Stylus chip, active stylus, screen chip, touch screen, and touch system

Abstract

The present application discloses a stylus chip, an active stylus, a screen chip, a touch screen, and a touch system. The active stylus comprises a stylus housing, a stylus electrode, and an isolation structure disposed in the stylus housing; the stylus chip comprises a first driving circuit, a second driving circuit, and a stylus controller; the first driving circuit is connected to both the stylus controller and the stylus electrode, and is configured to output a first driving signal to the stylus electrode on the basis of a first control signal outputted by the stylus controller; the second driving circuit is connected to both the stylus controller and the isolation structure, and is configured to output a second driving signal to the isolation structure on the basis of a second control signal outputted by the stylus controller, such that the isolation structure isolates a crosstalk signal between the active stylus and a hand; the stylus controller simultaneously outputs the first control signal and the second control signal, and thus the first driving circuit and the second driving circuit simultaneously output the first driving signal and the second driving signal, so that a crosstalk signal occurring simultaneously with the first driving signal can be isolated, so as to achieve the objective of effectively eliminating the crosstalk signal.

Description

Pen chip, active pen, screen chip, touch screen and touch system Technical Field

[0001] This application relates to the field of touch system technology, and more particularly to a pen chip, an active pen, a screen chip, a touch screen, and a touch system. Background Technology

[0002] Existing touch systems include an active pen and a touchscreen. The active pen and touchscreen operate based on a certain communication protocol. During operation, a coupling capacitor exists between the active pen and the touchscreen, through which signals are transmitted. When a user holds the active pen close to or touches the touchscreen—for example, when the user holds the active pen to tap the touchscreen, hovers it at a certain height on the touchscreen, or writes—the hand also approaches or touches the touchscreen. This causes the touchscreen to receive not only the capacitive projection signal formed by the coupling between the active pen and the touchscreen, but also the capacitive projection signal formed by the coupling between the hand and the touchscreen. The capacitive projection signal from the hand is generally out of phase with the capacitive projection signal from the active pen in the time domain. If the two capacitive projection signals are in the same sensing channel of the touchscreen, the capacitive projection signal from the active pen will be interfered with by the capacitive projection signal from the hand, thus affecting the envelope of the capacitive projection signal from the active pen on the touchscreen and reducing the accuracy of the signal recognized by the touchscreen. Summary of the Invention

[0003] This application provides a pen chip, an active pen, a screen chip, a touch screen, and a touch system to solve the hand-pen crosstalk problem between the active pen and the touch screen.

[0004] A pen chip is used in an active pen, the active pen including a pen shell, a pen electrode disposed on the pen shell, and an isolation structure disposed within the pen shell, the pen electrode being coupled to a screen electrode on a touch screen.

[0005] The pen chip is disposed inside the pen casing, and the pen chip includes a first driving circuit, a second driving circuit, and a pen controller;

[0006] The first driving circuit is connected to both the pen controller and the pen electrode, and is used to output a first driving signal to the pen electrode based on the first control signal output by the pen controller.

[0007] The second driving circuit is connected to both the pen controller and the isolation structure, and is used to output a second driving signal to the isolation structure based on the second control signal output by the pen controller, so that the isolation structure isolates the crosstalk signal between the active pen and the hand;

[0008] The pen controller is configured to simultaneously output the first control signal and the second control signal, so that the first driving circuit and the second driving circuit simultaneously output the first driving signal and the second driving signal.

[0009] Preferably, the signal parameters of the second driving signal are related to the signal parameters of a single first driving signal, or the second driving signal is related to the signal parameters of multiple first driving signals output simultaneously.

[0010] Preferably, the second driving signal and the first driving signal have the same frequency and phase;

[0011] The amplitude of the second driving signal is the product of the amplitude of the target driving signal and the first coefficient. The value of the first coefficient ranges from 0 to 20%. The target driving signal is a single first driving signal or a signal obtained by superimposing multiple first driving signals.

[0012] Alternatively, the amplitude of the second driving signal is the amplitude after weighting the amplitudes of multiple first driving signals and the second coefficients corresponding to the multiple first driving signals, wherein the value of the second coefficient is in the range of 0-20%.

[0013] Preferably, the first coefficient is negatively correlated with the first suspension height;

[0014] The first suspension height is the height between the electrode vertex of the active pen facing the touch screen and the touch screen.

[0015] Preferably, the second coefficient corresponding to each of the first driving signals is negatively correlated with the second suspension height of the pen electrode corresponding to each of the first driving signals; or, the amplitude corresponding to each of the first driving signals is positively correlated with the second suspension height of the pen electrode corresponding to each of the first driving signals.

[0016] The second suspension height of the pen electrode is the height between the point of the pen electrode closest to the touch screen and the touch screen.

[0017] Preferably, the value range of the first coefficient is 3%-10%; the value range of the second coefficient is 3%-10%.

[0018] Preferably, the second driving signal and the first driving signal have different frequencies, so that the touch screen can detect the first measured signal and the second measured signal, and compensate the first measured signal based on the second measured signal to determine the first driving signal output by the active pen;

[0019] The first measured signal is the signal coupled to the touch screen by the first driving signal, and the second measured signal is the signal coupled to the touch screen by the second driving signal.

[0020] Preferably, the plurality of first driving signals are respectively a first driving signal received by the main electrode and a first driving signal received by the sub-electrode;

[0021] Alternatively, the multiple first driving signals may be the first driving signal received by the main electrode, the first driving signal received by the secondary electrode, and the first driving signal received by the pen tail electrode.

[0022] An active pen includes a pen housing, a pen electrode disposed on the pen housing, and an isolation structure disposed within the pen housing, wherein the pen electrode is coupled to a screen electrode on a touch screen.

[0023] It also includes the aforementioned pen chip, which is disposed inside the pen housing and is connected to the pen electrode and the isolation structure.

[0024] Preferably, the pen casing has a gripping area; the isolation structure is disposed within the gripping area.

[0025] Preferably, the isolation structure includes a conductive spacer, which is assembled inside the pen housing;

[0026] Alternatively, the isolation structure includes a conductive coating applied to the inner wall of the pen casing;

[0027] Alternatively, the isolation structure may include a conductive component disposed on the pen casing.

[0028] Preferably, the pen casing includes a pen body and a pen tip disposed at one end of the pen body;

[0029] The pen electrode is disposed on the pen tip, and at least a portion of the pen electrode extends out of the pen tip.

[0030] Preferably, the pen tip is provided with an assembly hole;

[0031] The pen electrode includes a main electrode and a secondary electrode;

[0032] One end of the main electrode is disposed inside the pen housing, and the other end of the main electrode extends out of the pen housing through the assembly hole for positioning detection;

[0033] The secondary electrode is disposed inside the pen shell and sleeved outside the main electrode, and is used for tilt angle detection.

[0034] A screen chip is suitable for connection to screen electrodes on a touch screen, the screen electrodes being used to couple with pen electrodes on an active pen, the screen chip including a screen receiving circuit and a screen controller;

[0035] The screen receiving circuit is connected to both the screen electrode and the screen controller, and is used to send the measured signal detected by the screen electrode to the screen controller.

[0036] The screen controller is configured to determine the measured signal as the first driving signal output by the active pen when the measured signal is a single-frequency signal; and to compensate the first measured signal based on the second measured signal when the measured signal contains a first measured signal and a second measured signal with different frequencies, thereby determining the first driving signal output by the active pen.

[0037] The first measured signal is the signal coupled to the touch screen by the first driving signal, and the second measured signal is the signal coupled to the touch screen by the second driving signal.

[0038] Preferably, the first driving signal is the sum of the first measured signal and the compensation signal;

[0039] The compensation signal is the product of the second driving signal and the third coefficient.

[0040] A touch screen includes a screen body, screen electrodes, and the aforementioned screen chip;

[0041] The screen electrode is disposed on the screen body and is used to couple with the pen electrode on the active pen.

[0042] The screen chip is disposed outside the screen body and is electrically connected to the screen electrode.

[0043] A touch system, comprising the aforementioned active pen and the aforementioned touchscreen;

[0044] The pen electrode on the active pen is coupled to the screen electrode on the touch screen.

[0045] The aforementioned pen chip, active pen, screen chip, touchscreen, and touch system, by adding an isolation structure and a second driving circuit to the active pen, with the second driving circuit connecting the pen controller and the isolation structure, allow the pen controller to simultaneously control the second driving circuit to output a second driving signal to the isolation structure while controlling the first driving circuit to output a first driving signal to the pen electrodes. This eliminates or greatly reduces the direct coupling between the hand and the active pen system ground, thereby achieving the purpose of eliminating crosstalk signals between the active pen and the hand. Because the first and second driving signals are output simultaneously, the electric fields formed by the first and second driving signals occur simultaneously, thus isolating the crosstalk signals that occur simultaneously with the first driving signal, effectively eliminating crosstalk signals. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 is a schematic diagram of an active pen in an embodiment of this application;

[0048] Figure 2 is a schematic diagram of the communication between the active pen and the touch screen shown in Figure 1;

[0049] Figure 3 is a schematic diagram of a typical active pen;

[0050] Figure 4 shows the physical capacitive coupling model of the touch system formed by the typical active stylus and the touch screen shown in Figure 3 when the hand is on the touch screen.

[0051] Figure 5 shows the physical capacitive coupling model of the touch system formed by the typical active stylus and the touch screen shown in Figure 3 when the hand is not on the touch screen.

[0052] Figure 6 is a schematic diagram of signal crosstalk between the typical active pen and the hand shown in Figure 3;

[0053] Figure 7 is a physical capacitive coupling model of the touch system formed by the active stylus shown in Figure 1 and the touch screen when the hand is on the touch screen.

[0054] Figure 8 is a schematic diagram of eliminating signal crosstalk between the active pen and the hand shown in Figure 1;

[0055] Figure 9 is a schematic diagram of the second driving signal and the first driving signal in an embodiment of this application;

[0056] Figure 10 is a schematic diagram of the envelope of hand pen crosstalk signals at different detection frequencies.

[0057] In the diagram: 10. Active pen; 11. Pen casing; 12. Pen electrode; 121. Main electrode; 122. Sub-electrode; 13. Isolation structure; 14. Pen chip; 141. First driving circuit; 142. Second driving circuit; 143. Pen controller; 15. Power supply; 16. Power management module; 20. Touch screen; 21. Screen electrode; 211. Driving electrode; 212. Sensing electrode; 22. Screen chip; 221. Screen driving circuit; 222. Screen receiving circuit; 223. Screen controller; 224. Switch module; 2241. First switch selector; 2242. Second switch selector. Detailed Implementation

[0058] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] It should be understood that this application can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this application to those skilled in the art. In the drawings, for clarity, the dimensions of layers and regions, as well as their relative dimensions, may be exaggerated. The same reference numerals denote the same elements throughout.

[0060] To fully understand this application, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed in this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.

[0061] This application provides a pen chip 14 applicable to an active pen 10, as shown in Figures 1 and 2. The active pen 10 includes a pen housing 11, a pen electrode 12 disposed on the pen housing 11, and an isolation structure 13 disposed within the pen housing 11. The pen electrode 12 is coupled to a screen electrode 21 on a touch screen 20. The pen chip 14 is disposed within the pen housing 11 and includes a first driving circuit 141, a second driving circuit 142, and a pen controller 143. The first driving circuit 141 is connected to both the pen controller 143 and the pen electrode 12, and is used to output a first driving signal to the pen electrode 12 based on a first control signal output by the pen controller 143. The second driving circuit 142 is connected to both the pen controller 143 and the isolation structure 13, and is used to output a second driving signal to the isolation structure 13 based on a second control signal output by the pen controller 143, so that the isolation structure 13 isolates crosstalk signals between the active pen 10 and the hand. The pen controller 143 is used to simultaneously output the first control signal and the second control signal, so that the first driving circuit 141 and the second driving circuit 142 simultaneously output the first driving signal and the second driving signal.

[0062] Among them, the pen electrode 12 is an electrode set on the active pen 10. There can be one or more pen electrodes 12, which can be determined according to the actual situation.

[0063] The isolation structure 13 serves to isolate signals, specifically to isolate crosstalk signals between the active pen 10 and the hand. For example, the isolation structure 13 can be a structure made of conductive material for achieving signal isolation.

[0064] The first driving circuit 141 is connected to the pen electrode 12 and is used to drive the pen electrode 12 to work. The first control signal is a signal used to control the operation of the first driving circuit 141. The first driving signal is the driving signal output by the first driving circuit 141 to the pen electrode 12, and it is a driving signal that is not interfered with by crosstalk signals. In this example, the first driving circuit 141 can specifically output the first driving signal to the pen electrode 12 based on the first control signal output by the pen controller 143, control the pen electrode 12 to work, so that the pen electrode 12 is coupled with the screen electrode 21 on the touch screen 20, so that the active pen 10 and the touch screen 20 can communicate.

[0065] The second driving circuit 142 is connected to the isolation structure 13 and is used to drive the isolation structure 13 to operate. The second control signal is a signal used to control the operation of the second driving circuit 142. The second driving signal is the driving signal output by the second driving circuit 142 to the isolation structure 13. In this example, the second driving circuit 142 can specifically output a second driving signal to the isolation structure 13 based on the second control signal output by the pen controller 143, so that the isolation structure 13 isolates the crosstalk signal between the active pen 10 and the hand.

[0066] The first driving circuit 141 and the second driving circuit 142 can be circuits that reuse some of the components.

[0067] The pen controller 143 is a logic controller located on the active pen 10, specifically a microcontroller (MCU) within the active pen 10. The MCU serves as the core of the pen's computation and control, and is the final execution unit for information processing and program execution. It is primarily used to control the operation of the circuits and electrical components located on the active pen 10. In this example, the active pen 10 also includes a power supply 15 and a power management module 16. The power management module 16 is connected to the power supply 15 and to the pen controller 143 to control the power supply 15 to provide power to the pen controller 143 and other connected devices.

[0068] Figure 2 illustrates the touch system of the active stylus 10 and the touch screen 20. This touch system is only used to illustrate the crosstalk principle described above and does not limit the specific design form. As shown in Figure 2, the touch screen 20 includes a screen body (not shown in the figure), screen electrodes 21, and a screen chip 22. The screen electrodes 21 are disposed on the screen body and are used to couple with the stylus electrodes 12 on the active stylus 10. The screen chip 22 is disposed outside the screen body and is electrically connected to the screen electrodes 21. In this example, the screen chip 22 is disposed on a circuit board outside the screen body. This circuit board can be a flexible printed circuit board or a rigid printed circuit board. The screen electrodes 21 include driving electrodes 211 (D0-D3 in Figure 2) and sensing electrodes 212 (S0-S3 in Figure 2). It can be understood that the touch screen 20 may include multiple sets of driving electrodes 211 and sensing electrodes 212 as shown in the examples. In this example, the screen chip 22 includes a screen driving circuit 221, a screen receiving circuit 222, and a screen controller 223. The screen controller 223 is a logic controller disposed on the touch screen 20, specifically a microcontroller (MCU) disposed within the touch screen 20. The screen driving circuit 221 is connected to both the driving electrode 211 and the screen controller 223, and is used to control the driving electrode 211 to work according to the screen driving signal output by the screen controller 223. The screen receiving circuit 222 is connected to both the sensing electrode 212 and the screen controller 223, and is used to acquire and demodulate the measured signal output by the sensing electrode 212, and output the processed signal to the screen controller 223.

[0069] Furthermore, the touch screen 20 or screen chip 22 also includes a switch module 224 disposed on the circuit board. The switch module 224 includes a first switch selector 2241 and a second switch selector 2242. The first switch selector 2241 is used to connect the screen driving circuit 221 and multiple driving electrodes 211, and can control the on / off state of the driving electrodes 211 of the corresponding channel under the control of the screen controller 223. The second switch selector 2242 is used to connect the screen receiving circuit 222 and multiple sensing electrodes 212, and can control the on / off state of the sensing electrodes 212 of the corresponding channel under the control of the screen controller 223. The first switch selector 2241 and the second switch selector 2242 are connected, and under the control of the screen controller 223, the driving electrodes 211 can be connected to the screen receiving circuit 222 through the first switch selector 2241 and the second switch selector 2242, so that the touch screen 20 can cooperate with the active pen 10 to complete the detection function. When the active pen 10 approaches or touches the touch screen 20, the pen electrode 12 on the active pen 10 is coupled to the screen electrode 21 on the touch screen 20, and the active pen 10 and the touch screen 20 can communicate with each other through this coupling capacitor.

[0070] Referring to Figure 3, a typical active pen 10 includes a pen housing 11, pen electrodes 12 disposed on the pen housing 11, and a pen chip 14 disposed inside the pen housing 11. The pen chip 14 includes a first driving circuit 141 and a pen controller 143. That is, the pen housing 11 does not have an isolation structure 13, and the pen chip 14 does not have a second driving circuit 142 connected to the isolation structure 13. The pen controller 143 is connected to the pen electrodes 12 through the first driving circuit 141. When the active pen 10 approaches or touches the touch screen 20, the pen electrodes 12 on the active pen 10 are coupled to the screen electrodes 21 on the touch screen 20, so that the active pen 10 and the touch screen 20 can communicate through coupling capacitors. When a user holds the active stylus 10 and operates it on the touch screen 20, if the hand touches the screen electrode 21 of the touch screen 20, the touch screen 20 will receive not only the capacitive projection signal formed by the coupling between the active stylus 10 and the touch screen 20, but also the capacitive projection signal formed by the coupling between the hand and the touch screen 20. The capacitive projection signal of the hand and the capacitive projection signal of the active stylus 10 are opposite signals to each other, so the capacitive projection signal of the hand will affect the envelope of the capacitive projection signal of the active stylus 10 on the touch screen 20, that is, there is a hand-stylus crosstalk problem.

[0071] Referring to Figures 2 and 4, the following explanation, based on the physical capacitive coupling model established by the typical active stylus 10 and touchscreen 20 shown in Figure 3, uses the stylus electrode 12 of the active stylus 10 to illustrate the crosstalk principle between the active stylus 10 and the hand on the touchscreen 20. When a person holds the stylus electrode 12 of the active stylus 10 close to or in contact with the sensing electrode S1 of the touchscreen 20, and the hand is in contact with the sensing electrode S1 of the touchscreen 20, both the stylus electrode 12 and the hand form capacitive coupling with the sensing electrode S1 of the touchscreen 20. That is, there is a coupling capacitance C1 between the stylus electrode 12 of the active stylus 10 and the sensing electrode S1 of the touchscreen 20, and a coupling capacitance C5 between the hand and the sensing electrode S1 of the touchscreen 20. Since the hand is holding the active stylus 10, there is a coupling capacitance C2 between the hand and the active stylus system. In addition, there are two paths between the hand and the touchscreen system, one... There is a direct coupling capacitor C7, and another indirect coupling is formed through the coupling capacitor C3 between the hand and the ground and the coupling capacitor C4 between the ground and the touch screen system ground. There is also a coupling capacitor C6 between the active pen system ground and the touch screen system ground. The typical capacitance values ​​of C1-C7 are C1 (40fF), C2 (200pF), C3 (80pF), C4 (8pF), C5 (1pF), C6 (3pF), and C7 (2pF). These capacitances may vary depending on the specific screen and pen design, but this does not affect the principle explanation here.

[0072] Referring to Figures 2 and 4, when a person holds the pen electrode 12 of the active pen 10 close to or in contact with the sensing electrode S1 of the touch screen 20, and the hand touches the sensing electrode S1 of the touch screen 20, the pen controller 143 controls the first driving circuit 141 (i.e., voltage source AC1) to output a first driving signal. This first driving signal is transmitted sequentially through the path of "active pen system ground - voltage source AC1 - pen electrode 12 - coupling capacitor C1 - sensing electrode S1 - touch screen system ground - ground - hand - active pen system ground". That is, this path can transmit the capacitive projection signal between the active pen 10 and the touch screen 20. Because the hand is in contact with the sensing electrode S1, a coupling capacitor C5 exists between the hand and the sensing electrode S1 of the touch screen 20. This creates a path that transmits the capacitive projection signal (i.e., crosstalk signal) between the hand and the touch screen 20: "active pen system ground - coupling capacitor C2 - coupling capacitor C5 - parasitic resistance R1 of sensing electrode S1 - touch screen system ground". Since the current flows in opposite directions at the coupling capacitor C2 for the capacitive projection signals transmitted through the two paths, the capacitive projection signal between the hand and the sensing electrode S1 and the capacitive projection signal between the active pen 10 and the sensing electrode S1 are inverse signals. That is, when the hand is on the sensing electrode S1 of the touch screen 20, a crosstalk signal that is inversely related to the first driving signal will pass through the coupling capacitor C5 and the parasitic resistance R1 of the sensing electrode S1, interfering with the first driving signal of the active pen 10 corresponding to the sensing electrode S1, thus affecting the original signal quantity of the active pen 10.

[0073] Referring to Figures 2 and 5, when a person holds the stylus 10 with its stylus electrode 12 close to or in contact with the sensing electrode S1 of the touchscreen 20, but the hand does not touch the sensing electrode S1 of the touchscreen 20, a coupling capacitance C1 exists between the stylus electrode 12 of the stylus 10 and the sensing electrode S1 of the touchscreen 20 because the stylus electrode 12 is close to or in contact with the sensing electrode S1; since the hand does not touch the sensing electrode S1 of the touchscreen 20, there is no coupling capacitance C5 between the hand and the sensing electrode S1; and since the hand is holding the stylus 10, a coupling capacitance C2 exists between the hand and the stylus system. This process... The pen controller 143 controls the first driving circuit 141 (voltage source AC1) to output a first driving signal. This first driving signal is transmitted sequentially through the path of "active pen system ground - voltage source AC1 - pen electrode 12 - coupling capacitor C1 - sensing electrode S1 - touch screen system ground - ground - hand - active pen system ground". Since there is no coupling capacitor C5 between the hand and the sensing electrode S1, there is no crosstalk signal transmitted through the path of "active pen system ground - coupling capacitor C2 - coupling capacitor C5 - parasitic resistance R1 of sensing electrode S1 - touch screen system ground". That is, when the hand does not touch the sensing electrode S1 of the touch screen 20, there is no crosstalk signal opposite to the first driving signal that passes through the coupling capacitor C5 and the parasitic resistance R1 of the sensing electrode S1 and interferes with the first driving signal of the active pen 10 corresponding to the sensing electrode S1, thus affecting the original signal quantity of the active pen 10.

[0074] As shown in Figures 4 and 5, the physical capacitive coupling model indicates that the fundamental reason for the crosstalk signal between the hand and the touch screen 20 is the coupling capacitor C2 between the hand and the sensing electrode S1. This allows the crosstalk signal to be transmitted through the path of "active pen system ground - coupling capacitor C2 between the hand and the active pen system ground - coupling capacitor C5 between the hand and the sensing electrode S1 - parasitic resistance R1 of the sensing electrode S1 - touch screen system ground". Referring to Figures 1, 2, and 6, the active pen 10 in this embodiment includes not only a pen shell 11 and pen electrodes 12 disposed on the pen shell 11, but also an isolation structure 13 and a second driving circuit 142 disposed within the pen shell 11. The second driving circuit 142 is connected to both the pen controller 143 and the isolation structure 13. Based on the second control signal output by the pen controller 143, it can output a second driving signal to the isolation structure 13, so that the isolation structure 13 eliminates or greatly reduces the direct coupling between the hand and the active pen system ground. Specifically, it eliminates or reduces the coupling capacitance C2 between the hand and the active pen system ground, so that the path "active pen system ground - coupling capacitance C2 between the hand and the active pen system ground - coupling capacitance C5 between the hand and the sensing electrode S1 - parasitic resistance R1 of the sensing electrode S1 - touch screen system ground" cannot transmit signals, thereby achieving the purpose of eliminating and isolating crosstalk signals between the active pen 10 and the hand.

[0075] Referring to Figure 6, when the active pen 10 approaches or touches the touch screen 20, the pen electrode 12 on the active pen 10 couples with the screen electrode 21 on the touch screen 20. The first driving signal output by the active pen 10 to the touch screen 20 is transmitted sequentially through the path of "active pen system ground - voltage source AC1 - pen electrode 12 - coupling capacitor C1 - sensing electrode S1 - touch screen system ground - ground - hand - active pen system ground". During this process, if the hand touches the sensing electrode S1 on the touch screen 20, a crosstalk signal affecting the first driving signal will be formed between the hand and the active pen 10. This crosstalk signal is transmitted through the path of "active pen system ground - coupling capacitor C2 between hand and active pen system ground - coupling capacitor C5 between hand and sensing electrode S1 - sensing electrode". The path of transmission from the parasitic resistance R1 of S1 to the touch screen system ground is as follows: To eliminate this crosstalk signal, when the pen controller 143 outputs the first driving signal to the first driving circuit 141 (voltage source AC1), it can simultaneously output the second driving signal to the second driving circuit 142 (voltage source AC2) to drive the isolation structure 13 to work, so that it forms a coupling capacitance C2 between the hand and the active pen system ground, thereby eliminating or greatly reducing the coupling capacitance C2 between the hand and the active pen system ground. This interrupts the path of "active pen system ground - coupling capacitance C2 between the hand and the active pen system ground - coupling capacitance C5 between the hand and the sensing electrode S1 - parasitic resistance R1 of the sensing electrode S1 - touch screen system ground", thereby achieving the purpose of eliminating and isolating the crosstalk signal between the active pen 10 and the hand. In this example, the pen controller 143 outputs the first driving signal and the second driving signal at the same time, so that the electric field formed by the first driving signal and the second driving signal occurs simultaneously, thereby isolating the crosstalk signal that occurs simultaneously with the first driving signal, so as to effectively eliminate the crosstalk signal.

[0076] Referring to Figure 7, when the pen electrode 12 of a typical active pen 10 is close to or in contact with the sensing electrode ch16, and the hand touches the sensing electrode ch14, the active pen 10 forms a capacitive projection signal envelope centered on the sensing electrode ch16 to transmit the first driving signal. At this time, the crosstalk signal is transmitted through the coupling capacitance between the hand and the active pen system ground - the coupling capacitance between the hand and the sensing electrode ch14 - the parasitic resistance corresponding to the sensing electrode ch14, causing the hand to interfere with the capacitive projection signal envelope centered on the sensing electrode ch14. Specifically, the encoded value corresponding to the sensing electrode ch14 is much larger than the encoded values ​​corresponding to the adjacent sensing electrodes ch13 and ch15. In this way, the capacitive projection signal envelope of the active pen 10 is destroyed, affecting the accuracy of the communication between the active pen 10 and the touch screen 20.

[0077] Referring to Figure 8, in this embodiment of the active pen 10, when the pen electrode 12 is close to or in contact with the sensing electrode ch16, and the hand contacts the sensing electrode ch14, the active pen 10 forms a capacitance projection signal envelope centered on the sensing electrode ch16, which is used to transmit the first driving signal. At this time, the crosstalk signal is transmitted through the coupling capacitance between the hand and the active pen system ground - the coupling capacitance between the hand and the sensing electrode ch14 - the parasitic resistance corresponding to the sensing electrode ch14. Since the pen controller 143 controls the first driving circuit 141 to output the first driving signal to the pen electrode 12, it also controls the second driving circuit 142. A second driving signal is output to the isolation structure 13 to eliminate the coupling capacitance between the hand and the sensing electrode ch14, thereby interrupting the transmission path of the crosstalk signal and eliminating the crosstalk signal. The final output of the coded value corresponding to the sensing electrode ch14 is between the coded value corresponding to the sensing electrode ch13 and the coded value corresponding to the sensing electrode ch15. Furthermore, with the sensing electrode ch16 as the center, the coded values ​​corresponding to the sensing electrodes on both sides decrease sequentially, so that the capacitive projection signal formed with the sensing electrode ch16 as the center is basically unaffected by the capacitive projection signal formed between the hand and the touch screen 20.

[0078] In one embodiment, the signal parameters of the second driving signal are related to the signal parameters of a single first driving signal, or the second driving signal is related to the signal parameters of multiple first driving signals that are output simultaneously.

[0079] As an example, the active pen 10 includes at least one pen electrode 12. At any given time, the pen controller 143 controls the first driving circuit 141 to output a single first driving signal to one of the pen electrodes 12. Simultaneously, the pen controller 143 controls the second driving circuit 142 to output a second driving signal to the isolation structure 13, which is related to the single first driving signal. Alternatively, at any given time, the pen controller 143 can control the first driving circuit 141 to simultaneously output multiple first driving signals to multiple pen electrodes 12. In this case, the pen controller 143 controls the second driving signal output by the second driving circuit 142 to the isolation structure 13, along with the signal parameters of the simultaneously output multiple first driving signals. In this example, the signal parameters include, but are not limited to, frequency, phase, and amplitude.

[0080] In one embodiment, the second driving signal and the first driving signal have the same frequency and phase; the amplitude of the second driving signal is the product of the amplitude of the target driving signal and a first coefficient, the first coefficient being 0-20% in value, the target driving signal being a single first driving signal or a signal superimposed from multiple first driving signals; or, the amplitude of the second driving signal is the amplitude after weighting the amplitudes of multiple first driving signals and the second coefficients corresponding to the multiple first driving signals, the second coefficient being 0-20% in value.

[0081] As an example, as shown in Figure 9, the frequency of the second driving signal is the same as the frequency of the first driving signal, so that the second driving signal and the first driving signal are in the same bandwidth, allowing the touch screen 20 to recognize the two signals in the same bandwidth. Since the phase of the crosstalk signal formed between the active pen 10 and the hand is opposite to the phase of the first driving signal, the phase of the second driving signal is configured to be the same as the phase of the first driving signal, so that the phase of the second driving signal is opposite to the phase of the crosstalk signal. This allows the output second driving signal to eliminate or greatly reduce the direct coupling between the hand and the active pen system, thereby enabling the isolation structure 13 to isolate the crosstalk signal between the active pen 10 and the hand. Since the crosstalk signal formed between the active pen 10 and the hand is transmitted through the coupling capacitance between the hand and the touch screen 20 and the screen electrode 21 where its projection is located, given that the screen electrode 21 on the touch screen 20 is fixed, the amplitude (energy) of the crosstalk signal depends on the coupling capacitance between the hand and the touch screen 20, specifically on factors such as the distance between the hand and the touch screen 20, the projection area, and the relative permittivity. These factors are combined to determine the corresponding adjustment coefficient. In this example, the adjustment coefficient can be either a first coefficient or a second coefficient. The first coefficient is used to limit the amplitude scaling ratio between the second drive signal and the target drive signal. The first coefficient can be a preset fixed value or a dynamic value determined according to the actual situation. The second coefficient is used to limit the amplitude scaling ratio between the second drive signal and each first drive signal. The second coefficient can be a preset fixed value or a dynamic value determined according to the actual situation.

[0082] In one example, the amplitude of the second driving signal is the product of the amplitude of the target driving signal and the first coefficient. The value of the first coefficient ranges from 0 to 20%. The target driving signal is a single first driving signal or a signal resulting from the superposition of multiple first driving signals. Assuming the amplitude of the i-th first driving signal is Si, the amplitude of the target driving signal is Sm, the amplitude of the second driving signal is Sd, and the first coefficient is k1, since the target driving signal is a single first driving signal or a signal resulting from the superposition of multiple first driving signals, then Sm = ∑Si. Therefore, the amplitude of the second driving signal is Sd = k1*Sm = k1*∑Si, which enables the superposition of the amplitudes of multiple first driving signals. Based on the product of the superimposed amplitude and the first coefficient, it helps to ensure that the amplitude of the finally determined second driving signal can effectively eliminate crosstalk signals.

[0083] In another example, the amplitude of the second driving signal is the weighted amplitude of multiple first driving signals and their corresponding second coefficients. The second coefficients range from 0% to 20%. Assuming the amplitude of the i-th first driving signal is Si, the amplitude of the second driving signal is Sd, and the second coefficient corresponding to the i-th first driving signal is ki, then the amplitude of the second driving signal Sd = ∑Si*ki. This achieves weighted processing of the amplitudes of multiple first driving signals and their second coefficients, determining the weighted amplitude as the amplitude of the second driving signal. In this example, at least one of the amplitudes and the corresponding second coefficients of the multiple first driving signals is different. Specifically, multiple amplitudes can be the same but different second coefficients, or multiple amplitudes can be different but the same second coefficient, or multiple amplitudes and second coefficients can both be different. This can be adjusted according to the actual situation. Weighted processing based on the amplitudes and second coefficients of multiple first driving signals helps ensure that the final determined amplitude of the second driving signal can effectively eliminate crosstalk signals.

[0084] In one embodiment, the first coefficient is negatively correlated with the first suspension height; the first suspension height is the height between the electrode apex of the active pen 10 facing the touch screen 20 and the touch screen 20.

[0085] As an example, when the amplitude of the second driving signal is the product of the amplitude of the target driving signal and the first coefficient, the first coefficient is negatively correlated with the first floating height between the electrode vertex of the active pen 10 facing the touch screen 20 and the touch screen 20. That is, the lower the first floating height, the closer the active pen 10 is to the touch screen 20, and the greater the crosstalk signal it may generate. Therefore, its corresponding first coefficient needs to be larger, thereby making the amplitude of the corresponding second driving signal larger. Conversely, the higher the first floating height, the farther the active pen 10 is from the touch screen 20, and the smaller the crosstalk signal it generates. Therefore, its corresponding first coefficient needs to be smaller, thereby making the amplitude of the corresponding second driving signal smaller. In this example, the negative correlation between the first coefficient and the first floating height can be linear or non-linear, and can be determined independently according to the actual situation. In this example, after determining the first suspension height, the pen controller 143 can dynamically determine the corresponding first coefficient by querying a pre-set first height coefficient mapping table based on the first suspension height. Based on the product of the target driving signal (at least one first driving signal superimposed) and the first coefficient, a second driving signal is determined. The second driving circuit 142 is then controlled to output the second driving signal to the isolation structure 13, thereby isolating the active pen 10 from the hand. Here, the first height coefficient mapping table is a pre-set data table reflecting the mapping relationship between the first suspension height and the first coefficient.

[0086] In one embodiment, the second coefficient corresponding to each first driving signal is negatively correlated with the second floating height of the pen electrode 12 corresponding to each first driving signal; and / or, the amplitude corresponding to each first driving signal is positively correlated with the second floating height of the pen electrode 12 corresponding to each first driving signal; the second floating height of the pen electrode 12 is the height between the point of the pen electrode 12 closest to the touch screen 20 and the touch screen 20.

[0087] As an example, when the amplitude of the second driving signal is the weighted amplitude of multiple first driving signals and the second coefficients corresponding to the multiple first driving signals, the second coefficient corresponding to each first driving signal is negatively correlated with the second floating height of the pen electrode 12 corresponding to each first driving signal. The amplitudes corresponding to each first driving signal can be the same or different, and can be determined according to the actual situation. That is to say, the lower the second floating height of each pen electrode 12, the closer the pen electrode 12 is to the touch screen 20. At this time, the crosstalk signal between the active pen 10 and the hand is greater, so its corresponding second coefficient needs to be larger; conversely, the higher the second floating height of each pen electrode 12, the farther the pen electrode 12 is from the touch screen 20. At this time, the crosstalk signal between the active pen 10 and the hand is smaller, so its corresponding first coefficient needs to be smaller.

[0088] In this example, the pen controller 143 can determine the second suspension height of each pen electrode 12, and dynamically determine its corresponding second coefficient by querying a pre-set second height coefficient mapping table based on the second suspension height. The pen controller 143 can also determine the amplitude of the first driving signal corresponding to each pen electrode 12 according to actual conditions, perform weighted processing on the amplitudes of the first driving signals corresponding to multiple pen electrodes 12 and their second coefficients, determine the second driving signal, and control the second driving circuit 142 to output the second driving signal to the isolation structure 13, so that the isolation structure 13 isolates the crosstalk signal between the active pen 10 and the hand. The second height coefficient mapping table is a pre-set data table reflecting the mapping relationship between the second suspension height and the second coefficient.

[0089] For example, when the active pen 10 includes two pen electrodes 12, namely a main electrode 121 and a secondary electrode 122, and the amplitude of the first driving signal of the main electrode 121 is 40V and the amplitude of the first driving signal of the secondary electrode 122 is 30V, the second floating height h1 of the main electrode 121 (i.e., the height between the point of the main electrode 121 closest to the touch screen 20 and the touch screen 20) can be dynamically determined. Based on the second floating height h1, the second height coefficient mapping table is consulted to determine the second coefficient K21 corresponding to the main electrode 121; and the second floating height of the secondary electrode 122 is dynamically determined. The second floating height h2 (i.e., the height between the point of the secondary electrode 122 closest to the touch screen 20 and the touch screen 20) is used to query the second height coefficient mapping table to determine the second coefficient corresponding to the secondary electrode 122 as K22. Then, the amplitude of the first driving signal corresponding to the main electrode 121 and the secondary electrode 122 is weighted and processed to dynamically determine the amplitude of the second driving signal, that is, the amplitude of the second driving signal = 40V*K21+30V*K22, which helps to ensure that the amplitude of the finally determined second driving signal can effectively eliminate crosstalk signals.

[0090] As another example, when the pen controller 143 outputs the first driving signal and the second driving signal, the amplitude of each first driving signal is positively correlated with the second floating height of the pen electrode 12 corresponding to each first driving signal. The lower the second floating height of each pen electrode 12, the closer the pen electrode 12 is to the touch screen 20, and the smaller its driving energy. Therefore, the amplitude of the first driving signal output by the pen electrode 12 is smaller to save energy. The higher the second floating height of each pen electrode 12, the farther the pen electrode 12 is from the touch screen 20, and the greater its driving energy. The amplitude of the first driving signal output by the pen electrode 12 is larger. The second coefficients corresponding to each first driving signal can be the same or different. For example, in an active pen 10 that includes two pen electrodes 12, namely a main electrode 121 and a secondary electrode 122, the second coefficients of the main electrode 121 and the secondary electrode 122 can be predetermined based on their positions, shapes, and materials. Alternatively, the corresponding second coefficients can be determined based on their corresponding second floating heights or other measured data.

[0091] In this example, the pen controller 143 can determine the second floating height of each pen electrode 12, and dynamically determine the amplitude of the first driving signal of each pen electrode 12 based on the second floating height. For example, the amplitude of the first driving signal of each pen electrode 12 can be determined by looking up a table or other preset methods. Then, the second coefficient corresponding to each first driving signal is determined. Finally, the second driving signal is determined by weighting the amplitude of the first driving signal corresponding to multiple pen electrodes 12 and its second coefficient, and the second driving signal is output to the second driving circuit 142 to control the isolation structure 13 to work and isolate the crosstalk signal between the active pen 10 and the hand.

[0092] For example, when the pen controller 143 outputs the first driving signal and the second driving signal, it can make the amplitude of multiple first driving signals the same, and the second coefficients corresponding to the multiple first driving signals are negatively correlated with their corresponding second floating heights. Weighted processing is performed based on the amplitudes and second coefficients corresponding to the multiple first driving signals, making the control process simple and convenient. Alternatively, the amplitude of multiple first driving signals can be positively correlated with their corresponding second floating heights, and the second coefficients of the multiple first driving signals can be the same or different. Weighted processing is performed based on the amplitudes and second coefficients corresponding to the multiple first driving signals, making the control process simple and convenient, and enabling targeted elimination of crosstalk signals corresponding to each first driving signal.

[0093] In one embodiment, the value range of the first coefficient is 3%-10%; the value range of the second coefficient is 3%-10%.

[0094] As an example, the amplitude of the second driving signal is configured to be 3%-10% of the amplitude of the target driving signal. The range of the first coefficient is determined based on simulation tests under typical working conditions, so that it can effectively isolate crosstalk signals between the active pen 10 and the hand without causing energy waste.

[0095] As another example, when the amplitude of the second driving signal is the weighted amplitude of multiple first driving signals and the second coefficients corresponding to the multiple first driving signals, the second coefficient corresponding to each first driving signal is limited to 3%-10%. The value range of the second coefficient is a numerical range determined based on simulation experiments under typical working conditions. In this example, the amplitudes corresponding to the multiple first driving signals can be the same or different, and the second coefficients corresponding to the multiple first driving signals can also be the same or different. This ensures that the amplitude of the weighted second driving signal can effectively isolate crosstalk signals between the active pen 10 and the hand without causing energy waste.

[0096] In one embodiment, the second driving signal and the first driving signal have different frequencies so that the touch screen 20 can detect the first measured signal and the second measured signal. Based on the first measured signal and the second measured signal, the first driving signal output by the active pen 10 is determined. The first measured signal is the signal coupled to the touch screen 20 by the first driving signal, and the second measured signal is the signal coupled to the touch screen 20 by the second driving signal.

[0097] The first measured signal is the signal coupled to the touchscreen 20 by the first driving signal. Specifically, it refers to the signal transmitted to the touchscreen 20 through the coupling capacitor between the pen electrode 12 and the screen electrode 21, and is the encoded signal after the first driving signal has been interfered with by crosstalk signals. The second measured signal is the signal coupled to the touchscreen 20 by the second driving signal. Specifically, it refers to the signal transmitted to the touchscreen 20 through the coupling capacitor between the hand and the touchscreen 20, and is the driving signal after the second driving signal has been interfered with by crosstalk signals.

[0098] As an example, the pen controller 143 outputs a first driving signal and a second driving signal at different frequencies to ensure that the first driving signal and the second driving signal are within different bandwidths. This allows the touch screen 20 to collect the first measured signal and the second measured signal at different frequencies when the active pen 10 approaches or touches the touch screen 20. The first measured signal can be understood as the actual detected signal after the first driving signal has been interfered with by a crosstalk signal, and the second measured signal can be understood as the actual detected signal after the second driving signal has been interfered with by a crosstalk signal. Then, based on the built-in signal compensation algorithm, the signal characteristics of the first measured signal and the second measured signal can be compensated to identify the compensated signal characteristics as the first driving signal output by the active pen 10 without crosstalk interference, thereby significantly improving the signal-to-noise ratio of the first driving signal of the active pen 10.

[0099] As an example, the multiple first driving signals are the first driving signal received by the main electrode 121 and the first driving signal received by the sub-electrode 122; or, the multiple first driving signals are the first driving signal received by the main electrode 121, the first driving signal received by the sub-electrode 122 and the first driving signal received by the pen tail electrode (not shown in the figure); wherein, the main electrode 121 and the sub-electrode 122 are disposed on the pen tip of the active pen 10, and the pen tail electrode is disposed on the pen tail of the active pen 10.

[0100] As an example, when the active pen 10 has two pen electrodes 12, which are respectively the main electrode 121 and the auxiliary electrode 122 on the pen tip of the active pen 10, the pen controller 143 can control the first driving circuit 141 to simultaneously output two first driving signals. These two first driving signals are the first driving signal received by the main electrode 121 and the first driving signal received by the auxiliary electrode 122, respectively. In one possible implementation, the second driving signal has the same frequency and phase as the two first driving signals. The amplitude of the second driving signal can be the product of the target driving signal superimposed from the two first driving signals and the first coefficient. Alternatively, the amplitude of the second driving signal can be the weighted amplitude of the first driving signal corresponding to the main electrode 121, the second coefficient corresponding to the main electrode 121, the first driving signal corresponding to the auxiliary electrode 122, and the second coefficient corresponding to the auxiliary electrode 122. In another possible implementation, the two simultaneously output first driving signals have the same frequency, but the second driving signal has a different frequency from the two first driving signals, and its amplitude can be the same or different.

[0101] As an example, the active pen 10 has three pen electrodes 12, namely the main electrode 121 and the secondary electrode 122 on the pen tip, and the pen tail electrode on the pen tail. At the same time, the pen controller 143 can control the first driving circuit 141 to simultaneously output three first driving signals. These three first driving signals are the first driving signal received by the main electrode 121, the first driving signal received by the secondary electrode 122, and the first driving signal received by the pen tail electrode, respectively. In one possible implementation, the second driving signal has the same frequency and phase as the three first driving signals. The amplitude of the second driving signal can be the product of the target driving signal superimposed from the three first driving signals and the first coefficient. Alternatively, the amplitude of the second driving signal can be the weighted amplitude of the first driving signal corresponding to the main electrode 121, the second coefficient corresponding to the main electrode 121, the first driving signal corresponding to the secondary electrode 122, the second coefficient corresponding to the secondary electrode 122, the first driving signal corresponding to the pen tail electrode, and the second coefficient corresponding to the pen tail electrode. In another possible implementation, the three first drive signals output simultaneously have the same frequency, but the second drive signal has a different frequency from the three first drive signals, and its amplitude can be the same or different.

[0102] This application provides an active pen 10, including a pen housing 11, a pen electrode 12 disposed on the pen housing 11, and an isolation structure 13 disposed within the pen housing 11. The pen electrode 12 is coupled to a screen electrode 21 on a touch screen 20. It also includes a pen chip 14 as described in the above embodiment. The pen chip 14 is disposed within the pen housing 11 and is connected to the pen electrode 12 and the isolation structure 13.

[0103] In this example, an isolation structure 13 and a second driving circuit 142 are added to the active pen 10. The second driving circuit 142 is connected to the pen controller 143 and the isolation structure 13. When the pen controller 143 controls the first driving circuit 141 to output a first driving signal to the pen electrode 12, it can simultaneously control the second driving circuit 142 to output a second driving signal to the isolation structure 13. This allows the isolation structure 13 to eliminate or greatly reduce the direct coupling between the hand and the active pen system ground, thereby achieving the purpose of eliminating crosstalk signals between the active pen and the hand. Since the first driving signal and the second driving signal are output simultaneously, the electric fields formed by the first driving signal and the second driving signal occur simultaneously, thus isolating the crosstalk signal that occurs simultaneously with the first driving signal, thereby effectively eliminating the crosstalk signal.

[0104] In one embodiment, the pen casing 11 has a gripping area; the isolation structure 13 is disposed within the gripping area.

[0105] As an example, the pen casing 11 has a grip area, which is an area for the user's hand to hold. This grip area can be a humanoid grip position for the pen, ensuring a better grip experience and reducing hand fatigue for the active pen 10. In this example, when a grip area is provided on the grip area, the isolation structure 13 can be placed within the grip area. This isolates crosstalk signals between the active pen 10 and the hand, eliminating the need to place the isolation structure 13 in other locations on the active pen 10, thus helping to save on the manufacturing cost of the isolation structure 13.

[0106] In one embodiment, the isolation structure 13 includes a conductive spacer assembled inside the pen shell 11; or, the isolation structure 13 includes a conductive coating applied to the inner wall of the pen shell 11; or, the isolation structure 13 includes a conductive component disposed on the pen shell 11.

[0107] As an example, the isolation structure 13 can be a conductive spacer, which is a conductive structural component independent of the pen housing 11. For example, it can be made of aluminum, copper, or other conductive materials to form a conductive spacer that can be detachably installed in the pen housing 11. As long as the conductive spacer can achieve its conductive function and can be installed inside the pen housing 11, it can take any form. In this example, the conductive spacer is assembled inside the pen housing 11 and systematically connected to the active pen system, such that the outer wall of the conductive spacer is in contact with or spaced from the inner wall of the pen housing 11. The conductive spacer is electrically connected to the second drive circuit 142 disposed inside the pen housing 11, so that it can achieve the purpose of isolating crosstalk signals between the active pen 10 and the hand. In this example, the conductive spacer is assembled inside the pen housing 11, specifically disposed on the pen body of the pen housing 11. The outer wall of the conductive spacer can be in contact with or spaced from the inner wall of the pen body. A non-conductive component can be placed between them, or no non-conductive component can be placed.

[0108] As an example, the isolation structure 13 can be a conductive coating, which is formed by applying conductive paint (including but not limited to conductive varnish) to the inner wall of the pen shell 11. In this example, the conductive coating is electrically connected to the second drive circuit 142 disposed inside the pen shell 11, so that it can achieve the purpose of isolating crosstalk signals between the active pen 10 and the hand. Since the conductive coating is applied to the inner wall of the pen shell 11, the conductive coating and the pen shell 11 are integrated into a single structure, resulting in a simple overall structure that is easy to manufacture.

[0109] As an example, the isolation structure 13 can also be a conductive component disposed on the pen shell 11. Here, a conductive component refers to a part of the pen shell 11 that can conduct electricity; it can be the entire structure of the pen shell 11 or a part thereof. For example, when the pen shell 11 is a conductive housing made of conductive material, the isolation structure 13 can be the conductive housing itself. Or, for example, when the pen shell 11 includes an insulating housing and a conductive element embedded in the insulating housing, the isolation structure 13 can be the conductive element embedded in the insulating housing, thus achieving the purpose of isolating crosstalk signals between the active pen 10 and the hand. In this example, when the isolation structure 13 is a conductive component on the pen shell 11, it can reuse existing conductive components on the pen shell 11 for signal isolation, helping to save costs.

[0110] In one embodiment, the pen casing 11 includes a pen body and a pen tip disposed at one end of the pen body; a pen electrode 12 is disposed on the pen tip, and at least a portion of the pen electrode 12 extends out of the pen tip.

[0111] As an example, the pen casing 11 includes a pen body and a pen tip disposed at one end of the pen body, with a gripping area provided on the pen body. A pen electrode 12 is disposed on the pen tip, and at least a portion of the pen electrode 12 extends beyond the pen tip, allowing the user to control the pen electrode 12 on the pen tip to approach or contact the touchscreen 20, thereby coupling the pen electrode 12 with the screen electrode 21 on the touchscreen 20, and enabling the active pen 10 to transmit signals with the touchscreen 20. Generally, a pen controller 143 and a first driving circuit 141 are disposed within the pen body. The pen controller 143 is connected to the first driving circuit 141, and the first driving circuit 141 is connected to the pen electrode 12 disposed on the pen tip, so that the pen controller 143 can output a first driving signal to the first driving circuit 141, causing the first driving circuit 141 to control the pen electrode 12 to operate. Since the isolation structure 13 is mainly used to isolate crosstalk signals between the active pen 10 and the hand, its position is related to the hand's grip position on the active pen 10. The grip position on the active pen 10 is generally located on the pen body; therefore, the isolation structure 13 is positioned at the grip position on the pen body. Furthermore, the isolation structure 13 needs to be electrically connected to the pen controller 143 via the second drive circuit 142. If it were located on the outside of the pen body, connection holes or other connection structures would need to be made on the pen body, leading to complex manufacturing processes, low production efficiency, and high costs. Therefore, placing the isolation structure 13 and the second drive circuit 142 inside the pen body gives the active pen 10 advantages such as simple structure, high manufacturing efficiency, and low cost.

[0112] In one embodiment, the pen tip is provided with an assembly hole; the pen electrode 12 includes a main electrode 121 and a secondary electrode 122; one end of the main electrode 121 is disposed inside the pen housing 11, and the other end of the main electrode 121 extends out of the pen housing 11 through the assembly hole for positioning detection; the secondary electrode 122 is disposed inside the pen housing 11 and sleeved outside the main electrode 121 for tilt angle detection.

[0113] As an example, the pen tip has a mounting hole arranged along the axial direction of the active pen 10 for mounting the pen electrode 12, such that a portion of the pen electrode 12 extends out of the pen tip, and the other portion is connected to the first drive circuit 141 disposed in the pen body. The pen tip here is generally a tapered pen tip, with the larger end of the tapered pen tip connected to the pen body, and the smaller end of the tapered pen tip having a mounting hole.

[0114] As an example, the pen electrode 12 includes a main electrode 121 and a secondary electrode 122 connected to the first driving circuit 141. The main electrode 121 is used to realize the positioning detection function, and the secondary electrode 122 is used to realize the tilt angle detection function. In this example, one end of the main electrode 121 is disposed inside the pen shell 11 and connected to the first driving circuit 141, and the other end of the main electrode 121 extends out of the pen shell 11 through a mounting hole; the secondary electrode 122 is disposed inside the pen shell 11 and sleeved outside the main electrode 121. Specifically, the secondary electrode 122 is disposed in the gap between the main electrode 121 and the pen tip. The secondary electrode 122 is connected to the first driving circuit 141, so that at any time when the active pen 10 approaches or contacts the touch screen 20, the main electrode 121 and the secondary electrode 122 can couple with the screen electrode 21 on the touch screen 20, so that the active pen 10 and the touch screen 20 can communicate to ensure the realization of the positioning detection function and the tilt angle detection function.

[0115] In this example, the main electrode 121 includes a cylindrical body and a touch portion extending axially from one end of the cylindrical body. The cylindrical body passes through the mounting hole of the pen tip. The touch portion can be a cone, hemisphere, fan, or other shape, which can be customized according to user needs. The secondary electrode 122 includes a cone-shaped body with a through hole, so that the cone-shaped body can be fitted over the cylindrical body of the main electrode 121. The cone-shaped design of the secondary electrode 122 makes its signal envelope more stable.

[0116] This application provides a screen chip suitable for connection to screen electrodes 21 on a touch screen 20. The screen electrodes 21 are used to couple with pen electrodes 12 on an active pen 10. The screen chip includes a screen receiving circuit 222 and a screen controller 223. The screen receiving circuit 222 is connected to both the screen electrodes 21 and the screen controller 223, and is used to send the measured signal detected by the screen electrodes 21 to the screen controller 223. The screen controller 223 is used to determine the measured signal as a first driving signal output by the active pen 10 when the measured signal is a single-frequency signal; when the measured signal contains a first measured signal and a second measured signal with different frequencies, it compensates the first measured signal based on the second measured signal to determine the first driving signal output by the active pen 10. The first measured signal is a signal coupled to the touch screen 20 by the first driving signal, and the second measured signal is a signal coupled to the touch screen 20 by the second driving signal.

[0117] Figure 2 illustrates the touch system of the active stylus 10 and the touch screen 20. This touch system is only used to illustrate the crosstalk principle described above and does not limit the specific design form. As shown in Figure 2, the touch screen 20 includes a screen body (not shown in the figure), screen electrodes 21, and a screen chip 22. The screen electrodes 21 are disposed on the screen body and are used to couple with the stylus electrodes 12 on the active stylus 10. The screen chip 22 is disposed outside the screen body and is electrically connected to the screen electrodes 21. In this example, the screen chip 22 is disposed on a circuit board outside the screen body. This circuit board can be a flexible printed circuit board or a rigid printed circuit board. The screen electrodes 21 include driving electrodes 211 (D0-D3 in Figure 2) and sensing electrodes 212 (S0-S3 in Figure 2). It can be understood that the touch screen 20 may include multiple sets of driving electrodes 211 and sensing electrodes 212 as shown in the examples. In this example, the screen chip 22 includes a screen driving circuit 221, a screen receiving circuit 222, and a screen controller 223. The screen controller 223 is a logic controller disposed on the touch screen 20, specifically a microcontroller (MCU) disposed within the touch screen 20. The screen driving circuit 221 is connected to both the driving electrode 211 and the screen controller 223, and is used to control the driving electrode 211 to work according to the screen driving signal output by the screen controller 223. The screen receiving circuit 222 is connected to both the sensing electrode 212 and the screen controller 223, and is used to acquire and demodulate the measured signal output by the sensing electrode 212, and output the processed signal to the screen controller 223.

[0118] As an example, when the active pen 10 approaches or touches the touch screen 20, the active pen 10 is coupled to the screen electrode 2 through the pen electrode 12, so that the screen electrode 21 on the touch screen 20 can send the detected measured signal to the screen controller 223. Specifically, this includes the following two schemes:

[0119] The first solution is as follows: When the first driving signal and the second driving signal output by the pen controller 143 have the same frequency, specifically when the frequency and phase of the second driving signal and the first driving signal are the same, the measured signal sensed by the screen electrode 21 on the touch screen 20 is a single frequency signal. The screen controller 223 can directly determine the measured signal as the first driving signal output by the pen electrode 12 so as to perform subsequent control operations based on the first driving signal.

[0120] The second approach is as follows: When the first driving signal and the second driving signal output by the pen controller 143 have different frequencies, the measured signal sensed by the screen electrode 21 on the touch screen 20 includes the first measured signal and the second measured signal with different frequencies. Here, the first driving signal is transmitted to the touch screen 20 through the coupling capacitor between the pen electrode 12 and the screen electrode 21, and the second measured signal is transmitted to the touch screen 20 through the coupling capacitor between the hand and the touch screen 20. After receiving the first measured signal and the second measured signal with different frequencies, the screen controller 223 can perform signal feature compensation processing on the two signals based on the built-in signal compensation algorithm, so as to identify the signal feature after compensation as the first driving signal output by the active pen 10 without crosstalk interference, so that the signal-to-noise ratio of the first driving signal of the active pen 10 can be greatly improved.

[0121] In one embodiment, the first driving signal is the sum of the first measured signal and the compensation signal; the compensation signal is the product of the second measured signal and the third coefficient.

[0122] The compensation signal is used to compensate the first measured signal. The third coefficient is used to adjust the second measured signal, specifically a coefficient less than 1.

[0123] As an example, assuming the first measured signal is S1, the second measured signal is S2, and the third coefficient is k3, the screen controller 223 compensates the first measured signal based on the second measured signal to determine the first driving signal output by the active pen = S1 + k3 * S2, so as to use the second measured signal to compensate the first measured signal and determine the second driving signal without crosstalk, so as to ensure that the signal-to-noise ratio of the first driving signal recognized by the touch screen 20 can be greatly improved.

[0124] As shown in Figure 10, the first and second measured signals have different frequencies. When a hand touches the screen electrode 21 (i.e., in the same sensor channel) that projects the same direction as the pen electrode 12 of the active pen 10, two frequency signal envelopes will be generated within the screen electrode 21. The envelopes of the two frequency signals are similar, and the crosstalk effect of the hand can be compensated by the third coefficient k3. Assuming that at frequency f1, the first driving signal output by the active pen 10 is raw1, and the crosstalk signal between the active pen 10 and the hand is raw2, then the first measured signal that the touch screen 20 can detect is the S1 signal. Therefore, S1 = raw1 - raw2, raw1 = S1 + raw2; the S1 signal is the first measured signal after crosstalk of the first driving signal corresponding to frequency f1. At frequency f2, the crosstalk signal between the active pen 10 and the hand is raw3. The second measured signal that the touch screen 20 can detect is the S2 signal. The S2 signal is the second measured signal after crosstalk of the second driving signal corresponding to frequency f2. Since the crosstalk signals raw2 and raw3 at frequency f1 and frequency f2 have similar signal characteristics, they can be compensated by the crosstalk signal at frequency f2. The compensated first driving signal is raw1-raw2+k3*raw3. That is, the compensated signal is the crosstalk-free signal output by the active pen 10, i.e., the first driving signal, which greatly improves the signal-to-noise ratio of the first driving signal of the active pen 10.

[0125] This application provides a touch screen 20, including a screen body (not shown in the figure), a screen electrode 21, and a screen chip 22 as described in the above embodiment; the screen electrode 21 is disposed on the screen body and is used to couple with the pen electrode 12 on the active pen 10; the screen chip 22 is disposed outside the screen body and is electrically connected to the screen electrode 21.

[0126] As shown in Figure 2, the touch screen 20 includes a screen body (not shown in the figure), screen electrodes 21, and screen chip 22. The screen electrodes 21 are disposed on the screen body and are used to couple with the pen electrodes 12 on the active pen 10. The screen chip 22 is disposed outside the screen body and is electrically connected to the screen electrodes 21. The screen chip 22 includes a screen driving circuit 221, a screen receiving circuit 222, and a screen controller 223. When the active pen 10 approaches or touches the touch screen 20, the active pen 10 couples with the screen electrodes 21 through the pen electrodes 12, so that the screen electrodes 21 on the touch screen 20 can send the measured signal they detect to the screen controller 223, so that the screen controller 223 can determine the first driving signal output by the active pen 10 without crosstalk interference based on the measured signal it receives, so that the signal-to-noise ratio of the first driving signal of the active pen 10 can be greatly improved.

[0127] This application provides a touch system, including an active pen 10 and a touch screen 20 as described in the above embodiments; the pen electrode 12 on the active pen 10 is coupled to the screen electrode 21 on the touch screen 20.

[0128] In this example, when the pen controller 143 outputs a first driving signal to the first driving circuit 141, it can simultaneously output a second driving signal to the second driving circuit 142. This causes the second driving circuit 142 (i.e., AC2 in Figure 7) to drive the isolation structure 13, thereby eliminating or greatly reducing the direct coupling between the hand and the active pen system ground, thus achieving the purpose of eliminating and isolating crosstalk signals between the active pen 10 and the hand. The pen controller 143 simultaneously outputs the first driving signal and the second driving signal, causing the electric fields formed by the first driving signal and the second driving signal to occur simultaneously. This allows the crosstalk signal that occurs simultaneously with the first driving signal to be isolated, thereby effectively eliminating the crosstalk signal.

[0129] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A pen chip, applicable to an active pen, wherein, The active pen includes a pen housing, a pen electrode disposed on the pen housing, and an isolation structure disposed inside the pen housing. The pen electrode is coupled to a screen electrode on the touch screen. The pen chip is disposed inside the pen casing, and the pen chip includes a first driving circuit, a second driving circuit, and a pen controller; The first driving circuit is connected to both the pen controller and the pen electrode, and is used to output a first driving signal to the pen electrode based on the first control signal output by the pen controller. The second driving circuit is connected to both the pen controller and the isolation structure, and is used to output a second driving signal to the isolation structure based on the second control signal output by the pen controller, so that the isolation structure isolates the crosstalk signal between the active pen and the hand; The pen controller is configured to simultaneously output the first control signal and the second control signal, so that the first driving circuit and the second driving circuit simultaneously output the first driving signal and the second driving signal.

2. The pen chip according to claim 1, wherein, The signal parameters of the second driving signal are related to the signal parameters of a single first driving signal, or the second driving signal is related to the signal parameters of multiple first driving signals that are output simultaneously.

3. The pen chip according to claim 2, wherein, The second driving signal and the first driving signal have the same frequency and phase; The amplitude of the second driving signal is the product of the amplitude of the target driving signal and the first coefficient. The value of the first coefficient ranges from 0 to 20%. The target driving signal is a single first driving signal or a signal obtained by superimposing multiple first driving signals. Alternatively, the amplitude of the second driving signal is the amplitude obtained by weighting multiple first driving signals and the second coefficients corresponding to the multiple first driving signals, wherein the value of the second coefficients ranges from 0 to 20%, and the second coefficients corresponding to the multiple first driving signals have different values.

4. The pen chip according to claim 3, wherein, The first coefficient is negatively correlated with the first suspension height; The first suspension height is the height between the electrode vertex of the active pen facing the touch screen and the touch screen.

5. The pen chip according to claim 3, wherein, The second coefficient corresponding to each of the first driving signals is negatively correlated with the second suspension height of the pen electrode corresponding to each of the first driving signals; or, the amplitude corresponding to each of the first driving signals is positively correlated with the second suspension height of the pen electrode corresponding to each of the first driving signals. The second suspension height of the pen electrode is the height between the point of the pen electrode closest to the touch screen and the touch screen.

6. The pen chip according to claim 3, wherein, The first coefficient has a value range of 3%-10%; the second coefficient has a value range of 3%-10%.

7. The pen chip according to claim 2, wherein, The second driving signal and the first driving signal have different frequencies, so that the touch screen can detect the first measured signal and the second measured signal, and compensate the first measured signal based on the second measured signal to determine the first driving signal output by the active pen; The first measured signal is the signal coupled to the touch screen by the first driving signal, and the second measured signal is the signal coupled to the touch screen by the second driving signal.

8. The pen chip according to claim 2, wherein, The plurality of first driving signals are respectively the first driving signal received by the main electrode and the first driving signal received by the sub-electrode; Alternatively, the plurality of first driving signals may be the first driving signal received by the main electrode, the first driving signal received by the secondary electrode, and the first driving signal received by the pen tail electrode; The main electrode and the secondary electrode are disposed on the tip of the active pen, and the pen tail electrode is disposed on the tail of the active pen.

9. An active pen, wherein, The device includes a pen housing, a pen electrode disposed on the pen housing, and an isolation structure disposed within the pen housing, wherein the pen electrode is coupled to a screen electrode on the touch screen. It also includes the pen chip according to any one of claims 1-8, wherein the pen chip is disposed within the pen housing and is connected to the pen electrode and the isolation structure.

10. The active pen according to claim 9, wherein, The pen casing has a gripping area; the isolation structure is disposed within the gripping area.

11. The active pen according to claim 9, wherein, The isolation structure includes a conductive spacer, which is assembled inside the pen shell; Alternatively, the isolation structure includes a conductive coating applied to the inner wall of the pen casing; Alternatively, the isolation structure may include a conductive component disposed on the pen casing.

12. The active pen according to claim 9, wherein, The pen casing includes a pen body and a pen tip disposed at one end of the pen body; The pen electrode is disposed on the pen tip, and at least a portion of the pen electrode extends out of the pen tip.

13. The active pen according to claim 12, wherein, The pen tip is provided with an assembly hole; The pen electrode includes a main electrode and a secondary electrode; One end of the main electrode is disposed inside the pen housing, and the other end of the main electrode extends out of the pen housing through the assembly hole for positioning detection; The secondary electrode is disposed inside the pen shell and sleeved outside the main electrode, and is used for tilt angle detection.

14. A screen chip, suitable for connection to a screen electrode on a touch screen, wherein the screen electrode is coupled to a pen electrode on an active pen according to any one of claims 9-13, wherein, The screen chip includes a screen receiving circuit and a screen controller; The screen receiving circuit is connected to both the screen electrode and the screen controller, and is used to send the measured signal detected by the screen electrode to the screen controller. The screen controller is configured to determine the measured signal as the first driving signal output by the active pen when the measured signal is a single-frequency signal; and to compensate the first measured signal based on the second measured signal when the measured signal contains a first measured signal and a second measured signal with different frequencies, thereby determining the first driving signal output by the active pen. The first measured signal is the signal coupled to the touch screen by the first driving signal, and the second measured signal is the signal coupled to the touch screen by the second driving signal.

15. The screen chip according to claim 14, wherein, The first driving signal is the sum of the first measured signal and the compensation signal; The compensation signal is the product of the second driving signal and the third coefficient.

16. A touch screen, wherein, Includes a screen body, screen electrodes, and the screen chip as described in any one of claims 14-15; The screen electrode is disposed on the screen body and is used to couple with the pen electrode on the active pen. The screen chip is disposed outside the screen body and is electrically connected to the screen electrode.

17. A touch system, wherein, Includes the active pen as described in any one of claims 9-13 and the touch screen as described in claim 16; The pen electrode on the active pen is coupled to the screen electrode on the touch screen.

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