Touch circuit, driving method thereof, touch display panel and touch display device

Abstract

The application discloses a touch circuit, a driving method thereof, a touch display panel and a touch display device. The touch circuit comprises a first capacitor, a second capacitor and an output module. The first capacitor and the second capacitor are connected in series between a first signal end and a second signal end. A connection node of the first capacitor and the second capacitor is an induction node. The output module is used for outputting a voltage of the induction node. The voltage of the first signal end is greater than the voltage of the second signal end. In the absence of a touch operation, the voltage of the induction node is V21. In the presence of a touch operation, the voltage of the induction node is V22, and V21 is not equal to V22. According to the embodiment of the application, the traditional thinking is broken, and the simplified design of the touch circuit is facilitated.

Description

Technical Field

[0001] This application relates to the field of touch display technology, specifically to a touch circuit and its driving method, a touch display panel, and a touch display device. Background Technology

[0002] With the development of touch technology, touch technologies can be categorized into infrared, resistive, surface acoustic wave, and capacitive touch technologies based on different touch principles. Among them, capacitive touchscreens are widely used in electronic devices such as tablets, laptops, automotive displays, and mobile phones due to their advantages of high reliability, long lifespan, low maintenance costs, fast response speed, and high light transmittance.

[0003] For capacitive touch, there are complex design issues in the related technologies. Summary of the Invention

[0004] This application provides a touch circuit and its driving method, a touch display panel, and a touch display device, which breaks with traditional thinking and facilitates the simplified design of touch circuits.

[0005] In a first aspect, embodiments of this application provide a touch circuit, including a first capacitor, a second capacitor, and an output module; the first capacitor and the second capacitor are connected in series between a first signal terminal and a second signal terminal, the connection node of the first capacitor and the second capacitor is a sensing node, and the output module is used to output the voltage of the sensing node; the voltage of the first signal terminal is greater than the voltage of the second signal terminal, the voltage of the sensing node is V21 when there is no touch operation, and the voltage of the sensing node is V22 when there is a touch operation, V21≠V22.

[0006] In one possible implementation of the first aspect, the capacitance value of one of the first capacitor and the second capacitor is a fixed value, while the capacitance value of the other capacitor is different when there is no touch operation compared to when there is touch operation.

[0007] In one possible implementation of the first aspect, the first terminal of the first capacitor is electrically connected to the first signal terminal, the second terminal of the first capacitor and the first terminal of the second capacitor are electrically connected to the sensing node, and the second terminal of the second capacitor is electrically connected to the second signal terminal.

[0008] The touch circuit also includes an initialization module and a reset module;

[0009] The initialization module is electrically connected to the first terminal of the first capacitor, the sensing node, and the second terminal of the second capacitor, and is used to transmit the voltage of the first signal terminal to the sensing node and the second terminal of the second capacitor.

[0010] The reset module is electrically connected between the second terminal of the second capacitor and the second signal terminal, and is used to transmit the voltage of the second signal terminal to the second terminal of the second capacitor.

[0011] In one possible implementation of the first aspect, the initialization module includes a first transistor and a second transistor, the first terminal of the first transistor is electrically connected to the first terminal of the first capacitor, the second terminal of the first transistor is electrically connected to the sensing node and the first terminal of the second transistor, and the second terminal of the second transistor is electrically connected to the second terminal of the second capacitor.

[0012] The gate of the first transistor and the gate of the second transistor are electrically connected to the first control signal line;

[0013] Preferably, the output module includes a third transistor, the first electrode of the third transistor is electrically connected to the sensing node, the second electrode of the third transistor is electrically connected to the sensing signal line, and the gate of the third transistor is electrically connected to the driving signal line.

[0014] Preferably, the reset module includes a fourth transistor, the first electrode of the fourth transistor is electrically connected to the second electrode of the second capacitor, the second electrode of the fourth transistor is electrically connected to the second signal terminal, and the gate of the fourth transistor is electrically connected to the second control signal line.

[0015] Based on the same inventive concept, in a second aspect, embodiments of this application provide a method for driving a touch circuit, used to drive a touch circuit as described in any embodiment of the first aspect, the method comprising:

[0016] The control output module is turned on to obtain the voltage of the sensing node.

[0017] In one possible implementation of the second aspect, the first terminal of the first capacitor is electrically connected to the first signal terminal, the second terminal of the first capacitor and the first terminal of the second capacitor are electrically connected to the sensing node, and the second terminal of the second capacitor is electrically connected to the second signal terminal; the touch circuit further includes an initialization module and a reset module; the initialization module is electrically connected to the first terminal of the first capacitor, the sensing node, and the second terminal of the second capacitor, and is used to transmit the voltage of the first signal terminal to the sensing node and the second terminal of the second capacitor; the reset module is electrically connected between the second terminal of the second capacitor and the second signal terminal, and is used to transmit the voltage of the second signal terminal to the second terminal of the second capacitor;

[0018] Before the control output module is turned on to obtain the voltage of the sensing node, the method further includes:

[0019] The control initialization module is turned on so that the voltage at the first signal terminal is transmitted to the sensing node and the second terminal of the second capacitor;

[0020] The control reset module is turned on so that the voltage at the second signal terminal is transmitted to the second terminal of the second capacitor.

[0021] Based on the same inventive concept, in a third aspect, embodiments of this application provide a touch display panel, including the touch circuit described in any embodiment of the first aspect.

[0022] In one possible implementation of the third aspect, the touch display panel includes:

[0023] The circuit driving layer includes pixel circuitry, and at least a portion of the components of the touch circuitry are disposed on the circuit driving layer.

[0024] The functional layer is disposed on one side of the circuit driving layer in the thickness direction. The functional layer includes a light-emitting element and a virtual light-emitting element. The light-emitting element includes a first electrode, a light-emitting layer and a second electrode disposed in the thickness direction. The virtual light-emitting element includes a first electrode plate disposed in the same layer as the first electrode, a dielectric layer disposed in the same layer as the light-emitting layer and a second electrode plate disposed in the same layer as the second electrode.

[0025] The pixel circuit is electrically connected to the light-emitting element, the second electrodes of each light-emitting element are interconnected to form a second electrode area set in a whole layer, the second electrode plate of each virtual light-emitting element is disconnected from the second electrode area, and the virtual light-emitting element is reused as one of the first capacitor and the second capacitor in the touch circuit.

[0026] Preferably, the circuit driving layer further includes redundant traces, which are reused as the plates of one of the first capacitor and the second capacitor in the touch circuit.

[0027] Preferably, an isolation wall extending along the thickness direction is provided on the circuit driving layer, and the second electrode plate is disconnected from the second electrode area through the isolation wall;

[0028] Preferably, the circuit driving layer is provided with a plurality of annular grooves, each annular groove surrounding at least one virtual light-emitting element, and an isolation wall is provided at the bottom of the annular groove.

[0029] In one possible implementation of the third aspect, the touch display panel has a display area and a non-display area that at least partially surrounds the display area. The display area includes pixel circuits, touch circuits, power lines, and data lines, and the non-display area includes a power terminal and a data signal terminal.

[0030] The pixel circuit is electrically connected to the power supply terminal via a power line, and the power supply terminal is multiplexed as the first signal terminal. The touch circuit is also electrically connected to the power supply terminal via a power line; or...

[0031] The pixel circuit is electrically connected to the data signal terminal via a data line. The data signal terminal is multiplexed as the first signal terminal. The touch circuit is electrically connected to the data signal terminal via a data line. When the data signal terminal is multiplexed as the first signal terminal, the data signal terminal is used to provide a fixed signal to the touch circuit.

[0032] Preferably, the display area further includes a reset signal line, and the non-display area further includes a reset signal terminal. The reset signal terminal is multiplexed as a second signal terminal, and the touch circuit is electrically connected to the reset signal terminal through the reset signal line.

[0033] Preferably, the touch circuit includes an initialization module and a reset module. The control terminal of the initialization module is electrically connected to a first control signal line, and the control terminal of the reset module is electrically connected to a second control signal line. The pixel circuit is electrically connected to a first scan line and a second scan line. The first scan line is multiplexed as a first control signal line, and the second scan line is multiplexed as a second control signal line.

[0034] Based on the same inventive concept, in a fourth aspect, embodiments of this application provide a touch display device, including a touch display panel as described in any embodiment of the third aspect.

[0035] Preferably, the touch display panel includes a first display area and a second display area, the light transmittance of the first display area is greater than that of the second display area, and the touch display device includes a photosensitive component, the photosensitive component is positioned corresponding to the first display area, and the photosensitive component is located on the non-display surface of the touch display panel.

[0036] The touch circuit and its driving method, touch display panel and touch display device provided in this application break with traditional thinking. By utilizing the voltage division principle of series capacitors, only the voltage of the sensing node needs to be set by the output module. Therefore, touch detection can be achieved with fewer functional modules, and the design scheme is simple. Attached Figure Description

[0037] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings, in which the same or similar reference numerals denote the same or similar features, and the drawings are not drawn to scale.

[0038] Figure 1 This illustration shows a schematic diagram of a touch circuit provided in an embodiment of this application;

[0039] Figure 2 This illustration shows a schematic diagram of a touch circuit provided in an embodiment of this application;

[0040] Figure 3 This illustration shows a schematic diagram of a touch circuit provided in an embodiment of this application;

[0041] Figure 4 This diagram illustrates a possible layout of the touch circuit provided in an embodiment of this application.

[0042] Figure 5 This diagram illustrates a flowchart of a method for driving a touch circuit according to an embodiment of this application.

[0043] Figure 6 This illustration shows another flowchart of the driving method for the touch circuit provided in an embodiment of this application;

[0044] Figure 7 Show Figure 3 A timing diagram of a touch circuit;

[0045] Figure 8 This diagram shows a top view of a touch display panel provided in an embodiment of this application.

[0046] Figure 9 Show Figure 8 Enlarged schematic diagram of the mid-Q region;

[0047] Figure 10 Show Figure 9 A cross-sectional view along the AA direction;

[0048] Figure 11 This diagram illustrates the distribution of the second electrode region and the second virtual electrode provided in an embodiment of this application.

[0049] Figure 12 This illustration shows another cross-sectional view of the touch display panel provided in an embodiment of this application;

[0050] Figure 13 This illustration shows a schematic diagram of a touch state provided in an embodiment of this application;

[0051] Figure 14 This illustrates another schematic diagram of the touch state provided in an embodiment of this application;

[0052] Figure 15 This illustration shows a cross-sectional structural diagram of a touch circuit component in a touch display panel provided in an embodiment of this application.

[0053] Figure 16 This illustration shows another cross-sectional structural diagram of the touch circuit components in the touch display panel provided in the embodiments of this application;

[0054] Figure 17 This illustration shows a cross-sectional structural diagram of another part of the touch circuit in the touch display panel provided in an embodiment of this application.

[0055] Figure 18 This illustration shows a schematic diagram of a pixel circuit in a touch display panel provided in an embodiment of this application;

[0056] Figure 19 This is a schematic diagram of a display device provided in an embodiment of this application. Detailed Implementation

[0057] The features and exemplary embodiments of various aspects of this application will now be described in detail. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain this application and are not configured to limit this application. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples of this application.

[0058] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0059] It should be understood that when describing the structure of a component, when referring to a layer or region as being "above" or "on top of" another layer or region, it can mean that it is directly above the other layer or region, or that it contains other layers or regions between it and the other layer or region. Furthermore, if the component is flipped over, that layer or region will be located "below" or "under" the other layer or region.

[0060] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0061] It should be noted that when a component is described as "connected" or "electrically connected" to another component, it can be directly connected to the other component, or there may be one or more intermediate components in between.

[0062] Various modifications and variations can be made to this application without departing from its spirit or scope, which will be apparent to those skilled in the art. Therefore, this application is intended to cover modifications and variations falling within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the embodiments provided in this application can be combined with each other without contradiction.

[0063] Before describing the technical solutions provided in the embodiments of this application, in order to facilitate understanding of the embodiments of this application, this application first specifically explains the problems existing in the related technologies:

[0064] For capacitive touch, the touch circuit in related technologies generally includes several built-in modules such as touch driving channel, receiving channel, analog processing front-end module, data processing module, and communication output module, which is complex in design.

[0065] This application breaks with conventional thinking and provides a novel touch circuit and its driving method, a touch display panel, and a touch display device. The following will describe various embodiments of the touch circuit and its driving method, the touch display panel, and the touch display device in conjunction with the accompanying drawings.

[0066] First, the touch circuit provided in the embodiments of this application will be introduced.

[0067] like Figure 1 As shown, the touch circuit 12 provided in this embodiment may include a first capacitor C1, a second capacitor C2, and an output module 121. The first capacitor C1 and the second capacitor C2 are connected in series between the first signal terminal V11 and the second signal terminal V12. Figure 1 The diagram shows a first capacitor C1 connected to the first signal terminal V11 and a second capacitor C2 connected to the second signal terminal V12. It can be understood that as long as the first capacitor C1 and the second capacitor C2 are connected in series between the first signal terminal V11 and the second signal terminal V12, it is sufficient. In other examples, the first capacitor C1 can also be connected to the second signal terminal V12 and the second capacitor C2 can be connected to the first signal terminal V11.

[0068] The connection node between the first capacitor C1 and the second capacitor C2 is the sensing node P, and the output module 121 is used to output the voltage of the sensing node P.

[0069] The voltage at the first signal terminal V11 is greater than the voltage at the second signal terminal V12. For example, the voltage at the first signal terminal V11 can be positive, and the voltage at the second signal terminal V12 can be negative. As an example, the voltage at the first signal terminal V11 can be approximately +7V, and the voltage at the second signal terminal V12 can be approximately -3V.

[0070] Since the first capacitor C1 and the second capacitor C2 are connected in series, and the voltage of the first signal terminal V11 is greater than the voltage of the second signal terminal V12, the first capacitor C1 and the second capacitor C2 divide the voltage of the first signal terminal V11 and the second signal terminal V12. In other words, the sensing node P has a certain voltage.

[0071] When there is no touch operation, the voltage of sensing node P is V21. When there is touch operation, the voltage of sensing node P is V22, and V21≠V22.

[0072] Both the first capacitor C1 and the second capacitor C2 can include electrode plates. For example, in the event of a touch operation, the capacitance value of at least one of the first capacitor C1 and the second capacitor C2 can change, thereby changing the voltage of the sensing node P. The output module 121 can output the voltage of the sensing node P, thus achieving touch detection by acquiring the voltage of the sensing node P.

[0073] The touch circuit provided in this application breaks with traditional thinking. By utilizing the voltage division principle of series capacitors, it is only necessary to set the output module to output the voltage of the sensing node. Therefore, touch detection can be achieved with fewer functional modules, and the design scheme is simple.

[0074] In some embodiments, the capacitance value of one of the first capacitor C1 and the second capacitor C2 is a fixed value, while the capacitance value of the other is different when there is no touch operation compared to when there is touch operation. That is, one of the first capacitor C1 and the second capacitor C2 can be a fixed capacitor Cbase, and the other can be a sensing capacitor Cfinger. For example, the first capacitor C1 can be a fixed capacitor Cbase, and the second capacitor C2 can be a sensing capacitor Cfinger.

[0075] In this embodiment, one of the two capacitors is set as a fixed capacitor Cbase and the other is set as a sensing capacitor Cfinger. Since only the capacitance value of one capacitor changes when there is a touch operation, it is easier to identify the voltage change of the sensing node P, which is beneficial to improving the touch detection accuracy.

[0076] In some embodiments, such as Figure 2 As shown, the first terminal of the first capacitor C1 is electrically connected to the first signal terminal V11, the second terminal of the first capacitor C1 and the first terminal of the second capacitor C2 are electrically connected to the sensing node P, and the second terminal of the second capacitor C2 is electrically connected to the second signal terminal V12.

[0077] The touch circuit may also include an initialization module 122 and a reset module 123.

[0078] The initialization module 122 can be electrically connected to the first terminal of the first capacitor C1, the sensing node P, and the second terminal of the second capacitor C2. The initialization module 122 is used to transmit the voltage of the first signal terminal V11 to the sensing node P and the second terminal of the second capacitor C2.

[0079] The reset module 123 can be electrically connected between the second terminal of the second capacitor C2 and the second signal terminal V12. The reset module 123 is used to transmit the voltage of the second signal terminal V12 to the second terminal of the second capacitor C2.

[0080] In this embodiment, by setting the initialization module 122, the potential of point P can be prevented from becoming uncontrollable due to reasons such as charge retention or interference charge induced by other circuits when the capacitor is floating. By setting the reset module 123, the voltage of the second electrode of the second capacitor C2 can be pulled down from the voltage of the first signal terminal V11 to the voltage of the second signal terminal V12, thereby setting the voltage of the sensing node P.

[0081] In some embodiments, such as Figure 3 As shown, the initialization module 122 may include a first transistor T1 and a second transistor T2. The first terminal of the first transistor T1 is electrically connected to the first terminal of the first capacitor C1, the second terminal of the first transistor T1 is electrically connected to the sensing node P and the first terminal of the second transistor T2, and the second terminal of the second transistor T2 is electrically connected to the second terminal of the second capacitor C2.

[0082] The gates of the first transistor T1 and the second transistor T2 can be electrically connected to the first control signal line S1. When the signal on the first control signal line S1 is at the on level, the first transistor T1 and the second transistor T2 are turned on, and the voltage of the first signal terminal V11 can be transmitted to the sensing node P and the second terminal of the second capacitor C2 to initialize the sensing node P and the second terminal of the second capacitor C2.

[0083] In this embodiment, the signal on the first control signal line S1 can be used to control the first transistor T1 and the second transistor T2 simultaneously, which reduces the number of control signal lines and is more conducive to the simplified design of the touch circuit.

[0084] like Figure 3 As shown, the output module 121 may include a third transistor T3, the first electrode of the third transistor T3 is electrically connected to the sensing node P, the second electrode of the third transistor T3 is electrically connected to the sensing signal line Rx, and the gate of the third transistor T3 is electrically connected to the driving signal line Tx.

[0085] For example, the drive signal line Tx and the sensing signal line Rx can be electrically connected to the touch driver chip. The touch driver chip can provide a drive signal to the third transistor T3 through the drive signal line Tx. When the drive signal is at the on level, the third transistor T3 is turned on, and the third transistor T3 can output the voltage of the sensing node P, which is transmitted to the touch driver chip through the sensing signal line Rx. It is understood that the voltage of the sensing node P received by the touch driver chip when there is no touch operation is different from the voltage of the sensing node P received by the touch driver chip when there is a touch operation.

[0086] like Figure 3 As shown, the reset module 123 may include a fourth transistor T4, the first terminal of the fourth transistor T4 is electrically connected to the second terminal of the second capacitor C2, the second terminal of the fourth transistor T4 is electrically connected to the second signal terminal V12, and the gate of the fourth transistor T4 is electrically connected to the second control signal line S2.

[0087] When the signal on the second control signal line S2 is at the on level, the fourth transistor T4 is turned on, and the voltage of the second signal terminal V12 is transmitted to the second terminal of the second capacitor C2.

[0088] For example, such as Figure 4 As shown, in a touch product, multiple touch circuits 12 can be arranged in an array along a first direction X and a second direction Y. The first direction X and the second direction Y intersect.

[0089] For example, the first direction X can be the row direction, and the second direction Y can be the column direction. Touch circuits 12 in the same row can be connected to the same drive signal line Tx, and touch circuits 12 in the same column can be connected to the same sensing signal line Rx. Each row of touch circuits 12 can be driven sequentially.

[0090] Figure 4 The example illustrates a 4x5 touch circuit 12 with four drive signal lines Tx1, Tx2, Tx3, and Tx4, and five sensing signal lines Rx1, Rx2, Rx3, Rx4, and Rx5.

[0091] Based on the same inventive concept, embodiments of this application also provide a method for driving a touch circuit. For example... Figure 5 As shown, the driving method for the touch circuit provided in this application embodiment may include step 03.

[0092] Step 03: Control the output module to turn on in order to obtain the voltage of the sensing node.

[0093] The driving method for the touch circuit provided in this application breaks with traditional thinking. By utilizing the voltage division principle of series capacitors, it is only necessary to set the output module to obtain the voltage of the sensing node. Therefore, touch detection can be achieved with fewer functional modules, and the design scheme is simple.

[0094] like Figure 4 As shown, in a touch product comprising multiple rows of touch circuits, the output modules can be turned on row by row to obtain the voltage of the sensing nodes output by each row's output module. For example, the output modules of the first row can be turned on first to obtain the voltage of the sensing nodes in the first row; then the output modules of the second row can be turned on to obtain the voltage of the sensing nodes in the second row; then the output modules of the third row can be turned on to obtain the voltage of the sensing nodes in the third row; and so on, until the output modules of the last row are turned on to obtain the voltage of the sensing nodes in the last row.

[0095] like Figure 2 or Figure 3 As shown, the touch circuit may further include an initialization module and a reset module. In some embodiments, such as Figure 6 As shown, prior to step 03, the driving method for the touch circuit provided in this application embodiment may further include steps 01 and 02.

[0096] Step 01: Control the initialization module to turn on so that the voltage of the first signal terminal is transmitted to the sensing node and the second terminal of the second capacitor.

[0097] Step 02: Control the reset module to turn on so that the voltage at the second signal terminal is transmitted to the second terminal of the second capacitor.

[0098] In this embodiment, the voltage of the first signal terminal is transmitted to the sensing node and the second terminal of the second capacitor through the initialization module, which can prevent the potential of point P from becoming uncontrollable due to reasons such as charge retention or interference charge induced by other circuits when the capacitor is floating. The reset module can pull down the voltage of the second terminal of the second capacitor C2 from the voltage of the first signal terminal V11 to the voltage of the second signal terminal V12, thereby setting the voltage of the sensing node P.

[0099] To better understand the driving method of touch circuits, please refer to the reference. Figure 3 and Figure 7 , Figure 7Taking the touch circuit in the nth column and the mth row and the (m+1)th row as an example, Rx(n) represents the sensing signal line connected to the nth column touch circuit, Tx(m / n) represents the driving signal line connected to the nth column and the mth row touch circuit, Tx(m+1 / n) represents the driving signal line connected to the nth column and the (m+1)th row touch circuit, P(m / n) represents the sensing node of the nth column and the mth row touch circuit, P(m+1 / n) represents the sensing node of the nth column and the (m+1)th row touch circuit, S1(m / n) represents the first control signal line connected to the nth column and the mth row touch circuit, S1(m+1 / n) represents the first control signal line connected to the nth column and the (m+1)th row touch circuit, S2(m / n) represents the second control signal line connected to the nth column and the mth row touch circuit, S2(m+1 / n) represents the second control signal line connected to the nth column and the (m+1)th row touch circuit.

[0100] First, drive the m-th row touch circuit to detect the m-th row touch (TP) signal; then drive the (m+1)-th row touch circuit to detect the (m+1)-th row TP signal; then proceed with the detection of the TP signals for the subsequent x rows.

[0101] The following description uses the example of a touch circuit's functional module being turned on at a low level.

[0102] During the detection of the m-th row touch (TP) signal, in stage t(1 / m), the signal on the first control signal line S1(m / n) is at a low level, and the voltage of the first signal terminal V11 is transmitted to the second terminal of the sensing node P and the second capacitor C2 to initialize the touch circuit. Understandably, in stage t(1 / m), the potential of the sensing node P(m / n) is high. In stage t(2 / m), the signal on the second control signal line S1(m / n) is at a low level, and the voltage of the second signal terminal V12 is transmitted to the second terminal of the second capacitor C2 to reset the potential of the second terminal of the second capacitor C2, thus setting the potential of the sensing node P(m / n). Understandably, if no touch operation occurs in the n-th column, m-th row touch circuit, the potential of the sensing node P(m / n) in stage t(2 / m) is pulled low compared to the potential of the sensing node P(m / n) in stage t(1 / m). In stage t(3 / m), the signal on the drive signal line Tx(m / n) is low, and the voltage of the sensing node P(m / n) of the touch circuit in the m-th row is output on the sensing signal line Rx(n). It is understandable that if no touch operation occurs in the touch circuit in the n-th column and m-th row, a low voltage signal is output on the sensing signal line Rx(n) in stage t(3 / m).

[0103] During the detection of the (m+1)th row touch (TP) signal, in stage t(1 / m+1), the signal on the first control signal line S1(m+1 / n) is at a low level, and the voltage of the first signal terminal V11 is transmitted to the sensing node P(m+1 / n) and the second terminal of the second capacitor C2 to initialize the touch circuit. Understandably, in stage t(1 / m+1), the potential of the sensing node P(m+1 / n) is high. In stage t(2 / m+1), the signal on the second control signal line S1(m+1 / n) is at a low level, and the voltage of the second signal terminal V12 is transmitted to the second terminal of the second capacitor C2 to reset the potential of the second terminal of the second capacitor C2, thus setting the potential of the sensing node P(m+1 / n). Understandably, if a touch operation occurs in the touch circuit of the (m+1)th row of the nth column, the capacitance of at least one of the first capacitor C1 and the second capacitor C2 changes, causing a change in the voltage of the sensing node P. For example, in the event of a touch operation, the voltage of sensing node P can be increased. The potential of sensing node P(m+1 / n) in row m+1 at stage t(2 / m+1) is higher than that of sensing node P(m / n) in row m at stage t(2 / m). At stage t(3 / m+1), the signal on the drive signal line Tx(m / n) is low, and the voltage of sensing node P(m / n) in row m is output on the sensing signal line Rx(n). It can be understood that if a touch operation occurs in row m+1 of column n, the voltage on sensing signal line Rx(n) at stage t(3 / m+1) is higher than that at stage t(3 / m), thus the touch operation position can be detected based on the voltage change of sensing node P.

[0104] Based on the same inventive concept, embodiments of this application also provide a touch display panel, including the touch circuit as described in any of the above embodiments.

[0105] The inventors discovered that in related technologies, when touch display panels integrate touch functions, especially for embedded touch display panels, the cathode is mostly vapor-deposited across the entire surface, which acts as a shield for touch signals. This shields the touch signals, making the overall touch response of the display panel unresponsive and affecting the user experience.

[0106] To address the aforementioned technical problems, this application provides a novel touch display panel that integrates touch functionality, offers sensitive touch response, and optimizes the user experience.

[0107] Please see Figures 8 to 11 As shown, Figure 8 This is a top view structural diagram of a touch display panel provided in an embodiment of this application. Figure 9 yes Figure 8 Enlarged diagram of the mid-Q region, Figure 10 yes Figure 9 A cross-sectional view along the AA direction. Figure 11 This is a schematic diagram showing the distribution of the second electrode region and the second virtual electrode in an embodiment of this application.

[0108] The touch display panel 1 provided in this embodiment includes a circuit driving layer 10 and a functional layer 20. The circuit driving layer 10 includes pixel circuits 11, and at least some components of the touch circuit 12 can be disposed on the circuit driving layer 10. For example, the transistors of the touch circuit 12 can be disposed on the circuit driving layer 10.

[0109] The functional layer 20 is disposed on one side of the circuit driving layer 10 in the thickness direction Z. The functional layer 20 includes a light-emitting element 21 and a virtual light-emitting element 22. The light-emitting element 21 includes a first electrode 211, a light-emitting layer 212, and a second electrode 213 arranged sequentially along the thickness direction Z. The virtual light-emitting element 22 includes a first electrode plate 221 disposed in the same layer as the first electrode 211, a dielectric layer 222 disposed in the same layer as the light-emitting layer 212, and a second electrode plate 223 disposed in the same layer as the second electrode 213. The pixel circuit 11 is electrically connected to the light-emitting element 21. The second electrodes 213 of each light-emitting element 21 are interconnected to form a second electrode region 2131 disposed in an entire layer. The second electrode plates 223 of each virtual light-emitting element 22 are disconnected from the second electrode region 2131.

[0110] The circuit driving layer 10 can include multiple pixel circuits 11. Each pixel circuit 11 can be electrically connected to one of the light-emitting elements 21 and control the brightness and illumination duration of that light-emitting element 21. Of course, a pixel circuit 11 can also be electrically connected to two or more light-emitting elements 21 to synchronously drive two or more light-emitting elements 21. When driving two or more light-emitting elements 21 synchronously, the colors of the driven light-emitting elements 21 can be selected to be the same.

[0111] The light-emitting element 21 and the virtual light-emitting element 22 can be fabricated simultaneously. Taking the light-emitting element 21 as an OLED (Organic Light-Emitting Diode) as an example, the first electrode 211 of the light-emitting element 21 and the first electrode plate 221 of the virtual light-emitting element 22 can be formed by a patterned first metal layer. The light-emitting layer 212 and the dielectric layer 222 can both be formed by organic light-emitting material layers. The portion of the organic light-emitting material layer in the light-emitting element 21 is used for display, while the portion in the virtual light-emitting element 22 is used as an intermediate medium for the virtual light-emitting element 22. The light-emitting layer 212 and the dielectric layer 222 can be formed simultaneously. Similarly, the second electrode 213 and the second electrode plate 223 can also be formed by a patterned second metal layer.

[0112] like Figures 8 to 11As shown, the second electrodes 213 of each light-emitting element 21 are interconnected to form a second electrode region 2131 formed by the entire layer. The second electrode plates 223 of each virtual light-emitting element 22 are disconnected from the second electrode region 2131. This can be understood as follows: the integrity of the metal layer containing the second electrodes 213 of each light-emitting element 21 and the second electrode plates 223 of the virtual light-emitting element 22 is broken. The corresponding metal layer on the dielectric layer 222 of the virtual light-emitting element 22 is isolated to form the second electrode plate 223. The remaining parts of this metal layer are connected to form the second electrode region 2131, which includes multiple second electrodes 213 interconnected as a single unit. The virtual light-emitting element 22 is reused as one of the first capacitor C1 and the second capacitor C2 in the touch circuit of the above embodiments. For example, if the first capacitor C1 is used as the sensing capacitor Cfinger, the virtual light-emitting element 22 can be reused as the first capacitor C1. Similarly, if the second capacitor C2 is used as the sensing capacitor Cfinger, the virtual light-emitting element 22 can be reused as the second capacitor C2.

[0113] The touch display panel 1 provided in this embodiment of the application has a pixel circuit 11 in the circuit driving layer 10 and a functional layer 20 including a light-emitting element 21 and a virtual light-emitting element 22. The pixel circuit 11 is connected to the light-emitting element 21 and is used to control the light-emitting element 21 to realize the display requirements of the display panel 1. The light-emitting element 21 includes a first electrode 211, a light-emitting layer 212 and a second electrode 213 arranged sequentially along the thickness direction Z. The virtual light-emitting element 22 includes a first electrode plate 221 arranged in the same layer as the first electrode 211, a dielectric layer 222 arranged in the same layer as the light-emitting layer 212 and a second electrode plate 223 arranged in the same layer as the second electrode 213, which facilitates the synchronous forming of the virtual light-emitting element 22 and the light-emitting element 21. At the same time, the virtual light-emitting element 22 is reused as one of the first capacitor C1 and the second capacitor C2. The second electrode area 2131 is cut off from each of the second electrode plates 223, avoiding the shielding effect of the metal layer arranged on the whole surface on the touch signal, making the touch response sensitive and optimizing the user experience.

[0114] Furthermore, the implementation of the touch function utilizes the molding process of the light-emitting element 21 of the existing touch display panel 1 and the corresponding layer structure. The molding process is relatively mature and does not require additional layer structure, which helps to reduce the cost of the touch display panel 1 and meet the thinning requirements of the display panel.

[0115] In some embodiments, the touch display panel 1 provided in this application has the second electrode plate 223 and the second electrode area 2131 disposed on the same layer and with a gap between them.

[0116] For example, such as Figure 11As shown, during the forming process of the display panel, a plurality of through holes 2131a extending along the thickness direction Z can be provided on the second electrode area 2131. Each second electrode plate 223 is located in one of the through holes 2131a and a gap is formed between its outer periphery and the hole wall of the through hole 2131a.

[0117] The orthographic projection of the through hole 2131a provided on the second electrode region 2131 in the thickness direction Z can be a circle, an ellipse or a polygon. When it is a polygon, it can be a regular polygon.

[0118] Each second electrode plate 223 is located within a through hole 2131a. The shape of the second electrode plate 223 can match the shape of the through hole 2131a, but its area is smaller than the area of ​​the through hole 2131a. For example, if the through hole 2131a is quadrilateral, the shape of the second electrode plate 223 can also be quadrilateral, but its area is smaller than the area of ​​the through hole 2131a. Furthermore, gaps are formed between the four walls that enclose the through hole 2131a and the second electrode plate 223, and the second electrode plate 223 is independently disposed within the through hole 2131a and does not contact the hole wall of the through hole 2131a.

[0119] The gap values ​​between the outer periphery of the second electrode plate 223 and the hole wall of the through hole 2131a can be selected to be equal at all points. Of course, a certain amount of machining error is also allowed, as long as the two do not come into contact.

[0120] In the embodiment of this application, the display panel 1, the second electrode 213 of the light-emitting element 21, and the second electrode plate 223 of the virtual light-emitting element 22 can be formed by first forming a whole metal layer, and then using laser ablation technology to burn off the metal layer at the positions of each dielectric layer 222, thereby forming the aforementioned second electrode plate 223 and the overall second electrode region 2131. Of course, this is one forming method, and it is not limited to this in some embodiments.

[0121] Please see Figure 12 This is a cross-sectional view of a touch display panel 1 according to another embodiment of this application.

[0122] like Figure 12 As shown, the touch display panel 1 provided in this application embodiment can also have an isolation wall 24 extending along the thickness direction Z on the circuit driving layer 10, and the second electrode plate 223 and the second electrode area 2131 are disconnected through the isolation wall 24.

[0123] Optionally, the isolation wall 24 can be directly disposed on the driving circuit layer 10. Of course, other layer structures can also be disposed between the isolation wall 24 and the driving circuit layer 10, that is, the isolation wall 24 can also be indirectly disposed on the driving circuit layer 10.

[0124] By providing an isolation wall 24 on the circuit driving layer 10, when the metal layers of the second electrode 213 and the second electrode plate 223 are formed by methods such as vapor deposition, a portion of the conductive material corresponding to the isolation wall 24 is supported by the isolation wall 24, causing the conductive material on both sides of the isolation wall 24 to be disconnected, thereby disconnecting the second electrode plate 223 from the second electrode area 2131. This ensures the display requirements of the display panel 1, improves the touch response sensitivity of the display panel 1, and optimizes the user experience.

[0125] In some embodiments, the circuit driving layer 10 is provided with a plurality of annular grooves 23, each annular groove 23 being arranged around at least one virtual light-emitting element 22, and an isolation wall 24 being provided at the bottom of the annular groove 23.

[0126] like Figure 10 , Figure 12 As shown, in some embodiments, the touch display panel 1 provided in this application includes a circuit driving layer 10 further comprising a redundant trace 13, which can be reused as a plate of one of the first capacitor C1 and the second capacitor C2 in the touch circuit. For example, if the first capacitor C1 is a fixed capacitor Cbase, the redundant trace 13 can be reused as a plate of the first capacitor C1. Similarly, if the second capacitor C2 is a fixed capacitor Cbase, the redundant trace 13 can be reused as a plate of the second capacitor C2.

[0127] The display panel provided in this application embodiment, through the above-described settings, can increase the capacitance of a single sensing point of the virtual light-emitting element 22, thereby further improving the sensitivity of touch control.

[0128] For example, redundant trace 13 may be electrically connected to the first electrode 221 of virtual light-emitting element 22.

[0129] The circuit driving layer 10 may include multiple redundant traces 13 located in different film layers. The redundant traces 13 in different film layers can be interconnected through contact holes to ensure the electrical connection requirements with the first electrode plate 221.

[0130] For example, the material of redundant trace 13 may include indium tin oxide (ITO).

[0131] In some implementations, such as Figure 13 or Figure 14 As shown, the touch circuit 12 can be set one-to-one with the virtual light-emitting element 22. The touch circuit 12 can be used to transmit the signal required for touch detection and to receive the voltage of the sensing node P.

[0132] To better understand the physical structure of the touch circuit 12, please refer to... Figures 15 to 17 ,in, Figure 15The diagram illustrates a fixed capacitor Cbase (C1) and a sensing capacitor Cfinger (C2). Figure 16 The diagram illustrates the concept of a first capacitor C1 as the sensing capacitor Cfinger and a second capacitor C2 as the fixed capacitor Cbase. Figure 15 and Figure 16 The diagram illustrates the first transistor T1, the second transistor T2, and the fourth transistor T4. Figure 17 The third transistor T3 is shown.

[0133] Please refer to the reference. Figure 3 , Figure 15 and Figure 17 The first capacitor C1 is a fixed capacitor Cbase, and the second capacitor C2 is an inductive capacitor Cfinger. The first plate 221 can serve as the plate connecting the first capacitor C1, the first transistor T1, and the third transistor T3 to the second capacitor C2. The second plate 223 can serve as the plate connecting the second transistor T2 and the fourth transistor T3 to the second capacitor C2. The potential of the first plate 221 is equal to the potential of the inductive node P. The first plate 221 can also serve as the plate connecting the first capacitor C1 to the second capacitor C2. The redundant trace 13 can serve as the plate connecting the first capacitor C1 to the first transistor T1 and the first signal terminal V11.

[0134] Please refer to the reference. Figure 3 , Figure 16 and Figure 17 The first capacitor C1 is an inductive capacitor Cfinger, and the second capacitor C2 is a fixed capacitor Cbase. The first plate 221 can serve as the plate connecting the first capacitor C1 to the second capacitor C2, the first transistor T1, and the third transistor T3. The second plate 223 can serve as the plate connecting the first capacitor C1 to the first transistor T1 and the first signal terminal V11. The potential of the first plate 221 is equal to the potential of the inductive node P. The first plate 221 can also serve as the plate connecting the second capacitor C2 to the first capacitor C1. The redundant trace 13 can serve as the plate connecting the second capacitor C2 to the second transistor T2 and the fourth transistor T4.

[0135] In addition, the second terminal of the fourth transistor T4 is connected to the second signal terminal V12, and the second terminal of the third transistor T3 is connected to the sensing signal line Rx.

[0136] For example, the gate of each transistor may be located in the first metal layer M1, the connection line between the second terminal of the fourth transistor T4 and the second signal terminal V12 may be located in the second metal layer M2, and the redundant trace 13 may be located in the third metal layer M3.

[0137] For example, other conductive layers for setting redundant traces 13 may also be provided between the third metal layer M3 and the film layer where the first electrode plate 221 is located, and the redundant traces 13 of different film layers can be connected to each other through vias.

[0138] For example, the active layers of the first transistor T1, the second transistor T2, and the fourth transistor T4 can be interconnected as a single unit.

[0139] like Figure 8 As shown, in some embodiments, the touch display panel 1 provided in this application may have a first display area AA1, a second display area AA2 surrounding at least a portion of the first display area AA1, and a transition display area AA3 located between the first display area AA1 and the second display area AA2. Both the second display area AA2 and the first display area AA1 may be provided with a light-emitting element 21 and a virtual light-emitting element 22. The pixel circuit 11 electrically connected to the light-emitting element 21 in the first display area AA1 and the touch circuit 12 electrically connected to the virtual light-emitting element 22 in the first display area AA1 are both located in the transition display area AA3.

[0140] By setting a transition display area AA3 for both the pixel circuit 11 electrically connected to the light-emitting element 21 of the first display area AA1 and the touch circuit 12 electrically connected to the virtual light-emitting element 22, the number of devices in the first display area AA1 can be reduced, the light-blocking rate and reflectivity can be reduced, the light transmittance of the first display area AA1 can be improved, and the light requirements of devices such as the under-screen camera can be guaranteed.

[0141] Optionally, the light transmittance of the first display area AA1 can be greater than that of the second display area AA2 and the transition display area AA3. To ensure the light requirements of the touch display panel 1 when it is used for display devices and integrates functions such as under-display cameras, the light transmittance of the first display area AA1 can be greater than 15%, or even greater than 40%, or even have higher light transmittance.

[0142] In some embodiments, along the thickness direction Z, the orthographic projection of each light-emitting element 21 located in the second display area AA2 can cover the orthographic projection of the pixel circuit 11, and the orthographic projection of the virtual light-emitting element 22 located in the second display area AA2 can cover the orthographic projection of the touch circuit 12.

[0143] Since the pixel circuit 11 and touch circuit 12 in the first display area AA1 are both placed in the transition display area AA3, the transition display area AA3 must not only place the pixel circuit 11 and touch circuit 12 corresponding to the light-emitting element 21 in this area, but also the pixel circuit 11 and touch circuit 12 in the transition display area AA3. In order to save space, the size of the pixel circuit 11 and touch circuit 12 will be reduced, so that in the thickness direction Z, the orthographic projection of the light-emitting element 21 will cover the orthographic projection of the pixel circuit 11. Therefore, in order to ensure the consistency of the distribution pattern, each touch circuit 12 is set below the virtual light-emitting element 22, thereby ensuring the consistency of the distribution pattern in various places and reducing the probability of moiré patterns.

[0144] In some embodiments, such as Figure 8 As shown, the touch display panel has display areas AA1, AA2, AA3 and a non-display area NA that at least partially surrounds the display areas. Figure 18 A schematic diagram of a pixel circuit 11 is shown. The display area may include the pixel circuit 11, the touch circuit 12, the power line 14, and the data line 15. The non-display area NA includes a power supply terminal VDD and a data signal terminal Vdata. The power supply terminal VDD is used to provide a positive voltage signal, and the data signal terminal Vdata is used to provide a data signal.

[0145] The pixel circuit 11 can be electrically connected to the power supply terminal VDD via the power supply line 14. The power supply terminal VDD can be reused as the first signal terminal V11 connected to the touch circuit 12. In other words, it is not necessary to set up an additional first signal terminal V11 or additional signal lines. Instead, the touch circuit 12 can be directly connected to the power supply terminal VDD via the power supply line VDD, thereby simplifying the design and reducing costs.

[0146] Alternatively, the pixel circuit 11 can be electrically connected to the data signal terminal Vdata via the data line 15. The data signal terminal Vdata can be reused as the first signal terminal V11 connected to the touch circuit 12. This eliminates the need for an additional first signal terminal V11 and additional signal lines; instead, the touch circuit 12 can be directly electrically connected to the data signal terminal Vdata via the data line 15, simplifying the design and reducing costs. In the case where the data signal terminal is reused as the first signal terminal, the data signal terminal Vdata is used to provide a fixed signal to the touch circuit.

[0147] For example, such as Figure 18 As shown, the pixel circuit 11 may include transistors M1 to M7 and a storage capacitor Cst. The connection relationship of each device in the pixel circuit 11 can be referred to Figure 18 This will not be elaborated upon here.

[0148] The display area may also include a reset signal line 16, and the non-display area may also include a reset signal terminal Vref, which can be used to provide a negative voltage signal.

[0149] The reset signal terminal Vref can be reused as the second signal terminal V12. In this way, there is no need to set up an additional second signal terminal V12 or additional signal lines. Instead, the touch circuit can be electrically connected to the reset signal terminal Vref through the reset signal line 16, which simplifies the design and reduces costs.

[0150] like Figure 3As shown, the touch circuit 12 may include an initialization module 122 and a reset module 123. The control terminal of the initialization module 122 is electrically connected to the first control signal line S1, and the control terminal of the reset module 123 is electrically connected to the second control signal line S2.

[0151] like Figure 18 As shown, the pixel circuit is electrically connected to the first scan line SCAN1 and the second scan line SCAN2. The first scan line SCAN1 can be multiplexed as the first control signal line S1, and the second scan line SCAN2 can be multiplexed as the second control signal line S2.

[0152] In other words, the touch circuit 12 can use the scan lines connected to the pixel circuit and the signals on the scan lines. The timing of the touch circuit 12 can be consistent with the pixel light emission timing. In this way, there is no need to add signal lines and control signals required by the touch circuit, which is more conducive to simplifying the design.

[0153] Based on the same inventive concept, such as Figure 19 As shown in the figure, this application embodiment also provides a touch display device, including the touch display panel 1 of any of the above embodiments.

[0154] In some optional embodiments, the display panel 1 has a first display area AA1, a transition display area AA3, and a second display area AA2, wherein the light transmittance of the first display area AA1 is greater than that of the second display area AA2. The touch display panel 1 may include a first surface S1 and a second surface S2 opposite to each other, wherein the first surface S1 is the display surface and the second surface S2 is the non-display area surface. The touch display device further includes a photosensitive component 2, which is located on the second surface S2 side of the touch display panel 1, and the photosensitive component 2 corresponds to the position of the first display area AA1.

[0155] The photosensitive component 2 can be an image acquisition device used to acquire external image information. In this embodiment, the photosensitive component 2 can be a complementary metal-oxide-semiconductor (CMOS) image acquisition device. In other embodiments, the photosensitive component 2 can also be a charge-coupled device (CCD) image acquisition device or other forms of image acquisition device, such as a front-facing camera. It is understood that the photosensitive component 2 is not limited to an image acquisition device. For example, in some embodiments, the photosensitive component 2 can also be an infrared sensor, a proximity sensor, an infrared lens, a flood illuminator, an ambient light sensor, and a dot projector, etc., as a light sensor. In addition, the touch display device can also integrate other components on the second surface S2 of the touch display panel 1, such as an earpiece and a speaker.

[0156] It should be noted that the transistors in the embodiments of this application can be either P-type or N-type transistors. For P-type transistors, the on-level is low and the off-level is high. That is, when the gate potential of a P-type transistor is low, its first and second terminals are connected; when the gate potential of a P-type transistor is high, its first and second terminals are off. For N-type transistors, the on-level is high and the off-level is low. That is, when the gate potential of an N-type transistor is high, its first and second terminals are connected; when the gate potential of an N-type transistor is low, its first and second terminals are off. In specific implementation, the gate of each transistor is used as its control electrode. Furthermore, depending on the signal and type of the gate of each transistor, its first electrode can be used as the source and its second electrode as the drain, or its first electrode can be used as the drain and its second electrode as the source. No distinction is made here. In addition, the on-level and off-level in the embodiments of this application are general terms. The on-level refers to any level that can turn on the transistor, and the off-level refers to any level that can turn off / turn off the transistor.

[0157] The embodiments described above are not exhaustive, nor do they limit the application to the specific embodiments described herein. Clearly, many modifications and variations can be made based on the above description. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to effectively utilize this application and its modifications. This application is limited only by the claims and their full scope and equivalents.

Claims

1. A touch circuit, characterized in that, Includes a first capacitor, a second capacitor, and an output module; The first capacitor and the second capacitor are connected in series between the first signal terminal and the second signal terminal. The connection node between the first capacitor and the second capacitor is a sensing node. The output module is used to output the voltage of the sensing node. The voltage of the first signal terminal is greater than the voltage of the second signal terminal. When there is no touch operation, the voltage of the sensing node is V21, and when there is touch operation, the voltage of the sensing node is V22, where V21 ≠ V22. The first terminal of the first capacitor is electrically connected to the first signal terminal, the second terminal of the first capacitor and the first terminal of the second capacitor are electrically connected to the sensing node, and the second terminal of the second capacitor is electrically connected to the second signal terminal. The touch circuit also includes an initialization module and a reset module; The initialization module is electrically connected to the first terminal of the first capacitor, the sensing node, and the second terminal of the second capacitor, and is used to transmit the voltage of the first signal terminal to the sensing node and the second terminal of the second capacitor. The reset module is electrically connected between the second terminal of the second capacitor and the second signal terminal, and is used to transmit the voltage of the second signal terminal to the second terminal of the second capacitor; The initialization module includes a first transistor and a second transistor. The first terminal of the first transistor is electrically connected to the first terminal of the first capacitor. The second terminal of the first transistor is electrically connected to the sensing node and the first terminal of the second transistor. The second terminal of the second transistor is electrically connected to the second terminal of the second capacitor. The gates of the first transistor and the second transistor are electrically connected to the first control signal line; The output module includes a third transistor, the first electrode of which is electrically connected to the sensing node, the second electrode of which is electrically connected to the sensing signal line, and the gate of which is electrically connected to the driving signal line. The reset module includes a fourth transistor, the first terminal of which is electrically connected to the second terminal of the second capacitor, the second terminal of which is electrically connected to the second signal terminal, and the gate of which is electrically connected to the second control signal line.

2. The touch circuit according to claim 1, characterized in that, The capacitance value of one of the first capacitor and the second capacitor is a fixed value, while the capacitance value of the other capacitor is different when there is no touch operation compared to when there is touch operation.

3. A method for driving a touch circuit, characterized in that, The method for driving the touch circuit as described in any one of claims 1 to 2 includes: The output module is turned on to obtain the voltage of the sensing node.

4. The method according to claim 3, characterized in that, Before controlling the output module to turn on to obtain the voltage of the sensing node, the method further includes: The initialization module is turned on so that the voltage at the first signal terminal is transmitted to the sensing node and the second terminal of the second capacitor; The reset module is turned on so that the voltage at the second signal terminal is transmitted to the second terminal of the second capacitor.

5. A touch display panel, characterized in that, Includes the touch circuit as described in any one of claims 1-2.

6. The touch display panel according to claim 5, characterized in that, The touch display panel includes: The circuit driving layer includes pixel circuits, and at least a portion of the components of the touch circuit are disposed in the circuit driving layer; A functional layer is disposed on one side of the thickness direction of the circuit driving layer. The functional layer includes a light-emitting element and a virtual light-emitting element. The light-emitting element includes a first electrode, a light-emitting layer and a second electrode disposed along the thickness direction. The virtual light-emitting element includes a first electrode plate disposed in the same layer as the first electrode, a dielectric layer disposed in the same layer as the light-emitting layer and a second electrode plate disposed in the same layer as the second electrode. The pixel circuit is electrically connected to the light-emitting element, the second electrodes of each light-emitting element are interconnected to form a second electrode area that is set in a whole layer, the second electrode plate of each virtual light-emitting element is disconnected from the second electrode area, and the virtual light-emitting element is reused as one of the first capacitor and the second capacitor in the touch circuit.

7. The touch display panel according to claim 6, characterized in that, The circuit driving layer also includes redundant traces, which are multiplexed as the plates of one of the first capacitor and the second capacitor in the touch circuit.

8. The touch display panel according to claim 6, characterized in that, An isolation wall extending along the thickness direction is provided on the circuit driving layer, and the second electrode plate and the second electrode area are disconnected through the isolation wall.

9. The touch display panel according to claim 8, characterized in that, The circuit driving layer is provided with a plurality of annular grooves, each annular groove surrounding at least one of the virtual light-emitting elements, and the bottom of the annular groove is provided with the isolation wall.

10. The touch display panel according to claim 5 or 6, characterized in that, The touch display panel has a display area and a non-display area that at least partially surrounds the display area. The display area includes pixel circuits, the touch circuit, power lines, and data lines. The non-display area includes a power terminal and a data signal terminal. The pixel circuit is electrically connected to the power supply terminal via the power supply line, and the power supply terminal is multiplexed as the first signal terminal; the touch circuit is electrically connected to the power supply terminal via the power supply line; or... The pixel circuit is electrically connected to the data signal terminal via the data line. The data signal terminal is multiplexed as the first signal terminal. The touch circuit is electrically connected to the data signal terminal via the data line. When the data signal terminal is multiplexed as the first signal terminal, the data signal terminal is used to provide a fixed signal to the touch circuit.

11. The touch display panel according to claim 10, characterized in that, The display area also includes a reset signal line, and the non-display area also includes a reset signal terminal. The reset signal terminal is multiplexed as the second signal terminal, and the touch circuit is electrically connected to the reset signal terminal through the reset signal line.

12. The touch display panel according to claim 11, characterized in that, The touch circuit includes an initialization module and a reset module. The control terminal of the initialization module is electrically connected to a first control signal line, and the control terminal of the reset module is electrically connected to a second control signal line. The pixel circuit is electrically connected to a first scan line and a second scan line. The first scan line is multiplexed as the first control signal line, and the second scan line is multiplexed as the second control signal line.

13. A touch display device, characterized in that, Includes the touch display panel according to claim 7 or 8.

14. The touch display device according to claim 13, characterized in that, The touch display panel includes a first display area and a second display area. The light transmittance of the first display area is greater than that of the second display area. The touch display device includes a photosensitive component. The photosensitive component is positioned corresponding to the first display area and is located on the non-display surface of the touch display panel.

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