ground at different locations, as well as the differences in coupling capacitance between different sensing electrodes and the cathode plates (i.e., the differences in physical model parameters of the touch display panel), inconsistent display interference noise data is mixed in the original detection data obtained by detecting different sensing electrodes. This will lead to abnormal mutual capacitance data, which will be reflected in the touch position and cause phenomena such as dot appearance, dot disappearance, or coordinate jitter, thus affecting the accuracy of touch position detection on the touch display panel.

[0040] Therefore, this application obtains the display interference compensation value corresponding to the target sensing electrode in the touch layer of the touch display panel, and corrects the original detection data corresponding to the target sensing electrode based on the display interference compensation value, so as to remove the influence of display interference and improve the accuracy of touch detection.

[0041] The specific implementation of the embodiments of this application will be further described below with reference to the accompanying drawings.

[0042] Figure 6 A flowchart illustrating a touch detection method for a touch display panel according to an embodiment of this application is shown. The touch display panel includes a display layer and a touch layer, the touch layer including a plurality of sensing electrodes. Figure 6 As shown, the method includes:

[0043] S601. Detect the signals on multiple sensing electrodes in the touch layer to obtain the original detection data corresponding to each of the multiple sensing electrodes. The signals on the multiple sensing electrodes include display interference signals.

[0044] Specifically, during the driving period of the display layer, the display driving signal causes signal interference to the sensing electrodes. This interference signal includes the interference signal generated by the display layer on the sensing electrodes during the driving period. During touch detection, the touch detection circuit outputs a driving signal to the driving electrodes in the touch layer. Due to the mutual capacitance Cm between the driving electrodes and the sensing electrodes, a sensing signal is coupled to the sensing electrodes of the touch layer. When a touch occurs, the capacitance value of the mutual capacitance Cm between the driving electrode and the sensing electrode corresponding to the touch position changes; for example, the capacitance value of Cm decreases. Therefore, the sensing signal coupled to the sensing electrodes also changes. By detecting the amount of change in the sensing signal on the sensing electrodes, the touch coordinates can be determined.

[0045] As mentioned above, during the display layer's operation to display an image, the display layer traces exhibit various driving waveforms due to data refresh. During touch detection, these driving waveforms act as display interference and are coupled to the sensing electrodes. Therefore, the signals on the sensing electrodes also include display interference signals coupled to the sensing electrodes during the display layer's operation. Consequently, the raw detection data obtained by detecting the signals on the sensing electrodes in the touch layer contains display interference noise corresponding to the display interference signals.

[0046] In this embodiment, the signals on multiple sensing electrodes in the touch layer are detected by... Figure 12 This is achieved through the signal detection module 21 in the touch detection circuit 20 shown. Specifically, the signal detection module 21 includes multiple analog front-end circuits (AFE), each corresponding to a multiple sensing electrode, to detect the signals on the multiple sensing electrodes in the touch layer and obtain the raw detection data corresponding to the multiple sensing electrodes.

[0047] In one implementation, the analog front-end circuit can be as follows: Figure 7 The current-input type AFE 210A is shown. This current-input type AFE 210A includes a first gain amplifier circuit 211A, which can be a transimpedance amplifier circuit used to convert the change in current signal on the sensing electrode RXI into an amplified voltage signal Vout. For example... Figure 7As shown, the first gain amplifier circuit 211A includes a first operational amplifier. During touch detection, the non-inverting input of the first operational amplifier is connected to the sensing electrode RXI, and the inverting input is connected to the common-mode voltage VCMI, which is half of the power supply voltage. The inverting output of the first operational amplifier is connected to the non-inverting input via a feedback resistor Rf and a feedback capacitor Cf, and the non-inverting output is also connected to the inverting input via the feedback resistor Rf and the feedback capacitor Cf. The current-input type AFE 210A may also include an anti-aliasing filter (AAF) 212A and an analog-to-digital converter (ADC) 213A. The AAF 212A is connected to the non-inverting and inverting outputs of the first operational amplifier and is used to filter the output signal of the first operational amplifier. The ADC 213A is used to perform analog-to-digital conversion on the filtered output signal. It should be understood that the current-input type AFE may also include other circuits between AAF 212A and ADC 213A, such as sample-and-hold circuits and buffer circuits. In this embodiment, the raw detection data obtained by detecting the signals on multiple sensing electrodes in the touch layer can refer to the signal Vout output by the first operational amplifier, or it can refer to the digital signal obtained after processing the signal Vout output by the first operational amplifier through AAF 212A and 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 after processing by AAF 212A and ADC 213A, for ease of description, Vout will also refer to the digital signal obtained after processing the signal output by the first operational amplifier through AAF 212A and ADC 213A in the following text.

[0048] Analog front-end circuits can also be such as Figure 8The voltage-input type AFE 210B is shown. This voltage-input type AFE 210B includes a second gain amplifier circuit 211B, which amplifies the voltage signal change on the sensing electrode RXI to obtain an amplified voltage signal Vout. This second gain amplifier 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 is also connected to the common-mode voltage VCMI via a pull-up resistor Rb and a capacitor in parallel with the pull-up resistor Rb. The inverting input of the second operational amplifier is also connected to the common-mode voltage VCMI. The common-mode voltage VCMI is equal to half the power supply voltage. The connection of the non-inverting input of the second operational amplifier to the common-mode voltage VCMI via the pull-up resistor biases the input signal to the second operational amplifier to above 0V, thus allowing the AFE to amplify normally under single power supply. The non-inverting 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 AFE 210B may also include AAF 212B and ADC 212B, etc. The AAF 212B is connected to the non-inverting output terminal and the inverting output terminal of the second operational amplifier and is used to filter the output signal Vout of the second operational amplifier. The ADC 212B is used to perform analog-to-digital conversion on the filtered output signal to obtain a digital signal.

[0049] It should be understood that the voltage-input type AFE may also include other circuits between AAF 212B and ADC 213B, such as sample-and-hold circuits and buffer circuits. Similarly, in this embodiment, the raw detection data obtained by detecting the signals on multiple sensing electrodes in the touch layer can refer to the signal Vout output by the second operational amplifier, or it can refer to the digital signal obtained after processing the signal Vout output by the second operational amplifier through AAF 212B and 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 after processing by AAF 212B and ADC 213B, for ease of description, Vout will also refer to the digital signal obtained after processing the signal Vout output by the second operational amplifier through AAF 212B and ADC 213B in the following text.

[0050] It should be understood that Figure 7 and Figure 8 The analog front-end circuit described is merely an example. Furthermore, it should be understood that... Figure 7 and Figure 8The connection between one analog front-end circuit and the sensing electrode in the signal detection module is shown only. In practical applications, the signal detection module includes multiple analog front-end circuits, each corresponding to a sensing electrode, which is used to detect the signal on the sensing electrode and obtain the raw detection data corresponding to the sensing electrode.

[0051] S602. For the target sensing electrode among the plurality of sensing electrodes, determine the display interference compensation value corresponding to the target sensing electrode;

[0052] The target sensing electrode includes at least one of a plurality of sensing electrodes. The display interference compensation value is used to indicate the interference intensity of the display interference signal on the target sensing electrode.

[0053] In this embodiment, after obtaining the original detection data corresponding to multiple sensing electrodes, the sensing electrodes that have not been touched are initially determined based on the original detection data corresponding to multiple sensing electrodes. The target sensing electrode may include the sensing electrodes other than the sensing electrodes initially determined to be touched.

[0054] Due to the varying impedances of the cathode plates at different locations within the touch display panel to the system ground, as well as the differences in coupling capacitance between different sensing electrodes and the cathode plates (i.e., differences in the physical model parameters of the touch display panel), inconsistent display interference noise data is mixed in with the raw detection data obtained from detecting different sensing electrodes. For the target sensing electrode, the acquired raw detection data includes components corresponding to the mutual capacitance change and display interference noise. To better remove the display interference noise from the raw detection data corresponding to the target sensing electrode, it is necessary to obtain its corresponding display interference compensation value.

[0055] S603. Based on the display interference compensation value corresponding to the target sensing electrode, the original detection data corresponding to the target sensing electrode is corrected to obtain the target detection data corresponding to the target sensing electrode, which is used to determine the touch detection result.

[0056] In one implementation of this application, step S603 includes: 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 the target detection data corresponding to the target sensing electrode.

[0057] Since the display interference compensation value indicates the interference intensity of the display interference signal on the target sensing electrode, using the display interference compensation value corresponding to the target sensing electrode to correct the original detection data corresponding to the target sensing electrode can better remove the display interference noise corresponding to the target sensing electrode. Therefore, using the corrected target detection data to determine the touch detection result can ensure the accuracy of touch position detection.

[0058] based on Figure 6 In the embodiments shown, in some embodiments of this application, step S602 includes:

[0059] Curve fitting is performed based on the display interference gain coefficients corresponding to each of the multiple sensing electrodes in the touch layer, and the display interference compensation value corresponding to the target sensing electrode is determined based on the fitting results.

[0060] The display interference gain coefficient for each sensing electrode is related to its position in the touch layer. Specifically, the display interference gain coefficient for each sensing electrode indicates the relative gain value of the display interference signal coupled to each sensing electrode. By performing curve fitting on the display interference gain coefficients corresponding to multiple sensing electrodes in the touch layer, the relationship between different sensing electrodes and their corresponding display interference signal intensities can be obtained. Therefore, based on the fitting results, the display interference compensation value corresponding to the target sensing electrode can be determined.

[0061] Specifically, in one implementation, determining the display interference compensation value corresponding to the target sensing electrode based on the fitting results includes: calculating the display interference compensation value corresponding to the target sensing electrode based on the fitting results and the original detection data of at least one of the multiple sensing electrodes that is initially determined to be an untouched sensing electrode.

[0062] Since the raw detection data of the untouched sensing electrode can reflect the interference intensity of the display interference signal of the sensing electrode under the current display screen and display brightness, based on the fitting results and the raw detection data of at least one of the multiple sensing electrodes initially determined to be untouched, the interference intensity of the display interference signal of the target sensing electrode under the current display screen and display brightness can be determined. Using this display interference compensation value, the raw detection data corresponding to the target sensing electrode is corrected, which can better remove the display interference noise corresponding to the target sensing electrode. Thus, using the corrected target detection data to determine the touch detection result can ensure the accuracy of touch position detection.

[0063] like Figure 9 As shown, in some embodiments of this application, the interference gain coefficient for each sensing electrode is obtained in the following manner:

[0064] S901. When the touch display panel is in the off state, control inputs a calibration excitation signal to the input terminal of the analog front-end circuit corresponding to the sensing electrode, so as to inject the calibration excitation signal into the sensing electrode.

[0065] S902. Detect the signal generated on the sensing electrode in response to the injection of the calibration excitation signal to obtain the calibration detection data corresponding to the sensing electrode.

[0066] S903. Calculate the display interference gain coefficient corresponding to the sensing electrode based on the calibration and detection data corresponding to the sensing electrode.

[0067] In this embodiment, the display interference gain coefficient is obtained when the touch display panel is in a screen-off state during the power-on process of the electronic device containing the touch display panel, or when the touch display panel is in a screen-off state during the standby process of the electronic device. Since the touch display panel is in a screen-off state, the display layer does not display an image, so there is no display interference signal coupled to the sensing electrode at this time. At this time, for each sensing electrode, a calibration excitation signal is input to the input terminal of the analog front-end circuit corresponding to the sensing electrode to inject the calibration excitation signal into the sensing electrode. The calibration detection data corresponding to the sensing electrode obtained by detecting the signal generated on the sensing electrode in response to the injection of the calibration excitation signal through the analog front-end circuit corresponding to the sensing electrode can reflect the magnitude of the display interference transmission path related parameters in the touch layer corresponding to the sensing electrode, that is, the magnitude of the physical model parameters corresponding to the sensing electrode in the touch layer. The calibration detection data corresponding to different sensing electrodes can reflect the differences in the physical model parameters corresponding to different sensing electrodes, that is, the differences in the impedance Z from the cathode plate to the system ground corresponding to the location of different sensing electrodes and the coupling capacitance Cr2 between different sensing electrodes and the cathode plate. Furthermore, the calibration detection data corresponding to different sensing electrodes can reflect Figure 5 The diagram shows the differences in the equivalent impedance Z' in the interference model. Since the gain value of the display interference signal coupled to different sensing electrodes depends on the equivalent impedance Z', the display interference gain coefficient corresponding to the sensing electrode can be calculated based on the calibration test data corresponding to the sensing electrode.

[0068] In this embodiment, step S901 can be performed by... Figure 13 The excitation signal generation module 24 and control module 23 in the touch detection circuit 20 shown are used to execute step S902, which can be performed by... Figure 12 and Figure 13 The analog front-end circuit 210 corresponding to the corresponding sensing electrode in the signal detection module 21 is used to execute the signal detection module 21, and step S903 can be performed by... Figure 12 and Figure 13 The processing module 22 in the middle is used for execution. For ease of understanding, the following will be combined with the processing module 22. Figure 10 and Figure 11 The specific process of obtaining the display interference gain coefficient is illustrated through two implementation methods.

[0069] In the first implementation of this application, the analog front-end circuit adopts Figure 7 The analog front-end circuit 210A shown in this embodiment obtains the interference gain coefficient for each sensing electrode in the following way:

[0070] Step A1: When the touch display panel is in the off state, control the non-inverting input terminal of the first gain amplifier circuit to be connected to the sensing electrode, and control the input of the calibration excitation signal to the inverting input terminal of the first gain amplifier circuit.

[0071] Step A2: Detect the signal generated on the sensing electrode in response to the injection of the calibration excitation signal to obtain the calibration detection data corresponding to the sensing electrode.

[0072] Step A3: Calculate the display interference gain coefficient corresponding to the sensing electrode based on the calibration and detection data corresponding to the sensing electrode.

[0073] The following reference Figure 10 The above process will be explained in detail. For example... Figure 10 As shown, the non-inverting input of the first gain amplifier circuit 211A of the analog front-end circuit 210A is connected to the sensing electrode RXI, and the inverting input of the first gain amplifier circuit 211A is connected to the excitation signal generation module 24 and the common-mode voltage VCMI through the first switch SW1. When the touch display panel is in the off 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 of the first gain amplifier circuit 211A. In this embodiment, the calibration excitation signal Vtest can be a sine wave signal with a certain current driving capability. When the first switch SW1 is in the first closed state, the inverting input of the first gain amplifier circuit 211A is connected to the excitation signal generation module 24; when the first switch SW1 is in the second closed state, the inverting input of the first gain amplifier circuit 211A is connected to the common-mode voltage VCMI.

[0074] Due to the virtual short characteristic between the non-inverting and inverting input terminals of the first gain amplifier circuit 211A, it is equivalent to providing a calibration excitation signal Vtest at the non-inverting input terminal of the first gain amplifier circuit 211A. The non-inverting input terminal of the first gain amplifier circuit 211A is connected to the sensing electrode RXI, which allows the calibration excitation signal Vtest to be injected into the sensing electrode RXI corresponding to the analog front-end circuit.

[0075] When the touch display panel is in the off state, there is no display interference signal and no drive signal is applied to the drive electrode. Z' in the dashed box on the left of RXi represents the impedance Z from the cathode plate to the system ground corresponding to the location of the sensing electrode and the equivalent impedance of the coupling capacitance Cr2 between the sensing electrode and the cathode plate. When the calibration excitation signal Vtest is injected into the sensing electrode RXI, the signal generated on the sensing electrode RXI in response to the injection of the calibration excitation signal Vtest is detected to obtain the calibration detection data Vout1 corresponding to the sensing electrode. The calibration detection data Vout1 and the calibration excitation signal Vtest satisfy the following equation (1), which is:

[0076] Vout1=Vtest*(1+Rf / Z') (1).

[0077] That is, the amplification transfer function of the calibration detection signal is Vout1 / Vtest = (1+Rf / Z').

[0078] During touch detection, control module 23 controls the first switch SW1 to be in the second closed state, so that the inverting input terminal of the first gain amplifier circuit is connected to the common-mode voltage VCMI. At this time, the amplification transfer function of the signal on the sensing electrode is -Rf / Z'. Therefore, assuming that the display interference signal contained in the signal on the sensing electrode is Vnoise, and the component in the output signal of the first gain amplifier circuit 211A corresponding to the display interference signal is represented by Vout2, then Vout2 and the display interference signal Vnoise satisfy the following equation (2), which is:

[0079] Vout2=-Vnoise*Rf / Z'(2)

[0080] That is, the amplification transfer function (i.e., gain coefficient) of the display interference signal is Vout1 / 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, the display interference gain coefficient corresponding to the sensing electrode can be determined. Specifically, the value of Rf / Z' is calculated according to equations (1) and (2), i.e., Rf / Z' = (Vout1 / Vtest -1), and the calculated value of Rf / Z' is used as the display interference gain coefficient corresponding to the sensing electrode.

[0081] It should be understood 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, rather than the absolute gain value, other values ​​that are proportional to the value of -Rf / Z' can also be used as the display interference gain coefficient.

[0082] Furthermore, the signal detection module contains multiple analog front-end circuits corresponding to multiple sensing electrodes. Due to manufacturing process deviations, the gain value of the first gain amplifier circuit in each analog front-end circuit usually also has deviations. In order to further eliminate process deviations, in one implementation of this application, the initial display interference gain coefficient corresponding to the sensing electrode can be determined based on the relationship between the amplification transfer function of the calibration detection signal and the amplification transfer function of the display interference signal. The initial display interference gain coefficient is then processed based on the original detection data corresponding to the sensing electrode, and the processing result is used as the final display interference gain coefficient.

[0083] Specifically, the value of Rf / Z' is calculated based on Rf / Z'=Vout1 / Vtest -1 and used as the initial display interference gain coefficient. Subsequently, according to equation (4), The data is processed, and the processing result is used as the final display interference gain coefficient.

[0084] (4)

[0085] in, This represents the final display interference gain coefficient. This indicates that the actual acquired calibration test data has no gain error compared to the first gain amplifier. The ratio between ideal calibration test data under the given conditions, specifically, , This is the initial display of the interference gain coefficient.

[0086] because Considering the impact of the gain deviation of the first gain amplifier circuit on the display interference signal, therefore, the following is used: The final display interference gain coefficient can more accurately reflect the relative gain value of the display interference signal, thereby enabling the display interference gain coefficient to better eliminate the influence of display interference and improve the accuracy of touch detection.

[0087] Furthermore, in one implementation, such as Figure 10 As shown, the excitation signal generation module 24 may include a digital-to-analog converter circuit 241 and a buffer circuit 242 connected to the output of the digital-to-analog converter circuit 241. The digital-to-analog converter circuit 241 is used to generate an analog excitation signal, and the buffer circuit 242 is used to enhance the current driving capability of the analog excitation signal, so that the calibration detection signal can be input to the first gain amplifier circuit 211A corresponding to each sensing electrode through the same excitation signal generation module 24, thereby avoiding the error caused by using different excitation signal generation modules to input calibration detection signals to the second gain amplifier circuit 211A corresponding to each sensing electrode separately.

[0088] In the second implementation of this application, the analog front-end circuit adopts Figure 8 The analog front-end circuit 210B is shown. In this embodiment, the interference gain coefficient for each sensing electrode is obtained in the following way:

[0089] Step B1: When the touch display panel is in the off state, control the inverting input terminal of the second gain amplifier circuit 211B to connect to the common mode voltage VCMI, control the non-inverting input terminal of the second gain amplifier circuit 211B to connect to the sensing electrode RXI, and control the input of the calibration excitation signal Vtest to the non-inverting input terminal of the second gain amplifier circuit 211B so as to inject the calibration excitation signal Vtest into the sensing electrode RXI.

[0090] Step B2: Detect the signal generated on the sensing electrode RXI in response to the injection of the calibration excitation signal Vtest to obtain the calibration detection data corresponding to the sensing electrode.

[0091] Step B3: Calculate the display interference gain coefficient corresponding to the sensing electrode based on the calibration and detection data corresponding to the sensing electrode.

[0092] The following reference Figure 11 The above process is explained in detail. The inverting input of the second gain amplifier circuit 211B of the analog front-end circuit 210B is connected to the common-mode voltage VCMI. The non-inverting input of the second gain amplifier circuit 211B is connected to the sensing electrode RXI via the second switch SW2, and the non-inverting input of the second gain amplifier circuit 211B is connected to the excitation signal generation module 24 and the common-mode voltage VCMI via the third switch SW3. When the touch display panel is in the off state, the control module (not shown) controls the second switch SW2 to be closed, so that the non-inverting input of the second gain amplifier 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 generation module 24 injects the calibration excitation signal Vtest into the non-inverting input of the second gain amplifier circuit 211B. Specifically, as shown... Figure 11 As shown, when the third switch SW3 is in the first closed state, the non-inverting input of the second gain amplifier circuit is connected to the excitation signal generation module 24 via a pull-up resistor Rb and a capacitor Cb connected in parallel with the pull-up resistor. Similar to the first implementation, the calibration excitation signal Vtest can be a sine wave signal with a certain current driving capability.

[0093] like Figure 11As shown, since the second switch SW2 is in the closed state and the third switch SW3 is in the first closed state, the calibration excitation signal Vtest, which is input to the non-inverting input terminal of the second gain amplifier circuit 211B, is injected into the sensing electrode RXI. When the touch display panel is in the off state, there is no display interference signal, and no drive signal is applied to the driving electrode. Z' in the dashed box to the left of RXI represents the impedance Z from the cathode plate to the system ground corresponding to the location of the sensing electrode RXI 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, the signal generated on the sensing electrode RXI in response to the injection of the calibration excitation signal Vtest is detected, and the calibration detection data Vout3 corresponding to the sensing electrode satisfies the equation (5) with the calibration excitation signal Vtest. The equation (5) is:

[0094] Vout3=Vtest*G1*Z' / (Rb+Z') (5)

[0095] Wherein, G1 is the gain value of the second gain amplifier circuit.

[0096] According to the above relation (5), Z' / (Rb+Z') = Vout3 / (Vtest * G1) can be calculated. For ease of description, Z' / (Rb+Z') is represented by G2.

[0097] During touch detection, the control module controls the second switch SW2 to be closed, so that the non-inverting input of the second gain amplifier circuit 211B is electrically connected to the sensing electrode RXI, and controls the third switch SW3 to be closed, so that the non-inverting input of the second gain amplifier circuit 211B is connected to the common-mode voltage. When the display layer of the touch display panel is driven, display interference may exist. The display interference gain coefficient has two parts: one part is caused by Rb+Z', i.e., G3=Rb / (Rb+Z'), and the other part is the gain value G1 of the second gain amplifier circuit. Based on the relationship between G2 and G3, G3=1-G2 can be calculated. Therefore, since Vout3 and Vtest are known, the value of G3 can be calculated as the display interference gain coefficient when the gain value G1 of the second gain amplifier circuit is known. It should be understood 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 ​​that are proportional to the value of G3 can also be used as display interference gain coefficients.

[0098] Furthermore, each sensing electrode corresponds to an analog front-end circuit. Due to manufacturing processes, the gain values ​​of the second gain amplifier circuits in different analog front-end circuits are not entirely the same. To more accurately determine the display interference gain coefficient, in one implementation of this application, the process of obtaining the display interference gain coefficient further includes:

[0099] Step B4: When the touch display panel is in the off state, control the inverting input terminal of the second gain amplifier circuit 211B to be connected to the common mode voltage VCMI, control the non-inverting input terminal of the second gain amplifier circuit 211B to be disconnected from the sensing electrode, and control the injection of a calibration excitation signal into the non-inverting input terminal of the second gain amplifier circuit 211B.

[0100] Step B5: Calculate the gain value of the second gain amplifier circuit 211B based on the detection data obtained by collecting the output signal of the second gain amplifier circuit 211B.

[0101] Steps B4 and B5 can be performed before step B1. Specifically, refer to... Figure 11 When the touch display panel is in the off state, the control module controls the second switch SW2 to be in the open state, disconnecting the non-inverting input terminal of the second gain amplifier circuit 211B from the sensing electrode RXI, and controls the third switch to be in the first closed 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 amplifier circuit 211B. The analog front-end circuit 24 acquires the calibration excitation signal Vtest at the non-inverting input terminal of the second gain amplifier circuit 211B. The processing circuit calculates the gain value of the second gain amplifier circuit 211B based on the acquired detection data.

[0102] like Figure 11 As shown, when the first switch SW is disconnected and the calibration excitation signal Vtest is input to the non-inverting input terminal of the second gain amplifier circuit 211B, the detection data Vout4 collected by the front-end analog circuit 210B satisfies the relationship (6) with the calibration excitation signal Vtest. The relationship (6) is as follows:

[0103] Vout4=Vtest*G1(6)

[0104] Wherein, G1 is the gain value of the second gain amplifier circuit 211B. According to the relationship (6), the gain value G1 of the second gain amplifier circuit 211B can be calculated.

[0105] Subsequently, the control module controls the second switch SW2 to be closed, so that the non-inverting input terminal of the second gain amplifier circuit 211B is electrically connected to the sensing electrode RXI, and controls the third switch SW3 to be closed, so that the excitation signal generation module 24 injects the calibration excitation signal Vtest into the non-inverting input terminal of the second gain amplifier circuit 211B. Therefore, after the calibration excitation signal Vtest is injected into the sensing electrode, the signal generated on the sensing electrode in response to the injection of the calibration excitation signal is detected to obtain the calibration detection data Vout3 corresponding to the sensing electrode. The relationship between Vout3 and the calibration excitation signal Vtest is satisfied by the above-mentioned equation (5). Based on G1 calculated in step B5, the value of G2=Z' / (Rb+Z') can be calculated according to the relationship (5).

[0106] As mentioned above, the display interference gain coefficient consists of two parts: one part is caused by Rb+Z', i.e., G3=Rb / (Rb+Z'), and the other part is the gain value G1 of the second gain amplifier circuit. Based on the relationship between G2 and G3, G3=1-G2 can be calculated. Subsequently, the display interference gain coefficient can be determined based on the product of G3 and G1. It should be understood 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 ​​that have a preset proportional relationship with the product of G3*G1 can also be used as the display interference gain coefficient.

[0107] In this embodiment, since the influence of the difference in physical model parameters corresponding to different sensing electrodes in the touch display panel is considered not only when determining the display interference gain coefficient, but also when considering the difference in the gain value of the analog front-end circuit (i.e. the gain value of the second gain amplifier circuit) corresponding to different sensing electrodes, the display interference gain coefficient can be determined more accurately.

[0108] Furthermore, in one implementation, such as Figure 11 As shown, the excitation signal generation module 214 may include a digital-to-analog converter circuit 241 and a buffer circuit 242 connected to the output of the digital-to-analog converter circuit. The digital-to-analog converter circuit 241 is used to generate an analog excitation signal, and the buffer circuit 242 is used to enhance the current driving capability of the analog excitation signal, so that the calibration detection signal can be input to the second gain amplifier circuit 211B corresponding to each sensing electrode through the same excitation signal generation module, thereby avoiding the error caused by using different excitation signal generation modules to input calibration detection signals to the second gain amplifier circuit 211B corresponding to each sensing electrode separately.

[0109] Figure 12 This is a schematic diagram of a touch detection circuit for a touch display panel provided in an embodiment of this application. The touch display panel includes a display layer and a touch layer, and the touch layer includes multiple sensing electrodes. Figure 12 As shown, the touch detection circuit includes a signal detection module 21 and a processing module 22.

[0110] Signal detection module 21 is used to detect the signals on multiple sensing electrodes respectively to obtain the original detection data corresponding to each of the multiple sensing electrodes. The signals on the multiple sensing electrodes include display interference signals.

[0111] Processing module 22 is used to determine a display interference compensation value corresponding to a target sensing electrode among a plurality of sensing electrodes. The target sensing electrode includes at least one of the plurality of sensing electrodes. The display interference compensation value is used to indicate the interference intensity of the display interference signal on the target sensing electrode.

[0112] The processing module 22 is also used 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 the target detection data corresponding to the target sensing electrode for determining the touch detection result.

[0113] In one implementation of this application, the processing module 22 is further configured to:

[0114] Curve fitting is performed based on the display interference gain coefficients corresponding to each of the multiple sensing electrodes, and the display interference compensation value corresponding to the target sensing electrode is determined based on the fitting results. The display interference gain coefficient corresponding to each sensing electrode is related to the position of the sensing electrode in the touch layer.

[0115] In one implementation of this application, such as Figure 13 As shown, the touch detection circuit 20 also includes an excitation signal generation module 24 and a control module 23. The signal detection module 21 includes multiple analog front-end circuits 210, each corresponding to a multiple sensing electrode RXI. It should be understood that, for ease of illustration, Figure 13 Only one analog front-end circuit 210 and a corresponding sensing electrode are shown.

[0116] The excitation signal generation module 24 is used to generate a calibration excitation signal under the control of the control module 23;

[0117] The control module 23 is used to control the excitation signal generation module 24 to input calibration excitation signals to the input terminals of multiple analog front-end circuits 210 when the touch display panel is in the off state, so as to inject the calibration excitation signals into the multiple sensing electrodes RXI.

[0118] Multiple analog front-end circuits 210 are used to detect the signals generated on multiple sensing electrodes RXI in response to the injection of a calibration excitation signal, respectively, to obtain calibration detection data corresponding to each of the multiple sensing electrodes RXI; and

[0119] Processing module 22 is used to calculate the display interference gain coefficient corresponding to each of the multiple sensing electrodes based on the calibration and detection data corresponding to each of the multiple sensing electrodes.

[0120] In one implementation of this application, each analog front-end circuit 210 adopts Figure 7 The analog front-end circuit 210A is shown. (For example...) Figure 10 As shown, the analog front-end circuit 210A includes a first gain amplifier circuit 211A. The non-inverting input terminal of the first gain amplifier circuit 211A is connected to the sensing electrode RXI, and the inverting input terminal of the first gain amplifier circuit 211A is connected to the excitation signal generation module 24 and the common-mode voltage VCMI through the first switch SW1.

[0121] The control module 23 is used to control the first switch SW1 to be in the first closed state when the touch display panel is in the off state, so that the excitation signal generation module 24 inputs the calibration excitation signal Vtest to the inverting input terminal of the first gain amplifier circuit, so as to inject the calibration excitation signal Vtest into the sensing electrode RXI corresponding to the analog front-end circuit 210A.

[0122] In this implementation, such as Figure 10 As shown, the first gain amplifier circuit 211A is a transimpedance gain amplifier circuit.

[0123] In one implementation of this application, each analog front-end circuit 210 adopts Figure 8 The analog front-end circuit 210B is shown. (For example...) Figure 11 As shown, the analog front-end circuit 210B includes a second gain amplifier circuit 211B. The inverting input terminal of the second gain amplifier circuit 211B is connected to the common-mode voltage, the non-inverting input terminal of the second gain amplifier circuit 211B is connected to the sensing electrode RXI via the second switch SW2, and the non-inverting input terminal of the second gain amplifier circuit 211B is connected to the excitation signal generation module 24 and the common-mode voltage VCMI via the third switch.

[0124] The control module 23 is used to control the second switch SW2 to be closed when the touch display panel is in the off state, so that the non-inverting input terminal of the second gain amplifier circuit 211B is electrically connected to the sensing electrode RXI corresponding to the analog front-end circuit 210B, and to control the third switch SW3 to be in the 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 amplifier circuit 211B, so as to inject the calibration excitation signal Vtest into the sensing electrode RXI corresponding to the analog front-end circuit 210B.

[0125] In one possible implementation of this application, reference is made to... Figure 11 The control module 23 is also used to control the second switch SW22 to be in the open state when the touch display panel is in the off state, so that the non-inverting input terminal of the second gain amplifier circuit 211B is disconnected from the sensing electrode RXI corresponding to the analog front-end circuit 210B, and to control the third switch SW3 to be in the 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 amplifier circuit 211B.

[0126] The processing module is used to calculate the gain value of the second gain amplifier circuit based on the detection data obtained by detecting the calibration excitation signal at the non-inverting input terminal of the second gain amplifier circuit 211B.

[0127] In one possible implementation of this application, for each sensing electrode, the processing module 22 is used to calculate the display interference gain coefficient corresponding to the sensing electrode based on the calibration detection data corresponding to the sensing electrode and the gain value of the second gain amplifier circuit.

[0128] In one possible implementation of this application, the excitation signal generation module 24 includes a digital-to-analog converter circuit and a buffer circuit connected to the digital-to-analog converter circuit; the digital-to-analog converter circuit is used to generate an analog excitation signal; the buffer circuit is used to enhance the current driving capability of the analog excitation signal to obtain a calibration excitation signal.

[0129] The touch detection circuit provided in this application embodiment is used to perform the operations of the aforementioned method embodiment, and has the same beneficial effects as the aforementioned method embodiment, which will not be described in detail here.

[0130] This application provides a touch chip, including: the touch detection circuit in any embodiment of this application.

[0131] This application also provides an electronic device, which includes a touch display panel and a touch chip in any embodiment of this application.

[0132] The touch display panel in this embodiment includes a reference. Figures 1 to 4 The touch display panel in the illustrated embodiment. The electronic device of this application embodiment exists in various forms, including but not limited to:

[0133] (1) Mobile communication devices: These devices are characterized by their mobile communication capabilities and primarily aim to provide voice and data communication. These terminals include: smartphones (e.g., iPhones), multimedia phones, feature phones, and low-end phones, etc.

[0134] (2) Ultra-mobile personal computer devices: These devices fall under the category of personal computers, possessing computing and processing capabilities, and generally also have mobile internet access features. These terminals include PDAs, MIDs, and UMPCs, such as the iPad.

[0135] (3) Portable entertainment devices: These devices can display and play multimedia content. This category includes audio and video players (such as iPods), handheld game consoles, e-book readers, as well as smart toys and portable car navigation devices.

[0136] (4) Server: A device that provides computing services. The components of a server include a processor 810, hard disk, memory, system bus, etc. Servers are similar to general computer architectures, but because they need to provide highly reliable services, they have higher requirements in terms of processing power, stability, reliability, security, scalability, and manageability.

[0137] (5) Other electronic devices with data interaction functions.

[0138] Specific embodiments of the subject matter have now been described. Other embodiments are within the scope of the appended claims. In some cases, the actions described in the claims can be performed in a different order and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing can be advantageous.

[0139] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0140] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this 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: The signals on the plurality of sensing electrodes are detected respectively to obtain the original detection data corresponding to each of the plurality of sensing electrodes. The signals on the plurality of sensing electrodes include display interference signals. For a target sensing electrode among the plurality of sensing electrodes, a display interference compensation value corresponding to the target sensing electrode is determined. The target sensing electrode includes at least one of the plurality of sensing electrodes. The display interference compensation value is used to indicate the interference intensity of the display interference signal on the target sensing electrode. Based on the display interference compensation value corresponding to the target sensing electrode, the original detection data corresponding to the target sensing electrode is corrected to obtain the target detection data corresponding to the target sensing electrode, which is used to determine the touch detection result. The step of determining the display interference compensation value corresponding to the target sensing electrode among the plurality of sensing electrodes includes: Curve fitting is performed based on the display interference gain coefficients corresponding to each of the plurality of sensing electrodes, and the display interference compensation value corresponding to the target sensing electrode is determined based on the fitting results. The display interference gain coefficient corresponding to each sensing electrode is related to the position of the sensing electrode in the touch layer. For each sensing electrode, the display interference gain coefficient is obtained in the following way: When the touch display panel is in a screen-off state, a calibration excitation signal is input to the input terminal of the analog front-end circuit corresponding to the sensing electrode, so as to inject the calibration excitation signal into the sensing electrode. The signal generated on the sensing electrode in response to the injection of the calibration excitation signal is detected to obtain calibration detection data corresponding to the sensing electrode. The calibration detection data indicates the magnitude of the display interference transmission path related parameters corresponding to the sensing electrode in the touch layer. Calculate the display interference gain coefficient corresponding to the sensing electrode based on the calibration and detection data corresponding to the sensing electrode.

2. The method of claim 1, wherein, The analog front-end circuit includes a first gain amplifier circuit; When the touch display panel is in a screen-off state, controlling the input of a calibration excitation signal to the input terminal of the analog front-end circuit corresponding to the sensing electrode, so as to inject the calibration excitation signal into the sensing electrode, includes: When the touch display panel is in a screen-off state, the non-inverting input terminal of the first gain amplifier circuit is connected to the sensing electrode, and the calibration excitation signal is input to the inverting input terminal of the first gain amplifier circuit to inject the calibration excitation signal into the sensing electrode.

3. The method of claim 1, wherein, The analog front-end circuit includes a second gain amplifier circuit. When the touch display panel is in a screen-off state, controlling the input of a calibration excitation signal to the input terminal of the analog front-end circuit corresponding to the sensing electrode, so as to inject the calibration excitation signal into the sensing electrode, includes: When the touch display panel is in a screen-off state, the inverting input terminal of the second gain amplifier circuit is connected to the common-mode voltage, the non-inverting input terminal of the second gain amplifier circuit is connected to the sensing electrode, and the calibration excitation signal is input to the non-inverting input terminal of the second gain amplifier circuit to inject the calibration excitation signal into the sensing electrode.

4. The method of claim 3, wherein, The step of calculating the display interference gain coefficient corresponding to the sensing electrode based on the calibration detection data corresponding to the sensing electrode includes: Based on the calibration and detection data and the gain value of the second gain amplifier circuit, the display interference gain coefficient corresponding to the sensing electrode is calculated.

5. The method according to claim 4, further comprising: When the touch display panel is in the off state, the inverting input terminal of the second gain amplifier circuit is connected to the common mode voltage, the non-inverting input terminal of the second gain amplifier circuit is disconnected from the sensing electrode, and the calibration excitation signal is input to the non-inverting input terminal of the second gain amplifier circuit. The gain value of the second gain amplifier circuit is calculated based on the detection data obtained by detecting the calibration excitation signal at the non-inverting input terminal of the second gain amplifier circuit.

6. The method of any one of claims 1-5, wherein, The calibration excitation signal input to the analog front-end circuit corresponding to each sensing electrode is generated by the same excitation signal generation module.

7. The method of claim 6, wherein, The excitation signal generation module includes a digital-to-analog converter circuit and a buffer circuit connected to the digital-to-analog converter circuit.

8. The method of claim 1, wherein, Based on the display interference compensation value corresponding to the target sensing electrode, the original detection data corresponding to the target sensing electrode is corrected to obtain the target detection data corresponding to the target sensing electrode, including: The target detection data corresponding to the target sensing electrode is obtained by subtracting the display interference compensation value corresponding to the target sensing electrode from the original detection data corresponding to the target sensing electrode.

9. 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 including: The signal detection module is used to detect the signals on the plurality of sensing electrodes respectively, and obtain the original detection data corresponding to each of the plurality of sensing electrodes. The signals on the plurality of sensing electrodes include display interference signals. The processing module is used to determine a display interference compensation value corresponding to a target sensing electrode among the plurality of sensing electrodes, wherein the target sensing electrode includes at least one of the plurality of sensing electrodes, and the display interference compensation value is used to indicate the 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 the target detection data corresponding to the target sensing electrode for determining the touch detection result; The processing module is specifically used to: perform curve fitting based on the display interference gain coefficients corresponding to each of the plurality of sensing electrodes, and determine the display interference compensation value corresponding to the target sensing electrode based on the fitting results, wherein the display interference gain coefficient corresponding to each sensing electrode is related to the position of the sensing electrode in the touch layer; The touch detection circuit further includes: an excitation signal generation module and a control module. The signal detection module includes multiple analog front-end circuits, each of which corresponds to a multiple sensing electrode. The excitation signal generation module is used to generate a calibration excitation signal under the control of the control module. The control module is used to control the excitation signal generation module to input a calibration excitation signal to the input terminals 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 signal into the plurality of sensing electrodes. The plurality of analog front-end circuits are respectively used to detect the signals generated on the plurality of sensing electrodes in response to the injection of the calibration excitation signal, to obtain calibration detection data corresponding to each of the plurality of sensing electrodes, wherein the calibration detection data indicates the magnitude of the display interference transmission path related parameters corresponding to the sensing electrodes in the touch layer; and The processing module is used to calculate the display interference gain coefficient corresponding to each of the plurality of sensing electrodes based on the calibration and detection data corresponding to each of the plurality of sensing electrodes.

10. The touch detection circuit of claim 9, wherein, Each of the analog front-end circuits includes a first gain amplifier circuit, the non-inverting input of the first gain amplifier circuit is connected to the sensing electrode corresponding to the analog front-end circuit, and the inverting input of the first gain amplifier circuit is connected to the excitation signal generation module and the common-mode voltage through a first switch. The control module is used to control 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 terminal of the first gain amplifier circuit, so as to inject the calibration excitation signal into the sensing electrode corresponding to the analog front-end circuit.

11. The touch detection circuit of claim 9, wherein, Each of the analog front-end circuits includes a second gain amplifier circuit, the inverting input of which is connected to a common-mode voltage, the non-inverting input of which is connected to the corresponding sensing electrode of the analog front-end circuit via a second switch, and the non-inverting input of which is connected to the excitation signal generation module and the common-mode voltage via a third switch. The control module is configured to, when the touch display panel is in a screen-off state, control the second switch to be in a closed state so that the non-inverting input terminal of the second gain amplifier circuit is electrically connected to the sensing electrode corresponding to the analog front-end circuit, and control the third switch to be in a first closed state so that the excitation signal generation module injects the calibration excitation signal into the non-inverting input terminal of the second gain amplifier circuit so as to inject the calibration excitation signal into the sensing electrode corresponding to the analog front-end circuit.

12. The touch detection circuit of claim 11, wherein, For each of the aforementioned sensing electrodes The processing module is used to calculate the display interference gain coefficient corresponding to the sensing electrode based on the calibration detection data corresponding to the sensing electrode and the gain value of the second gain amplifier circuit.

13. The touch detection circuit according to claim 12, wherein, The control module is further configured to, when the touch display panel is in a screen-off state, control the second switch to be in an open state so that the non-inverting input terminal of the second gain amplifier circuit is disconnected from the sensing electrode corresponding to the analog front-end circuit, and control the third switch to be in a first closed state so that the excitation signal generation module injects the calibration excitation signal into the non-inverting input terminal of the second gain amplifier circuit. The processing module is used to calculate the gain value of the second gain amplifier circuit based on the detection data obtained by detecting the calibration excitation signal at the non-inverting input terminal of the second gain amplifier circuit.

14. The touch detection circuit according to any one of claims 9-13, wherein the excitation signal generation module includes a digital-to-analog converter circuit and a buffer circuit connected to the digital-to-analog converter circuit. The digital-to-analog converter circuit is used to generate analog excitation signals; The buffer circuit is used to enhance the current driving capability of the analog excitation signal in order to generate the calibration excitation signal.

15. A touch chip comprising: The touch detection circuit as described in any one of claims 9-14.

16. An electronic device comprising a touch display panel and a touch chip according to claim 15.

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