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

Abstract

Embodiments of the present application provide a touch detection method and touch detection circuit for a touch display panel, a touch chip, and an electronic device. The touch display panel comprises a display layer and a touch layer, and the touch layer comprises a plurality of sensing electrodes. The method comprises: separately detecting signals on a plurality of sensing electrodes to obtain pieces of original detection data respectively corresponding to the plurality of sensing electrodes, the signals on the plurality of sensing electrodes comprising display interference signals; for a target sensing electrode among the plurality of sensing electrodes, determining a display interference compensation value corresponding to the target sensing electrode, the target sensing electrode comprising at least one of the plurality of sensing electrodes, and the display interference compensation value being used for indicating the interference intensity of the display interference signal on the target sensing electrode; and, on the basis of the display interference compensation value corresponding to the target sensing electrode, correcting original detection data corresponding to the target sensing electrode to obtain target detection data corresponding to the target sensing electrode for determining the result of touch detection.

Description

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

[0001] The embodiments of the present application relate to the field of touch technology, and in particular to a touch detection method, a touch detection circuit, a touch chip, and an electronic device for a touch display panel. Background Art

[0002] In recent years, as screens have become thinner, the distance between the touch layer and the display layer in the screen has become closer, resulting in the various driving waveforms of the display layer due to refresh data having an increasingly greater impact on the touch layer. The display interference coupled to the touch sensor in the touch layer has become increasingly serious, ultimately resulting in a decrease in the accuracy of touch detection.

[0003] Summary of the Invention

[0004] In view of this, one of the technical problems 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, so as to at least partially solve the above technical problems.

[0005] In a first aspect, an embodiment of the present application provides a touch detection method for a touch display panel, wherein the touch display panel includes a display layer and a touch layer, and the touch layer includes a plurality of sensing electrodes. The method includes:

[0006] detecting signals on the plurality of sensing electrodes respectively to obtain original detection data corresponding to the plurality of sensing electrodes, wherein the signals on the plurality of sensing electrodes include display interference signals;

[0007] determining, for a target sensing electrode among the plurality of sensing electrodes, a display interference compensation value corresponding to the target sensing electrode, the target sensing electrode including at least one of the plurality of sensing electrodes, the display interference compensation value being used to indicate interference intensity of the display interference signal on the target sensing electrode;

[0008] 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, so as to determine the touch detection result.

[0009] In a second aspect, an embodiment of the present application further provides a touch detection circuit for a touch display panel, wherein 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:

[0010] a signal detection module, configured to detect signals on the plurality of sensing electrodes respectively to obtain original detection data corresponding to the plurality of sensing electrodes, wherein the signals on the plurality of sensing electrodes include display interference signals;

[0011] a processing module, configured to determine, for a target sensing electrode among the plurality of sensing electrodes, a display interference compensation value corresponding to the target sensing electrode, the target sensing electrode including at least one of the plurality of sensing electrodes, the display interference compensation value being used to indicate an interference intensity of the display interference signal on the target sensing electrode;

[0012] 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 to obtain target detection data corresponding to the target sensing electrode for determining a touch detection result.

[0013] In a third aspect, an embodiment of the present application further provides a touch chip, comprising the touch detection circuit provided in the second aspect.

[0014] In a fourth aspect, an embodiment of the present application further provides an electronic device, comprising a touch display panel and a touch chip as provided in the third aspect.

[0015] In the technical solution provided by the embodiments of the present application, signals on multiple sensing electrodes in the touch layer of a touch display panel are separately detected to obtain raw detection data corresponding to each of the multiple sensing electrodes. A display interference compensation value corresponding to a target sensing electrode among the multiple sensing electrodes is determined. Based on the display interference compensation value corresponding to the target sensing electrode, the raw 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 a touch detection result. Because the display interference compensation value indicates the interference intensity of the display interference signal on the target sensing electrode, correcting the raw detection data corresponding to the target sensing electrode using the display interference compensation coefficient corresponding to the target sensing electrode 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Hereinafter, some specific embodiments of the present application will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the drawings:

[0017] FIG1 is a schematic diagram of the stacking of a touch display panel provided in an embodiment of the present application;

[0018] FIG2 is a top view of a touch display panel provided in an embodiment of the present application;

[0019] FIG3 is a schematic diagram of display interference intensity in the RX direction of a touch display panel provided by an embodiment of the present application;

[0020] FIG4 is a schematic diagram showing the display interference intensity in the TX direction of a touch display panel provided by an embodiment of the present application;

[0021] 5a to 5c are schematic diagrams of a display interference model of a touch display panel provided in an embodiment of the present application;

[0022] FIG6 is a schematic flow chart of a touch detection method for a touch display panel provided in an embodiment of the present application;

[0023] FIG7 is a schematic diagram of the structure of a front-end analog circuit provided in an embodiment of the present application;

[0024] FIG8 is a schematic diagram of the structure of another front-end analog circuit provided in an embodiment of the present application;

[0025] FIG9 is a flow chart of a method for obtaining a display interference compensation coefficient according to an embodiment of the present application;

[0026] FIG10 is a schematic circuit diagram of a touch detection circuit provided in an embodiment of the present application;

[0027] FIG11 is a schematic circuit diagram of another touch detection circuit provided in an embodiment of the present application;

[0028] FIG12 is a schematic structural diagram of a touch detection circuit provided in an embodiment of the present application;

[0029] FIG13 is a schematic structural diagram of another touch detection circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] The technical solution in this application will be described below with reference to the accompanying drawings.

[0031] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field should fall within the scope of protection of the embodiments of the present application.

[0032] Referring to FIG1 , FIG1 is a schematic diagram of the stacking structure of a touch display panel for an electronic device. The electronic device may be a smartphone, smartwatch, tablet computer, laptop computer, in-vehicle 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).

[0033] A cathode plate 130 is located above the display layer 110. This plate provides 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. As shown in FIG2 , the touch electrodes in the touch layer 120 include a plurality of drive 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 drive electrodes TXi and the sensing electrodes RXi.

[0034] 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 electrodes 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, shown as a trace).

[0035] The display layer includes the display layer wiring of the OLED light-emitting unit. These display layer wiring has various drive waveforms due to the continuous data refresh of the display layer. This drive waveform is coupled to the cathode plate 130 via the second coupling capacitor Cp2 between the display layer 110 and the cathode plate 130. The cathode plate 130 is coupled to the touch electrode via the first coupling capacitor Cp1 between the cathode plate 130 and the touch electrode, thereby coupling the touch layer 120 to the display interference. With the development of OLED manufacturing technology, the thickness of the TFE layer 140 has become thinner and thinner, resulting in an increasing first coupling capacitor Cp1 between the cathode plate 130 and the touch electrode. As a result, the display interference coupled to the touch sensor has become increasingly serious, thereby reducing the sensitivity and accuracy of touch detection.

[0036] As shown in Figure 2, one end of the cathode plate 130 is grounded. Specifically, the end of the cathode plate 130 near the display driver IC (DDIC) is connected to the system ground GND. Due to the resistivity of the cathode plate 130, the longer the path to the system ground, the greater the impedance. In other words, the impedance increases at locations on the cathode plate farther from the system ground. Correspondingly, the display interference increases at locations on the cathode plate farther from the system ground. As shown in Figure 2, the impedance at locations on the cathode plate corresponding to the sensing electrodes RXi increases along the direction indicated by arrow D1, and the display interference increases the further away the sensing electrodes RXi are from the DDIC. Figure 3 shows the display interference characteristics in the RX direction. As shown in Figure 3, the display interference differences of the RX sensing electrodes distributed along the bottom-up direction indicated by arrow D1 in Figure 2 are arched.

[0037] In addition, due to process variations, the thickness of the cathode plate 130 may not be completely consistent (for example, it may be thicker in the middle and thinner at the ends). Therefore, the distances between different touch electrodes in the touch layer 120 and the cathode plate may vary randomly, resulting in random variations in the coupling capacitance between different touch electrodes and the cathode plate. Due to the random variations in the coupling capacitance between different sensing electrodes in the touch electrodes and the cathode plate, as well as due to process variations in the amplification factor of the analog front end (AFE) connected to the different sensing electrodes in the touch electrodes, the display interference appears as a sawtooth superimposed on the arch, as shown in FIG3 .

[0038] Continuing to refer to Figure 2, since the grounding of the DDIC is located on both sides of the flexible printed circuit (PFC), 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 large and the impedance on both sides is small. Accordingly, for the display interference in the TX direction, as shown in Figure 4, the impedance in the middle is large and the impedance on both sides is small. It should be understood that Figure 4 only shows the display interference characteristics in the Tx direction, which are large in the middle and small on both sides. Due to process differences, in fact, there are random deviations in the coupling capacitance between different drive electrodes and the cathode plate, that is, a sawtooth shape (not shown) is superimposed on the display interference in the Tx direction shown in Figure 4.

[0039] The following further details the reasons why the display interference along the RX direction and the TX direction differ with reference to the display interference model shown in (a) to (c) of Figure 5. As shown in Figure 5, the coupling capacitor Cr1 represents the coupling capacitance between the drive electrode TX and the cathode plate, the coupling capacitor Cr2 represents the coupling capacitance between the sensing electrode RX and the cathode plate, and the capacitor Cm represents the mutual capacitance between the drive electrode TX and the sensing electrode RX. Touch is detected by detecting the capacitance change of the mutual capacitance Cm. Due to the influence of the process differences mentioned above, there are differences in the coupling capacitance between different sensing electrodes and drive electrodes and the cathode plate. Therefore, the coupling capacitors Cr1 and Cr2 are both represented by variable capacitors. In addition, as mentioned above, the impedance from different positions of the cathode plate to the system ground is different, so the variable impedance Z is used to represent the impedance from different positions of the cathode plate to the system ground. The current source Inoise represents the display interference current, and the input resistor Rin represents the equivalent impedance of the circuit connection between the sensing electrode and the touch chip (specifically, the front-end circuit in the touch chip). The display interference model described in Figure 5(a) is obtained by equivalently changing the current source and voltage source to the display interference model shown in Figure 5(b). The parallel circuit of the current source Inoise and the impedance Z in the dashed box in Figure 5(a) is equivalently converted to the series circuit of the voltage source Vnoise and the impedance Z in Figure 5(b), where Vnoise = Inoise * Z. As can be seen from the display interference model shown in Figure 5(b), the display interference voltage Vnoise is equivalent to being transmitted to the touch chip through the impedance Z and the coupling capacitor Cr2.

[0040] For the sake of clarity, the display interference model shown in Figure 5 (b) is further equivalent to obtain the display interference model of Figure 5 (c). Specifically, as shown in Figure 5 (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, the display interference model of Figure 5 (c) is obtained. The impedance Z' in Figure 5 (c) is equivalent to the series value of the impedance Z from the different positions of the cathode plate in the dotted box in Figure 5 (b) to the system ground, the impedance corresponding to the coupling capacitance Cr2, and the impedance of the input resistor Rin. As can be seen from FIG5(a) and FIG5(c), due to the different impedances between the cathode plates at different positions and the system ground, and 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), the original detection data obtained by detecting different sensing electrodes is mixed with inconsistent display interference noise data, which will lead to abnormal mutual capacitance data. When reflected in the touch position, it will cause phenomena such as popping or disappearing points or coordinate jitter, thereby affecting the accuracy of touch position detection on the touch display panel.

[0041] To this end, in this application, 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 to remove the influence of display interference and improve the accuracy of touch detection.

[0042] The specific implementation of the embodiment of the present application is further explained below in conjunction with the accompanying drawings of the embodiment of the present application.

[0043] FIG6 shows a flow chart of a touch detection method for a touch display panel according to an embodiment of the present application. The touch display panel includes a display layer and a touch layer, and the touch layer includes a plurality of sensing electrodes. As shown in FIG6 , the method includes:

[0044] S601, detecting signals on a plurality of sensing electrodes in the touch layer to obtain original detection data corresponding to each of the plurality of sensing electrodes, where the signals on the plurality of sensing electrodes include a display interference signal;

[0045] Specifically, when the display layer is in the driving period, the display driving signal causes signal interference to the sensing electrode. The display interference signal includes the interference signal generated by the display layer on the sensing electrode when it is in the driving period. During the touch detection period, the touch detection circuit outputs a driving signal to the driving electrode in the touch layer. Due to the mutual capacitance Cm coupled between the driving electrode and the sensing electrode, the sensing electrode of the touch layer will be coupled to the sensing signal. When there is a touch, the capacitance value of the mutual capacitance Cm between the driving electrode and the sensing electrode corresponding to the touch position will change. For example, the capacitance value of the mutual capacitance Cm decreases. Therefore, the sensing signal coupled to the sensing electrode will also change. By detecting the change in the sensing signal on the sensing electrode, the touch coordinates can be determined.

[0046] As mentioned above, when the display layer is driven to display images, the display layer traces have various drive waveforms due to refresh data. During touch detection, these drive waveforms couple to the sensing electrodes as display interference. Therefore, the signals on the sensing electrodes also include the display interference signals coupled to the sensing electrodes during the display layer's driving period. Accordingly, 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.

[0047] In this embodiment, the detection of signals on the multiple sensing electrodes in the touch layer is implemented by the signal detection module 21 in the touch detection circuit 20 shown in FIG12 . Specifically, the signal detection module 21 includes multiple analog front-end circuits (AFEs), each corresponding to the multiple sensing electrodes. The AFEs detect the signals on the multiple sensing electrodes in the touch layer and obtain raw detection data corresponding to the multiple sensing electrodes.

[0048] In one implementation, the analog front-end circuit can be a current-input AFE 210A as shown in FIG7 . The current-input AFE 210A includes a first gain amplifier circuit 211A, which can be a transimpedance amplifier circuit for converting the change in the current signal on the sensing electrode RXi into an amplified voltage signal Vout. As shown in FIG7 , 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, the inverting input of the first operational amplifier is connected to the common-mode voltage VCMI, which is half the power supply voltage, and the inverting output of the first operational amplifier is connected to the non-inverting input of the first operational amplifier via a feedback resistor Rf and a feedback capacitor Cf. The non-inverting output of the first operational amplifier is connected to the inverting input of the first operational amplifier via the feedback resistor Rf and the feedback capacitor Cf. The current-input AFE 210A may further 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 output terminals of the first operational amplifier and is configured to filter the output signal of the first operational amplifier. The ADC 213A is configured to perform analog-to-digital conversion on the filtered output signal. It should be understood that the current-input AFE may further include other circuits between the AAF 212A and the ADC 213A, such as a sample-and-hold circuit and a buffer circuit. In this embodiment, the raw detection data obtained by detecting the signals on the multiple sensing electrodes in the touch layer may refer to the signal Vout output by the first operational amplifier, or may refer to the digital signal obtained after the signal Vout output by the first operational amplifier is processed by 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 after the signal is processed by the AAF 212A and the ADC 213A, hereinafter, for ease of description, Vout also represents the digital signal obtained after the signal output by the first operational amplifier is processed by the AAF 212A and the ADC 213A.

[0049] The analog front-end circuit can also be a voltage-input AFE 210B as shown in FIG8 . This voltage-input AFE 210B includes a second gain amplifier circuit 211B, which is used to amplify the change in the voltage signal on the sensing electrode RXi to obtain an amplified voltage signal Vout. The 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. The non-inverting input of the second operational amplifier 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 connected to the common-mode voltage VCMI. The common-mode voltage VCMI is equal to half the power supply voltage. The non-inverting input of the second operational amplifier is connected to the common-mode voltage VCMI via the pull-up resistor, which can bias the input signal to the second operational amplifier to above 0V, so that the AFE can amplify normally when powered by a 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 AFE 210B may also include an AAF 212B and an ADC 212B. The AAF 212B is connected to the positive-phase output terminal and the negative-phase 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.

[0050] It should be understood that a voltage-input AFE may also include other circuits between the AAF 212B and the ADC 213B, such as a sample-and-hold circuit and a buffer circuit. Similarly, in this embodiment, the raw detection data obtained by detecting the signals on the multiple sensing electrodes in the touch layer may refer to the signal Vout output by the second operational amplifier, or may refer to the digital signal obtained after the signal Vout output by the second operational amplifier is processed by the AAF 212B and the ADC 213B. Because there is a one-to-one correspondence between the signal Vout output by the first operational amplifier and the digital signal obtained after the signal Vout is processed by the AAF 212B and the ADC 213B, for ease of description below, Vout also refers to the digital signal obtained after the signal Vout output by the second operational amplifier is processed by the AAF 212B and the ADC 213B.

[0051] It should be understood that the analog front-end circuits shown in Figures 7 and 8 are merely examples. Furthermore, it should be understood that Figures 7 and 8 illustrate only the connection between one analog front-end circuit and the sensing electrodes in the signal detection module. In actual applications, the signal detection module includes multiple analog front-end circuits, each corresponding to a sensing electrode, for detecting the signal on that sensing electrode and obtaining raw detection data corresponding to that sensing electrode.

[0052] S602: determining, for a target sensing electrode among the plurality of sensing electrodes, a display interference compensation value corresponding to the target sensing electrode;

[0053] 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.

[0054] In this embodiment, after obtaining raw detection data corresponding to the plurality of sensing electrodes, untouched sensing electrodes are preliminarily determined based on the raw detection data corresponding to the plurality of sensing electrodes. The target sensing electrodes may include sensing electrodes among the plurality of sensing electrodes excluding the sensing electrodes preliminarily determined to be touched.

[0055] Due to the varying impedances between the cathode plate and system ground at different locations on the touch display panel, as well as differences in coupling capacitance between different sensing electrodes and the cathode plate (i.e., differences in the physical model parameters of the touch display panel), the raw detection data obtained from different sensing electrodes contains inconsistent display interference noise data. For a target sensing electrode, the raw detection data obtained includes a component corresponding to the change in mutual capacitance 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 a display interference compensation value for that target sensing electrode.

[0056] S603 : Based on the display interference compensation value corresponding to the target sensing electrode, correct the original detection data corresponding to the target sensing electrode to obtain target detection data corresponding to the target sensing electrode for determining a touch detection result.

[0057] In one implementation of the present 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.

[0058] Since the display interference compensation value indicates the interference intensity of the display interference signal on the target sensing electrode, the display interference compensation value corresponding to the target sensing electrode is used to correct the original detection data corresponding to the target sensing electrode, which can better remove the display interference noise corresponding to the target sensing electrode. Therefore, the touch detection result is determined using the corrected target detection data, which can ensure the accuracy of touch position detection.

[0059] Based on the embodiment shown in FIG6 , in some embodiments of the present application, step S602 includes:

[0060] Curve fitting is performed based on the display interference gain coefficients corresponding to the plurality of sensing electrodes in the touch layer, and based on the fitting result, a display interference compensation value corresponding to the target sensing electrode is determined.

[0061] The display interference gain coefficient corresponding to each sensing electrode is related to the position of that sensing electrode in the touch layer. Specifically, 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. By performing curve fitting on the display interference gain coefficients corresponding to each of the multiple sensing electrodes in the touch layer, the relationship between different sensing electrodes and the intensity of their corresponding display interference signals can be obtained. Based on the fitting results, the display interference compensation value corresponding to the target sensing electrode can be determined.

[0062] Specifically, in one implementation, determining the display interference compensation value corresponding to the target sensing electrode based on the fitting result includes calculating the display interference compensation value corresponding to the target sensing electrode based on the fitting result and original detection data of at least one sensing electrode preliminarily determined to be untouched among the multiple sensing electrodes.

[0063] Since the raw detection data of the untouched sensing electrode can reflect the interference strength of the display interference signal of the sensing electrode under the current display screen and display brightness, based on the fitting result and the raw detection data of at least one sensing electrode preliminarily determined to be untouched among the multiple sensing electrodes, the interference strength 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. Therefore, the touch detection result is determined using the corrected target detection data, which can ensure the accuracy of touch position detection.

[0064] As shown in FIG9 , in some embodiments of the present application, for each sensing electrode, the display interference gain coefficient is obtained in the following manner:

[0065] S901, when the touch display panel is in a screen-off state, controlling the input of a calibration excitation signal to an input end of an analog front-end circuit corresponding to a sensing electrode, so as to inject the calibration excitation signal into the sensing electrode;

[0066] S902, detecting signals generated on the sensing electrodes in response to injection of the calibration excitation signal, and obtaining calibration detection data corresponding to the sensing electrodes;

[0067] S903: Calculate the display interference gain coefficient corresponding to the sensing electrode according to the calibration detection data corresponding to the sensing electrode.

[0068] In this embodiment, the display interference gain coefficient is obtained when the touch display panel is in the off-screen state during the power-on process of the electronic device on which the touch display panel is located, or when the touch display panel is in the off-screen state during the standby process of the electronic device. Since the touch display panel is in the off-screen state, the display layer does not display an image, and therefore, no display interference signal is 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 by controlling the calibration excitation signal to be injected into the sensing electrode. The calibration detection data corresponding to the sensing electrode obtained by detecting the signal generated by the analog front-end circuit corresponding to the sensing electrode in response to the injection of the calibration excitation signal can reflect the magnitude of the display interference transmission path-related parameters corresponding to the sensing electrode in the touch layer, that is, the magnitude of the physical model parameters corresponding to the sensing electrode in the touch layer. The calibration test data corresponding to different sensing electrodes can reflect the differences in the physical model parameters corresponding to these electrodes, namely, the differences in the impedance Z from the cathode plate to the system ground and the coupling capacitance Cr2 between the different sensing electrodes and the cathode plate corresponding to the different sensing electrode locations. Furthermore, the calibration test data corresponding to different sensing electrodes can reflect the differences in the equivalent impedance Z' in the display interference model shown in Figure 5. Because 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.

[0069] In this embodiment, step S901 can be performed by the excitation signal generation module 24 and the control module 23 in the touch detection circuit 20 shown in FIG13, step S902 can be performed by the analog front-end circuit 210 corresponding to the corresponding sensing electrode in the signal detection module 21 in FIG12 and FIG13, and step S903 can be performed by the processing module 22 in FIG12 and FIG13. For ease of understanding, the specific process of obtaining the display interference gain coefficient is described below in conjunction with FIG10 and FIG11 through two implementation methods.

[0070] In the first implementation of the present application, the analog front-end circuit uses the analog front-end circuit 210A shown in FIG7 . In this embodiment, for each sensing electrode, the display interference gain coefficient is obtained by the following method:

[0071] Step A1: When the touch display panel is in a screen-off state, controlling the positive input terminal of the first gain amplifier circuit to be connected to the sensing electrode, and controlling the input of a calibration excitation signal to the negative input terminal of the first gain amplifier circuit;

[0072] Step A2: Detect the signal generated on the sensing electrode in response to the injection of the calibration excitation signal to obtain calibration detection data corresponding to the sensing electrode.

[0073] Step A3: Calculate the display interference gain coefficient corresponding to the sensing electrode according to the calibration detection data corresponding to the sensing electrode.

[0074] The above process is described in detail below with reference to FIG10. As shown in FIG10, the non-inverting input terminal 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 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. 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 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 terminal of the first gain amplifier circuit 211A is connected to the excitation signal generation module 24, and when the first switch SW1 is in the second closed state, the inverting input terminal of the first gain amplifier circuit 211A is connected to the common-mode voltage VCMI.

[0075] Due to the virtual short characteristic between the positive and negative input terminals of the first gain amplifier circuit 211A, the calibration excitation signal Vtest is provided at the positive input terminal of the first gain amplifier circuit 211A. The positive input terminal of the first gain amplifier circuit 211A is connected to the sensing electrode RXi, so that the calibration excitation signal Vtest is injected into the corresponding sensing electrode RXi of the analog front-end circuit.

[0076] When the touch display panel is in the off state, there is no display interference signal, and no driving signal is applied to the driving electrode. Z' in the dotted box on the left side of RXi represents the impedance Z from the cathode plate to the system ground corresponding to the position of the sensing electrode and the equivalent impedance of the coupling capacitor Cr2 between the sensing electrode 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 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: 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, the 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 included in the signal on the sensing electrode is Vnoise, the component corresponding to the display interference signal in the output signal of the first gain amplifier circuit 211A is represented by Vout2. Then, the relationship between Vout2 and the display interference signal Vnoise satisfies the following equation (2): Equation (2) is: Vout2 = -Vnoise*Rf / Z' (2).

[0079] 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 Rf / Z' value is used as the display interference gain coefficient corresponding to the sensing electrode.

[0080] 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 in a preset proportional relationship with the value of -Rf / Z' may also be used as the display interference gain coefficient.

[0081] In addition, there are multiple analog front-end circuits corresponding to multiple sensing electrodes in the signal detection module. 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 the present 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 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.

[0082] Specifically, the value of Rf / Z' is calculated as the initial display interference gain coefficient A according to Rf / Z'=Vout1 / Vtest-1. f Afterwards, according to formula (4), A f The processing is performed and the processing result is used as the final display interference gain coefficient.

[0083] Among them, Cali represents the final display interference gain coefficient, Cali t represents the ratio between the actually acquired calibration detection data and the ideal calibration detection data when the first gain amplifier does not have the gain error ΔA. Specifically, A f Initial display of interference gain coefficient.

[0084] Since Cali takes into account the impact of the gain value deviation of the first gain amplifier circuit on the display interference signal, using Cali as 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 impact of display interference and improve the accuracy of touch detection.

[0085] Furthermore, in one implementation, as shown in FIG10 , the excitation signal generation module 24 may include a digital-to-analog conversion circuit 241 and a buffer circuit 242 connected to the output of the digital-to-analog conversion circuit 241. The digital-to-analog conversion circuit 241 is used to generate an analog excitation signal, and the buffer circuit 242 is used to improve 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 errors caused by using different excitation signal generation modules to separately input the calibration detection signal to the second gain amplifier circuit 211A corresponding to each sensing electrode.

[0086] In the second implementation of the present application, the analog front-end circuit adopts the analog front-end circuit 210B shown in Figure 8. In this embodiment, for each sensing electrode, the display interference gain coefficient is obtained by the following method:

[0087] Step B1: When the touch display panel is in the off state, the inverting input terminal of the second gain amplifier circuit 211B is controlled to be connected to the common-mode voltage VCMI, the non-inverting input terminal of the second gain amplifier 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 amplifier circuit 211B so as to inject the calibration excitation signal Vtest into the sensing electrode RXi.

[0088] Step B2: Detect the signal generated on the sensing electrode RXi in response to the injection of the calibration excitation signal Vtest, and obtain calibration detection data corresponding to the sensing electrode.

[0089] Step B3: Calculate the display interference gain coefficient corresponding to the sensing electrode based on the calibration detection data corresponding to the sensing electrode.

[0090] The above process is described in detail below with reference to FIG11 . 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 a 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 in FIG11 , 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 the pull-up resistor Rb and the capacitor Cb connected in parallel with the pull-up resistor. Similar to the first implementation, the calibration excitation signal Vtest may be a sine wave signal with a certain current driving capability.

[0091] As shown in FIG11 , since the second switch SW2 is in a closed state and the third switch SW3 is in a first closed state, the calibration excitation signal Vtest 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-screen state, there is no display interference signal, and no driving signal is applied to the driving electrode. The Z' in the dotted box on the left side of RXi represents the impedance Z from the cathode plate to the system ground corresponding to the position of the sensing electrode RXi and the equivalent impedance of the coupling capacitor 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 is obtained. The calibration excitation signal Vtest satisfies equation (5), which is: Vout3 = Vtest*G1*Z' / (Rb+Z') (5)

[0092] Wherein, G1 is the gain value of the second gain amplifier circuit.

[0093] According to the above relationship (5), Z' / (Rb+Z')=Vout3 / (Vtest*G1) can be calculated. For the convenience of description, Z' / (Rb+Z') is represented by G2.

[0094] During touch detection, the control module controls the second switch SW2 to be in a closed state, electrically connecting the non-inverting input of the second gain amplifier circuit 211B to the sensing electrode RXi. Furthermore, the control module controls the third switch SW3 to be in a second closed state, connecting the non-inverting input of the second gain amplifier circuit 211B 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 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 can be calculated as 1-G2. Therefore, since Vout3 and Vtest are known, the value of G3 can be calculated as the display interference gain coefficient if 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 ​​in a preset proportional relationship with the value of G3 can also be used as the display interference gain coefficient.

[0095] In addition, each sensing electrode corresponds to an analog front-end circuit. Due to process reasons, the gain values ​​of the second gain amplifier circuits in different analog front-end circuits are not exactly the same. In order to more accurately determine the display interference gain coefficient, in one implementation of the present application, the process of obtaining the display interference gain coefficient further includes:

[0096] Step B4: When the touch display panel is in the off state, the inverting input terminal of the second gain amplifier circuit 211B is controlled to be connected to the common mode voltage VCMI, the non-inverting input terminal of the second gain amplifier circuit 211B is controlled to be disconnected from the sensing electrode, and the calibration excitation signal is controlled to be injected into the non-inverting input terminal of the second gain amplifier circuit 211B;

[0097] Step B5: Calculate the gain value of the second gain amplifier circuit 211B according to the detection data obtained by collecting the output signal of the second gain amplifier circuit 211B.

[0098] Steps B4 and B5 can be performed before step B1. Specifically, referring to FIG11 , 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 collects 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 collected detection data.

[0099] As shown in FIG11 , 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 amplifier circuit 211B, the detection data Vout4 collected by the front-end analog circuit 210B and the calibration excitation signal Vtest satisfy the relationship (6), which is: Vout4 = Vtest*G1 (6)

[0100] Wherein, G1 is the gain value of the second gain amplifier circuit 211B. According to equation (6), the gain value G1 of the second gain amplifier circuit 211B can be calculated.

[0101] 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 amplifier 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 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 calibration detection data Vout3 corresponding to the sensing electrode. The relationship between Vout3 and the calibration excitation signal Vtest satisfies the above-mentioned relationship (5). Based on G1 calculated in step B5, according to relationship (5), the value of G2 = Z' / (Rb+Z') can be calculated.

[0102] As mentioned above, the display interference gain coefficient consists of two parts: one part is caused by Rb + Z', namely 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. Thereafter, 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 are in a predetermined proportional relationship with the product of G3 * G1 can also be used as the display interference gain coefficient.

[0103] In this embodiment, since the display interference gain coefficient is determined by not only considering the influence of differences in physical model parameters corresponding to different sensing electrodes in the touch display panel, but also considering the influence of differences in gain values ​​of the analog front-end circuit corresponding to the different sensing electrodes (i.e., the gain value of the second gain amplifier circuit), the display interference gain coefficient can be determined more accurately.

[0104] Furthermore, in one implementation, as shown in FIG11 , the excitation signal generation module 214 may include a digital-to-analog conversion circuit 241 and a buffer circuit 242 connected to the output of the digital-to-analog conversion circuit. The digital-to-analog conversion circuit 241 is configured to generate an analog excitation signal, and the buffer circuit 242 is configured to enhance the current driving capability of the analog excitation signal, thereby enabling the calibration detection signal to be input to the second gain amplifier circuit 211B corresponding to each sensing electrode through the same excitation signal generation module. This avoids errors caused by using different excitation signal generation modules to input the calibration detection signal to the second gain amplifier circuit 211B corresponding to each sensing electrode.

[0105] Figure 12 is a schematic diagram of the structure of a touch detection circuit for a touch display panel provided in an embodiment of the present application. The touch display panel includes a display layer and a touch layer, which includes multiple sensing electrodes. As shown in Figure 12, the touch detection circuit includes a signal detection module 21 and a processing module 22.

[0106] a signal detection module 21 for detecting signals on the plurality of sensing electrodes respectively to obtain original detection data corresponding to the plurality of sensing electrodes, wherein the signals on the plurality of sensing electrodes include display interference signals;

[0107] The processing module 22 is configured to determine, for a target sensing electrode among the multiple sensing electrodes, a display interference compensation value corresponding to the target sensing electrode, where the target sensing electrode includes at least one of the multiple 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.

[0108] 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 to obtain target detection data corresponding to the target sensing electrode for determining the touch detection result.

[0109] In one implementation of the present application, the processing module 22 is further configured to:

[0110] Curve fitting is performed based on display interference gain coefficients corresponding to each of the plurality of sensing electrodes, and a display interference compensation value corresponding to a target sensing electrode is determined based on the fitting result, wherein the display interference gain coefficient corresponding to each sensing electrode is related to a position of the sensing electrode in the touch layer.

[0111] In one implementation of the present application, as shown in FIG13 , the touch detection circuit 20 further 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 plurality of sensing electrodes RXi. It should be understood that for ease of illustration, FIG13 only shows one analog front-end circuit 210 and a corresponding sensing electrode.

[0112] An excitation signal generating module 24 is configured to generate a calibration excitation signal under the control of the control module 23;

[0113] The control module 23 is configured to control the excitation signal generation module 24 to input a calibration excitation signal to the input terminals of the multiple analog front-end circuits 210 when the touch display panel is in the off state, so as to inject the calibration excitation signal into the multiple sensing electrodes RXi;

[0114] Multiple analog front-end circuits 210 are respectively used to detect signals generated by the multiple sensing electrodes RXi in response to the injection of the calibration excitation signal, and obtain calibration detection data corresponding to each of the multiple sensing electrodes RXi; and

[0115] The processing module 22 is configured to calculate the 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.

[0116] In one implementation of the present application, each analog front-end circuit 210 employs the analog front-end circuit 210A shown in FIG7 . As shown in FIG10 , the analog front-end circuit 210A includes a first gain amplifier circuit 211A, wherein a non-inverting input terminal of the first gain amplifier circuit 211A is connected to the sensing electrode RXi, and an 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 via a first switch SW1.

[0117] 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 to inject the calibration excitation signal Vtest into the sensing electrode RXi corresponding to the analog front-end circuit 210A.

[0118] In this implementation, as shown in FIG10 , the first gain amplifier circuit 211A is a transimpedance gain amplifier circuit.

[0119] In one implementation of the present application, each analog front-end circuit 210 employs the analog front-end circuit 210B shown in FIG8 . As shown in FIG11 , the analog front-end circuit 210B includes a second gain amplifier circuit 211B, wherein 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 a 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 a third switch.

[0120] 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 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 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 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.

[0121] In one possible implementation of the present application, referring to FIG11 , the control module 23 is further configured to, when the touch display panel is in the off state, control the second switch SW22 to be in an open 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 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 amplifier circuit 211B.

[0122] A 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

[0123] In a possible implementation of the present application, for each sensing electrode, the processing module 22 is configured to calculate a display interference gain coefficient corresponding to the sensing electrode according to the calibration detection data corresponding to the sensing electrode and the gain value of the second gain amplifier circuit.

[0124] 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 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.

[0125] The touch detection circuit provided in the embodiment of the present application 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.

[0126] An embodiment of the present application provides a touch control chip, including: the touch detection circuit in any embodiment of the present application.

[0127] An embodiment of the present application further provides an electronic device, which includes a touch display panel and the touch chip according to any embodiment of the present application.

[0128] The touch display panel in this embodiment includes the touch display panel in the embodiment shown in Figures 1 to 4. The electronic device of the embodiment of the present application exists in various forms, including but not limited to:

[0129] (1) Mobile communication devices: These devices are characterized by their mobile communication capabilities and are primarily designed to provide voice and data communications. These terminals include smartphones (e.g., iPhones), multimedia phones, feature phones, and low-end phones.

[0130] (2) Ultra-mobile personal computer devices: These devices fall under the category of personal computers, have computing and processing capabilities, and generally also have mobile Internet access. These terminals include PDAs, MIDs, and UMPCs, such as the iPad.

[0131] (3) Portable entertainment devices: These devices can display and play multimedia content. These devices include audio and video players (such as iPods), handheld game consoles, e-books, smart toys, and portable car navigation devices.

[0132] (4) Server: A device that provides computing services. The server consists of a processor 810, a hard disk, memory, a system bus, etc. The server is similar to a general computer architecture, but because it needs to provide highly reliable services, it has higher requirements in terms of processing power, stability, reliability, security, scalability, and manageability.

[0133] (5) Other electronic devices with data interaction functions.

[0134] Thus far, specific embodiments of the present subject matter have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing may be advantageous.

[0135] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.

[0136] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. 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: Detecting signals on the plurality of sensing electrodes respectively to obtain original detection data corresponding to each of the plurality of sensing electrodes, wherein the signals on the plurality of sensing electrodes include display interference signals; For a target sensing electrode among the plurality of sensing electrodes, determining a display interference compensation value corresponding to the target sensing electrode, the target sensing electrode including at least one of the plurality of sensing electrodes, the display interference compensation value being 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, correcting the original detection data corresponding to the target sensing electrode to obtain target detection data corresponding to the target sensing electrode, for determining a touch detection result.

2. The method according to claim 1, wherein The step of, for a target sensing electrode among the plurality of sensing electrodes, determining a display interference compensation value corresponding to the target sensing electrode, includes: Performing curve fitting based on display interference gain coefficients corresponding to each of the plurality of sensing electrodes, and based on the fitting result, determining the display interference compensation value corresponding to the target sensing electrode, wherein the display interference gain coefficient corresponding to each sensing electrode is related to the position of the sensing electrode in the touch layer.

3. The method according to claim 2, wherein, For each sensing electrode, the display interference gain coefficient is obtained by the following method: 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 into the sensing electrode; Detecting a signal generated on the sensing electrode in response to the injection of the calibration excitation signal to obtain calibration detection data corresponding to the sensing electrode; Calculating the display interference gain coefficient corresponding to the sensing electrode according to the calibration detection data corresponding to the sensing electrode.

4. The method according to claim 3, wherein, The analog front-end circuit includes a first gain amplification circuit; The step of, 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 into the sensing electrode, includes: When the touch display panel is in a screen-off state, controlling the non-inverting input end of the first gain amplification circuit to be connected to the sensing electrode, and controlling to input the calibration excitation signal to the inverting input end of the first gain amplification circuit, so as to inject the calibration excitation signal into the sensing electrode.

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

6. The method according to claim 5, wherein, Calculating the display interference gain coefficient corresponding to the sensing electrode according to the calibration detection data corresponding to the sensing electrode includes: Calculating the display interference gain coefficient corresponding to the sensing electrode according to the calibration detection data and the gain value of the second gain amplifier circuit.

7. The method according to claim 6, further comprising: When the touch display panel is in the screen-off state, control the inverting input terminal of the second gain amplifier circuit to be connected to the common-mode voltage, control the non-inverting input terminal of the second gain amplifier circuit to be disconnected from the sensing electrode, and control the calibration excitation signal to be input to the non-inverting input terminal of the second gain amplifier circuit; Calculating the gain value of the second gain amplifier circuit according to the detection data obtained by detecting the calibration excitation signal at the non-inverting input terminal of the second gain amplifier circuit.

8. The method according to any one of claims 3-7, 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.

9. The method according to claim 8, wherein The excitation signal generation module includes a digital-to-analog conversion circuit and a buffer circuit connected to the digital-to-analog conversion circuit.

10. The method according to claim 1, wherein, Based on the display interference compensation value corresponding to the target sensing electrode, correcting the original detection data corresponding to the target sensing electrode to obtain the target detection data corresponding to the target sensing electrode, including: 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.

11. A touch detection circuit for a touch display panel, 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: A signal detection module, configured to respectively detect signals on the plurality of sensing electrodes to obtain original detection data corresponding to the plurality of sensing electrodes, and the signals on the plurality of sensing electrodes include display interference signals; A processing module, configured to determine a display interference compensation value corresponding to a target sensing electrode for the target sensing electrode among the plurality of sensing electrodes, 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 to obtain the target detection data corresponding to the target sensing electrode for determining a touch detection result.

12. The touch detection circuit according to claim 11, wherein, The processing module is specifically configured to: Curve fitting is performed based on the display interference gain coefficients corresponding to the multiple induction electrodes, and based on the fitting result, the display interference compensation value corresponding to the target induction electrode is determined, where the display interference gain coefficient corresponding to each induction electrode is related to the position of the induction electrode in the touch layer.

13. The touch detection circuit according to claim 12 further includes: An excitation signal generation module and a control module, the signal detection module includes a plurality of analog front-end circuits, and the plurality of analog front-end circuits respectively correspond to the plurality of induction electrodes; The excitation signal generation module is configured to generate a calibration excitation signal under the control of the control module; The control module is configured to, when the touch display panel is in the off-screen state, control the excitation signal generation module to input a calibration excitation signal to the input ends of the plurality of analog front-end circuits, so as to inject the calibration excitation signal into the plurality of induction electrodes; The plurality of analog front-end circuits are respectively configured to detect signals generated on the plurality of induction electrodes in response to the injection of the calibration excitation signal, and obtain calibration detection data corresponding to the plurality of induction electrodes respectively; And The processing module is configured to calculate the display interference gain coefficients corresponding to the plurality of induction electrodes respectively according to the calibration detection data corresponding to the plurality of induction electrodes respectively.

14. The touch detection circuit according to claim 13, wherein, Each of the analog front-end circuits includes a first gain amplification circuit, a positive-phase input end of the first gain amplification circuit is connected to the induction electrode corresponding to the analog front-end circuit, and a negative-phase input end of the first gain amplification circuit is connected to the excitation signal generation module and a common-mode voltage through a first switch; The control module is configured to, when the touch display panel is in the off-screen state, control the first switch to be in a first closed state, so that the excitation signal generation module inputs the calibration excitation signal to the negative-phase input end of the first gain amplification circuit, so as to inject the calibration excitation signal into the induction electrode corresponding to the analog front-end circuit.

15. The touch detection circuit according to claim 13, wherein, Each of the analog front-end circuits includes a second gain amplification circuit, a negative-phase input end of the second gain amplification circuit is connected to a common-mode voltage, a positive-phase input end of the second gain amplification circuit is connected to the induction electrode corresponding to the analog front-end circuit through a second switch, and the positive-phase input end of the second gain amplification circuit is connected to the excitation signal generation module and a common-mode voltage through a third switch; The control module is configured to, when the touch display panel is in the off-screen state, control the second switch to be in a closed state, so that the positive-phase input end of the second gain amplification circuit is electrically connected to the induction 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 positive-phase input end of the second gain amplification circuit, so as to inject the calibration excitation signal into the induction electrode corresponding to the analog front-end circuit.

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

17. The touch detection circuit according to claim 16, wherein the control module is further configured to control the second switch to be in an open state when the touch display panel is in a screen-off 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 configured to calculate the gain value of the second gain amplifier circuit according to the detection data obtained by detecting the calibration excitation signal at the non-inverting input terminal of the second gain amplifier 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 configured to generate an analog excitation signal; the buffer circuit is configured to enhance the current driving ability of the analog excitation signal to generate the calibration excitation signal.

19. A touch chip, comprising: The touch detection circuit according to any one of claims 11-18.

20. An electronic device, comprising a touch display panel and the touch chip according to claim 19.

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