Touch driving circuit and touch driving method

Abstract

The application provides a touch driving circuit and a touch driving method. The touch driving circuit comprises a first power supply voltage generating circuit and a switch circuit. The first power supply voltage generating circuit is configured to generate a first power supply voltage. The switch circuit is configured to control the touch electrode to be connected to the first power supply voltage generating circuit in a first time period, to charge the equivalent capacitance of the touch electrode in the first time period, so that the voltage of the touch electrode is equal to a first intermediate voltage; control the touch electrode to be disconnected from the first power supply voltage generating circuit in a second time period, so that the voltage of the touch electrode remains the first intermediate voltage; and control the touch electrode to be connected to the first power supply voltage generating circuit in a third time period, to charge the equivalent capacitance of the touch electrode in the third time period, so that the voltage of the touch electrode is equal to the first power supply voltage; wherein the first intermediate voltage is between a ground voltage and the first power supply voltage. The technical solution can reduce the interference of touch detection on display.

Description

Touch driving circuit and touch driving method Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to a touch driving circuit and a touch driving method. Background Technology

[0002] With the development of smartphones and tablets, most displays now have touch functionality; these displays are also called touchscreens or touch panels. Touchscreens typically consist of a display layer and a touch layer. As the thickness of touchscreens decreases, the coupling between these two layers increases, not only increasing interference from the screen display to touch detection, but also increasing interference from touch detection to the screen display, to a level easily discernible to the human eye.

[0003] Therefore, how to reduce the interference of touch detection on the display in a touch screen is a technical problem that urgently needs to be solved. Summary of the Invention

[0004] This application provides a touch driving circuit and a touch driving method that can reduce the interference of touch detection on the display.

[0005] In a first aspect, a touch driving circuit is provided for outputting a driving signal to drive the touch electrode of a touch display device. The touch driving circuit includes: a first power supply voltage generating circuit and a switching circuit; the first power supply voltage generating circuit generates a first power supply voltage; the switching circuit includes a first input terminal and an output terminal, the first input terminal being connected to the first power supply voltage generating circuit and the output terminal being connected to the touch electrode; the switching circuit controls the touch electrode to be connected to the first power supply voltage generating circuit during a first time period, wherein the first power supply voltage generating circuit charges the equivalent capacitance of the touch electrode during the first time period, such that the voltage of the touch electrode is equal to a first intermediate voltage; controls the touch electrode to be disconnected from the first power supply voltage generating circuit during a second time period, such that the voltage of the touch electrode remains at the first intermediate voltage; and controls the touch electrode to be connected to the first power supply voltage generating circuit during a third time period, wherein the first power supply voltage generating circuit charges the equivalent capacitance of the touch electrode during the third time period, such that the voltage of the touch electrode is equal to the first power supply voltage; wherein the first intermediate voltage is located between ground voltage and the first power supply voltage.

[0006] Through the technical solution of this application embodiment, the driving signal output by the touch driving circuit to the touch electrode introduces a stable first intermediate voltage between zero and the first power supply voltage. Compared with the case in related technologies where the driving voltage of the driving signal changes directly from zero to the first power supply voltage, the voltage change slope of the driving signal provided in this application embodiment is smaller, and the transient current caused by the driving signal is smaller, thereby reducing the impact of the driving signal on the display screen in the touch display device and improving the user experience.

[0007] In some possible implementations, the switching circuit is also used to control the touch electrode to disconnect from the first power supply voltage generating circuit during the fourth time period, so that the voltage of the touch electrode remains at the first power supply voltage.

[0008] Through the technical solution of this embodiment, on the one hand, the slope of the driving voltage applied to the touch electrode can be further reduced, so as to reduce the influence of the driving signal on the displayed image in the touch display device. On the other hand, the power of the first power supply voltage generation circuit can be saved, and the power consumption of the touch driving circuit can be reduced.

[0009] In some possible implementations, the touch driving circuit further includes: a ground terminal; the switching circuit further includes a second input terminal connected to the ground terminal; the switching circuit is used to control the touch electrode to be connected to the ground terminal in a fifth time period, the equivalent capacitance of the touch electrode discharges to the ground terminal in the fifth time period, so that the voltage of the touch electrode is equal to the second intermediate voltage; control the touch electrode to be disconnected from the ground terminal in a sixth time period, so that the voltage of the touch electrode remains at the second intermediate voltage; control the touch electrode to be connected to the ground terminal in a seventh time period, the equivalent capacitance of the touch electrode discharges to the ground terminal in the seventh time period, so that the voltage of the touch electrode is equal to the ground voltage; wherein, the second intermediate voltage is located between the ground voltage and the first power supply voltage.

[0010] In the technical solution of this application embodiment, by adding a ground terminal and related control of the switching circuit in the touch driving circuit, a stable second intermediate voltage can be introduced between the first power supply voltage and the ground voltage. Compared with the case in related technologies where the driving voltage of the driving signal changes directly from the first power supply voltage to zero, the voltage change slope of the driving signal provided in this application embodiment is smaller, and the transient current caused by the driving signal is smaller, thereby further reducing the impact of the driving signal on the display screen in the touch display device and improving the user experience.

[0011] In some possible implementations, the switching circuit is also used to control the voltage of the touch electrode to maintain the ground voltage during the eighth time period.

[0012] In some possible implementations, the voltage value of the second intermediate voltage is the same as the voltage value of the first intermediate voltage.

[0013] The technical solution of this embodiment has a high degree of symmetry in the driving voltage waveform of the driving signal, which is beneficial to ensuring the touch performance of the touch display device.

[0014] In some possible implementations, the touch driving circuit further includes: a second power supply voltage generating circuit for generating a second power supply voltage, wherein the first power supply voltage and the second power supply voltage are positive and negative voltages, respectively; a switching circuit further includes a second input terminal connected to the second power supply voltage generating circuit; the switching circuit is used to control the touch electrode to be connected to the second power supply voltage generating circuit in a fifth time period, wherein the second power supply voltage generating circuit charges the equivalent capacitance of the touch electrode in the fifth time period, such that the voltage of the touch electrode is equal to a second intermediate voltage; to control the touch electrode to be disconnected from the second power supply voltage generating circuit in a sixth time period, such that the voltage of the touch electrode remains at the second intermediate voltage; and to control the touch electrode to be connected to the second power supply voltage generating circuit in a seventh time period, wherein the second power supply voltage generating circuit charges the equivalent capacitance of the touch electrode in the seventh time period, such that the voltage of the touch electrode is equal to the second power supply voltage; wherein the second intermediate voltage is located between the first power supply voltage and the second power supply voltage.

[0015] Through the technical solution of this embodiment, the first power supply voltage and the second power supply voltage can be positive and negative power supply voltages, respectively, thereby increasing the signal voltage amplitude of the driving signal. When the voltage amplitude of the driving signal is large, the signal quantity of the touch detection signal can be increased, thereby improving the touch detection effect. In addition, by intermittently charging the equivalent capacitance of the touch electrode with the first and second power supply voltages, the voltage change slope of the driving signal is reduced simultaneously while improving the touch detection effect, thereby reducing the impact of touch detection on the displayed image and comprehensively ensuring the touch detection performance and display performance of the touch display device.

[0016] In some possible implementations, the switching circuit is also used to control the touch electrode to disconnect from the second power supply voltage generating circuit during the eighth time period, so that the voltage of the touch electrode remains at the second power supply voltage.

[0017] Through the technical solution of this embodiment, on the one hand, the voltage slope of the driving signal applied to the touch electrode can be further reduced, so as to reduce the influence of the driving signal on the displayed image in the touch display device. On the other hand, the power of the second power supply voltage generation circuit can be saved, and the power consumption of the touch driving circuit can be reduced.

[0018] In some possible implementations, the touch driving circuit further includes: a second power supply voltage generating circuit for generating a second power supply voltage, wherein the first power supply voltage and the second power supply voltage are positive and negative voltages, respectively; a switching circuit further includes a third input terminal connected to the second power supply voltage generating circuit; the switching circuit is used to control the touch electrode to be connected to the second power supply voltage generating circuit during a ninth time period, wherein the second power supply voltage generating circuit charges the equivalent capacitance of the touch electrode during the ninth time period, such that the voltage of the touch electrode is equal to a third intermediate voltage; to control the touch electrode to be disconnected from the second power supply voltage generating circuit during a tenth time period, such that the voltage of the touch electrode remains at the third intermediate voltage; and to control the touch electrode to be connected to the second power supply voltage generating circuit during an eleventh time period, wherein the second power supply voltage generating circuit charges the equivalent capacitance of the touch electrode during the eleventh time period, such that the voltage of the touch electrode is equal to the second power supply voltage; wherein the third intermediate voltage is located between the ground voltage and the second power supply voltage.

[0019] This embodiment of the technical solution, based on the use of a first power supply voltage and ground voltage to realize the driving signal, further provides a second power supply voltage. This second power supply voltage can increase the voltage amplitude of the driving signal, thereby improving the touch detection effect. In addition, through the relevant control of the switching circuit, the second power supply voltage can intermittently charge the equivalent capacitance of the touch electrode, reducing the voltage change slope of the driving signal, thereby reducing the impact of touch detection on the displayed image, and comprehensively ensuring the touch detection performance and display performance of the touch display device.

[0020] In some possible implementations, the switching circuit is also used to control the touch electrode to disconnect from the second power supply voltage generating circuit during the twelfth time period, so that the voltage of the touch electrode remains at the second power supply voltage.

[0021] In some possible implementations, the switching circuit is used to control the touch electrode to be connected to ground during the thirteenth time period, and the equivalent capacitance of the touch electrode discharges to ground during the thirteenth time period, so that the voltage of the touch electrode is equal to the fourth intermediate voltage; to control the touch electrode to be disconnected from ground during the fourteenth time period, so that the voltage of the touch electrode remains at the fourth intermediate voltage; to control the touch electrode to be connected to ground during the fifteenth time period, and the equivalent capacitance of the touch electrode discharges to ground during the fifteenth time period, so that the voltage of the touch electrode is equal to the ground voltage; and to control the voltage of the touch electrode to remain at the ground voltage during the sixteenth time period; wherein the fourth intermediate voltage is located between the ground voltage and the second power supply voltage.

[0022] In some possible implementations, the voltage value of the fourth intermediate voltage is the same as the voltage value of the third intermediate voltage.

[0023] The technical solution of this embodiment has a high degree of symmetry in the driving voltage waveform of the driving signal, which is beneficial to ensuring the touch performance of the touch display device.

[0024] In some possible implementations, the switching circuit is also used to control the voltage of the touch electrode to be equal to the fifth intermediate voltage before the third time period and then maintain the fifth intermediate voltage, which is different from the first intermediate voltage and is located between the ground voltage and the first power supply voltage.

[0025] Through the technical solution of this embodiment, the driving signal applied to the touch electrode introduces multiple stable intermediate voltages between the ground voltage and the first power supply voltage, thereby further reducing the voltage change slope of the driving signal, so as to further reduce the impact of the driving signal on the display screen in the touch display device and improve the user experience.

[0026] Secondly, a touch driving circuit is provided for outputting a driving signal to drive the touch electrode of a touch display device. The touch driving circuit includes: a first power supply voltage generating circuit, a first intermediate voltage generating circuit, and a switching circuit. The first power supply voltage generating circuit generates a first power supply voltage, and the first intermediate voltage generating circuit generates an intermediate voltage located between the first power supply voltage and ground voltage. The switching circuit includes a first input terminal, a second input terminal, and an output terminal. The first input terminal is connected to the first power supply voltage generating circuit, the second input terminal is connected to the first intermediate voltage generating circuit, and the output terminal is connected to the touch electrode. The switching circuit controls the touch electrode to connect to the first intermediate voltage generating circuit during a first time period, during which the first intermediate voltage generating circuit charges the equivalent capacitance of the touch electrode so that the voltage of the touch electrode is equal to the first intermediate voltage. During a second time period, the switching circuit controls the touch electrode to connect to the first power supply voltage generating circuit, during which the first power supply voltage generating circuit charges the equivalent capacitance of the touch electrode so that the voltage of the touch electrode is equal to the first power supply voltage.

[0027] The technical solution of this application incorporates a first intermediate voltage generation circuit into the touch driving circuit. This circuit introduces a first intermediate voltage between the change in the driving signal of the touch electrode from ground voltage to the first power supply voltage. Compared to directly charging the equivalent capacitance of the touch electrode using a larger first power supply voltage, resulting in a driving signal with a large voltage change slope, charging the equivalent capacitance with a smaller first intermediate voltage reduces the voltage change slope of the driving signal. This reduces the impact of the driving signal on the displayed image in the touch display device, improving the user experience.

[0028] In some possible implementations, the first intermediate voltage generating circuit is a storage capacitor that stores a charge to provide an intermediate voltage between the first power supply voltage and the ground voltage.

[0029] The technical solution of this embodiment uses an energy storage capacitor as the first intermediate voltage generating circuit. The energy storage capacitor has low manufacturing cost and can easily exchange charges with the equivalent capacitance of the touch electrode to charge the equivalent capacitance of the touch electrode.

[0030] In some possible implementations, the touch driving circuit further includes a ground terminal, and the switching circuit further includes a third input terminal connected to the ground terminal; the switching circuit is used to control the touch electrode to be connected to the first intermediate voltage generating circuit in a third time period, the first intermediate voltage generating circuit charging the equivalent capacitance of the touch electrode in the third time period so that the voltage of the touch electrode is equal to the second intermediate voltage, and controlling the touch electrode to be connected to the ground terminal in a fourth time period so that the voltage of the touch electrode is equal to the ground voltage.

[0031] In this embodiment, by adding a ground terminal and related control to the switching circuit in the touch driving circuit, a second intermediate voltage can be introduced between the change of the driving signal from the first power supply voltage to the ground voltage. Compared to the case in related technologies where the driving voltage of the driving signal changes directly from the first power supply voltage to the ground voltage, the voltage change slope of the driving signal provided in this embodiment is smaller, and the transient current caused by the driving signal is smaller. This further reduces the impact of the driving signal on the displayed image in the touch display device, improving the user experience.

[0032] In some possible implementations, the touch driving circuit further includes: a second power supply voltage generating circuit for generating a second power supply voltage, wherein the first power supply voltage and the second power supply voltage are positive and negative voltages, respectively; the switching circuit further includes a third input terminal connected to the second power supply voltage generating circuit; the switching circuit is used to control the touch electrode to be connected to a first intermediate voltage generating circuit during a third time period, wherein the first intermediate voltage generating circuit charges the equivalent capacitance of the touch electrode during the third time period, such that the voltage of the touch electrode is equal to the second intermediate voltage; and to control the touch electrode to be connected to the second power supply voltage generating circuit during a fourth time period, wherein the second power supply voltage generating circuit charges the equivalent capacitance of the touch electrode during the fourth time period, such that the voltage of the touch electrode is equal to the second power supply voltage.

[0033] Through the technical solution of this embodiment, the first power supply voltage and the second power supply voltage can be positive and negative power supply voltages, respectively, thereby increasing the signal voltage amplitude of the driving signal. When the voltage amplitude of the driving signal is large, the signal quantity of the touch detection signal can be increased, thereby improving the touch detection effect. In addition, through the relevant control of the switching circuit, a second intermediate voltage can be introduced between the change of the driving signal from the first power supply voltage to the second power supply voltage. While improving the touch detection effect, the voltage change slope of the driving signal is reduced simultaneously, thereby reducing the impact of touch detection on the displayed image and comprehensively ensuring the touch detection performance and display performance of the touch display device.

[0034] In some possible implementations, the touch driving circuit further includes: a second power supply voltage generating circuit and a second intermediate voltage generating circuit, the second power supply voltage generating circuit being used to generate a second power supply voltage, the first power supply voltage and the second power supply voltage being a positive voltage and a negative voltage, respectively; the second intermediate voltage generating circuit being used to generate an intermediate voltage located between the second power supply voltage and the ground voltage; the switching circuit further includes a fourth input terminal and a fifth input terminal, the fourth input terminal being connected to the second intermediate voltage generating circuit, and the fifth input terminal being connected to the second power supply voltage generating circuit; the switching circuit is used to control the touch electrode to be connected to the second intermediate voltage generating circuit in a fifth time period, the second intermediate voltage generating circuit charging the equivalent capacitance of the touch electrode in the fifth time period, such that the voltage of the touch electrode is equal to the third intermediate voltage, and to control the touch electrode to be connected to the second power supply voltage generating circuit in a sixth time period, the second power supply voltage generating circuit charging the equivalent capacitance of the touch electrode in the sixth time period, such that the voltage of the touch electrode is equal to the second power supply voltage.

[0035] This embodiment of the technical solution, based on the use of a first power supply voltage and a ground voltage to realize the driving signal, further provides a second power supply voltage. This second power supply voltage can increase the voltage amplitude of the driving signal, thereby improving the touch detection effect. In addition, a second intermediate voltage generation circuit is added to the touch device. Through the relevant control of the switching circuit, a third intermediate voltage can be introduced between the ground voltage transformation to the second power supply voltage and the second power supply voltage transformation to the ground voltage, thereby reducing the voltage change slope of the driving signal, reducing the impact of touch detection on the displayed image, and comprehensively ensuring the touch detection performance and display performance of the touch display device.

[0036] In some possible implementations, the switching circuit is used to control the touch electrode to be connected to the second intermediate voltage generating circuit in the seventh period, the second intermediate voltage generating circuit charging the equivalent capacitance of the touch electrode in the seventh period so that the voltage of the touch electrode is equal to the fourth intermediate voltage, and controlling the touch electrode to be connected to the ground terminal in the eighth period so that the voltage of the touch electrode is equal to the ground voltage.

[0037] In some possible implementations, the touch driving circuit further includes: a third intermediate voltage generating circuit; the switching circuit further includes a third input terminal connected to the third intermediate voltage generating circuit; the switching circuit is configured to control the touch electrode to be connected to the third intermediate voltage generating circuit before the first time period, the third intermediate voltage generating circuit charging the equivalent capacitance of the touch electrode so that the voltage of the touch electrode is equal to the fifth intermediate voltage; the switching circuit is further configured to control the touch electrode to be connected to the third intermediate voltage generating circuit between the third time period and the fourth time period, the third intermediate voltage generating circuit charging the equivalent capacitance of the touch electrode so that the voltage of the touch electrode is equal to the sixth intermediate voltage.

[0038] The technical solution of this embodiment introduces multiple intermediate voltages between the power supply voltage and the ground voltage, or between two power supply voltages, through multiple intermediate voltage generation circuits. This further reduces the voltage change slope of the driving signal, thereby further reducing the impact of the driving signal on the displayed image in the touch display device and improving the user experience.

[0039] In some possible implementations, both the first intermediate voltage generating circuit and the third intermediate voltage generating circuit are energy storage capacitors. The capacitance values ​​of the energy storage capacitors of the first and third intermediate voltage generating circuits are between 1 and 5 times the capacitance value of the equivalent capacitance of the touch electrode. The first intermediate voltage is not equal to the second intermediate voltage, and the fifth intermediate voltage is not equal to the sixth intermediate voltage.

[0040] In some possible implementations, both the first intermediate voltage generating circuit and the third intermediate voltage generating circuit are energy storage capacitors. The capacitance values ​​of the energy storage capacitors in the first and third intermediate voltage generating circuits are greater than 5 times the capacitance value of the equivalent capacitance of the touch electrode. The first intermediate voltage is equal to the second intermediate voltage, and the fifth intermediate voltage is equal to the sixth intermediate voltage.

[0041] Thirdly, a touch driver chip is provided, characterized in that it includes a touch driver circuit as described in the first aspect or any possible implementation of the first aspect, or a touch driver circuit as described in the second aspect or any possible implementation of the second aspect.

[0042] Fourthly, a touch display device is provided, including the touch driver chip described in the third aspect.

[0043] Fifthly, a touch driving method is provided for controlling a touch driving circuit to output a driving signal to drive touch electrodes of a touch display device. The touch driving circuit has a first power supply voltage. The touch driving method includes: controlling the driving signal output by the touch driving circuit to change from an initial voltage to a first intermediate voltage in a first time period, the first intermediate voltage being located between ground voltage and the first power supply voltage; controlling the driving signal output by the touch driving circuit to maintain the first intermediate voltage in a second time period; and controlling the driving signal output by the touch driving circuit to change from the first intermediate voltage to the first power supply voltage in a third time period.

[0044] In a sixth aspect, a touch driving method is provided, which controls a touch driving circuit to output a driving signal to drive the touch electrodes of a touch display device. The touch driving circuit has a first power supply voltage and a first intermediate voltage, the first intermediate voltage being located between ground voltage and the first power supply voltage. The touch driving method includes: controlling the driving signal output by the touch driving circuit to change from an initial voltage to a first intermediate voltage in a first time period.

[0045] The drive signal output by the control touch driving circuit changes from the first intermediate voltage to the first power supply voltage during the second time period. Attached Figure Description

[0046] Figure 1 is a schematic structural diagram of a touch display system provided in an embodiment of this application.

[0047] Figure 2 is a schematic diagram of the touch display device in Figure 1.

[0048] Figure 3 is a circuit diagram of a touch driving circuit provided in an embodiment of this application.

[0049] Figure 4 shows the waveforms of the drive signal and switch control signal of the touch drive circuit in Figure 3.

[0050] Figure 5 is a circuit diagram of another touch driving circuit provided in an embodiment of this application.

[0051] Figure 6 shows the waveforms of the drive signal and switch control signal of the touch drive circuit in Figure 5.

[0052] Figure 7 is a circuit diagram of another touch driving circuit provided in an embodiment of this application.

[0053] Figure 8 shows the waveforms of the drive signal and switch control signal of the touch drive circuit in Figure 7.

[0054] Figure 9 is a circuit diagram of another touch driving circuit provided in an embodiment of this application.

[0055] Figure 10 shows the waveforms of the drive signal and switch control signal of the touch drive circuit in Figure 9.

[0056] Figure 11 is a waveform diagram of another driving signal of the touch driving circuit in Figure 3.

[0057] Figure 12 is a circuit diagram of another touch driving circuit provided in an embodiment of this application.

[0058] Figure 13 shows the waveforms of the drive signal and switch control signal of the touch drive circuit in Figure 12.

[0059] Figure 14 is a circuit diagram of another touch driving circuit provided in an embodiment of this application.

[0060] Figure 15 shows the waveforms of the drive signal and switch control signal of the touch drive circuit in Figure 14.

[0061] Figure 16 is a circuit diagram of another touch driving circuit provided in an embodiment of this application.

[0062] Figure 17 is a waveform diagram of the drive signal and switch control signal of the touch drive circuit in Figure 16.

[0063] Figure 18 is a circuit diagram of another touch driving circuit provided in an embodiment of this application.

[0064] Figure 19 shows the waveforms of the drive signal and switch control signal of the touch drive circuit in Figure 18.

[0065] Figure 20 is a circuit diagram of another touch driving circuit provided in an embodiment of this application.

[0066] Figure 21 is a waveform diagram of the drive signal and switch control signal of the touch drive circuit in Figure 20.

[0067] Figure 22 is another waveform diagram of the drive signal and switch control signal of the touch drive circuit in Figure 20.

[0068] Figure 23 is a schematic flowchart of a touch driving method provided in an embodiment of this application.

[0069] Figure 24 is a schematic flowchart of another touch driving method provided in an embodiment of this application. Detailed Implementation

[0070] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0071] This application relates to a touch display system. The touch display system may include a touch display device and related driving devices for driving the touch display device, such as a touch driving circuit. The touch display device may include a touch layer and a display layer. Touch electrodes are formed in the touch layer, and the touch driving circuit outputs driving signals to drive the touch electrodes. The display layer may be a display screen, allowing users to perform corresponding touch operations by touching icons or text on the display screen using their fingers, styluses, or other conductors. Examples of displays include, but are not limited to, liquid crystal displays (LCDs), organic light-emitting displays (OLEDs), plasma display panels (PDPs), and cathode ray tube (CRT) displays, etc.

[0072] Figure 1 shows a schematic structural diagram of a touch display system 100 provided in an embodiment of this application.

[0073] As shown in Figure 1, the touch display system 100 includes a touch display device 110 and a touch driving device 120. In the touch display device 110, the bottom layer is a display layer 113, which may contain light-emitting units. The layer above the display layer 113 is a cathode plate 112, used to lead out the ground (GND) of the circuit in the light-emitting unit, and also to isolate the touch layer 111 and the display layer 113. The layer above the cathode plate 112 is a touch layer 111, in which touch electrodes are formed. The touch driving device 120 can input driving signals to the touch electrodes in the touch layer 111, enabling the touch layer 111 to perform mutual capacitance detection and / or self-capacitance detection, thereby enabling touch operation by the user's finger or stylus on the touch display device 110. A protective cover plate (not shown in Figure 1) may also be provided on the top layer of the touch display device 110, i.e., the top layer of the touch display device 110.

[0074] In addition to the touch display device 110 and the touch driving device 120, as shown in FIG1, the touch display system 100 may further include a display driving device 140 and a main control device 130. The display driving device 140 is used to output driving signals to the display layer 113 to drive the display layer 113 to display images. The main control device 130 is used to transmit control signals to the display driving device 140 and the touch driving device 120 to realize touch control and display control of the touch display system 100.

[0075] It is understood that, as an example, Figure 1 shows the display driver 140 and the touch driver 120 as two separate devices. For example, the display driver 140 and the touch driver 120 can be two separate driver chips. In some alternative embodiments, the display driver 140 and the touch driver 120 can also be integrated into a single device, for example, they can be integrated into a single driver chip.

[0076] Figure 2 shows a schematic diagram of the touch display device 110 in Figure 1.

[0077] As shown in Figure 2, an emitter (Tx) electrode and a receiver (Rx) electrode are formed in the touch layer 111. A coupling capacitor C is formed between the Tx electrode and the cathode plate 112. dg A coupling capacitance C is formed between the Rx electrode and the cathode plate 112. sg .

[0078] When the touch driving device 120 (not shown in Figure 2) sends a touch driving signal 121 to the Tx electrode and / or Rx electrode in the touch layer 111 for self-capacitance and mutual capacitance detection and active pen uplink coding, the touch driving signal can be coupled through the coupling capacitor C. dg and / or C sg It is coupled to the cathode plate 112.

[0079] When the display driving device 140 (not shown in FIG. 2) sends a display driving signal 122 to the display layer 113 for image display, the signal coupled to the cathode plate 112 by the touch driving signal 121 will be further coupled to the buffer capacitor C of the light-emitting unit 1131. D This affects the display data of the current row of pixels, thus affecting the displayed image. When the coupling interference caused by the touch drive signal 121 to the light-emitting unit 1131 exceeds a certain threshold, it will cause C... D If the voltage is too high or too low, the pixels in that row will be too bright or too dark, and the human eye can observe that there are stripes of light and dark in the current display screen.

[0080] In some related technologies, to increase the amount of electrical signal collected by the analog front-end circuit, the touch driving device 120 typically sends a square wave signal 121 to the touch layer 111. This square wave signal has a large amplitude variation at its edge level, generally a jump between ground voltage and power supply voltage or between positive and negative power supply voltage. This large amplitude variation easily causes a large transient current, resulting in significant coupling interference between the touch driving signal 121 and the light-emitting unit 1131. As the touch display device 110 becomes thinner, the interference effect of the driving signal (or coding signal) of the touch driving device 120 on the display layer 113 becomes increasingly apparent.

[0081] In view of this, this application provides a touch driving circuit that can reduce the interference of the touch driving signal 121 on the display screen and improve or even eliminate display abnormalities that can be perceived by the human eye.

[0082] Figure 3 shows a circuit diagram of a touch driving circuit 200 provided in an embodiment of this application. Figure 4 shows the waveforms of the driving signal and the switch control signal of the touch driving circuit 200 in Figure 3.

[0083] Optionally, the touch driving circuit 200 can be applied to the touch display device 110 shown in Figures 1 and 2. The touch driving circuit 200 is used to output driving signals to drive the touch electrodes (e.g., Tx electrodes and / or Rx electrodes) of the touch display device 110. Optionally, the touch driving circuit 200 can be disposed in the touch driving device 120 shown in Figure 1.

[0084] As shown in Figure 3, the touch driving circuit 200 includes a first power supply voltage generating circuit 210 and a switching circuit 230. The first power supply voltage generating circuit 210 generates a first power supply voltage VDD1. The switching circuit 230 includes a first input terminal and an output terminal. The first input terminal is connected to the first power supply voltage generating circuit 210, and the output terminal is connected to the touch electrode 201. The touch electrode 201 has an equivalent capacitance CL.

[0085] Referring to Figures 3 and 4, the switching circuit 230 controls the touch electrode 201 to be connected to the first power supply voltage generating circuit 210 during the first time period T1. The first power supply voltage generating circuit 210 charges the equivalent capacitance CL of the touch electrode 201 during the first time period T1, so that the voltage of the touch electrode 201 is equal to the first intermediate voltage VC1. During the second time period T2, the switch circuit 230 controls the touch electrode 201 to be disconnected from the first power supply voltage generating circuit 210, so that the voltage of the touch electrode 201 remains at the first intermediate voltage VC1. During the third time period T3, the switch circuit 230 controls the touch electrode 201 to be connected to the first power supply voltage generating circuit 210, so that the first power supply voltage generating circuit 210 charges the equivalent capacitance CL of the touch electrode 201 during the third time period T3, so that the voltage of the touch electrode 201 is equal to the first power supply voltage VDD1.

[0086] Specifically, in this embodiment, the first power supply voltage VDD1 generated by the first power supply voltage generating circuit 210 can be a positive voltage or a negative voltage. Optionally, the first power supply voltage generating circuit 210 can be set up separately to provide power supply voltage to the touch driving circuit 200, or it can be shared with other circuit modules in the touch driving chip.

[0087] As shown in Figure 3, the equivalent capacitance CL of the touch electrode 201 is connected to the switching circuit 230 through a driving resistor RL. This driving resistor RL can include the equivalent resistance of the touch electrode 201 and the touch driving circuit 200. In this embodiment, the signal after passing through the driving resistor RL at the output of the switching circuit 230 is the driving signal provided to the touch electrode 201. The driving voltage Vout of this driving signal can also be understood as the voltage across the equivalent capacitance CL.

[0088] The switching circuit 230 may include a first switch SW1, which can receive a first switch control signal S1 to open and close, thereby connecting and disconnecting the first power supply voltage generation circuit 210 and the touch electrode 201. As shown in FIG4, the first control signal S1 of the first switch SW1 may be, for example, a square wave signal. When the voltage of the first control signal S1 is high, it controls the first switch SW1 to close; when the voltage of the first control signal S1 is low, it controls the first switch SW1 to open. This embodiment does not limit the specific voltage values ​​of the high and low levels of the first control signal S1. The first control signal S1 may be a control signal generated by the touch driving device 120 or the main control device 130 in FIG1.

[0089] As shown in Figures 3 and 4, in the initial state, the voltage across the equivalent capacitor CL is zero, meaning the initial voltage of the drive signal is zero. When a valid drive signal needs to be output, the first switch SW1 closes during the first time period T1 under the action of the first control signal S1. This causes the first power supply voltage generating circuit 210 to charge the equivalent capacitor CL of the touch electrode 201 during the first time period. The voltage of the touch electrode 201 changes from zero to a first intermediate voltage VC1, which can be located between the first power supply voltage VDD1 and ground.

[0090] Then, under the action of the first control signal S1, the first switch SW1 is opened during the second time period T2, so that the voltage across the equivalent capacitor CL is maintained at the first intermediate voltage VC1, that is, the voltage of the touch electrode 201 is maintained at the first intermediate voltage VC1. Further, the first switch SW1 is closed during the third time period T3, and the first power supply voltage generating circuit 210 can be reconnected to the touch electrode 201 during the third time period T3 to continue charging the equivalent capacitor CL. The voltage of the touch electrode 201 can change from the first intermediate voltage VC1 to the first power supply voltage VDD1.

[0091] In the technical solution of this application embodiment, the driving voltage Vout of the driving signal output by the touch driving circuit 200 to the touch electrode 201 does not change directly from zero to the first power supply voltage VDD1. Instead, it first changes from zero to a first intermediate voltage VC1, maintains the first intermediate voltage VC1, and then changes to the first power supply voltage VDD1. In other words, the driving voltage Vout introduces a stable first intermediate voltage VC1 between zero and the first power supply voltage VDD1. Compared with the case in related technologies where the driving voltage of the driving signal changes directly from zero to the first power supply voltage VDD1, the voltage change slope of the driving signal provided in this application embodiment is smaller, and the transient current caused by the driving signal is smaller. This reduces the impact of the driving signal on the displayed image in the touch display device and improves the user experience.

[0092] Optionally, in some embodiments, as shown in FIG4, the switching circuit 230 is further configured to control the touch electrode 201 to disconnect from the first power supply voltage generating circuit 210 during the fourth time period T4, so that the voltage of the touch electrode 201 remains at the first power supply voltage VDD1.

[0093] Specifically, in the switching circuit 230, the first switch SW1 is opened in the fourth time period T4 under the action of the first control signal S1, so that the voltage across the equivalent capacitance CL of the touch electrode 201 is maintained at the first power supply voltage VDD1, that is, the voltage of the touch electrode 201 is maintained at the first power supply voltage VDD1.

[0094] Through the technical solution of this embodiment, on the one hand, the slope of the driving voltage applied to the touch electrode 201 can be further reduced, so as to reduce the influence of the driving signal on the displayed image in the touch display device. On the other hand, the power of the first power supply voltage generation circuit 210 can be saved, and the power consumption of the touch driving circuit 200 can be reduced.

[0095] Figure 5 shows a circuit diagram of another touch driving circuit 200 provided in an embodiment of this application. Figure 6 shows the waveforms of the driving signal and the switch control signal of the touch driving circuit 200 in Figure 5.

[0096] Referring to Figures 5 and 6, based on the embodiments shown in Figures 3 and 4, the touch driving circuit 200 further includes a ground terminal 220, and the switching circuit 230 further includes a second input terminal connected to the ground terminal 220. The switching circuit 230 is used to control the touch electrode 201 to connect to the ground terminal 220 during the fifth time period T5, causing the equivalent capacitance CL of the touch electrode 201 to discharge to the ground terminal 220 during the fifth time period T5, making the voltage of the touch electrode 201 equal to the second intermediate voltage VC2; to control the touch electrode 201 to disconnect from the ground terminal 220 during the sixth time period T6, causing the voltage of the touch electrode 201 to maintain the second intermediate voltage VC2; and to control the touch electrode 201 to connect to the ground terminal 220 during the seventh time period T7, causing the equivalent capacitance CL of the touch electrode 201 to discharge to the ground terminal 220 during the seventh time period T7, making the voltage of the touch electrode 201 equal to the ground voltage.

[0097] Optionally, as shown in FIG5, the switching circuit 230 may include a first switch SW1 and a second switch SW2, wherein the input terminal of the first switch SW1 serves as the first input terminal of the switching circuit 230 and is connected to the first power supply voltage generating circuit 210; the input terminal of the second switch SW2 serves as the second input terminal of the switching circuit 230 and is connected to the ground terminal 220; the output terminals of the first switch SW1 and the second switch SW2 are interconnected and serve as the output terminal of the switching circuit 230, connected to the touch electrode 201. Of course, in other examples, the switching circuit 230 may also include other types of switches, such as single-pole double-throw switches, etc., which are not specifically limited in this embodiment.

[0098] As shown in Figure 6, when the switching circuit 230 includes a first switch SW1 and a second switch SW2, it can receive a first control signal S1 for controlling the first switch SW1 and a second control signal S2 for controlling the second switch SW2.

[0099] During the first time period T1 to the fourth time period T4, the second control signal S2 controls the second switch SW2 to remain open, and the first control signal S1 controls the first switch SW1 to close in the first time period T1, open in the second time period T2, close in the third time period T3, and open in the fourth time period T4. Through the relevant control of the above-mentioned switch circuit 230, the first power supply voltage VDD1 can intermittently charge the equivalent capacitance CL of the touch electrode 201. The charging and discharging process of the equivalent capacitance CL of the touch electrode 201 during the first time period T1 to the fourth time period T4 can be referred to the relevant description of the embodiments shown in Figures 3 and 4 above, and will not be elaborated further here.

[0100] During the fifth period T5 to the seventh period T7, the first control signal S1 controls the first switch SW1 to remain open, and the second control signal S2 controls the second switch SW2 to close in the fifth period T5, open in the sixth period T6, and close in the seventh period T7.

[0101] When the second switch SW2 is closed, the touch electrode 201 is connected to the ground terminal 220, and the equivalent capacitance CL of the touch electrode 201 can discharge to the ground terminal 220. The voltage of the touch electrode 201 changes with the discharge time. The voltage value of the second intermediate voltage VC2 depends on the duration of the fifth time period T5, and the second intermediate voltage VC2 can be located between the first power supply voltage VDD1 and the ground voltage.

[0102] When the second switch SW2 is off, the voltage across the equivalent capacitance CL of the touch electrode 201 remains unchanged, meaning that the voltage of the touch electrode 201 can be stably maintained at the second intermediate voltage VC2 during the sixth time period T6.

[0103] In the technical solution of this application embodiment, by adding a ground terminal 220 and related control of the switching circuit 230 to the touch driving circuit 200, a stable second intermediate voltage VC2 can be introduced between the first power supply voltage VDD1 and the ground voltage. Compared with the case in related technologies where the driving voltage of the driving signal changes directly from the first power supply voltage VDD1 to zero, the voltage change slope of the driving signal provided in this application embodiment is smaller, and the transient current caused by the driving signal is smaller, thereby further reducing the impact of the driving signal on the display screen in the touch display device and improving the user experience.

[0104] Optionally, in some embodiments, the switching circuit 230 is also used to control the voltage of the touch electrode 201 to remain at ground voltage during the eighth time period T8. For example, as shown in FIG6, the second control signal S2 can control the second switch SW2 in the switching circuit 230 to open during the eighth time period T8, so that the voltage of the touch electrode 201 remains at ground voltage. Alternatively, in an alternative embodiment, the second control signal S2 can control the second switch SW2 in the switching circuit 230 to close during the eighth time period T8, and the touch electrode 201 is connected to the ground terminal 220, which can also keep the voltage of the touch electrode 201 at ground voltage.

[0105] Refer to Figure 6 for the driving voltage Vout waveform of the driving signal. After the eighth time period T8, the switching circuit 230 can cyclically execute the relevant actions from the first time period T1 to the eighth time period T8 to continuously output a driving signal with a small voltage slope. That is, the first time period T1 to the eighth time period T8 can be considered as one cycle of the driving signal provided in the embodiments of this application.

[0106] Optionally, as shown in Figure 6, the voltage value of the second intermediate voltage VC2 can be the same as the voltage value of the first intermediate voltage VC1. In this case, the driving voltage Vout waveform of the driving signal has high symmetry, which is beneficial to ensuring the touch performance of the touch display device.

[0107] In some examples, the voltage value of the second intermediate voltage VC2 and the first intermediate voltage VC1 can be half the voltage value of the first power supply voltage VDD1.

[0108] Alternatively, in an alternative embodiment, the voltage value of the second intermediate voltage VC2 may also be different from the voltage value of the first intermediate voltage VC1. This application embodiment does not specifically limit the voltage values ​​of the first intermediate voltage VC1 and the second intermediate voltage VC2.

[0109] Figure 7 shows a circuit diagram of another touch driving circuit 200 provided in an embodiment of this application. Figure 8 shows the waveforms of the driving signal and the switch control signal of the touch driving circuit 200 in Figure 7.

[0110] As shown in Figures 7 and 8, based on the embodiments shown in Figures 3 and 4 above, the touch driving circuit 200 further includes: a second power supply voltage generating circuit 240, used to generate a second power supply voltage VDD2, wherein the first power supply voltage VDD1 and the second power supply voltage VDD2 are positive voltage and negative voltage, respectively.

[0111] The switching circuit 230 also includes a second input terminal connected to the second power supply voltage generation circuit 240. The switching circuit 230 controls the touch electrode 201 to connect to the second power supply voltage generation circuit 240 during a fifth time period T5, whereby the second power supply voltage generation circuit 240 charges the equivalent capacitance CL of the touch electrode 201, making the voltage of the touch electrode 201 equal to the second intermediate voltage VC2. During a sixth time period T6, the switching circuit 230 controls the touch electrode 201 to disconnect from the second power supply voltage generation circuit 240, maintaining the voltage of the touch electrode 201 at the second intermediate voltage VC2. During a seventh time period T7, the switching circuit 230 controls the touch electrode 201 to connect to the second power supply voltage generation circuit 240, whereby the second power supply voltage generation circuit 240 charges the equivalent capacitance CL of the touch electrode 201, making the voltage of the touch electrode 201 equal to the second power supply voltage VDD2.

[0112] Specifically, in this embodiment, the circuit structure of the touch driving circuit 200 can be similar to the circuit structure shown in Figure 5 above, except that the ground terminal 220 in Figure 5 is replaced by the second power supply voltage generating circuit 240 in Figure 7. Related solutions can be found in the above description, and will not be elaborated further here.

[0113] Additionally, referring to Figure 8, the waveforms of the first control signal S1 and the second control signal S2 of the first switch SW1 and the second switch SW2 in the switching circuit 230 can also be the same as the waveforms in the embodiment shown in Figure 6 above. In other words, the open or closed states of the first switch SW1 and the second switch SW2 in each time period in the embodiments of this application can also be referred to the relevant description above, and will not be elaborated further here.

[0114] Specifically, through the control of the switching circuit 230, during the first time period T1 to the fourth time period T4, the first power supply voltage VDD1 intermittently charges the equivalent capacitance CL of the touch electrode 201. During the fifth time period T5 to the seventh time period T7, the second power supply voltage VDD2 intermittently charges the equivalent capacitance CL of the touch electrode 201. The first power supply voltage VDD1 and the second power supply voltage VDD2 can be positive and negative power supply voltages, respectively, thereby increasing the signal voltage amplitude of the driving signal. For example, when the voltage value of the first power supply voltage VDD1 is +VDD and the voltage value of the second power supply voltage VDD2 is -VDD, the maximum voltage amplitude of the driving signal is 2VDD. A larger voltage amplitude of the driving signal can increase the signal quantity of the touch detection signal, thereby improving the touch detection effect.

[0115] In addition, by intermittently charging the equivalent capacitance CL of the touch electrode 201 with the first power supply voltage VDD1 and the second power supply voltage VDD2, the voltage change slope of the driving signal is reduced at the same time while improving the touch detection effect, thereby reducing the impact of touch detection on the displayed image and comprehensively ensuring the touch detection performance and display performance of the touch display device.

[0116] Optionally, in some embodiments, the switching circuit 230 is further configured to control the touch electrode 201 to disconnect from the second power supply voltage generating circuit 240 during the eighth time period T8, so that the voltage of the touch electrode 201 remains at the second power supply voltage VDD2. For example, as shown in FIG8, the second control signal S2 can control the second switch SW2 in the switching circuit 230 to disconnect during the eighth time period T8, so that the voltage of the touch electrode 201 remains at the second power supply voltage VDD2.

[0117] Through the technical solution of this embodiment, on the one hand, the voltage slope of the driving signal applied to the touch electrode 201 can be further reduced, so as to reduce the influence of the driving signal on the display screen in the touch display device. On the other hand, the power of the second power supply voltage generation circuit 240 can be saved, and the power consumption of the touch driving circuit 200 can be reduced.

[0118] Refer to Figure 8 for the waveform of the driving voltage Vout of the driving signal. After the eighth time period T8, the switching circuit 230 can cyclically execute the relevant actions from the first time period T1 to the eighth time period T8 to continuously output a driving signal with a small voltage slope. Specifically, during the ninth time period T9, the first switch SW1 is closed, the second switch SW2 is open, and the voltage of the touch electrode 201 changes from the second power supply voltage VDD2 to the first intermediate voltage VC1. The voltage change process in subsequent time periods can be the same as that from the second time period T2 to the eighth time period T8.

[0119] Optionally, in this embodiment, the first intermediate voltage VC1 and the second intermediate voltage VC2 are any voltages between the first power supply voltage VDD1 and the second power supply voltage VDD2. The voltage values ​​of the first intermediate voltage VC1 and the second intermediate voltage VC2 can be the same or different. The first intermediate voltage VC1 and the second intermediate voltage VC2 can both be positive voltages, both be negative voltages, or one can be positive and the other negative. This embodiment does not specifically limit the voltage values ​​of the first intermediate voltage VC1 and the second intermediate voltage VC2.

[0120] Figure 9 shows a circuit diagram of another touch driving circuit 200 provided in an embodiment of this application. Figure 10 shows the waveforms of the driving signal and the switch control signal of the touch driving circuit 200 in Figure 9.

[0121] As shown in Figures 9 and 10, based on the embodiments shown in Figures 5 and 6 above, the touch driving circuit 200 further includes: a second power supply voltage generating circuit 240, used to generate a second power supply voltage VDD2, wherein the first power supply voltage VDD1 and the second power supply voltage VDD2 are positive voltage and negative voltage, respectively.

[0122] The switching circuit 230 includes a first input terminal, a second input terminal, a third input terminal, and an output terminal. The first input terminal is connected to the first power supply voltage generating circuit 210, the second input terminal is connected to ground 220, and the third input terminal is connected to the second power supply voltage generating circuit 240. The output terminal is connected to the touch electrode 201.

[0123] The relevant technical solutions for the switching circuit 230 between the first time period T1 and the eighth time period T8 can be found in the description of the embodiments shown in Figures 5 and 6 above.

[0124] The switching circuit 230 controls the touch electrode 201 to be connected to the second power supply voltage generating circuit 240 during the ninth time period T9. During the ninth time period T9, the second power supply voltage generating circuit 240 charges the equivalent capacitance CL of the touch electrode 201, so that the voltage of the touch electrode 201 is equal to the third intermediate voltage VC3. During the tenth time period T10, the switch controls the touch electrode 201 to be disconnected from the second power supply voltage generating circuit 240, so that the voltage of the touch electrode 201 remains at the third intermediate voltage VC3. During the eleventh time period T11, the switch controls the touch electrode 201 to be connected to the second power supply voltage generating circuit 240. During the eleventh time period T11, the second power supply voltage generating circuit 240 charges the equivalent capacitance CL of the touch electrode 201, so that the voltage of the touch electrode 201 is equal to the second power supply voltage VDD2.

[0125] Optionally, as shown in FIG9, the switching circuit 230 may include a first switch SW1, a second switch SW2, and a third switch SW3. The input terminal of the first switch SW1 serves as the first input terminal of the switching circuit 230 and is connected to the first power supply voltage generating circuit 210; the second switch SW2 serves as the second input terminal of the switching circuit 230 and is connected to ground 220; the third switch SW3 serves as the third input terminal of the switching circuit 230 and is connected to the second power supply voltage generating circuit 240; the output terminals of the first switch SW1, the second switch SW2, and the third switch SW3 are interconnected and serve as the output terminal of the switching circuit 230. Of course, in other examples, the switching circuit 230 may also include other types of switches, such as a single-pole three-throw switch, etc., which are not specifically limited in this embodiment.

[0126] As shown in Figure 10, when the switching circuit 230 includes a first switch SW1, a second switch SW2 and a third switch SW3, it can receive a first control signal S1 for controlling the first switch SW1, a second control signal S2 for controlling the second switch SW2 and a third control signal S3 for controlling the third switch SW3.

[0127] During the first time period T1 to the fourth time period T4, the second control signal S2 and the third control signal S3 keep the second switch SW2 and the third switch SW3 in the open state. The first control signal S1 controls the first switch SW1 to close in the first time period T1, open in the second time period T2, close in the third time period T3, and open in the fourth time period T4. During the fifth time period T5 to the eighth time period T8, the first control signal S1 and the third control signal S3 keep the first switch SW1 and the third switch SW3 in the open state. The second control signal S2 controls the second switch SW2 to close in the fifth time period T5, open in the sixth time period T6, close in the seventh time period T7, and open in the eighth time period T8.

[0128] During the first time period T1 to the eighth time period T8, through the relevant control of the aforementioned switching circuit 230, the first power supply voltage VDD1 can intermittently charge the equivalent capacitance CL of the touch electrode 201, and the equivalent capacitance CL can intermittently discharge to ground. The charging and discharging process of the equivalent capacitance CL of the touch electrode 201 during the first time period T1 to the eighth time period T8 can be referred to the relevant description of the embodiments shown in Figures 5 and 6 above, and will not be elaborated further here.

[0129] During the ninth period T9 to the eleventh period T11, the first control signal S1 and the second control signal S2 control the first switch SW1 and the second switch SW2 to remain in the open state, and the third control signal S3 controls the third switch SW3 to close in the ninth period T9, open in the tenth period T10, and close in the eleventh period T11.

[0130] When the third switch SW3 is closed, the touch electrode 201 is connected to the second power supply voltage generation circuit 240. The second power supply voltage VDD2 charges the equivalent capacitance CL of the touch electrode 201, and the voltage of the touch electrode 201 changes with the charging time. The voltage value of the third intermediate voltage VC3 depends on the duration of the ninth time period T9, and the third intermediate voltage VC3 can be located between the second power supply voltage VDD2 and ground.

[0131] When the third switch SW3 is off, the voltage across the equivalent capacitance CL of the touch electrode 201 remains unchanged, meaning that the voltage of the touch electrode 201 can be stably maintained at the third intermediate voltage VC3 during the tenth time period T10.

[0132] The technical solution of this application embodiment, based on the use of a first power supply voltage VDD1 and ground voltage to realize the driving signal, further provides a second power supply voltage VDD2. This second power supply voltage VDD2 can increase the voltage amplitude of the driving signal, thereby improving the touch detection effect. Furthermore, through the relevant control of the switching circuit 230, the second power supply voltage VDD2 can intermittently charge the equivalent capacitance CL of the touch electrode 201, reducing the voltage change slope of the driving signal, thereby reducing the impact of touch detection on the displayed image, and comprehensively ensuring the touch detection performance and display performance of the touch display device.

[0133] Referring again to Figure 10, the switching circuit 230 is also used to control the touch electrode 201 to disconnect from the second power supply voltage generation circuit 240 during the twelfth time period T12, so that the voltage of the touch electrode 201 remains at the second power supply voltage VDD2.

[0134] Specifically, in the switching circuit 230, the third switch SW3 is opened in the twelfth time period T12 under the action of the third control signal S3, so that the voltage across the equivalent capacitance CL of the touch electrode 201 is maintained at the second power supply voltage VDD2, that is, the voltage of the touch electrode 201 is maintained at the second power supply voltage VDD2, thereby saving the power of the second power supply voltage generating circuit 240 and reducing the power consumption of the touch driving circuit 200.

[0135] Referring again to Figure 10, the switching circuit 230 is also used to control the touch electrode 201 to be connected to the ground terminal 220 during the thirteenth time period T13, and the equivalent capacitance CL of the touch electrode 201 discharges to the ground terminal 220 during the thirteenth time period T13, so that the voltage of the touch electrode 201 is equal to the fourth intermediate voltage VC4; during the fourteenth time period T14, the touch electrode 201 is disconnected from the ground terminal 220, so that the voltage of the touch electrode 201 remains at the fourth intermediate voltage VC4; during the fifteenth time period T15, the touch electrode 201 is connected to the ground terminal 220, and the equivalent capacitance CL of the touch electrode 201 discharges to the ground terminal 220 during the fifteenth time period T15, so that the voltage of the touch electrode 201 is equal to the ground voltage; during the sixteenth time period T16, the voltage of the touch electrode 201 remains at the ground voltage.

[0136] Specifically, during the thirteenth period T13 to the sixteenth period T16, the first control signal S1 and the third control signal S3 control the first switch SW1 and the third switch SW3 to remain in the open state, and the second control signal S2 controls the second switch SW2 to close in the thirteenth period T13, open in the fourteenth period T14, close in the fifteenth period T15, and open or close in the sixteenth period T16.

[0137] Refer to Figure 10 for the driving voltage Vout waveform of the driving signal. After the sixteenth time period T16, the switching circuit 230 can cyclically execute the relevant actions from the first time period T1 to the sixteenth time period T16 to continuously output a driving signal with a small voltage slope and a large voltage amplitude.

[0138] Optionally, as shown in Figure 10, the voltage value of the second intermediate voltage VC2 can be the same as the voltage value of the first intermediate voltage VC1. And / or, the voltage value of the third intermediate voltage VC3 can be the same as the voltage value of the fourth intermediate voltage VC4. In this case, the driving voltage Vout waveform of the driving signal has high symmetry, which is beneficial to ensuring the touch performance of the touch display device.

[0139] In some examples, the voltage values ​​of the second intermediate voltage VC2 and the first intermediate voltage VC1 can be half the voltage value of the first power supply voltage VDD1. And / or, the voltage values ​​of the third intermediate voltage VC3 and the fourth intermediate voltage VC4 can be half the voltage value of the second power supply voltage VDD2.

[0140] Alternatively, in an alternative embodiment, the voltage value of the second intermediate voltage VC2 may be different from the voltage value of the first intermediate voltage VC1, and / or the voltage value of the third intermediate voltage VC3 may be different from the voltage value of the fourth intermediate voltage VC4. This application does not specifically limit the voltage values ​​of the first intermediate voltage VC1, the second intermediate voltage VC2, the third intermediate voltage VC3, and the fourth intermediate voltage VC4.

[0141] In the embodiments described above, an intermediate voltage is introduced during the monotonic variation of the driving voltage Vout of the touch electrode 201 between ground voltage and power supply voltage, or during the monotonic variation between two power supply voltages. For example, in the embodiments shown in Figures 3 and 4 above, a stable first intermediate voltage VC1 is introduced during the process of the driving voltage Vout changing from ground voltage to the first power supply voltage VDD1. In other embodiments, multiple intermediate voltages may be introduced during the monotonic variation of the driving voltage Vout of the touch electrode 201.

[0142] Figure 11 shows the waveform of another driving signal of the touch driving circuit 200 in Figure 3.

[0143] As shown in Figure 11, the switching circuit 230 is also used to control the voltage of the touch electrode 201 to be equal to the fifth intermediate voltage VC5 before the third time period T3 and then maintain the fifth intermediate voltage VC5. The fifth intermediate voltage VC5 is different from the first intermediate voltage VC1 and is located between the ground voltage and the first power supply voltage VDD1.

[0144] As an example, as shown in Figure 11, after the switching circuit 230 controls the drive voltage Vout to change from ground voltage to the first intermediate voltage VC1 in the first time period T1, it controls the drive voltage Vout to maintain the first intermediate voltage VC1 in the second time period T2. Then, after the switching circuit 230 controls the drive voltage Vout to change from the first intermediate voltage VC1 to the fifth intermediate voltage VC5 in the first additional time period T1', it controls the drive voltage Vout to maintain the fifth intermediate voltage VC5 in the second additional time period T2', which is located between the first intermediate voltage VC1 and the first power supply voltage VDD1. In the third time period T3, the switching circuit 230 controls the drive voltage Vout to change from the fifth intermediate voltage VC5 to the first power supply voltage VDD1. In the fourth time period T4, the switching circuit 230 controls the drive voltage Vout to maintain the first power supply voltage VDD1.

[0145] Optionally, when the switching circuit 230 includes a first switch SW1, the first control signal S1 can control the first switch SW1 to close during the first time period T1, the first additional time period T1', and the third time period T3, so that the first power supply voltage generating circuit 210 is connected to the touch electrode 201, and the first power supply voltage generating circuit 210 charges the equivalent capacitance CL of the touch electrode 201 during the first time period T1, the first additional time period T1', and the third time period T3. The first control signal S1 can also control the first switch SW1 to open during the second time period T2 and the second additional time period T2', so as to maintain the voltage across the equivalent capacitance CL of the touch electrode 201.

[0146] Through the technical solution of this application embodiment, the driving signal applied to the touch electrode 201 introduces multiple stable intermediate voltages between the ground voltage and the first power supply voltage VDD1, thereby further reducing the voltage change slope of the driving voltage Vout, so as to further reduce the impact of the driving voltage Vout of the driving signal on the displayed screen in the touch display device and improve the user experience.

[0147] As an example, in the embodiment shown in FIG11, the voltage value of the first intermediate voltage VC1 can be 1 / 3 of the voltage value of the first power supply voltage VDD1, and the voltage value of the fifth intermediate voltage VC5 can be 2 / 3 of the voltage value of the first power supply voltage VDD1.

[0148] It is understood that, in addition to the first intermediate voltage VC1 and the second intermediate voltage VC5, a number of intermediate voltages can be introduced between the change of the driving voltage Vout from the ground voltage to the first power supply voltage VDD1. The embodiments of this application do not specifically limit the number and voltage value of such intermediate voltages.

[0149] In addition, during other monotonic changes in the driving voltage Vout, such as the change from the first power supply voltage VDD1 to ground voltage, the change from the first power supply voltage VDD1 to the second power supply voltage VDD2, the change from ground voltage to the second power supply voltage VDD2, and the change from the second power supply voltage VDD2 to ground voltage in the above embodiment, multiple intermediate voltages can also be introduced. For details, please refer to the relevant description of the embodiment shown in Figure 11 above, which will not be elaborated on here.

[0150] In the embodiments shown in Figures 3 to 11 above, several technical solutions were introduced to introduce a continuously stable intermediate voltage into the driving voltage Vout of the touch electrode through the relevant control of the switching circuit 230, so as to reduce the slope of the change of the driving voltage Vout. Below, with reference to Figures 12 to 21, another technical solution for reducing the slope of the change of the driving voltage Vout provided by the embodiments of this application will be described.

[0151] Figure 12 shows a circuit diagram of another touch driving circuit 200 provided in an embodiment of this application. Figure 13 shows the waveforms of the driving signal and the switch control signal of the touch driving circuit 200 in Figure 12.

[0152] As shown in Figure 12, the touch driving circuit 200 includes: a first power supply voltage generating circuit 210, a first intermediate voltage generating circuit 250, and a switching circuit 230. The first power supply voltage generating circuit 210 is used to generate a first power supply voltage VDD1, and the first intermediate voltage generating circuit 250 is used to generate an intermediate voltage located between the first power supply voltage VDD1 and the ground voltage.

[0153] The switching circuit 230 includes a first input terminal, a second input terminal, and an output terminal. The first input terminal is connected to the first power supply voltage generating circuit 210, the second input terminal is connected to the first intermediate voltage generating circuit 250, and the output terminal is connected to the touch electrode 201.

[0154] Referring to Figures 12 and 13, the switching circuit 230 controls the touch electrode 201 to be connected to the first intermediate voltage generating circuit 250 during the first time period φ1. The first intermediate voltage generating circuit 250 charges the equivalent capacitance CL of the touch electrode 201 during the first time period φ1, so that the voltage of the touch electrode 201 is equal to the first intermediate voltage VC1. During the second time period φ2, the switching circuit 230 controls the touch electrode 201 to be connected to the first power supply voltage generating circuit 210. The first power supply voltage generating circuit 210 charges the equivalent capacitance CL of the touch electrode 201 during the second time period φ2, so that the voltage of the touch electrode 201 is equal to the first power supply voltage VDD1.

[0155] Optionally, as shown in FIG12, the switching circuit 230 may include a first switch SW1 and a second switch SW2, wherein the input terminal of the first switch SW1 serves as the first input terminal of the switching circuit 230 and is connected to the first power supply voltage generating circuit 210; the input terminal of the second switch SW2 serves as the second input terminal of the switching circuit 230 and is connected to the first intermediate voltage generating circuit 250; the output terminals of the first switch SW1 and the second switch SW2 are interconnected and serve as the output terminal of the switching circuit 230, connected to the touch electrode 201. Of course, in other examples, the switching circuit 230 may also include other types of switches, such as single-pole double-throw switches, etc., which are not specifically limited in this embodiment.

[0156] Optionally, the first intermediate voltage generating circuit 250 can generate any voltage between the first power supply voltage VDD1 and the ground voltage.

[0157] To reduce the manufacturing cost of the touch driver circuit 200, the first intermediate voltage generation circuit 250 can be an energy storage capacitor. The energy storage capacitor stores a charge to provide any intermediate voltage between the first power supply voltage VDD1 and the ground voltage.

[0158] When the first intermediate voltage generating circuit 250 is an energy storage capacitor, the first power supply voltage generating circuit 210 can be used to charge the energy storage capacitor so that it stores enough charge to provide an intermediate voltage.

[0159] As an example, the switching circuit 230 can sequentially close the first switch SW1 and the second switch SW2. When the first switch SW1 is closed and the second switch SW1 is open, the first power supply voltage generating circuit 210 charges the equivalent capacitor CL. When the first switch SW1 is open and the second switch SW2 is closed, charge transfer is realized between the equivalent capacitor CL and the energy storage capacitor. The energy storage capacitor can carry a charge, thereby providing an intermediate voltage.

[0160] After the energy storage capacitor carries a charge, during the first time period φ1, the first switch SW1 is open and the second switch SW2 is closed. The energy storage capacitor of the first intermediate voltage generating circuit 250 can charge the equivalent capacitor CL so that the voltage across the equivalent capacitor CL is the first intermediate voltage VC1, that is, the voltage of the touch electrode 201 is the first intermediate voltage VC1. During the second time period φ2, the first switch SW1 is closed and the second switch SW2 is open. The first power supply voltage generating circuit 210 can charge the equivalent capacitor CL so that the voltage across the equivalent capacitor CL is the first power supply voltage VDD1, that is, the voltage of the touch electrode 201 is the first power supply voltage VDD1.

[0161] By incorporating a first intermediate voltage generation circuit 250 into the touch driving circuit 200 through the technical solution of this application embodiment, a first intermediate voltage VC1 can be introduced between the change of the driving voltage Vout of the touch electrode 201 from ground voltage to the first power supply voltage VDD1. Compared to directly using a larger first power supply voltage VDD1 to charge the equivalent capacitance CL of the touch electrode 201, resulting in a driving signal with a large voltage change slope, using a smaller first intermediate voltage VC1 to charge the equivalent capacitance CL first can reduce the change slope of the driving voltage Vout in the driving signal, thereby reducing the impact of the driving signal on the displayed image in the touch display device and improving the user experience.

[0162] Based on Figures 12 and 13 above, Figure 14 shows a circuit diagram of another touch driving circuit 200 provided in an embodiment of this application. Figure 15 shows the waveforms of the driving signal and the switch control signal of the touch driving circuit 200 in Figure 14.

[0163] As shown in Figure 14, the touch driving circuit 200 further includes a ground terminal 220, and the switch circuit 230 further includes a third input terminal connected to the ground terminal 220.

[0164] As shown in Figures 14 and 15, the switching circuit 230 controls the touch electrode 201 to be connected to the first intermediate voltage generating circuit 250 during the third time period φ3. The first intermediate voltage generating circuit 250 charges the equivalent capacitance CL of the touch electrode 201 during the third time period φ3, so that the voltage of the touch electrode 201 is equal to the second intermediate voltage VC2. During the fourth time period φ4, the touch electrode 201 is connected to the ground terminal 220, so that the voltage of the touch electrode 201 is equal to the ground voltage.

[0165] Optionally, as shown in FIG14, the switching circuit 230 may include a first switch SW1, a second switch SW2, and a third switch SW3. The input terminal of the first switch SW1 serves as the first input terminal of the switching circuit 230 and is connected to the first power supply voltage generating circuit 210; the second switch SW2 serves as the second input terminal of the switching circuit 230 and is connected to the first intermediate voltage generating circuit 250; the third switch SW3 serves as the third input terminal of the switching circuit 230 and is connected to ground 220; the output terminals of the first switch SW1, the second switch SW2, and the third switch SW3 are interconnected and serve as the output terminal of the switching circuit 230. Of course, in other examples, the switching circuit 230 may also include other types of switches, such as a single-pole three-throw switch, etc., which are not specifically limited in this embodiment.

[0166] As shown in Figure 15, when the switching circuit 230 includes a first switch SW1, a second switch SW2 and a third switch SW3, it can receive a first control signal S1 for controlling the first switch SW1, a second control signal S2 for controlling the second switch SW2 and a third control signal S3 for controlling the third switch SW3.

[0167] During the first time period φ1, the second switch SW2 is closed, and the first switch SW1 and the third switch SW3 are open. The first intermediate voltage generating circuit 250 charges the equivalent capacitance CL of the touch electrode 201 during the first time period φ1, so that the voltage of the touch electrode 201 reaches the first intermediate voltage VC1.

[0168] During the second time period φ2, the first switch SW1 is closed, and the second switch SW2 and the third switch SW3 are open. The first power supply voltage generating circuit 210 charges the equivalent capacitance CL of the touch electrode 201 during the second time period φ2, so that the driving voltage of the touch electrode 201 increases from the first intermediate voltage VC1 to the first power supply voltage VDD1.

[0169] During the third time period φ3, the second switch SW2 is closed, and the first switch SW1 and the third switch SW3 are open. The first intermediate voltage generating circuit 250 charges the equivalent capacitance CL of the touch electrode 201 during the third time period φ3, so that the voltage of the touch electrode 201 changes from the first power supply voltage VDD1 to the second intermediate voltage VC2.

[0170] During the fourth time period φ4, the third switch SW3 is closed, and the first switch SW1 and the second switch SW2 are open. The equivalent capacitance CL of the touch electrode 201 discharges to the ground terminal 220 during the fourth time period φ4, causing the voltage of the touch electrode 201 to decrease from the second intermediate voltage VC2 to the ground voltage.

[0171] In the technical solution of this application embodiment, by adding a ground terminal 220 and related control of the switching circuit 230 to the touch driving circuit 200, a second intermediate voltage VC2 can be introduced between the change of the driving signal from the first power supply voltage VDD1 to the ground voltage. Compared with the case in the related art where the driving voltage of the driving signal changes directly from the first power supply voltage VDD1 to the ground voltage, the voltage change slope of the driving signal provided in this application embodiment is smaller, and the transient current caused by the driving signal is smaller, thereby further reducing the impact of the driving signal on the display screen in the touch display device and improving the user experience.

[0172] Refer to Figure 15 for the driving voltage Vout waveform of the driving signal. After the fourth time period φ4, the switching circuit 230 can cyclically execute the related actions from the first time period φ1 to the fourth time period φ4 to continuously output a driving signal with a small voltage slope. That is, the first time period φ1 to the fourth time period φ4 can be considered as one cycle of the driving signal provided in the embodiments of this application.

[0173] Based on Figures 12 and 13 above, Figure 16 shows a circuit diagram of another touch driving circuit 200 provided in an embodiment of this application. Figure 17 shows the waveforms of the driving signal and the switch control signal of the touch driving circuit 200 in Figure 16.

[0174] As shown in Figure 16, the touch driving circuit 200 further includes: a second power supply voltage generating circuit 240, used to generate a second power supply voltage VDD2, wherein the first power supply voltage VDD1 and the second power supply voltage VDD2 are positive and negative voltages, respectively. The switching circuit 230 further includes a third input terminal, which is connected to the second power supply voltage generating circuit 240;

[0175] Referring to Figures 16 and 17, the switching circuit 230 controls the touch electrode 201 to connect to the first intermediate voltage generating circuit 250 during the third time period φ3. During the third time period φ3, the first intermediate voltage generating circuit 250 charges the equivalent capacitance CL of the touch electrode 201, making the voltage of the touch electrode 201 equal to the second intermediate voltage VC2. During the fourth time period φ4, the switching circuit 230 controls the touch electrode 201 to connect to the second power supply voltage generating circuit 240. During the fourth time period φ4, the second power supply voltage generating circuit 240 charges the equivalent capacitance CL of the touch electrode 201, making the voltage of the touch electrode 201 equal to the second power supply voltage VDD2.

[0176] Specifically, in this embodiment, the circuit structure of the touch driving circuit 200 can be similar to the circuit structure shown in Figure 5 above, except that the ground terminal 220 in Figure 14 is replaced by the second power supply voltage generating circuit 240 in Figure 16. Related solutions can be found in the above description, and will not be elaborated further here.

[0177] Additionally, referring to Figure 17, the waveforms of the first control signal S1 and the second control signal S2 of the first switch SW1 and the second switch SW2 in the switching circuit 230 can also be the same as the waveforms in the embodiment shown in Figure 15 above. In other words, the open or closed states of the first switch SW1 and the second switch SW2 in each time period in the embodiments of this application can also be referred to the relevant description above, and will not be elaborated further here.

[0178] Through the technical solution of this application embodiment, the first power supply voltage VDD1 and the second power supply voltage VDD2 can be positive and negative power supply voltages, respectively, thereby increasing the signal voltage amplitude of the driving signal. When the voltage amplitude of the driving signal is large, the signal amount of the touch detection signal can be increased, thereby improving the touch detection effect. In addition, through the relevant control of the switching circuit 230, a second intermediate voltage VC2 can be introduced between the change of the driving signal from the first power supply voltage VDD1 to the second power supply voltage VDD2. While improving the touch detection effect, the voltage change slope of the driving signal is reduced simultaneously, thereby reducing the impact of touch detection on the displayed image and comprehensively ensuring the touch detection performance and display performance of the touch display device.

[0179] Refer to Figure 17 for the drive voltage Vout waveform of the drive signal. After the fourth time period φ4, the switching circuit 230 can cyclically execute the relevant actions from the first time period φ1 to the fourth time period φ4 to continuously output a drive signal with a small voltage slope.

[0180] In the above embodiment, the capacitance value of the energy storage capacitor of the first intermediate voltage generating circuit 250 can be close to or slightly larger than the equivalent capacitance CL of the touch electrode. For example, the capacitance value of the energy storage capacitor of the first intermediate voltage generating circuit 250 can be between one and five times the capacitance value of the equivalent capacitance CL. In this case, the intermediate voltage formed by the first intermediate voltage generating circuit 250 charging the equivalent capacitance CL of the touch electrode 201 at different time periods is different, that is, the first intermediate voltage VC1 in the above embodiment is different from the second intermediate voltage VC2.

[0181] In other embodiments, the capacitance value of the energy storage capacitor of the first intermediate voltage generating circuit 250 can be much larger than the equivalent capacitance CL of the touch electrode 201. For example, the capacitance value of the energy storage capacitor of the first intermediate voltage generating circuit 250 can be more than five times the capacitance value of the equivalent capacitance CL. In this case, the first intermediate voltage VC1 in the above embodiments can be close to or even equal to the second intermediate voltage VC2. For example, in the embodiments shown in Figures 14 and 15, the voltage values ​​of the first intermediate voltage VC1 and the second intermediate voltage VC2 are half of the first power supply voltage VDD1. In the embodiments shown in Figures 16 and 17, the voltage values ​​of the first intermediate voltage VC1 and the second intermediate voltage VC2 are half of the voltage difference between the first power supply voltage VDD1 and the second power supply voltage VDD2.

[0182] Based on the embodiments shown in Figures 14 and 15 above, Figure 18 shows a circuit diagram of another touch driving circuit 200 provided in this application embodiment. Figure 19 shows the waveforms of the driving signal and the switch control signal of the touch driving circuit 200 in Figure 18.

[0183] Referring to Figures 18 and 19, the touch driving circuit 200 further includes: a second power supply voltage generating circuit 240, which generates a second power supply voltage VDD2, wherein the first power supply voltage VDD1 and the second power supply voltage VDD2 are positive and negative voltages, respectively; and a second intermediate voltage generating circuit 260, which generates an intermediate voltage between the second power supply voltage VDD2 and ground. Optionally, the second intermediate voltage generating circuit 260 may also be an energy storage capacitor.

[0184] The switching circuit 230 also includes a fourth input terminal and a fifth input terminal. The fourth input terminal is connected to the second intermediate voltage generating circuit 260, and the fifth input terminal is connected to the second power supply voltage generating circuit 240.

[0185] The relevant technical solutions for the switching circuit 230 during the first time period φ1 to the fourth time period φ4 can be found in the description of the embodiments shown in Figures 14 and 15 above. As an example, as shown in Figure 19, the first intermediate voltage VC1 generated by the touch driving circuit 200 during the first time period φ1 to the fourth time period φ4 can be equal to the second intermediate voltage VC2. The voltage values ​​of the first intermediate voltage VC1 and the second intermediate voltage VC2 can be half of the first power supply voltage VDD1.

[0186] The switching circuit 230 controls the touch electrode 201 to connect to the second intermediate voltage generating circuit 260 during the fifth time period (φ5). During this fifth time period, the second intermediate voltage generating circuit 260 charges the equivalent capacitance CL of the touch electrode 201, making the voltage of the touch electrode 201 equal to the third intermediate voltage VC3. During the sixth time period (φ6), the switch controls the touch electrode 201 to connect to the second power supply voltage generating circuit 240. During this sixth time period (φ6), the second power supply voltage generating circuit 240 charges the equivalent capacitance CL of the touch electrode 201, making the voltage of the touch electrode 201 equal to the second power supply voltage VDD2. During the seventh time period (φ7), the switch controls the touch electrode 201 to connect to the second intermediate voltage generating circuit 260. During this seventh time period (φ7), the second intermediate voltage generating circuit 260 charges the equivalent capacitance CL of the touch electrode 201, making the voltage of the touch electrode 201 equal to the fourth intermediate voltage VC4. During the eighth time period (φ8), the switch controls the touch electrode 201 to connect to the ground terminal 220, making the voltage of the touch electrode 201 equal to the ground voltage.

[0187] As an example, as shown in Figure 19, when the capacitance value of the energy storage capacitor in the second intermediate voltage generation circuit 260 is much larger than the capacitance value of the equivalent capacitance CL of the touch electrode 201, the third intermediate voltage VC3 generated by the touch driving circuit 200 during the fifth time period φ5 to the eighth time period φ8 can be equal to the fourth intermediate voltage VC4. For example, the voltage values ​​of the third intermediate voltage VC3 and the fourth intermediate voltage VC4 can be half of the second power supply voltage VDD2.

[0188] Alternatively, in other examples, when the capacitance value of the energy storage capacitor of the second intermediate voltage generating circuit 260 is close to or equal to the capacitance value of the equivalent capacitance CL of the touch electrode 201, the third intermediate voltage VC3 generated by the touch driving circuit 200 during the fifth time period φ5 to the eighth time period φ8 may be different from the fourth intermediate voltage VC4.

[0189] Optionally, as shown in Figure 18, the switching circuit 230 may include a first switch SW1 to a fifth switch SW5. The input terminal of the first switch SW1 serves as the first input terminal of the switching circuit 230 and is connected to the first power supply voltage generating circuit 210; the second switch SW2 serves as the second input terminal of the switching circuit 230 and is connected to the first intermediate voltage generating circuit 250; the third switch SW3 serves as the third input terminal of the switching circuit 230 and is connected to ground 220; the fourth switch SW4 serves as the fourth input terminal of the switching circuit 230 and is connected to the second intermediate voltage generating circuit 260; and the fifth switch SW5 serves as the fifth input terminal of the switching circuit 230 and is connected to the second power supply voltage generating circuit 240. The output terminals of the first switch SW1 to the fifth switch SW5 are interconnected to serve as the output terminals of the switching circuit 230.

[0190] As shown in Figure 19, when the switching circuit 230 includes a first switch SW1 to a fifth switch SW5, it can receive a first control signal S1 to a fifth control signal S5 for corresponding to the five switches.

[0191] During the first time period φ1, the second switch SW2 is closed and the other switches are open. The first intermediate voltage generating circuit 250 charges the equivalent capacitance CL of the touch electrode 201, making the voltage of the touch electrode 201 equal to the first intermediate voltage VC1.

[0192] During the second time period φ2, the first switch SW1 is closed and the other switches are open. The first power supply voltage generating circuit 210 charges the equivalent capacitance CL of the touch electrode 201, causing the voltage of the touch electrode 201 to change from the first intermediate voltage VC1 to the first power supply voltage VDD1.

[0193] During the third time period φ3, the second switch SW2 is closed and the other switches are open. The first intermediate voltage generating circuit 250 charges the equivalent capacitance CL of the touch electrode 201, causing the voltage of the touch electrode 201 to change from the first power supply voltage VDD1 to the second intermediate voltage VC2.

[0194] During the fourth time period φ4, the third switch SW3 is closed and the other switches are open. The equivalent capacitance CL of the touch electrode 201 discharges to the ground terminal 220, causing the voltage of the touch electrode 201 to change from the second intermediate voltage VC2 to the ground voltage.

[0195] During the fifth time period φ5, the fourth switch SW4 is closed and the other switches are open. The second intermediate voltage generating circuit 260 charges the equivalent capacitance CL of the touch electrode 201, causing the voltage of the touch electrode 201 to change from ground voltage to the third intermediate voltage VC3.

[0196] During the sixth time period φ6, the fifth switch SW5 is closed and the other switches are open. The second power supply voltage generating circuit 240 charges the equivalent capacitance CL of the touch electrode 201, causing the voltage of the touch electrode 201 to change from the third intermediate voltage VC3 to the second power supply voltage VDD2.

[0197] During the seventh time period φ7, the fourth switch SW4 is closed and the other switches are open. The second intermediate voltage generating circuit 260 charges the equivalent capacitance CL of the touch electrode 201, causing the voltage of the touch electrode 201 to change from the second power supply voltage VDD2 to the fourth intermediate voltage VC4.

[0198] During the eighth period φ8, the third switch SW3 is closed and the other switches are open. The equivalent capacitance CL of the touch electrode 201 discharges to the ground terminal 220, causing the voltage of the touch electrode 201 to change from the fourth intermediate voltage VC4 to the ground voltage.

[0199] The technical solution of this application embodiment, based on the use of the first power supply voltage VDD1 and ground voltage to realize the driving signal, further provides a second power supply voltage VDD2. The second power supply voltage VDD2 can increase the voltage amplitude of the driving signal, thereby improving the touch detection effect. In addition, a second intermediate voltage generation circuit 260 is added to the touch driving circuit 200. Through the relevant control of the switching circuit 230, a third intermediate voltage VC3 and a fourth intermediate voltage VC4 can be introduced between the ground voltage transformation to the second power supply voltage VDD2 and the transformation of the second power supply voltage VDD2 to the ground voltage, thereby reducing the voltage change slope of the driving signal, reducing the impact of touch detection on the displayed image, and comprehensively ensuring the touch detection performance and display performance of the touch display device.

[0200] Refer to Figure 19 for the driving voltage Vout waveform of the driving signal. After the fourth time period φ4, the switching circuit 230 can cyclically execute the related actions from the first time period φ1 to the eighth time period φ8 to continuously output a driving signal with a small voltage slope. That is, the first time period φ1 to the eighth time period φ8 can be considered as one cycle of the driving signal provided in the embodiments of this application.

[0201] In the embodiments described above, the driving voltage Vout of the touch electrode 201 monotonically changes between the ground voltage and the power supply voltage, or, during the monotonically changing process between two power supply voltages, an intermediate voltage is introduced. In other embodiments, multiple intermediate voltages may be introduced during the monotonically changing process of the driving voltage Vout of the touch electrode 201.

[0202] Based on the embodiments shown in Figures 12 and 13, Figure 20 shows a circuit diagram of another touch driving circuit 200 provided in this application embodiment. Figure 21 shows the waveforms of the driving signal and the switch control signal of the touch driving circuit 200 in Figure 20.

[0203] Referring to Figures 20 and 21, in this embodiment of the application, in addition to the first power supply voltage generating circuit 210, the first intermediate voltage generating circuit 250, and the switching circuit 230, the touch driving circuit 200 further includes a third intermediate voltage generating circuit 270 for generating a third intermediate voltage VC3. The switching circuit 230 also includes a third input terminal connected to the third intermediate voltage generating circuit 270. Optionally, the third intermediate voltage generating circuit 270 can be an energy storage capacitor.

[0204] The switching circuit 230 is used to control the touch electrode 201 to be connected to the third intermediate voltage generating circuit 270. The third intermediate voltage generating circuit 270 charges the equivalent capacitance CL of the touch electrode 201, so that the voltage of the touch electrode 201 is equal to the fifth intermediate voltage VC5.

[0205] As shown in Figure 21, during the first additional time period φ1' before the first time period φ1, the switching circuit 230 controls the third switch SW3 connected to the third intermediate voltage generating circuit 270 to close, and the other switches to open, so that the third intermediate voltage generating circuit 270 charges the equivalent capacitance CL of the touch electrode 201, and the voltage of the touch electrode 201 is equal to the fifth intermediate voltage VC5.

[0206] Then, during the first time period φ1, the switching circuit 230 controls the second switch SW2 connected to the first intermediate voltage generating circuit 250 to close, and the other switches to open, so that the first intermediate voltage generating circuit 250 charges the equivalent capacitance CL of the touch electrode 201, and the voltage of the touch electrode 201 changes from the fifth intermediate voltage VC3 to the first intermediate voltage VC1.

[0207] During the second time period φ2, the switching circuit 230 controls the first switch SW1 connected to the first power supply voltage generation circuit 210 to close, and the other switches to open, so that the first power supply voltage generation circuit 210 charges the equivalent capacitance CL of the touch electrode 201, and the voltage of the touch electrode 201 changes from the first intermediate voltage VC1 to the first power supply voltage VDD1.

[0208] Furthermore, in the embodiment shown in FIG20, the touch driving circuit 200 also shows a second power supply voltage generating circuit 240 or a ground terminal 220, and the switching circuit 230 further includes a fourth input terminal connected to the second power supply voltage generating circuit 240 or the ground terminal 220.

[0209] When the touch driving circuit 200 includes a first power supply voltage generation circuit 210 and a second power supply voltage generation circuit 240, the first intermediate voltage VC1 and the fifth intermediate voltage VC5 can be any two voltages between the first power supply voltage VDD1 and the second power supply voltage VDD2.

[0210] Similarly, when the touch driving circuit 200 includes a first power supply voltage generation circuit 210 and a ground terminal 220, the first intermediate voltage VC1 and the fifth intermediate voltage VC5 can be any two voltages between the first power supply voltage VDD1 and the ground voltage.

[0211] Referring to Figure 21, during the third time period φ3, the switching circuit 230 controls the second switch SW2 connected to the first intermediate voltage generating circuit 250 to close, while the other switches are opened, so that the first intermediate voltage generating circuit 250 charges the equivalent capacitance CL of the touch electrode 201, and the voltage of the touch electrode 201 changes from the first power supply voltage VDD1 to the second intermediate voltage VC2.

[0212] Then, during the third additional time period φ3' after the third time period φ3, the switching circuit 230 controls the third switch SW3 connected to the third intermediate voltage generating circuit 270 to close, and the other switches to open, so that the third intermediate voltage generating circuit 270 charges the equivalent capacitance CL of the touch electrode 201, and the voltage of the touch electrode 201 changes from the second intermediate voltage VC2 to the sixth intermediate voltage VC6.

[0213] During the fourth time period φ4, the switching circuit 230 controls the fourth switch SW4, which is connected to the second power supply voltage generation circuit 240 or the ground terminal 220, to close, while the other switches are opened. This causes the second power supply voltage generation circuit 240 to charge the equivalent capacitance CL of the touch electrode 201, and the voltage of the touch electrode 201 changes from the sixth intermediate voltage VC6 to the second power supply voltage VDD2. Alternatively, the equivalent capacitance CL of the touch electrode 201 discharges to the ground terminal 220, and the voltage of the touch electrode 201 changes from the sixth intermediate voltage VC6 to the ground voltage.

[0214] In some other embodiments, the capacitance values ​​of the energy storage capacitors of the first intermediate voltage generating circuit 250 and the third intermediate voltage generating circuit 270 can be close to the capacitance value of the equivalent capacitor CL. For example, the capacitance values ​​of the energy storage capacitors of the first intermediate voltage generating circuit 250 and the third intermediate voltage generating circuit 270 can be between one and five times the capacitance value of the equivalent capacitor CL.

[0215] In this case, as shown in Figure 21, the first intermediate voltage VC1 may not be equal to the second intermediate voltage VC2, and the fifth intermediate voltage VC5 may not be equal to the sixth intermediate voltage VC6.

[0216] In some embodiments, the capacitance values ​​of the energy storage capacitors of the first intermediate voltage generating circuit 250 and the third intermediate voltage generating circuit 270 can be much larger than the capacitance value of the equivalent capacitor CL. For example, the capacitance values ​​of the energy storage capacitors of the first intermediate voltage generating circuit 250 and the third intermediate voltage generating circuit 270 can be more than five times the capacitance value of the equivalent capacitor CL.

[0217] In this case, Figure 22 shows another waveform diagram of the drive signal and switch control signal of the touch driving circuit 200 in Figure 20. As shown in Figure 22, the first intermediate voltage VC1 can be equal to the second intermediate voltage VC2, and their voltage values ​​can be 2 / 3 of the voltage difference between the first power supply voltage VDD1 and the second power supply voltage VDD2 or ground GND. The fifth intermediate voltage VC5 can be equal to the sixth intermediate voltage VC6, and their voltage values ​​can be 1 / 3 of the voltage difference between the first power supply voltage VDD1 and the second power supply voltage VDD2 or ground GND. It should be noted that Figures 20 to 22 are only schematic diagrams illustrating that the touch driving circuit 200 includes two intermediate voltage generating circuits to introduce two intermediate voltages between the first power supply voltage VDD1 and ground voltage or between the first power supply voltage VDD1 and the second power supply voltage VDD2. The touch driving circuit 200 can also include more intermediate voltage generating circuits to introduce more intermediate voltages.

[0218] It should also be noted that the touch driving circuit 200 shown in Figure 20 may simultaneously include a ground terminal 220 and a second power supply voltage generation circuit 240. The touch driving circuit 200 may include multiple intermediate voltage generation circuits, which can introduce multiple intermediate voltages not only between the first power supply voltage VDD1 and the ground voltage, but also between the ground voltage and the second power supply voltage VDD2. This application embodiment does not specifically limit the number of such intermediate voltage generation circuits.

[0219] The technical solution of this embodiment introduces multiple intermediate voltages between the power supply voltage and the ground voltage, or between two power supply voltages, through multiple intermediate voltage generation circuits. This further reduces the slope of the driving voltage change, thereby further reducing the impact of the driving voltage of the driving signal on the displayed image in the touch display device and improving the user experience.

[0220] Optionally, in the above embodiments, the first intermediate voltage generating circuit 250, the second intermediate voltage generating circuit 260, and the third intermediate voltage generating circuit 270 can all be energy storage capacitors, which have low manufacturing costs and can easily exchange charges with the equivalent capacitance CL of the touch electrode 201 to charge the equivalent capacitance CL of the touch electrode 201.

[0221] This application provides a touch driver chip, which includes the touch driver circuit 200 provided in the above embodiment.

[0222] It should be noted that the touch driver chip may also include other circuits, such as a control circuit, for controlling the switch circuit 230 to periodically cyclically conduct according to the conduction sequence provided in the above embodiment.

[0223] When the touch driving circuit 200 is applied to an active pen scenario, the driving signal output by the touch driving circuit 200 can be an uplink signal sent to the active pen, and the driving voltage Vout of the driving signal can vary from -20V to 40V.

[0224] This application provides a touch display device, which includes the touch driver chip provided in the above embodiments.

[0225] The touch display device may include a display, such as a liquid crystal display, an organic light-emitting display, a plasma display, and a cathode ray display.

[0226] The apparatus embodiments provided in this application have been described above with reference to Figures 3 to 22. The method embodiments provided in this application will be described below with reference to Figures 23 and 24. It should be understood that the method embodiments described below may correspond to the apparatus embodiments described above. Unless otherwise specified, the specific implementation schemes in the methods described below can be found in the relevant descriptions of the embodiments above.

[0227] Figure 23 shows a schematic flowchart of a touch driving method 300 provided in an embodiment of this application. This touch driving method 300 can be used to control the touch driving circuit 200 shown in Figures 3, 5, 7, or 9 above to output a driving signal to drive the touch electrodes of a touch display device. The touch driving circuit 200 has a first power supply voltage.

[0228] As shown in Figure 23, the touch driving method 300 may include the following steps.

[0229] S310: The drive signal output by the control touch drive circuit changes from the initial voltage to the first intermediate voltage in the first time period. The first intermediate voltage is located between the ground voltage and the first power supply voltage.

[0230] S320: Controls the drive signal output by the touch drive circuit to maintain the first intermediate voltage during the second time period.

[0231] S330: Controls the drive signal output by the touch drive circuit to change from the first intermediate voltage to the first power supply voltage during the third time period.

[0232] Specifically, in step S310, the initial voltage can be ground voltage or any other voltage applied to the touch electrode in the initial state.

[0233] Specifically, the execution body of the touch driving method 300 can be a control circuit, which controls the touch driving circuit 200 in the embodiment shown in FIG2 to output a driving signal. The specific voltage waveform of the driving signal can be referred to the Vout waveform in the embodiment shown in FIG3 above.

[0234] In some embodiments, the touch driving method 300 further includes: controlling the driving signal output by the touch driving circuit to maintain a first power supply voltage during a fourth time period.

[0235] In some embodiments, the touch driving circuit also has a ground voltage or a second power supply voltage; the touch driving method 300 further includes: controlling the driving signal output by the touch driving circuit to change from a first power supply voltage to a second intermediate voltage in a fifth time period, the second intermediate voltage being located between the first power supply voltage and the ground voltage, or the second intermediate voltage being located between the first power supply voltage and the second power supply voltage; controlling the driving signal output by the touch driving circuit to maintain the second intermediate voltage in a sixth time period; and controlling the driving signal output by the touch driving circuit to change from the second intermediate voltage to a ground voltage or the second power supply voltage in a seventh time period.

[0236] In some embodiments, the touch driving method 300 further includes: controlling the driving signal output by the touch driving circuit to maintain a ground voltage or a second power supply voltage during an eighth time period.

[0237] Specifically, in this embodiment, the specific voltage waveform of the driving signal can be seen in the Vout waveform of the embodiment shown in Figure 6 or Figure 8 above.

[0238] In some embodiments, the voltage value of the second intermediate voltage is the same as the voltage value of the first intermediate voltage.

[0239] In some embodiments, when the touch driving circuit has a ground voltage, the touch driving circuit also has a second power supply voltage; the touch driving method 300 further includes: controlling the driving signal output by the touch driving circuit to change from the ground voltage to a third intermediate voltage in a ninth time period, the third intermediate voltage being located between the ground voltage and the second power supply voltage; controlling the driving signal output by the touch driving circuit to maintain the third intermediate voltage in a tenth time period; controlling the driving signal output by the touch driving circuit to change from the third intermediate voltage to the second power supply voltage in an eleventh time period; and controlling the driving signal output by the touch driving circuit to maintain the second power supply voltage in a twelfth time period.

[0240] In some embodiments, the touch driving method 300 further includes: controlling the driving signal output by the touch driving circuit to change from a second power supply voltage to a fourth intermediate voltage during a thirteenth time period, the fourth intermediate voltage being located between ground voltage and the second power supply voltage; controlling the driving signal output by the touch driving circuit to maintain the fourth intermediate voltage during a fourteenth time period; controlling the driving signal output by the touch driving circuit to change from the fourth intermediate voltage to ground voltage during a fifteenth time period; and controlling the driving signal output by the touch driving circuit to maintain ground voltage during a sixteenth time period.

[0241] Specifically, in this embodiment, the specific voltage waveform of the driving signal can be seen in the Vout waveform of the embodiment shown in Figure 10 above.

[0242] In some implementations, the voltage value of the fourth intermediate voltage is the same as the voltage value of the third intermediate voltage.

[0243] In some embodiments, step S330 may include: controlling the drive signal output by the touch driving circuit to change from a first intermediate voltage to a fifth intermediate voltage in the first sub-period of the third time period, the fifth intermediate voltage being located between ground voltage and the first power supply voltage; controlling the drive signal output by the touch driving circuit to maintain the fifth intermediate voltage in the second sub-period of the third time period; and controlling the drive signal output by the touch driving circuit to change from the fifth intermediate voltage to the first power supply voltage in the third sub-period of the third time period.

[0244] Specifically, in this embodiment, the specific voltage waveform of the driving signal can be seen in the Vout waveform of the embodiment shown in Figure 11 above.

[0245] In addition, in this embodiment, the first sub-period in the third time period can be regarded as T1' shown in FIG11, the second sub-period in the third time period can be regarded as T2' shown in FIG11, and the third sub-period in the third time period can be regarded as T3 shown in FIG11.

[0246] Figure 24 shows a schematic flowchart of a touch driving method 400 provided in an embodiment of this application. The touch driving method 400 can be used to control the touch driving circuit 200 shown in Figures 12, 14, 16, 18, or 20 above to output a driving signal to drive the touch electrodes of a touch display device. The touch driving circuit 200 has a first power supply voltage and a first intermediate voltage, the first intermediate voltage being located between ground voltage and the first power supply voltage.

[0247] As shown in Figure 24, the touch driving method 400 may include the following steps.

[0248] S410: Controls the drive signal output by the touch drive circuit to change from the initial voltage to the first intermediate voltage in the first time period.

[0249] S420: The drive signal output by the control touch drive circuit changes from the first intermediate voltage to the first power supply voltage in the second time period.

[0250] Specifically, in step S410, the initial voltage can be ground voltage or any other voltage applied to the touch electrode in the initial state.

[0251] Specifically, the execution body of the touch driving method 400 can be a control circuit, which is used to control the touch driving circuit 200 in the embodiment shown in Figure 12 above to output a driving signal. The specific voltage waveform of the driving signal can be seen from the Vout waveform in the embodiment shown in Figure 13 above.

[0252] In some embodiments, the touch driving circuit has a ground voltage or a second power supply voltage. The touch driving method 400 further includes: controlling the driving signal output by the touch driving circuit to change from a first intermediate voltage to a second intermediate voltage in a third time period, wherein the second intermediate voltage is located between the ground voltage and the first power supply voltage, or the second intermediate voltage is located between the second power supply voltage and the first power supply voltage; and controlling the driving signal output by the touch driving circuit to change from the second intermediate voltage to the ground voltage or the second power supply voltage in a fourth time period.

[0253] Specifically, in this embodiment, the specific voltage waveform of the driving signal can be seen in the Vout waveform of the embodiment shown in Figure 15 or Figure 17 above.

[0254] In some embodiments, when the touch driving circuit has a ground voltage, the touch driving circuit also has a second power supply voltage; the touch driving method 400 further includes: controlling the driving signal output by the touch driving circuit to change from the second power supply voltage to a third intermediate voltage in a fifth time period, the third intermediate voltage being located between the second power supply voltage and the ground voltage; and controlling the driving signal output by the touch driving circuit to change from the third intermediate voltage to the second power supply voltage in a sixth time period.

[0255] In some embodiments, the touch driving method 400 further includes: controlling the driving signal output by the touch driving circuit to change from a second power supply voltage to a fourth intermediate voltage in a seventh time period, the fourth intermediate voltage being located between the second power supply voltage and the ground voltage; and controlling the driving signal output by the touch driving circuit to change from the fourth intermediate voltage to the ground voltage in an eighth time period.

[0256] Specifically, in this embodiment, the specific voltage waveform of the driving signal can be seen in the Vout waveform of the embodiment shown in Figure 19 above.

[0257] In some embodiments, step S410 may include: controlling the drive signal output by the touch driving circuit to change from an initial voltage to a fifth intermediate voltage in the first sub-period of the first time period, the fifth intermediate voltage being located between ground voltage and the first intermediate voltage; and controlling the drive signal output by the touch driving circuit to change from the fifth intermediate voltage to the first intermediate voltage in the second sub-period of the first time period.

[0258] In some embodiments, the driving signal output by the touch driving circuit is changed from a second intermediate voltage to a ground voltage or a second power supply voltage in the fourth time period, including: changing the driving signal output by the touch driving circuit from a second intermediate voltage to a sixth intermediate voltage in the first sub-time period of the fourth time period, wherein the sixth intermediate voltage is located between the second intermediate voltage and the ground voltage or the second power supply voltage; and changing the driving signal output by the touch driving circuit from the sixth intermediate voltage to a ground voltage or the second power supply voltage in the second sub-time period of the fourth time period.

[0259] Specifically, in this embodiment, the specific voltage waveform of the driving signal can be seen in the Vout waveform of the embodiment shown in Figure 21 or Figure 22 above. Furthermore, in the above embodiment, the first sub-period in the first time period can be considered as φ1' shown in Figures 21 and 22, and the second sub-period in the first time period can be considered as φ1 shown in Figures 21 and 22. The first sub-period in the fourth time period can be considered as φ3' shown in Figures 21 and 22, and the second sub-period in the fourth time period can be considered as φ4 shown in Figures 21 and 22.

[0260] It should be understood that the specific implementation methods in the embodiments of this application are only for helping those skilled in the art to better understand the embodiments of this application, and are not intended to limit the scope of the embodiments of this application. Those skilled in the art can make various improvements and modifications based on the above embodiments, and all such improvements or modifications fall within the protection scope of this application.

Claims

1. A touch driving circuit, characterized in that, The touch driving circuit is used to output a driving signal to drive the touch electrode of the touch display device. The touch driving circuit includes: a first power supply voltage generating circuit and a switching circuit; the first power supply voltage generating circuit is used to generate a first power supply voltage; the switching circuit includes a first input terminal and an output terminal, the first input terminal is connected to the first power supply voltage generating circuit, and the output terminal is connected to the touch electrode; the switching circuit is used to control the touch electrode to be connected to the first power supply voltage generating circuit in a first time period, wherein the first power supply voltage generating circuit charges the equivalent capacitance of the touch electrode in the first time period, so that the voltage of the touch electrode is equal to a first intermediate voltage; control the touch electrode to be disconnected from the first power supply voltage generating circuit in a second time period, so that the voltage of the touch electrode remains at the first intermediate voltage; control the touch electrode to be connected to the first power supply voltage generating circuit in a third time period, wherein the first power supply voltage generating circuit charges the equivalent capacitance of the touch electrode in the third time period, so that the voltage of the touch electrode is equal to the first power supply voltage; wherein the first intermediate voltage is located between ground voltage and the first power supply voltage.

2. The touch driving circuit according to claim 1, characterized in that, The switching circuit is also used to control the touch electrode to disconnect from the first power supply voltage generating circuit during the fourth time period, so that the voltage of the touch electrode remains at the first power supply voltage.

3. The touch driving circuit according to claim 1 or 2, characterized in that, The touch driving circuit further includes a ground terminal, and the switching circuit further includes a second input terminal connected to the ground terminal; the switching circuit is used to control the touch electrode to be connected to the ground terminal in a fifth time period, wherein the equivalent capacitance of the touch electrode discharges to the ground terminal in the fifth time period, so that the voltage of the touch electrode is equal to a second intermediate voltage; to control the touch electrode to be disconnected from the ground terminal in a sixth time period, so that the voltage of the touch electrode remains at the second intermediate voltage; and to control the touch electrode to be connected to the ground terminal in a seventh time period, wherein the equivalent capacitance of the touch electrode discharges to the ground terminal in the seventh time period, so that the voltage of the touch electrode is equal to the ground voltage; wherein the second intermediate voltage is located between the ground voltage and the first power supply voltage.

4. The touch driving circuit according to claim 3, characterized in that, The switching circuit is also used to control the voltage of the touch electrode to maintain the ground voltage during the eighth time period.

5. The touch driving circuit according to claim 1 or 2, characterized in that, The touch driving circuit further includes: a second power supply voltage generating circuit for generating a second power supply voltage, wherein the first power supply voltage and the second power supply voltage are positive and negative voltages, respectively; the switching circuit further includes a second input terminal connected to the second power supply voltage generating circuit; the switching circuit is used to control the touch electrode to be connected to the second power supply voltage generating circuit in a fifth time period, wherein the second power supply voltage generating circuit charges the equivalent capacitance of the touch electrode in the fifth time period, such that the voltage of the touch electrode is equal to a second intermediate voltage; to control the touch electrode to be disconnected from the second power supply voltage generating circuit in a sixth time period, such that the voltage of the touch electrode remains at the second intermediate voltage; to control the touch electrode to be connected to the second power supply voltage generating circuit in a seventh time period, wherein the second power supply voltage generating circuit charges the equivalent capacitance of the touch electrode in the seventh time period, such that the voltage of the touch electrode is equal to the second power supply voltage; the switching circuit is also used to control the touch electrode to be disconnected from the second power supply voltage generating circuit in an eighth time period, such that the voltage of the touch electrode remains at the second power supply voltage; wherein the second intermediate voltage is located between the first power supply voltage and the second power supply voltage.

6. The touch driving circuit according to claim 5, characterized in that, The switching circuit is also used to control the touch electrode to disconnect from the second power supply voltage generating circuit during the eighth time period, so that the voltage of the touch electrode remains at the second power supply voltage.

7. The touch driving circuit according to claim 3, characterized in that, The touch driving circuit further includes: a second power supply voltage generating circuit for generating a second power supply voltage, wherein the first power supply voltage and the second power supply voltage are positive and negative voltages, respectively; the switching circuit further includes a third input terminal connected to the second power supply voltage generating circuit; the switching circuit is used to control the touch electrode to be connected to the second power supply voltage generating circuit during a ninth time period, wherein the second power supply voltage generating circuit charges the equivalent capacitance of the touch electrode during the ninth time period, such that the voltage of the touch electrode is equal to a third intermediate voltage; to control the touch electrode to be disconnected from the second power supply voltage generating circuit during a tenth time period, such that the voltage of the touch electrode remains at the third intermediate voltage; and to control the touch electrode to be connected to the second power supply voltage generating circuit during an eleventh time period, wherein the second power supply voltage generating circuit charges the equivalent capacitance of the touch electrode during the eleventh time period, such that the voltage of the touch electrode is equal to the second power supply voltage; wherein the third intermediate voltage is located between the ground voltage and the second power supply voltage.

8. The touch driving circuit according to claim 7, characterized in that, The switching circuit is also used to control the touch electrode to disconnect from the second power supply voltage generating circuit during the twelfth time period, so that the voltage of the touch electrode remains at the second power supply voltage.

9. The touch driving circuit according to claim 7, characterized in that, The switching circuit is used to control the touch electrode to be connected to the ground terminal during the thirteenth time period, and the equivalent capacitance of the touch electrode discharges to the ground terminal during the thirteenth time period, so that the voltage of the touch electrode is equal to the fourth intermediate voltage; to control the touch electrode to be disconnected from the ground terminal during the fourteenth time period, so that the voltage of the touch electrode maintains the fourth intermediate voltage; to control the touch electrode to be connected to the ground terminal during the fifteenth time period, and the equivalent capacitance of the touch electrode discharges to the ground terminal during the fifteenth time period, so that the voltage of the touch electrode is equal to the ground voltage; and to control the voltage of the touch electrode to maintain the ground voltage during the sixteenth time period; wherein the fourth intermediate voltage is located between the ground voltage and the second power supply voltage.

10. The touch driving circuit according to claim 1 or 2, characterized in that, The switching circuit is also used to control the voltage of the touch electrode to be equal to the fifth intermediate voltage before the third time period and then maintain the fifth intermediate voltage, which is different from the first intermediate voltage and is located between the ground voltage and the first power supply voltage.

11. A touch driving circuit, characterized in that, The touch driving circuit is used to output a driving signal to drive the touch electrode of the touch display device. The touch driving circuit includes: a first power supply voltage generating circuit, a first intermediate voltage generating circuit, and a switching circuit. The first power supply voltage generating circuit generates a first power supply voltage, and the first intermediate voltage generating circuit generates an intermediate voltage located between the first power supply voltage and ground voltage. The switching circuit includes a first input terminal, a second input terminal, and an output terminal. The first input terminal is connected to the first power supply voltage generating circuit, the second input terminal is connected to the first intermediate voltage generating circuit, and the output terminal is connected to the touch electrode. The switching circuit controls the touch electrode to be connected to the first intermediate voltage generating circuit during a first time period, during which the first intermediate voltage generating circuit charges the equivalent capacitance of the touch electrode so that the voltage of the touch electrode is equal to the first intermediate voltage. During a second time period, the switching circuit controls the touch electrode to be connected to the first power supply voltage generating circuit, during which the first power supply voltage generating circuit charges the equivalent capacitance of the touch electrode so that the voltage of the touch electrode is equal to the first power supply voltage.

12. The touch driving circuit according to claim 11, characterized in that, The first intermediate voltage generating circuit is an energy storage capacitor, which stores a charge to provide an intermediate voltage between the first power supply voltage and the ground voltage.

13. The touch driving circuit according to claim 11, characterized in that, The touch driving circuit further includes a ground terminal, and the switching circuit further includes a third input terminal connected to the ground terminal; the switching circuit is used to control the touch electrode to be connected to the first intermediate voltage generating circuit in a third time period, the first intermediate voltage generating circuit charging the equivalent capacitance of the touch electrode in the third time period, so that the voltage of the touch electrode is equal to the second intermediate voltage, and controlling the touch electrode to be connected to the ground terminal in a fourth time period, so that the voltage of the touch electrode is equal to the ground voltage.

14. The touch driving circuit according to claim 11, characterized in that, The touch driving circuit further includes: a second power supply voltage generating circuit for generating a second power supply voltage, wherein the first power supply voltage and the second power supply voltage are positive and negative voltages, respectively; the switching circuit further includes a third input terminal connected to the second power supply voltage generating circuit; the switching circuit is used to control the touch electrode to connect to the first intermediate voltage generating circuit during a third time period, wherein the first intermediate voltage generating circuit charges the equivalent capacitance of the touch electrode during the third time period, such that the voltage of the touch electrode is equal to the second intermediate voltage; and to control the touch electrode to connect to the second power supply voltage generating circuit during a fourth time period, wherein the second power supply voltage generating circuit charges the equivalent capacitance of the touch electrode during the fourth time period, such that the voltage of the touch electrode is equal to the second power supply voltage.

15. The touch driving circuit according to claim 13, characterized in that, The touch driving circuit further includes: a second power supply voltage generating circuit and a second intermediate voltage generating circuit, wherein the second power supply voltage generating circuit generates a second power supply voltage, and the first power supply voltage and the second power supply voltage are positive and negative voltages, respectively; the second intermediate voltage generating circuit generates an intermediate voltage located between the second power supply voltage and ground voltage; the switching circuit further includes a fourth input terminal and a fifth input terminal, wherein the fourth input terminal is connected to the second intermediate voltage generating circuit, and the fifth input terminal is connected to the second power supply voltage generating circuit; the switching circuit controls the touch electrode to be connected to the second intermediate voltage generating circuit during a fifth time period, wherein the second intermediate voltage generating circuit charges the equivalent capacitance of the touch electrode during the fifth time period, such that the voltage of the touch electrode is equal to the third intermediate voltage; and controls the touch electrode to be connected to the second power supply voltage generating circuit during a sixth time period, wherein the second power supply voltage generating circuit charges the equivalent capacitance of the touch electrode during the sixth time period, such that the voltage of the touch electrode is equal to the second power supply voltage.

16. The touch driving circuit according to claim 15, characterized in that, The switching circuit is used to control the touch electrode to be connected to the second intermediate voltage generating circuit during the seventh time period. The second intermediate voltage generating circuit charges the equivalent capacitance of the touch electrode during the seventh time period so that the voltage of the touch electrode is equal to the fourth intermediate voltage. During the eighth time period, the circuit controls the touch electrode to be connected to the ground terminal so that the voltage of the touch electrode is equal to the ground voltage.

17. The touch driving circuit according to any one of claims 13 to 16, characterized in that, The touch driving circuit further includes a third intermediate voltage generating circuit; the switching circuit further includes a third input terminal connected to the third intermediate voltage generating circuit; the switching circuit is used to control the touch electrode to be connected to the third intermediate voltage generating circuit before the first time period, the third intermediate voltage generating circuit charging the equivalent capacitance of the touch electrode so that the voltage of the touch electrode is equal to a fifth intermediate voltage; the switching circuit is also used to control the touch electrode to be connected to the third intermediate voltage generating circuit between the third time period and the fourth time period, the third intermediate voltage generating circuit charging the equivalent capacitance of the touch electrode so that the voltage of the touch electrode is equal to a sixth intermediate voltage.

18. The touch driving circuit according to claim 17, characterized in that, Both the first intermediate voltage generating circuit and the third intermediate voltage generating circuit are energy storage capacitors. The capacitance values ​​of the energy storage capacitors in the first and third intermediate voltage generating circuits are between 1 and 5 times the capacitance value of the equivalent capacitance of the touch electrode. The first intermediate voltage is not equal to the second intermediate voltage, and the fifth intermediate voltage is not equal to the sixth intermediate voltage. Alternatively, both the first and third intermediate voltage generating circuits are energy storage capacitors. The capacitance values ​​of the energy storage capacitors in the first and third intermediate voltage generating circuits are greater than 5 times the capacitance value of the equivalent capacitance of the touch electrode. The first intermediate voltage is equal to the second intermediate voltage, and the fifth intermediate voltage is equal to the sixth intermediate voltage.

19. A touch driving method, characterized in that, The touch driving method is used to control a touch driving circuit to output a driving signal to drive the touch electrodes of a touch display device. The touch driving circuit has a first power supply voltage. The touch driving method includes: controlling the driving signal output by the touch driving circuit to change from an initial voltage to a first intermediate voltage in a first time period, the first intermediate voltage being located between ground voltage and the first power supply voltage; controlling the driving signal output by the touch driving circuit to maintain the first intermediate voltage in a second time period; and controlling the driving signal output by the touch driving circuit to change from the first intermediate voltage to the first power supply voltage in a third time period.

20. A touch driving method, characterized in that, The touch driving circuit is used to control the output of a drive signal to drive the touch electrodes of a touch display device. The touch driving circuit has a first power supply voltage and a first intermediate voltage, wherein the first intermediate voltage is located between ground voltage and the first power supply voltage. The touch driving method includes: controlling the driving signal output by the touch driving circuit to change from an initial voltage to a first intermediate voltage during a first time period; The driving signal output by the touch driving circuit changes from the first intermediate voltage to the first power supply voltage during the second time period.

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