Pen chip and active pen

Abstract

The present application discloses a pen chip and an active pen. The active pen comprises a pen housing, a pen electrode disposed on the pen housing, and a coupling structure disposed inside the pen housing. The pen electrode is used for coupling with a screen electrode on a touch screen. A pen chip is arranged inside the pen housing, is connected to the pen electrode and the coupling structure, and is used for processing a first uplink signal received by the pen electrode and a second uplink signal received by the coupling structure, so as to determine a raw uplink signal outputted by the touch screen. The pen chip can utilize the second uplink signal to perform compensation on the attenuated first uplink signal, thereby determining the raw uplink signal outputted by the touch screen, so as to ensure the accuracy of the active pen in recognizing the raw uplink signal outputted by the touch screen.

Description

Pen chip and active pen TECHNICAL FIELD

[0001] The present application relates to the technical field of touch control systems, and in particular to a pen chip and an active pen. BACKGROUND

[0002] The existing touch control system includes an active pen and a touch screen, and the active pen and the touch screen work based on a certain communication protocol. When working, there is a coupling capacitor between the active pen and the touch screen, and signals are transmitted between the two through the coupling capacitor. When a user holds the active pen close to or in contact with the touch screen, for example, when the user holds the active pen to click on the touch screen or to hover or write at a certain height on the touch screen, the hand will also be close to or in contact with the touch screen. When the screen electrodes of the touch screen send uplink signals (also known as Uplink signals in the industry) to the pen electrodes of the active pen, the hand will couple a large amplitude of the uplink signals, and the uplink signals will be coupled to the system ground of the active pen through a parasitic capacitor (since the hand is also holding the active pen). In this case, the uplink signals obtained by the pen electrodes of the active pen as a reference to the system ground of the active pen will be greatly attenuated, affecting the accuracy of the active pen in identifying the uplink signals. SUMMARY

[0003] Embodiments of the present application provide a pen chip and an active pen to solve the problem of large attenuation of the uplink signals received by the pen electrodes of the active pen.

[0004] Embodiments of the present application provide a pen chip, which is applicable to an active pen. The active pen includes a pen shell, a pen electrode arranged on the pen shell, and a coupling structure arranged in the pen shell. The pen electrode is used to couple with screen electrodes on a touch screen. The pen chip is arranged in the pen shell, and is connected to the pen electrode and the coupling structure. The pen chip is used to process first uplink signals received by the pen electrode and second uplink signals received by the coupling structure, and to determine original uplink signals output by the touch screen.

[0005] Embodiments of the present application provide an active pen, which includes a pen shell, a pen electrode arranged on the pen shell, and a coupling structure arranged inside the pen shell. The pen electrode is coupled with screen electrodes on a touch screen. The active pen also includes the above-mentioned pen chip. The pen chip is arranged in the pen shell, and is connected to the pen electrode and to the coupling structure.

[0006] Embodiments of the present application provide a pen chip and an active pen. By adding a coupling structure to the active pen, the pen chip is connected to the pen electrode and the coupling structure, so that the pen chip can simultaneously receive first uplink signals received by the pen electrode and second uplink signals received by the coupling structure. The second uplink signals are used to compensate for the first uplink signals that have been attenuated, and to determine original uplink signals output by the touch screen, so as to ensure the accuracy of the active pen in identifying the original uplink signals output by the touch screen. BRIEF DESCRIPTION OF DRAWINGS

[0007] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.

[0008] Fig. 1 is a structural schematic diagram of a stylus according to an embodiment of the present application;

[0009] Fig. 2 is a schematic diagram of the stylus and a touch screen in communication;

[0010] Fig. 3 is a structural schematic diagram of a typical stylus;

[0011] Fig. 4 is a physical capacitive coupling model of a touch system formed by the typical stylus shown in Fig. 3 and a touch screen;

[0012] Fig. 5 is a physical capacitive coupling model of a touch system formed by the stylus shown in Fig. 1 and a touch screen;

[0013] Fig. 6 is a comparison diagram of output signals of the pen receiving circuit of the typical scheme shown in Fig. 3 and the optimized scheme shown in Fig. 1;

[0014] Fig. 7 is a first circuit schematic diagram of the stylus shown in Fig. 1;

[0015] Fig. 8 is a second circuit schematic diagram of the stylus shown in Fig. 1;

[0016] Fig. 9 is a third circuit schematic diagram of the stylus shown in Fig. 1;

[0017] Fig. 10 is a third circuit schematic diagram of the stylus shown in Fig. 1;

[0018] Fig. 11 is a physical capacitive coupling model of a touch system formed by the typical stylus shown in Fig. 3 and a touch screen when a hand is on the touch screen;

[0019] Fig. 12 is a physical capacitive coupling model of a touch system formed by the typical stylus shown in Fig. 3 and a touch screen when a hand is not on the touch screen;

[0020] Fig. 13 is a physical capacitive coupling model of a touch system formed by the stylus shown in Fig. 1 and a touch screen when a hand is on the touch screen;

[0021] Fig. 14 is a schematic diagram of signal crosstalk between the typical stylus shown in Fig. 3 and a hand;

[0022] Fig. 15 is a schematic diagram of eliminating signal crosstalk between the stylus shown in Fig. 1 and a hand;

[0023] Fig. 16 is a schematic diagram of a second driving signal and a first driving signal in an embodiment of the present application;

[0024] Fig. 17 is a schematic diagram of different detection frequency pen crosstalk signal envelopes.

[0025] Fig. 10 is a schematic diagram of a pen and a touch screen according to an embodiment of the present application. In the figure: 10, a pen; 11, a pen shell; 12, pen electrodes; 121, a main electrode; 122, a sub electrode; 13, a coupling structure; 14, a pen chip; 141, a pen receiving circuit; 1411, a superimposed amplification circuit; 1412, a superimposed analog-to-digital converter; 1413, a first amplification circuit; 1414, a first analog-to-digital converter; 1415, a second amplification circuit; 1416, a second analog-to-digital converter; 142, a pen controller; 143, a pen driving circuit; 1431, a first driving circuit; 1432, a second driving circuit; 144, a multiplexer; 1441, a first multiplexer; 1442, a second multiplexer; 15, a power supply; 16, a power management module; 17, a gain adjustment circuit; 20, a touch screen; 21, screen electrodes; 211, driving electrodes; 212, sensing electrodes; 22, a screen chip; 221, a screen driving circuit; 222, a screen receiving circuit; 223, a screen controller; 224, a switch module; 2241, a first switch selector; 2242, a second switch selector. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0027] It should be understood that the present application can be implemented in various forms, and should not be interpreted as being limited to the embodiments set forth herein. On the contrary, the embodiments are provided to make the disclosure complete and fully convey the scope of the present application to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions can be exaggerated for clarity throughout the drawings, and the same reference numerals indicate the same elements.

[0028] In order to understand the present application thoroughly, detailed structures and steps will be set forth in the following description to explain the technical solutions proposed by the present application. The preferred embodiments of the present application are described in detail as follows, however, the present application can have other implementation manners besides these detailed descriptions.

[0029] The embodiment of the present application provides a pen chip 14, which is suitable for being arranged on a stylus 10, as shown in Figure 1, the stylus 10 comprises a pen shell 11, a pen electrode 12 arranged on the pen shell 11 and a coupling structure 13 arranged in the pen shell 11, the pen electrode 12 is used for coupling with a screen electrode 21 on a touch screen 20; the pen chip 14 is arranged in the pen shell 11, and the pen chip 14 is connected with the pen electrode 12 and the coupling structure 13, and is used for processing a first uplink signal received by the pen electrode 12 and a second uplink signal received by the coupling structure 13, and determining an original uplink signal output by the touch screen 20.

[0030] The pen electrode 12 is an electrode arranged on the stylus 10, the pen electrode 12 can be one or multiple, and can be determined according to actual conditions. The coupling structure 13 is a structure used for realizing signal coupling, for example, the coupling structure 13 can be a structure used for realizing signal coupling and made of conductive material.

[0031] The original uplink signal refers to an uplink signal output by the touch screen 20. The first uplink signal refers to an uplink signal received by the pen electrode 12, and is specifically an uplink signal transmitted through a coupling capacitor between the pen electrode 12 and the screen electrode 21, the first uplink signal is an uplink signal after the original uplink signal is attenuated in a transmission process. The second uplink signal refers to an uplink signal received by the coupling structure 13. The uplink signal herein refers to a signal transmitted from the touch screen 20 to the stylus 10.

[0032] Figure 2 shows a touch system of the stylus 10 and the touch screen 20, and the touch system is only used for describing the working principle and does not limit the specific design form. As shown in Figure 2, the touch screen 20 comprises a screen main body (not shown in the figure), the screen electrode 21 and a screen chip 22; the screen electrode 21 is arranged on the screen main body and is used for coupling with the pen electrode 12 on the stylus 10; and the screen chip 22 is arranged outside the screen main body and is electrically connected with the screen electrode 21. In the present example, the screen chip 22 is arranged on a circuit board outside the screen main body, and the circuit board can be a flexible circuit board (Flexible Printed Circuit) or a rigid circuit board (Printed Circuit Board). The screen electrode 21 comprises driving electrodes 211 (D0-D3 in Figure 2) and sensing electrodes 212 (S0-S3 in Figure 2), and it can be understood that the touch screen 20 can comprise multiple groups of the driving electrodes 211 and the sensing electrodes 212. In the present example, the screen chip 22 comprises a screen driving circuit 221, a screen receiving circuit 222 and a screen controller 223, wherein the screen controller 223 is a logic controller arranged on the touch screen 20, and is specifically a micro controller (Micro Controller Unit, MCU for short).

[0033] Further, the touch screen 20 or the screen chip 22 further comprises a switch module 224 disposed on the circuit board, the switch module 224 comprises 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 the plurality of driving electrodes 211, and can control the on-off 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 the plurality of sensing electrodes 212, and can control the on-off 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 can also make the driving electrodes 211 connect to the screen receiving circuit 222 through the first switch selector 2241 and the second switch selector 2242 under the control of the screen controller 223, so that the touch screen 20 can complete the detection function in cooperation with the active pen 10. When the active pen 10 is close to or contacts the touch screen 20, the pen electrode 12 on the active pen 10 is coupled with 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 the coupling capacitor.

[0034] Referring to FIG. 3, the typical active pen 10 comprises a pen shell 11, a pen electrode 12 disposed on the pen shell 11, and a pen chip 14 disposed in the pen shell 11, the pen chip 14 is connected with the pen electrode 12, and the pen chip 14 is provided with a pen receiving circuit 141, the pen receiving circuit 141 is connected with the pen electrode 12, and the pen electrode 12 receives the first uplink signal and sends the received first uplink signal to the pen receiving circuit 141. That is, the active pen 10 provided in the embodiment of the present application is provided with a coupling structure 13 connected with the pen chip 14, and the typical scheme does not have the coupling structure 13.

[0035] Referring to Fig. 4, a physical capacitive coupling model of a touch system formed by a typical active pen 10 and a touch screen 20 is shown to illustrate the principle of the attenuation of the uplink signal received by the active pen 10 due to the hand touching the touch screen 20. There is a coupling capacitor CI between the pen electrode 12 of the active pen 10 and the screen electrode 21 of the touch screen 20, and there is a coupling capacitor C2 between the hand and the screen electrode 21 of the touch screen 20. The hand holds the active pen 10, so there is a coupling capacitor C3 between the hand and the active pen system. In addition, the hand has two paths to the touch screen system, one is a direct coupling capacitor C6, and the other is an indirect coupling formed by a coupling capacitor C4 between the hand and the ground and a coupling capacitor C7 between the ground and the touch screen system. There is a coupling capacitor C5 between the active pen system and the ground, and there is a coupling capacitor C8 between the active pen system and the touch screen system. It is assumed that the pen electrode 12 of the active pen 10 is suspended at a height of 10 mm above the touch screen 20, and the typical capacitance values of C1-C8 are C1 (40 fF), C2 (50 pF), C3 (100 pF), C4 (68 pF), C5 (7 pF), C6 (12 pF), C7 (40 pF), and C8 (1 pF). These coupling capacitances may vary due to different designs of the screen and the pen, but do not affect the principle described here.

[0036] The screen electrode 21 of the touch screen 20 is driven by an AC voltage source (i.e., the screen driving circuit 221 in Fig. 2) to flow back to the touch screen system through the coupling capacitor CI, the active pen system, and the ground. When the hand touches or approaches the touch screen 20, the AC voltage source will generate a larger voltage signal Vb (with reference to the touch screen system) at the hand touch position (i.e., point B in Fig. 4) through the coupling capacitor C2 and the coupling capacitor C6. Since point B is coupled to the active pen system through a large coupling capacitor C3, the voltage of the active pen system (also with reference to the touch screen system) is close to the voltage Vb of point B. Assuming that the voltage of point A in Fig. 4 is Va (Va is the voltage of the AC voltage source built-in in the touch screen 20, with reference to the touch screen system), then the equivalent signal received by the pen receiving circuit 141 of the active pen system at point A is Va-Vb (assuming the same phase, in fact, due to the effects of parasitic resistance and capacitance in the backflow path, there is a small phase difference), which is the fundamental reason for the attenuation of the uplink signal received by the active pen 10 when the hand touches the touch screen 20. Assuming that the hand is far away from the touch screen 20, then the coupling capacitor C2 in Fig. 4 will sharply decrease to close to 0, and the equivalent circuit will be in an open state, so the voltage Vb of point B is close to 0V, and the equivalent voltage of point A received by the pen receiving circuit 141 of the active pen system is close to Va, which can be considered as no attenuation.

[0037] Referring to the active pen 10 shown in Fig. 1, a coupling structure 13 is arranged in the active pen 10 for coupling a second uplink signal of the hand, the coupling structure 13 can be directly connected with a pen chip 14 of the active pen 10, the pen chip 14 is provided with a pen receiving circuit 141; the coupling structure 13 can be coupled with an input end of the pen receiving circuit 141, can also be coupled with the input end of the pen receiving circuit 141 through a capacitor, can also be coupled with the input end of the pen receiving circuit 141 through a resistor, can also be coupled with the input end of the pen receiving circuit 141 through a switch or other elements, and the second uplink signal received by the coupling structure 13 is sent to the pen receiving circuit 141 to compensate the first uplink signal received by the pen electrode 12 by using the second uplink signal, so as to determine the original uplink signal with no attenuation.

[0038] Referring to Fig. 5, a physical capacitive coupling model of the touch system formed by the active pen 10 and the touch screen 20 according to the optimization scheme shown in Fig. 1 is shown, which is only used for principle illustration and some actual existing non-critical parasitic paths are not shown. In Fig. 5, the coupling structure 13 is coupled to the input end of the pen receiving circuit 141 through a gain adjusting circuit 17 (which can be but is not limited to the adjusting capacitor C9 shown in Fig. 5), and the C9 capacitor value is recommended to be 10 pF-20 pF. As shown in Fig. 5, since the coupling structure 13 is arranged in the active pen 10, there is an additional parasitic capacitor C10 from the coupling structure 13 to the active pen system ground, and the typical capacitor value of the parasitic capacitor C10 is 50 pF-100 pF. There is also a parasitic capacitor C11 from the active pen system ground to the touch screen system ground, and the typical capacitor value of the parasitic capacitor C11 is 1 pF-2 pF. In Fig. 5, other capacitor values are referred to the values given above C1 (40 fF), C2 (50 pF), C3 (100 pF), C4 (68 pF), C5 (7 pF), C6 (12 pF), C7 (40 pF), and C8 (1 pF). The capacitor value depends on the structure design of the active pen 10 and the touch screen 20 and other factors, and this scheme does not limit the specific value. As can be seen from the physical capacitive coupling model of the touch system shown in Fig. 5, when the hand touches the touch screen 20, the pen receiving circuit 141 can simultaneously detect a first uplink signal coupled to the pen electrode 12 through the screen electrode 21 and a second uplink signal coupled by the hand through the coupling structure 13, so that the pen chip 14 can determine the original uplink signal output by the touch screen 20 based on the first uplink signal and the second uplink signal. Understandably, when the hand touches or approaches the touch screen 20, the original uplink signal output by the touch screen 20 is attenuated, so that the pen electrode 12 outputs the first uplink signal after attenuation to the pen chip 14. Due to the hand touching the touch screen 20, the signal amount of the attenuated part can be transmitted to the pen chip 14 through the coupling structure 13 in the active pen 10, that is, the coupling structure 13 can transmit the second uplink signal to the pen chip 14, so that the pen chip 14 can determine the original uplink signal output by the touch

[0039] Referring to Fig. 6, when the original uplink signal output by the touch screen 20 is the same, the suspension height of the pen electrode 12 of the active pen 10 is the same, and the pen receiving circuit 141 built in the active pen 10 is the same, the signal strength of the output signal after the pen receiving circuit 141 in the pen chip 14 of the optimization scheme shown in Fig. 1 and the pen receiving circuit 141 in the pen chip 14 of the typical scheme shown in Fig. 3 is detected and processed is more than 2 times of the signal strength of the output signal after the processing of the existing scheme, that is, the optimization scheme is basically free of signal attenuation, which helps to ensure the accuracy of the pen chip 14.

[0040] In an embodiment, as shown in FIG. 7, the pen chip 14 comprises a pen receiving circuit 141, the pen receiving circuit 141 comprising a superposition amplification circuit 1411 and a superposition analog-to-digital converter 1412; the superposition amplification circuit 1411 is connected to the pen electrode 12 and the coupling structure 13 simultaneously, and is configured to amplify the signal after superposition of the first uplink signal and the second uplink signal, and output a superposition amplified signal; the superposition analog-to-digital converter 1412 is connected to the superposition amplification circuit 1411, and is configured to perform analog-to-digital conversion on the superposition amplified signal, and determine the original uplink signal output by the touch screen 20.

[0041] In the formula, the pen receiving circuit 141 is a circuit for receiving the uplink signal and is arranged on the pen chip 14. The superposition amplification circuit 1411 is a circuit for signal amplification of the superpositioned analog signal. The superposition analog-to-digital converter 1412 is a circuit for converting the analog signal output by the superposition amplification circuit 1411 into a digital signal.

[0042] In the formula, the pen controller 142 is a logic controller arranged on the active pen 10, specifically a micro controller unit (MCU) arranged in the active pen 10. The MCU is the final execution unit of information processing and program running as the operation and control core of the pen, and is mainly configured to control the circuit and electrical components arranged on the active pen 10 to work. Understandably, the pen controller 142 can be arranged in the pen chip 14 or outside the pen chip 14, and in the embodiments of the present application, the pen controller 142 is arranged in the pen chip 14 as an example. Further, the active pen 10 further comprises a power supply 15 and a power management module 16, the power management module 16 being connected to the power supply 15 and the pen controller 142, so as to control the power supply 15 to supply power to the pen controller 142 and other devices connected thereto.

[0043] As an example, the pen chip 14 comprises a pen receiving circuit 141, the pen receiving circuit 41 comprising a superposition amplification circuit 1411 and a superposition analog-to-digital converter; the first input end of the superposition amplification circuit 1411 is connected to the pen electrode 12 and the connecting structure 13 simultaneously, the second input end of the superposition amplification circuit 1411 is connected to the common mode voltage terminal VCM, so that the first uplink signal received by the pen electrode 12 and the second uplink signal received by the coupling structure 13 are superimposed and input into the input end of the superposition amplification circuit 1411, so that the superposition amplification circuit 1411 can amplify the signal after superposition of the first uplink signal and the second uplink signal, output a superposition amplified signal. The superposition amplified signal is the signal after amplification of the signal after superposition of the two uplink signals. The superposition analog-to-digital converter 1412 is connected to the superposition amplification circuit, and can perform analog-to-digital conversion on the superposition amplified signal, and determine the original uplink signals output by the touch screen 20.

[0044] In the example, the pen chip 14 further comprises a pen controller 142 connected with the pen receiving circuit 141, the pen controller 142 is connected with the superimposed analog-to-digital converter 1412, and is used to receive the original uplink signal output by the superimposed analog-to-digital converter 1412, so as to perform subsequent logic control based on the original uplink signal, and the logic control process is similar to that of a typical pen controller 142, which will not be described here.

[0045] In the example, the superimposed amplification circuit 1411 can comprise a trans-impedance amplifier (TIA for short), a first resistor R1, a second resistor Rf and a first capacitor Cf; the first input end of the trans-impedance amplifier is connected with the pen electrode 12 and the coupling structure 13 through the first resistor R1, the second input end of the trans-impedance amplifier is connected with the common-mode voltage end VCM; the two ends of the second resistor Rf are connected with the first input end of the trans-impedance amplifier and the output end of the trans-impedance amplifier respectively; and the two ends of the first capacitor Cf are connected with the first input end of the trans-impedance amplifier and the output end thereof respectively. In the example, the first resistor R1, the second resistor Rf and the first capacitor Cf are components built in the superimposed amplification circuit 1411 for adjusting the gain of the trans-impedance amplifier, and the gain adjustment process is a prior art, which will not be described here.

[0046] In an embodiment, as shown in FIGS. 5 and 7, the active pen 10 further comprises a gain adjustment circuit 17, the first end of the gain adjustment circuit 17 is connected with the coupling structure 13, and the second end of the gain adjustment circuit 17 is connected with the superimposed amplification circuit 1411, which is used for gain adjustment of the second uplink signal and outputs the adjusted second uplink signal to the superimposed amplification circuit 1411.

[0047] As shown in FIGS. 5 and 7, the coupling structure 13 is coupled to the input end of the pen receiving circuit 141 (i.e. the first input end of the superimposed amplification circuit 1411) through the gain adjustment circuit 17 (which can adopt but is not limited to the adjustment capacitor C9 shown in FIG. 5), and the capacitance value of C9 is recommended to be 10 pF-20 pF. The gain adjustment circuit 17 is arranged between the coupling structure 13 and the superimposed amplification circuit 1411, and is used for gain adjustment of the second uplink signal received by the coupling structure 13, so as to enhance the signal strength of the second uplink signal, and output the adjusted second uplink signal to the superimposed amplification circuit 1411, so that the superimposed amplification circuit 1411 performs amplification processing on the signal after superimposition of the first uplink signal and the adjusted second uplink signal, thereby guaranteeing the signal strength and signal quality of the superimposed amplified signal output by the superimposed amplification circuit 1411. Generally, the signal strength of the first uplink signal is much greater than that of the second uplink signal, and therefore, the gain adjustment circuit 17 is arranged between the coupling structure 13 and the superimposed amplifying circuit 1411 to perform gain adjustment on the second uplink signal, so as to make the adjusted second uplink signal.

[0048] Further, when the superposition amplification circuit 1411 comprises a trans-impedance amplifier TIA, a first resistor R1, a second resistor Rf and a first capacitor Cf; the first input end of the trans-impedance amplifier is connected to the pen electrode 12 and the coupling structure 13 through the first resistor R1, the second input end of the trans-impedance amplifier is connected to the common mode voltage terminal VCM; the two ends of the second resistor Rf are connected to the first input end of the trans-impedance amplifier and the output end of the trans-impedance amplifier respectively; when the two ends of the first capacitor Cf are connected to the first input end of the trans-impedance amplifier and the output end of the trans-impedance amplifier respectively, the gain adjustment circuit 17 is arranged between the coupling structure 13 and the first resistor R1; the gain adjustment circuit 17 cooperates with the first resistor R1, the second resistor Rf and the first capacitor Cf to realize gain adjustment on the second uplink signal.

[0049] In an embodiment, as shown in FIG. 8, the pen chip 14 comprises a pen receiving circuit 141, the pen receiving circuit 141 is used to connect a pen controller 142, the pen receiving circuit 141 comprises a first amplification circuit 1413, a first analog-to-digital converter 1414, a second amplification circuit 1415 and a second analog-to-digital converter 1416; the first amplification circuit 1413 is connected to the pen electrode 12, used to amplify the first uplink signal and output a first amplified signal; the first analog-to-digital converter 1414 is connected to the first amplification circuit 1413 and the pen controller 142, used to perform analog-to-digital conversion on the first amplified signal and output a first digital signal to the pen controller 142; the second amplification circuit 1415 is connected to the coupling structure 13, used to amplify the second uplink signal and output a second amplified signal; the second analog-to-digital converter 1416 is connected to the second amplification circuit 1415 and the pen controller 142, used to perform analog-to-digital conversion on the second amplified signal and output a second digital signal to the pen controller 142; the pen controller 142 is used to perform operation processing on the first digital signal and the second digital signal, and determine the original uplink signal output by the touch screen 20.

[0050] Among them, the first amplification circuit 1413 is an amplification circuit connected to the pen electrode 12, the second amplification circuit 1415 is an amplification circuit connected to the coupling structure 13, and the two amplification circuits are circuits for realizing signal amplification. The first analog-to-digital converter 1414 is an analog-to-digital converter connected to the first amplification circuit 1413, and the second analog-to-digital converter 1416 is an analog-to-digital converter connected to the second amplification circuit 1415. The analog-to-digital converter is a circuit for converting an analog signal into a digital signal.

[0051] As an example, the pen chip 14 includes a pen receiving circuit 141 and a pen controller 142, the pen receiving circuit 141 includes a first amplification circuit 1413, a first analog-to-digital converter 1414, a second amplification circuit 1415 and a second analog-to-digital converter 1416. A first input end of the first amplification circuit 1413 is connected with the pen electrode 12, a second input end of the first amplification circuit 1413 is connected with a common mode voltage terminal VCM, an output end of the first amplification circuit 1413 is connected with the first analog-to-digital converter 1414, for amplifying the first uplink signal and outputting a first amplified signal to the first analog-to-digital converter 1414, the first amplified signal being a signal after the first uplink signal is amplified. The first analog-to-digital converter 1414 is connected with the first amplification circuit 1413 and the pen controller 142, for analog-to-digital conversion of the first amplified signal and outputting a first digital signal to the pen controller 142, the first digital signal being a digital signal corresponding to the first amplified signal. A first input end of the second amplification circuit 1415 is connected with the coupling structure 13, a second input end of the second amplification circuit 1415 is connected with the common mode voltage terminal VCM, an output end of the second amplification circuit 1415 is connected with the second analog-to-digital converter 1416, for amplifying the second uplink signal and outputting a second amplified signal to the second analog-to-digital converter 1416, the second amplified signal being a signal after the second uplink signal is amplified. The second analog-to-digital converter 1416 is connected with the second amplification circuit 1415 and the pen controller 142, for analog-to-digital conversion of the second amplified signal and outputting a second digital signal to the pen controller 142, the second digital signal being a digital signal corresponding to the second amplified signal. The pen controller 142 is connected with the first analog-to-digital converter 1414 and the second analog-to-digital converter 1416, for operation processing of the first digital signal and the second digital signal, determining a signal after the two are superimposed as an original uplink signal output by the touch screen 20, so as to perform subsequent logic control based on the original uplink signal, and the logic control process is similar to that of a typical pen controller 142, which will not be described here.

[0052] In the example, the first amplification circuit 1413 and the second amplification circuit 1415 each include a trans-impedance amplifier TIA, a first resistor R1, a second resistor Rf and a first capacitor Cf; a first input end of the trans-impedance amplifier in the first amplification circuit 1413 is connected with the pen electrode 12 through the first resistor R1, a first input end of the trans-impedance amplifier in the second amplification circuit 1415 is connected with the coupling structure 13 through the first resistor R1, and the connection relationship of other structures is the same as that of the above-described embodiment, which will not be described here to avoid repetition.

[0053] In an embodiment, as shown in FIG. 5 and FIG. 8, the pen receiving circuit 141 further comprises a gain adjusting circuit 17, a first end of the gain adjusting circuit 17 is connected with the coupling structure 13, and a second end of the gain adjusting circuit 17 is connected with the second amplification circuit 1415, for gain adjustment of the second uplink signal, and output of the adjusted second uplink signal to the second amplification circuit 1415.

[0054] As an example, the coupling structure 13 is coupled to the input end of the pen receiving circuit 141 through the gain adjusting circuit 17, and specifically coupled to the first input end of the second amplification circuit 1415, and the gain adjusting circuit 17 is used to adjust the gain of the second uplink signal received by the coupling structure 13, to enhance the signal strength of the second uplink signal, and output the adjusted second uplink signal to the second amplification circuit 1415, so that the second amplification circuit 1415 performs amplification processing on the adjusted second uplink signal, and outputs the second amplified signal to the second analog-to-digital converter 1416l. Generally, the signal strength of the first uplink signal is much greater than that of the second uplink signal, and therefore, the gain adjusting circuit 17 is arranged between the coupling structure 13 and the second amplification circuit 1415, to adjust the gain of the second uplink signal, so as to output the adjusted second uplink signal.

[0055] In an embodiment, the gain adjusting circuit 17 comprises an adjusting capacitor C9, an adjusting resistor, or an adjusting unit comprising the adjusting capacitor C9 and the adjusting resistor in series or in parallel.

[0056] As an example, as shown in FIG. 5, FIG. 7 and FIG. 8, the gain adjusting circuit 17 can only comprise the adjusting capacitor C9, and the two ends of the adjusting capacitor C9 are respectively connected with the coupling structure 13 and the amplification circuit connected with the coupling structure 13. For example, in a specific embodiment, the adjusting capacitor C9 can be arranged between the coupling structure 13 and the superposition amplification circuit 1411, and in another specific embodiment, the adjusting capacitor C9 can be arranged between the coupling structure 13 and the second amplification circuit 1415, and the adjusting capacitor C9 can cooperate with the built-in elements of the superposition amplification circuit 1411 (including but not limited to the first resistor R1, the second resistor Rf and the first capacitor Cf) to adjust the gain of the second uplink signal received by the coupling structure 13.

[0057] As an example, as shown in FIG. 9, the gain adjustment circuit 17 can only include an adjustment resistor R2, two ends of the adjustment resistor R2 being connected with the coupling structure 13 and the amplification circuit connected with the coupling structure 13 respectively. For example, in one specific embodiment, the adjustment resistor R2 can be arranged between the coupling structure 13 and the superposition amplification circuit 1411, and in another specific embodiment, the adjustment resistor R2 can be arranged between the coupling structure 13 and the second amplification circuit 1415, which can cooperate with the built-in elements (including but not limited to the first resistor R1, the second resistor Rf and the first capacitor Cf) of the superposition amplification circuit 1411 to adjust the gain of the second uplink signal received by the coupling structure 13.

[0058] As an example, as shown in FIG. 10, the gain adjustment circuit 17 can include an adjustment unit including an adjustment capacitor C9 and an adjustment resistor R2 in series or in parallel, two ends of the adjustment unit being connected with the coupling structure 13 and the amplification circuit connected with the coupling structure 13 respectively. For example, in one specific embodiment, the adjustment unit can be arranged between the coupling structure 13 and the superposition amplification circuit 1411, and in another specific embodiment, the adjustment unit can be arranged between the coupling structure 13 and the second amplification circuit 1415, which can cooperate with the built-in elements (including but not limited to the first resistor R1, the second resistor Rf and the first capacitor Cf) of the superposition amplification circuit 1411 to adjust the gain of the second uplink signal received by the coupling structure 13.

[0059] In one embodiment, the gain adjustment circuit 17 is arranged in the pen chip 14, or the gain adjustment circuit 17 is arranged outside the pen chip 14.

[0060] As an example, the gain adjustment circuit 17 can be arranged in the pen chip 14 (as shown in FIG. 8) or arranged outside the pen chip 14 (as shown in FIG. 7, FIG. 9 and FIG. 10), and the specific position can be determined autonomously according to actual conditions.

[0061] In one embodiment, as shown in FIG. 9, the pen chip 14 further includes a pen controller 142, a pen driving circuit 143 and a multiplexer 144; the multiplexer 144 is connected with the pen electrode 12 and the coupling structure 13 simultaneously, and connected with the pen receiving circuit 141 or the pen driving circuit 143; the pen controller 142 is connected with the multiplexer 144, used to control the second end of the multiplexer 144 to connect the pen receiving circuit 141 or the pen driving circuit 143, and when the second end of the multiplexer 144 is connected with the pen driving circuit 143, the pen controller 142 also controls the pen driving circuit 143 to output the first driving signal to the pen electrode 121 and output the second driving signal to the coupling structure 13 simultaneously, so as to make the coupling structure 13 isolate the crosstalk signal between the active pen 10 and the hand.

[0062] The multiplexer 144 is a device for switching the connection state between multiple inputs and multiple outputs. The first drive signal is a drive signal output by the pen drive circuit 143 to the pen electrode 12, which is not interfered by the crosstalk signal. The second drive signal is a drive signal output by the pen drive circuit 143 to the coupling structure 13.

[0063] As an example, the pen chip 14 further comprises a pen drive circuit 143 and a multiplexer 144, the multiplexer 144 is connected to the pen electrode 12 and the coupling structure 13 simultaneously, and the multiplexer 144 is further connected to the pen receiving circuit 141 or the pen drive circuit 143. The pen controller 142 is further connected to the multiplexer 144, and can output a control signal to the multiplexer 144 to control the pen electrode 12 and the coupling structure 13 to be connected to the pen receiving circuit 141 simultaneously, so that the pen electrode 12 and the coupling structure 13 output the first uplink signal and the second uplink signal to the pen receiving circuit 141 simultaneously, so as to determine the original uplink signal output by the touch screen 20 without attenuation based on the first uplink signal and the second uplink signal subsequently. Alternatively, the pen controller 142 outputs a control signal to control the pen electrode 12 and the coupling structure 13 to be connected to the pen drive circuit 143 simultaneously, so that the pen drive circuit 143 outputs the first drive signal to the pen electrode 12 and outputs the second drive signal to the coupling structure 13 simultaneously, so that the coupling structure 13 can isolate the crosstalk signal between the active stylus 10 and the hand.

[0064] Referring to FIGS. 11 and 12, the crosstalk principle between the active stylus 10 and the hand on the touch screen 20 is described below by taking the pen electrode 12 of one active stylus 10 as an example based on the physical capacitive coupling model of the touch system established by the typical active stylus 10 shown in FIG. 3 and the touch screen 20. When the hand holding the pen electrode 12 of the active stylus 10 is close to or contacts the sensing electrode S1 of the touch screen 20, and the hand contacts the sensing electrode S1 of the touch screen 20, the pen electrode 12 and the hand form capacitive coupling with the sensing electrode S1 of the touch screen 20, that is, the pen electrode 12 of the active stylus 10 and the sensing electrode S1 of the touch screen 20 have a coupling capacitance C1, and the hand and the sensing electrode S1 of the touch screen 20 have a coupling capacitance C5. The hand holds the active stylus 10, so the hand and the active stylus systemically have a coupling capacitance C2. In addition, the hand and the touch screen systemically have two paths, one is a direct coupling capacitance C7, and the other is an indirect coupling through the coupling capacitance C3 between the hand and the ground and the coupling capacitance C4 between the ground and the touch screen. The active stylus systemically and the touch screen systemically also have a coupling capacitance C6. The typical capacitance values of C1-C7 can be C1(40 fF), C2(200 pF), C3(80 pF), C4(8 pF), C5(1 pF), C6(3 pF), and C7(2 pF). These capacitances may vary due to different designs of the screen and the pen, but do not affect the principle description herein.

[0065] Referring to Fig. 11, when the pen electrode 12 of the active stylus 10 is close to or contacts the sensing electrode S1 of the touch screen 20, and the hand contacts the sensing electrode S1 of the touch screen 20, the pen controller 142 controls the pen driving circuit 143 (i.e. the voltage source AC1) to output a first driving signal, which is transmitted through the path of "active stylus system ground - voltage source AC1 - pen electrode 12 - coupling capacitor C1 - sensing electrode S1 - touch screen system ground - ground - hand - active stylus system ground" in turn, i.e. the path can transmit the capacitive coupling signal between the active stylus 10 and the touch screen 20. In this process, due to the contact between the hand and the sensing electrode S1, the coupling capacitor C5 between the hand and the sensing electrode S1 of the touch screen 20 is formed, and the path of "active stylus system ground - coupling capacitor C2 - coupling capacitor C5 - parasitic resistance R0 of sensing electrode S1 - touch screen system ground" is also formed to transmit the capacitive coupling signal (i.e. the crosstalk signal) between the hand and the touch screen 20. Since the current flow directions of the capacitive coupling signals transmitted by the two paths are opposite at the coupling capacitor C2, the capacitive coupling signal between the hand and the sensing electrode S1 and the capacitive coupling signal between the active stylus 10 and the sensing electrode S1 are inverse signals of each other. That is, when the hand is on the sensing electrode S1 of the touch screen 20, a crosstalk signal opposite to the first driving signal will pass through the parasitic resistance R0 of the coupling capacitor C5 and the sensing electrode S1 and be coupled to the first driving signal of the sensing electrode S1 corresponding to the active stylus 10, affecting the original signal amount of the active stylus 10.

[0066] Referring to FIG. 12, when the pen electrode 12 of the active stylus 10 is close to or contacts the sensing electrode S1 of the touch screen 20 and the hand does not contact the sensing electrode S1 of the touch screen 20, the coupling capacitance C1 exists between the pen electrode 12 of the active stylus 10 and the sensing electrode S1 of the touch screen 20 due to the close contact between the pen electrode 12 and the sensing electrode S1, the coupling capacitance C5 does not exist between the hand and the sensing electrode S1 due to the hand not contacting the sensing electrode S1, and the coupling capacitance C2 exists between the hand and the active stylus due to the hand holding the active stylus. In this process, the pen controller 142 controls the pen driving circuit 143 (voltage source AC1) to output a first driving signal, which is transmitted through the path of "active stylus system ground-voltage source AC1-pen electrode 12-coupling capacitance C1-sensing electrode S1-touch screen system ground-ground-active stylus system ground" in turn. Since the coupling capacitance C5 does not exist between the hand and the sensing electrode S1, there is no crosstalk signal transmitted through the path of "active stylus system ground-coupling capacitance C2-coupling capacitance C5-sensing electrode S1 parasitic resistance R0-touch screen system ground". That is, when the hand does not contact the sensing electrode S1 of the touch screen 20, there is no crosstalk signal opposite to the first driving signal transmitted through the coupling capacitance C5 and the parasitic resistance R0 of the sensing electrode S1, and the crosstalk signal is transmitted to the first driving signal of the sensing electrode S1 of the active stylus 10, which affects the original signal of the active stylus 10.

[0067] As can be seen from the physical capacitance coupling models shown in FIGS. 11 and 12, the fundamental reason for the crosstalk signal between the hand and the touch screen 20 is that the coupling capacitance C2 exists between the hand and the sensing electrode S1, so that the crosstalk signal can be transmitted through the path of "active stylus system ground-coupling capacitance C2 between the hand and the active stylus system ground-coupling capacitance C5 between the hand and the sensing electrode S1-sensing electrode S1 parasitic resistance R0-touch screen system ground". The active stylus 10 in the embodiment of the present application not only includes the pen shell 11 and the pen electrode 12 arranged on the pen shell 11, but also includes the coupling structure 13 arranged in the pen shell 11 and the pen driving circuit 143. The pen driving circuit 143 is connected to the pen controller 142 and the coupling structure 13 at the same time, and can output a second driving signal to the coupling structure 13 based on the control signal output by the pen controller 142, so as to eliminate or greatly reduce the direct coupling between the hand and the active stylus system ground. Specifically, the coupling capacitance C2 between the hand and the active stylus system ground is eliminated or reduced, so that the path of "active stylus system ground-coupling capacitance C2 between the hand and the active stylus system ground-coupling capacitance C5 between the hand and the sensing electrode S1-sensing electrode S1 parasitic resistance R0-touch screen system ground" cannot transmit signals, thereby achieving the purpose of eliminating the crosstalk signal between the active stylus 10 and the hand.

[0068] Referring to Fig. 13, when the active pen 10 is close to or contacts the touch screen 20, the pen electrode 12 on the active pen 10 is coupled with the screen electrode 21 on the touch screen 20, and the first driving signal output by the active pen 10 to the touch screen 20 through the pen driving circuit 143 is transmitted along 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 contacts 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, and the crosstalk signal is transmitted along 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 R0 of the sensing electrode S1 - touch screen system ground". In order to eliminate the crosstalk signal, the pen controller 142 can output a second driving signal to the coupling structure 13 through the pen driving circuit 143 at the same time when outputting the first driving signal to the pen electrode 12l through the pen driving circuit 143, so as to drive the coupling structure 13 to work, so as to form a coupling capacitor C2 between the hand and the active pen system ground, so as to interrupt the path of "active pen system ground - coupling capacitor C2 between the hand and the active

[0069] In an embodiment, as shown in Fig. 10, the multiplexer 144 includes a first converter 1441 and a second converter 1442; the first converter 1441 is connected with the pen electrode 12 and the coupling structure 13 at the same time, and is connected with the pen receiving circuit 141; the second converter 1442 is connected with the pen electrode 12 and the coupling structure 13 at the same time, is connected with the pen driving circuit 143; the pen controller 142 is connected with the first converter 1441 and the second converter 1442, and is used to control any one of the first converter 1441 and the second converter 1442 to be turned on and the other to be turned off.

[0070] Among them, the first converter 1441 is a converter for connecting the pen electrode 12, the coupling structure 13 and the pen receiving circuit 141. The second converter 1442 is a converter for connecting the pen electrode 12, the coupling structure 13 and the pen driving circuit 143.

[0071] As an example, the first end of the first switch 1441 is connected to the pen electrode 12 and the coupling structure 13 simultaneously, the second end of the first switch 1441 is connected to the pen receiving circuit 141, and the first switch 1441 is further connected to the pen controller 142. Based on the control signal output by the pen controller 142, the pen receiving circuit 141 is controlled to be connected to the pen electrode 12 and the coupling structure 13 simultaneously, so that the pen receiving circuit 141 can receive the first uplink signal received by the pen electrode 12 and the second uplink signal received by the coupling structure 13 simultaneously, to determine the original uplink signal output by the touch screen 20 based on the first uplink signal and the second uplink signal. The first end of the second switch 1442 is connected to the pen electrode 12 and the coupling structure 13 simultaneously, the second end of the second switch 1442 is connected to the pen driving circuit 143, and the second switch 1442 is further connected to the pen controller 142. Based on the control signal output by the pen controller 142, the pen driving circuit 143 is controlled to be connected to the pen electrode 12 and the coupling structure 13 simultaneously, so that the pen driving circuit 143 can control the pen electrode 12 to output the first driving signal and the coupling structure 13 to output the second driving signal simultaneously, to isolate the crosstalk signal between the active pen 10 and the hand.

[0072] In the example, the pen controller 142 is connected to the first switch 1441 and the second switch 1442, and can control either of the first switch 1441 and the second switch 1442 to be turned on and the other to be turned off. Specifically, the pen controller 142 can control the first switch 1441 to be turned on and the second switch 1442 to be turned off, so that the pen electrode 12 and the coupling structure 13 can output the first uplink signal and the second uplink signal to the pen receiving circuit 141 simultaneously; or the pen controller 142 can also control the first switch 1441 to be turned off and the second switch 1442 to be turned on, so that the pen driving circuit 143 can output the first driving signal to the pen electrode 12 and output the second driving signal to the coupling structure 13.

[0073] In an embodiment, as shown in FIG. 9, the pen driving circuit 143 comprises a first driving circuit 1431 and a second driving circuit 1432; a first end of the first driving circuit 1431 is connected with the pen controller 142, a second end of the first driving circuit 1431 is connected with the pen electrode 12 through the multiplexer 144, and is configured to output a first driving signal to the pen electrode 12 based on a first control signal output by the pen controller 142; a first end of the second driving circuit 1432 is connected with the pen controller 142, a second end of the second driving circuit 1432 is connected with the coupling structure 13 through the multiplexer 144, and is configured to output a second driving signal to the coupling structure 13 based on a second control signal output by the pen controller 142, so as to make the coupling structure 13 isolate the crosstalk signal between the active pen 10 and the hand; the pen controller 142 is configured to control the multiplexer 144 to connect the first driving circuit 1431 and the pen electrode 12, and to connect the second driving circuit 1432 and the coupling structure 13, and simultaneously output the first control signal and the second control signal, so as to make the first driving circuit 1431 and the second driving circuit 1432 simultaneously output the first driving signal and the second driving signal.

[0074] The first driving circuit 1431 is a circuit connected with the pen electrode 12 and configured to drive the pen electrode 12 to work. The first control signal is a signal configured to control the first driving circuit 1431 to work. The first driving signal is a driving signal output by the first driving circuit 1431 to the pen electrode 12, and is a driving signal not interfered by the crosstalk signal. In this example, the first driving circuit 1431 can specifically output the first driving signal to the pen electrode 12 based on the first control signal output by the pen controller 142, control the pen electrode 12 to work, so as to make the pen electrode 12 coupled with the screen electrode 21 on the touch screen 20, and make the active pen 10 and the touch screen 20 capable of communicating.

[0075] The second driving circuit 1432 is a circuit connected with the coupling structure 13 and configured to drive the coupling structure 13 to work. The second control signal is a signal configured to control the second driving circuit 1432 to work. The second driving signal is a driving signal output by the second driving circuit 1432 to the coupling structure 13. In this example, the second driving circuit 1432 can specifically output the second driving signal to the coupling structure 13 based on the second control signal output by the pen controller 142, so as to make the coupling structure 143 isolate the crosstalk signal between the active pen 10 and the hand.

[0076] The first driving circuit 1431 and the second driving circuit 1432 can be circuits that multiplex a part of components.

[0077] Referring to FIG. 13, when the active pen 10 is close to or contacts the touch screen 20, the pen electrode 12 on the active pen 10 is coupled with the screen electrode 21 on the touch screen 20, and the first driving signal output by the active pen 10 to the touch screen 20 is transmitted 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" in turn. During this process, if the hand contacts the sensing electrode S1 on the touch screen 20, a crosstalk signal affecting the first driving signal is formed between the hand and the active pen 10, and the crosstalk signal is transmitted through the path of "coupling capacitor C2 between the active pen system ground and the hand - coupling capacitor C5 between the hand and the sensing electrode S1 - parasitic resistance R0 of the sensing electrode S1 - touch screen system ground". In order to eliminate the crosstalk signal, the pen controller 142 can output a second driving signal to the second driving circuit 1432 (voltage source AC2) while outputting the first driving signal to the first driving circuit 1431 (voltage source AC1), so as to drive the coupling structure 13 to work, so as to form or greatly reduce the coupling capacitor C2 between the hand and the active pen system ground, so that the path of "coupling capacitor C2 between the active pen system ground and the hand - coupling capacitor C5 between the hand and the sensing electrode S1 - parasitic resistance R0 of the sensing electrode S1 - touch screen system ground" is interrupted, so as to achieve the purpose of eliminating the crosstalk signal between the active pen 10 and the hand. In this example, the pen controller 142 simultaneously outputs the first driving signal and the second driving signal, so that the electric field formed by the first driving signal and the second driving signal occurs at the same time, and then the crosstalk signal occurring at the same time as the first driving signal can be isolated, so as to effectively eliminate the crosstalk signal.

[0078] Referring to FIG. 14, the pen electrode 12 of the typical active pen 10 is close to or contacts the sensing electrode ch16, and the hand contacts the sensing electrode ch14, so that the active pen 10 forms a capacitive 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 path of "coupling capacitor between the hand and the active pen system ground - coupling capacitor between the hand and the sensing electrode ch14 - parasitic resistance corresponding to the sensing electrode ch14", so that the hand interferes with the capacitive projection signal envelope centered on the sensing electrode ch14, which specifically means that the encoding value corresponding to the sensing electrode ch14 is much larger than the encoding values corresponding to the sensing electrode ch13 and the sensing electrode ch15 adjacent to the sensing electrode ch14. In this way, the capacitive projection signal envelope of the active pen 10 is destroyed, which affects the accuracy of communication between the active pen 10 and the touch screen 20.

[0079] Referring to FIG. 15, when the pen electrode 12 of the active pen 10 is close to or contacts 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 for transmitting the first driving signal, at this time, the crosstalk signal is transmitted through the "coupling capacitance between the hand and the system ground of the active pen - coupling capacitance between the hand and the sensing electrode ch14 - parasitic resistance corresponding to the sensing electrode ch14", since the pen controller 142 controls the second driving circuit 1432 to output the second driving signal to the coupling structure 13 while controlling the first driving circuit 1431 to output the first driving signal to the pen electrode 12l, so that the coupling structure 13 eliminates the coupling capacitance between the hand and the sensing electrode ch14, so that the transmission path of the crosstalk signal is interrupted, so as to eliminate the crosstalk signal, so that the finally output sensing electrode ch14 corresponding code value is between the sensing electrode ch13 corresponding code value and the sensing electrode ch15 corresponding code value, and the sensing electrode 212 corresponding code value on both sides of the sensing electrode ch16 decreases in turn, so that the sensing electrode ch16 centered forms a capacitance projection signal which is not interfered by the capacitance projection signal formed between the hand and the touch screen 20.

[0080] In the present example, when it is necessary to control the active pen 1 to output the driving signal to the touch screen 2, the pen controller 142 needs to output the control signal to the multiplexer 144, so that the multiplexer 144 connects the first driving circuit 1431 and the pen electrode 12, and connects the second driving circuit 1432 and the coupling structure 13, so that the pen controller 142 can output the first driving signal and the second driving signal at the same time through the first driving circuit 1431 and the second driving circuit 1432, so that the electric field formed by the first driving signal and the second driving signal occurs at the same time, and then the crosstalk signal occurring at the same time as the first driving signal can be isolated, so as to achieve the purpose of effectively eliminating the crosstalk signal.

[0081] In an 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 output at the same time.

[0082] As an example, the active pen 10 includes at least one pen electrode 12. At the same time, the pen controller 142 controls the first driving circuit 1431 to output a single first driving signal to one of the pen electrodes 12, and the pen controller 142 controls the second driving circuit 1432 to receive a second driving signal coupled to the coupling structure 13, which is related to the single first driving signal. Alternatively, at the same time, the pen controller 142 can control the first driving circuit 1431 to output multiple first driving signals to multiple pen electrodes 12 simultaneously, and the pen controller 142 controls the second driving circuit 1432 to receive a second driving signal coupled to the coupling structure 13, which is related to the signal parameters of the multiple first driving signals output simultaneously. In the present example, the signal parameters include, but are not limited to, frequency, phase, and amplitude.

[0083] In an embodiment, the second driving signal has the same frequency and phase as the first driving signal, and 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 in the range of 0-20%, the target driving signal being a single first driving signal or a signal obtained by superimposing multiple first driving signals; or the amplitude of the second driving signal is the sum of the amplitudes of the multiple first driving signals and the amplitudes of the multiple first driving signals after weighted processing by a second coefficient, the second coefficient being in the range of 0-20%.

[0084] As an example, as shown in FIG. 16, 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 frequency bandwidth, so that the touch screen 20 can identify the two signals in the same frequency 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, so that the output second driving signal can eliminate or greatly reduce the direct coupling existing between the hand and the active pen system, so that the coupling structure 13 can 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 capacitor between the hand and the touch screen 20 and the screen electrode 21 where the projection is located, under the condition of the screen electrode 21 on the touch screen 20, the amplitude (energy size) of the crosstalk signal depends on the coupling capacitor between the hand and the touch screen 20, specifically depends on the distance, projection area and relative dielectric constant between the hand and the touch screen 20 and other factors, which comprehensively determine the corresponding adjustment coefficient. In the example, the adjustment coefficient can be a first coefficient or a second coefficient. The first coefficient is used to limit the amplitude scaling ratio of the second driving signal and the target driving signal, and the first coefficient can be a pre-set fixed value or a dynamic value determined according to actual conditions. The second coefficient is used to limit the amplitude scaling ratio between the second driving signal and each first driving signal, and the second coefficient can be a pre-set fixed value or a dynamic value determined according to actual conditions.

[0085] In an 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 range of the first coefficient is 0-20%, the target driving signal is a single first driving signal or a signal after superposition of multiple first driving signals, assuming that 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 after superposition of multiple first driving signals, Sm = ∑Si, then the amplitude of the second driving signal Sd = k1*Sm = k1*∑Si, to realize the superposition processing of the amplitudes of multiple first driving signals, based on the product of the superimposed amplitude and the first coefficient, it is helpful to ensure that the amplitude of the finally determined second driving signal can effectively eliminate the crosstalk signal.

[0086] In another example, the amplitude of the second driving signal is the amplitude of the plurality of first driving signals and the amplitude of the plurality of first driving signals after the second coefficient weighting processing, the value range of the second coefficient is 0-20%, assuming that 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, to realize the weighting processing of the amplitude of the plurality of first driving signals and the second coefficient, and determine the amplitude of the second driving signal after the weighting processing. In this example, at least one of the amplitudes corresponding to the plurality of first driving signals and the second coefficients corresponding to the plurality of first driving signals is different, specifically, the amplitudes can be the same and the second coefficients are different, or the amplitudes are different and the second coefficients are the same, or the amplitudes and the second coefficients are different, which can be adjusted according to actual conditions. The weighting processing based on the amplitudes and the second coefficients corresponding to the plurality of first driving signals helps to ensure that the amplitude of the finally determined second driving signal can effectively eliminate the crosstalk signal.

[0087] In an embodiment, 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 10 facing the touch screen 20 and the touch screen 20.

[0088] 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 suspension height of the electrode vertex of the active pen 10 facing the touch screen 20 and the touch screen 20, that is, the lower the first suspension height, the closer the active pen 10 to the touch screen 20, the greater the crosstalk signal it can generate, therefore, the greater the first coefficient corresponding to it, and the greater the amplitude of the second driving signal corresponding to it; on the contrary, the higher the first suspension height, the farther the active pen 10 from the touch screen 20, the smaller the crosstalk signal it generates, therefore, the smaller the first coefficient corresponding to it, and the smaller the amplitude of the second driving signal corresponding to it. In this example, the first coefficient is negatively correlated with the first suspension height, which can be linear correlation or nonlinear correlation, which can be determined according to actual conditions. In this example, after the pen controller 142 determines the first suspension height, it can query the pre-set first height coefficient mapping table based on the first suspension height, dynamically determine the first coefficient corresponding to it, determine the second driving signal based on the product of the target driving signal after superposition of at least one first driving signal and the first coefficient, and control the second driving circuit 1432 to output the second driving signal to the coupling structure 13, so as to isolate the crosstalk signal between the active pen 10 and the hand. The first height coefficient mapping table here is a data table pre-set to reflect the mapping relationship between the first suspension height and the first coefficient.

[0089] In an 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 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 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.

[0090] As an example, when the amplitude of the second driving signal is the amplitude of the plurality of first driving signals and the amplitude after the weighting processing of the plurality of first driving signals corresponding to the second coefficients, 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 the amplitude of each first driving signal can be the same or different, which can be determined according to actual conditions. That is, the lower the second floating height of each pen electrode 12, the closer the pen electrode 12 to the touch screen 20, at this time, the crosstalk signal between the active pen 10 and the hand is larger, therefore, the corresponding second coefficient needs to be larger; on the contrary, the higher the second floating height of each pen electrode 12, the farther the pen electrode 12 from the touch screen 20, at this time, the crosstalk signal between the active pen 10 and the hand is smaller, therefore, the corresponding first coefficient needs to be smaller.

[0091] In the present example, the pen controller 142 can determine the second floating height of each pen electrode 12, query the pre-set second height coefficient mapping table based on the second floating height, and dynamically determine the corresponding second coefficient; the pen controller 142 can determine the amplitude of the first driving signal corresponding to each pen electrode 12 according to actual conditions, weight the amplitude of the first driving signal corresponding to the plurality of pen electrodes 12 and the second coefficient, determine the second driving signal, control the second driving circuit 1432 to output the second driving signal to the coupling structure 13, so as to isolate the crosstalk signal between the active pen 10 and the hand. The second height coefficient mapping table is a data table pre-set to reflect the mapping relationship between the second floating height and the second coefficient.

[0092] For example, when the active stylus 10 includes two pen electrodes 12, a main electrode 121 and a sub electrode 122, the amplitude of the first driving signal of the main electrode 121 is 40V, and the amplitude of the first driving signal of the sub electrode 122 is 30V, the second suspension 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, the second height coefficient mapping table is queried based on the second suspension height h1, and the second coefficient K21 corresponding to the main electrode 121 is determined; and the second suspension height h2 of the sub electrode 122 (i.e. the height between the point of the sub electrode 122 closest to the touch screen 20 and the touch screen 20) is dynamically determined, the second height coefficient mapping table is queried based on the second suspension height h2, and the second coefficient K22 corresponding to the sub electrode 122 is determined; then, the amplitude of the first driving signal corresponding to the main electrode 121 and the sub electrode 122 and the second coefficient are weighted, and the amplitude of the second driving signal is dynamically determined, i.e. 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 the crosstalk signal.

[0093] As another example, the pen controller 142 is positively correlated with the second suspension height of each pen electrode 12 when outputting the first driving signal and the second driving signal. The lower the second suspension height of each pen electrode 12, the closer the pen electrode 12 to the touch screen 20, and the smaller the driving energy, so the smaller the amplitude of the first driving signal output by the pen electrode 12 to save energy; the higher the second suspension height of each pen electrode 12, the farther the pen electrode 12 from the touch screen 20, and the greater the driving energy, so the greater the amplitude of the first driving signal output by the pen electrode 12. The second coefficient corresponding to each first driving signal can be the same or different, for example, when the active stylus 10 includes two pen electrodes 12, a main electrode121 and a sub electrode 122, the second coefficient of the main electrode 121 and the second coefficient of the sub electrode 122 can be determined in advance according to the position, shape and material of the main electrode 121 and the sub electrode 122; or the second coefficient corresponding to each pen electrode 12 can be determined according to the corresponding second suspension height or other measured data.

[0094] In this example, the pen controller 142 can determine the second suspension height of each pen electrode 12, dynamically determine the amplitude of the first driving signal of each pen electrode 12 based on the second suspension height, for example, by looking up a table or other preset method to determine the amplitude of the first driving signal of each pen electrode 12; then, determine the second coefficient corresponding to each first driving signal; finally, based on the amplitude of the first driving signal corresponding to each pen electrode 12 and the second coefficient, the second driving signal is determined by weighting processing, and the second driving signal is output to the second driving circuit 1432 to control the coupling structure 13 to work, and isolate the crosstalk signal between the active stylus 10 and the hand.

[0095] For example, the pen controller 142 can make the amplitudes of the plurality of first driving signals the same when outputting the first driving signals and the second driving signals, the second coefficients corresponding to the plurality of first driving signals are negatively correlated with the second hovering heights corresponding thereto, and the weighting processing is performed based on the amplitudes and the second coefficients corresponding to the plurality of first driving signals, so that the control process is simple and convenient; or the amplitudes of the plurality of first driving signals are positively correlated with the second hovering heights corresponding thereto, the second coefficients of the plurality of first driving signals are the same or different, and the weighting processing is performed based on the amplitudes and the second coefficients corresponding to the plurality of first driving signals, so that the control process is simple and convenient, and the crosstalk signal corresponding to each first driving signal can be eliminated in a targeted manner.

[0096] In an embodiment, the first coefficient is in a range of 3% to 10%; and the second coefficient is in a range of 3% to 10%.

[0097] As an example, the amplitude of the second driving signal is configured to be 3% to 10% of the amplitude of the target driving signal, and the range of the first coefficient is a range of values determined based on simulation tests under typical working conditions, so that the crosstalk signal between the active pen 10 and the hand can be effectively isolated, and energy waste is avoided. As another example, when the amplitude of the second driving signal is the amplitude of the plurality of first driving signals and the amplitude after the weighting processing of the plurality of first driving signals corresponding to the second coefficients, the second coefficient corresponding to each first driving signal is limited to be in a range of 3% to 10%, and the range of the second coefficient is a range of values determined based on simulation tests under typical working conditions. In this example, the amplitudes corresponding to the plurality of first driving signals can be the same or different, and the second coefficients corresponding to the plurality of first driving signals can be the same or different, so that the amplitude of the second driving signal after the weighting processing can effectively isolate the crosstalk signal between the active pen 10 and the hand, and energy waste is avoided.

[0098] In an 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, and determine the first driving signal output by the active pen 10 based on the first measured signal and the second measured signal. The first measured signal is a signal in which the first driving signal is coupled to the touch screen 20, and the second measured signal is a signal in which the second driving signal is coupled to the touch screen 20.

[0099] The first measured signal is a signal of the first driving signal coupled to the touch screen 20, specifically a signal of the first driving signal transmitted to the touch screen 20 through a coupling capacitor between the pen electrode 12 and the screen electrode 21, which is a code signal of the first driving signal after interference of a crosstalk signal. The second measured signal is a signal of the second driving signal coupled to the touch screen 20, specifically a signal of the second measured signal transmitted to the touch screen 20 through a coupling capacitor between the hand and the touch screen 20, which is a driving signal of the second driving signal after interference of a crosstalk signal.

[0100] As an example, the pen controller 142 outputs the first driving signal and the second driving signal at different frequencies to ensure that the first driving signal and the second driving signal are in different frequency bands, so that when the stylus 10 approaches or contacts the touch screen 20, the touch screen 20 can collect the first measured signal and the second measured signal with different frequencies. The first measured signal can be understood as an actually detected signal of the first driving signal after interference of a crosstalk signal, and the second measured signal can be understood as an actually detected signal of the second driving signal after interference of 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 are compensated to identify the first driving signal output by the stylus 10 without interference of a crosstalk signal, so that the signal-to-noise ratio of the first driving signal of the stylus 10 can be greatly improved.

[0101] As an example, the plurality of first driving signals are respectively a first driving signal received by the main electrode 121 and a first driving signal received by the auxiliary electrode 122; or the plurality of first driving signals are respectively a first driving signal received by the main electrode 121, a first driving signal received by the auxiliary electrode 122, and a first driving signal received by a tail electrode (not shown in the figure). The main electrode 121 and the auxiliary electrode 122 are arranged on the pen head of the stylus 10, and the tail electrode is arranged on the pen tail of the stylus 10.

[0102] As an example, when two pen electrodes 12 are provided on the active stylus 10, the two pen electrodes 12 are respectively a main electrode 121 and a sub electrode 122 provided on the pen head of the active stylus 10, at the same time, the pen controller 142 can control the first driving circuit 1431 to simultaneously output two first driving signals, the two first driving signals are respectively a first driving signal received by the main electrode 121 and a first driving signal received by the sub electrode 122. In a possible implementation, the second driving signal has the same frequency and phase as the two first driving signals, and the amplitude of the second driving signal can be a product of the target driving signal after superposition of the two first driving signals and the first coefficient, or the amplitude of the second driving signal can be the amplitude after weighting 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 sub electrode 122, and the second coefficient corresponding to the sub electrode 122. In another possible implementation, the two first driving signals simultaneously output have the same frequency, but the second driving signal has a different frequency from the two first driving signals, and the amplitudes can be the same or different.

[0103] As an example, when three pen electrodes 12 are provided on the active stylus 10, the three pen electrodes 12 are respectively a main electrode 121 and a sub electrode 122 provided on the pen head, and a pen tail electrode provided on the pen tail, at the same time, the pen controller 142 can control the first driving circuit 1431 to simultaneously output three first driving signals, the three first driving signals are respectively a first driving signal received by the main electrode 121, a first driving signal received by the sub electrode 122, and a first driving signal received by the pen tail electrode. In a possible implementation, the second driving signal has the same frequency and phase as the three first driving signals, and the amplitude of the second driving signal can be a product of the target driving signal after superposition of the three first driving signals and the first coefficient, or the amplitude of the second driving signal can be the amplitude after weighting 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 sub electrode 122, the second coefficient corresponding to the sub 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 driving signals simultaneously output have the same frequency, but the second driving signal has a different frequency from the three first driving signals, and the amplitudes can be the same or different.

[0104] The embodiment of the present application provides a kind of active stylus 10, including pen shell 11, pen electrode 12 and coupling structure 13 being set on pen shell 11, pen electrode 12 is coupled with screen electrode 21 on touch screen 20;It also includes the pen chip 14 in the above embodiment, pen chip 14 is set in pen shell 11, pen chip 14 is connected with pen electrode 12 and coupling structure 13.

[0105] In the example, the coupling structure 13 is arranged in the pen shell 11 of the active pen 10, and the coupling structure 13 is connected to the pen chip 14. When the active pen 10 receives the uplink signal output by the touch screen 20, the pen chip 14 can receive the first uplink signal received by the pen electrode 12 and the second uplink signal received by the coupling structure 13 at the same time, and process the first uplink signal and the second uplink signal to determine the original uplink signal output by the touch screen 20 with little attenuation, so as to ensure the accuracy of the received uplink signal.

[0106] Alternatively, when the active pen 10 outputs the driving signal to the touch screen, the pen driving circuit 143 can output the first driving signal to the pen electrode 12l and output the second driving signal to the coupling structure 13 at the same time, so that the coupling structure 13 eliminates or greatly reduces the direct coupling between the hand and the active pen system, thereby achieving the purpose of eliminating the crosstalk signal between the active pen 10 and the hand.

[0107] In an embodiment, the pen shell 11 is provided with a holding area, and the coupling structure 13 is arranged in the holding area.

[0108] As an example, the pen shell 11 is provided with a holding area, which is an area for holding by the hand of a user. The holding area can be a holding position of a pen with a human design, so as to ensure that the active pen 10 has a better holding experience and reduces hand fatigue. In the example, when the holding area is provided on the pen shell 11, the coupling structure 13 can be arranged in the holding area. The coupling structure 13 can receive the second uplink signal and isolate the crosstalk signal between the active pen 10 and the hand, without the need to arrange the coupling structure 13 at other positions of the active pen 10, which helps to save the manufacturing cost of the coupling structure 13.

[0109] In an embodiment, when the coupling structure 13 includes a conductive partition, the conductive partition is assembled in the pen shell 11; or when the coupling structure 13 includes a conductive coating, the conductive coating is coated on the inner wall of the pen shell 11; or when the coupling structure 13 includes a conductive component, the conductive component is arranged on the pen shell 11.

[0110] As an example, the coupling structure 13 can be a conductive partition, which is a structure that is conductive independently of the pen shell 11. For example, the conductive partition can be made of aluminum, copper or other conductive material and detachably installed in the pen shell 11, as long as the conductive partition can be conductive and installed in the pen shell 11. In this example, the conductive partition is installed in the pen shell 11 and connected to the active pen systemically, so that the outer wall of the conductive partition is in contact with or spaced apart from the inner wall of the pen shell 11. The conductive partition is electrically connected to the second driving circuit 1432 installed in the pen shell 11, so that it can receive the second uplink signal and isolate the crosstalk signal between the active pen 10 and the hand.

[0111] As an example, the coupling structure 13 can be a conductive coating, which is a coating formed by coating the inner wall of the pen shell 11 with conductive paint (including but not limited to conductive paint). In this example, the conductive coating is electrically connected to the second driving circuit 1432 installed in the pen shell 11, so that it can receive the second uplink signal and isolate the crosstalk signal between the active pen 10 and the hand. Since the conductive coating is coated on the inner wall of the pen shell 11, the conductive coating and the pen shell 11 form an integral structure, which is simple in structure and convenient to manufacture.

[0112] As an example, the coupling structure 13 can also be a conductive component provided on the pen shell 11. The conductive component refers to a conductive component on the pen shell 11, which can be the entire structure of the pen shell 11 or a part of the structure of the pen shell 11. For example, when the pen shell 11 is a conductive shell made of conductive material, the coupling structure 13 can be the conductive shell itself. For another example, when the pen shell 11 includes an insulating shell and a conductive body embedded in the insulating shell, the coupling structure 13 can be the conductive body embedded in the insulating shell, so that it can receive the second uplink signal and isolate the crosstalk signal between the active pen 10 and the hand

[0113] In an embodiment, the pen shell 11 includes a pen body and a pen tip provided at one end of the pen body; the pen electrode 12 is provided on the pen tip, and at least part of the pen electrode 12 extends out of the pen tip.

[0114] As an example, the pen shell 11 includes a pen body and a pen head arranged at one end of the pen body, and the pen body is provided with a holding area. The pen electrode 12 is arranged on the pen head, and at least part of the pen electrode 12 extends out of the pen head, so that the user can control the pen electrode 12 on the pen head to be close to or contact the touch screen 20, so that the pen electrode 12 is coupled with the screen electrode 21 on the touch screen 20, thereby enabling the active pen 10 to perform signal transmission with the touch screen 20. Generally, the pen controller 142 and the first driving circuit 1431 are arranged in the pen body, the pen controller 142 is connected with the first driving circuit 1431, and the first driving circuit 1431 is connected with the pen electrode 12 arranged on the pen head, so that the pen controller 142 can output a first driving signal to the first driving circuit 1431, so that the first driving circuit 1431 controls the pen electrode 12 to work. Since the coupling structure 13 mainly realizes signal transmission through the coupling capacitance formed by the contact between the hand and the active pen 1, the setting position thereof is related to the holding position of the hand on the active pen 10, and the holding position on the active pen 10 is generally arranged on the pen body, so the coupling structure 13 is arranged at the holding position of the pen body. Moreover, the coupling structure 13 needs to be electrically connected with the pen controller 142 through the second driving circuit 1432, if it is arranged outside the pen body, a connecting hole or other connecting structure needs to be arranged on the pen body, which will cause problems such as complex manufacturing process, low production efficiency, high cost and the like, so the coupling structure 13 and the second driving circuit 1432 are arranged in the pen body, so that the active pen 10 has advantages such as simple structure, high production efficiency and low cost.

[0115] In an embodiment, the pen head is provided with an assembly hole; the pen electrode 12 includes a main electrode 121 and an auxiliary electrode 122; one end of the main electrode 121 is arranged in the pen shell 11, and the other end of the main electrode 121 extends out of the pen shell 11 through the assembly hole, for positioning detection; the auxiliary electrode 122 is arranged in the pen shell 11, and the auxiliary electrode 122 is sleeved outside the main electrode 121, for inclination angle detection.

[0116] As an example, the pen head is provided with an assembly hole, the assembly hole is arranged along the axial direction of the active pen 10, for mounting the pen electrode 12, so that part of the pen electrode 12 extends out of the pen head, and the other part is connected with the first driving circuit 1431 arranged in the pen body. Here, the pen head is generally a conical pen head, the large end of the conical pen head is connected with the pen body, and the assembly hole is arranged on the small end of the conical pen head.

[0117] As an example, the pen electrode 12 includes a main electrode 121 connected with the first driving circuit 1431 and a sub electrode 122, the main electrode 121 is used to realize the positioning detection function, and the sub electrode 122 is used to realize the tilt angle detection function. In the example, one end of the main electrode 121 is arranged in the pen shell 11 and connected with the first driving circuit 1431, and the other end of the main electrode 121 extends out of the pen shell 11 through the assembly hole; the sub electrode 122 is arranged in the pen shell 11, and the sub electrode 122 is sleeved outside the main electrode 121, and specifically, the sub electrode 122 is arranged in the gap between the main electrode 121 and the pen head, and the sub electrode 122 is connected with the first driving circuit 1431, so that the main electrode 121 and the sub electrode 122 can be coupled with the screen electrode 21 on the touch screen 20 at any time when the active pen 10 approaches or contacts the touch screen 20, so that the active pen 10 and the touch screen 20 can communicate, to ensure that the positioning detection function and the tilt angle detection function are realized.

[0118] In the example, the main electrode 121 includes a cylindrical body and a touch control part extending out of one end of the cylindrical body in the axial direction, the cylindrical body is arranged in the assembly hole of the pen head, and the touch control part can be a conical body, a hemispherical body, a fan-shaped body or other shapes, which can be set according to user needs. The sub electrode 122 includes a conical body, and a through hole is arranged on the conical body, so that the conical body can be sleeved outside the cylindrical body of the main electrode 121, and the sub electrode 122 adopts a conical design, which can make the signal envelope more stable.

[0119] The screen chip 22 provided by the embodiment of the application is suitable for being connected with the screen electrode 21 on the touch screen 20, the screen electrode 21 is used to be coupled with the pen electrode 12 on the active pen 10, and the screen chip 22 includes a screen receiving circuit 222 and a screen controller 223; the screen receiving circuit 222 is connected with the screen electrode 21 and the screen controller 223 simultaneously, and is used to send a measured signal detected by the screen electrode 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, and is used to compensate the first measured signal based on a second measured signal when the measured signal includes the first measured signal and the second measured signal with different frequencies, and determine the first driving signal output by the active pen 10; the first measured signal is a signal that the first driving signal is coupled to the touch screen 20, and the second measured signal is a signal that the second driving signal is coupled to the touch screen 20.

[0120] Figure 2 shows a touch system of the active pen 10 and the touch screen 20, which is only used to illustrate the above-mentioned crosstalk principle and does not limit the specific design form. As shown in Figure 2, the touch screen 20 includes a screen body, screen electrodes 21 and a screen chip 22; the screen electrodes 21 are arranged on the screen body and are used to couple with the pen electrodes 12 on the active pen 10; and the screen chip 22 is arranged outside the screen body and is electrically connected with the screen electrodes 21. In this example, the screen chip 22 is arranged on a circuit board outside the screen body, and the circuit board here can be a flexible circuit board (Flexible Printed Circuit) or a rigid circuit board (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), and it can be understood that the touch screen 20 can include multiple groups of the driving electrodes 211 and the sensing electrodes 212 in the example. In this example, the screen chip 22 includes a screen driving circuit 221, a screen receiving circuit 222 and a screen controller 223, wherein the screen controller 223 is a logic controller arranged on the touch screen 20, specifically a microcontroller (Microcontroller Unit, MCU) arranged in the touch screen 20. The screen driving circuit 221 is connected with the driving electrodes 211 and the screen controller 223 at the same time, and is used to control the driving electrodes 211 to work according to a screen driving signal output by the screen controller 223; and the screen receiving circuit 222 is connected with the sensing electrodes 212 and the screen controller 223 at the same time, and is used to collect and demodulate a measured signal output by the sensing electrodes 212, and output the processed signal to the screen controller 223.

[0121] As an example, when the active pen 10 is close to or contacts 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 a measured signal detected by the screen electrodes 21 to the screen controller 223, which includes the following two schemes:

[0122] The first scheme is that when the first driving signal and the second driving signal output by the pen controller 142 have the same frequency, specifically applicable to the scenario that the second driving signal and the first driving signal have the same frequency and phase, the measured signal sensed by the screen electrodes 21 on the touch screen 20 is a single frequency signal, and the screen controller 223 can directly determine the measured signal as the first driving signal output by the pen electrodes 12, so as to perform subsequent control operation based on the first driving signal.

[0123] The second solution is that when the first driving signal and the second driving signal output by the pen controller 142 are different in frequency, the measured signal sensed by the screen electrode 21 on the touch screen 20 includes a first measured signal and a second measured signal different in frequency. The first driving signal is transmitted to the touch screen 20 through the coupling capacitance between the pen electrode 12 and the screen electrode 21. The second measured signal is transmitted to the touch screen 20 through the coupling capacitance between the hand and the touch screen 20. After receiving the first measured signal and the second measured signal different in frequency, the screen controller 223 can compensate the signal characteristics of the first measured signal and the second measured signal based on the built-in signal compensation algorithm, so as to recognize the signal characteristics after the compensation as the first driving signal output by the active pen 10 without the interference of the crosstalk signal, so that the signal-to-noise ratio of the first driving signal of the active pen 10 can be greatly improved.

[0124] In an embodiment, the first driving signal is the sum of the first measured signal and a compensation signal; and the compensation signal is the product of the second measured signal and a third coefficient.

[0125] The compensation signal is a signal used for compensating the first measured signal. The third coefficient is a coefficient used for adjusting the second measured signal, specifically a coefficient less than 1. As an example, assuming that 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 10 = S1+k3*S2, so as to compensate the first measured signal by using the second measured signal to 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. The frequencies of the first measured signal and the second measured signal are different, as shown in FIG. 17, when the hand touches the same screen electrode 21 (i.e., the same sensor channel) as the pen electrode 12 of the active pen 10, two frequency signal envelopes will be generated in the screen electrode 21, and the two frequency signal envelopes are similar, and the third coefficient k3 can be used to compensate the crosstalk effect of the hand. Assuming that, under the 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, the first measured signal that can be detected by the touch screen 20 is the S1 signal, and S1 = raw1-raw2, raw1 = S1+raw2; the S1 signal is the first measured signal of the first driving signal corresponding to the frequency f1 after crosstalk. Under the frequency f2, the crosstalk signal between the active pen 10 and the hand is raw3, the second measured signal that can be detected by the touch screen 20 is the S2 signal, and the S2 signal is the second measured signal of the second driving signal corresponding to the frequency f2 after crosstalk; since the crosstalk signals raw2 and raw3 under the frequencies f1 and f2 have similar signal characteristics, the crosstalk signal under the frequency f2 can be compensated, and 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, that is, the first driving signal, so that the signal-to-noise ratio of the first driving signal of the active pen 10 recognized can be greatly improved.

[0126] The embodiment of the present application provides a touch screen 20, which comprises a screen main body, a screen electrode 21, and a screen chip 22 in the above embodiment; the screen electrode 21 is arranged on the screen main body and is used for coupling with a pen electrode 12 on the active pen 10; and the screen chip 22 is arranged outside the screen main body and is electrically connected with the screen electrode 21.

[0127] As shown in Fig. 2, the touch screen 20 comprises a screen body, screen electrodes 21 and a screen chip 22; the screen electrodes 21 are arranged on the screen body and used for coupling with the pen electrodes 12 on the active pen 10; the screen chip 22 is arranged outside the screen body and electrically connected with the screen electrodes 21; the screen chip 22 comprises a screen driving circuit 221, a screen receiving circuit 222 and a screen controller 223; when the active pen 10 is close to or contacts the touch screen 20, the active pen 10 is coupled with the screen electrodes 21 through the pen electrodes 12, so that the screen electrodes 21 on the touch screen 20 can send the detected measured signals to the screen controller 223, so that the screen controller 223 determines the first driving signal output by the active pen 10 without the interference of crosstalk signals, so that the signal-to-noise ratio of the first driving signal of the active pen 10 can be greatly improved.

[0128] The embodiment of the present application provides a touch system, which comprises the active pen 10 in the above embodiment and the touch screen 20 in the above embodiment; the pen electrodes 12 on the active pen 10 are coupled with the screen electrodes 21 on the touch screen 20.

[0129] In the present example, the coupling structure 13 arranged in the pen shell 11 is additionally arranged on the active pen 10, and the coupling structure 13 is connected with the pen chip 14; when the active pen 10 receives the uplink signals output by the touch screen 20, the pen chip 14 can receive the first uplink signals received by the pen electrodes 12 and the second uplink signals received by the coupling structure 13 at the same time, and process the first uplink signals and the second uplink signals to determine the original uplink signals output by the touch screen 20 without attenuation, so as to guarantee the accuracy of the received uplink signals.

[0130] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limit the same; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; the modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present 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 a coupling structure disposed within the pen housing. The pen electrode is used to couple with a screen electrode on the touch screen. The pen chip is disposed inside the pen housing and is connected to the pen electrode and the coupling structure. It is used to process the first uplink signal received by the pen electrode and the second uplink signal received by the coupling structure to determine the original uplink signal output by the touch screen.

2. The pen chip according to claim 1, wherein, The pen chip includes a pen receiving circuit, which includes a superimposed amplifier circuit and a superimposed analog-to-digital converter. The superposition amplification circuit is connected to both the pen electrode and the coupling structure, and is used to amplify the signal after the first uplink signal and the second uplink signal are superimposed, and output the superposition amplified signal. The superimposed analog-to-digital converter is connected to the superimposed amplification circuit and is used to perform analog-to-digital conversion on the superimposed amplified signal to determine the original uplink signal output by the touch screen.

3. The pen chip according to claim 2, wherein, The active pen also includes a gain adjustment circuit. The first end of the gain adjustment circuit is connected to the coupling structure, and the second end of the gain adjustment circuit is connected to the superposition amplification circuit. The gain adjustment is used to adjust the second uplink signal and output the adjusted second uplink signal to the superposition amplification circuit.

4. The pen chip according to claim 1, wherein, The pen chip includes a pen receiving circuit for connecting to a pen controller. The pen receiving circuit includes a first amplifier circuit, a first analog-to-digital converter, a second amplifier circuit, and a second analog-to-digital converter. The first amplification circuit, connected to the pen electrode, is used to amplify the first uplink signal and output the first amplified signal. The first analog-to-digital converter is connected to the first amplifier circuit and the pen controller, and is used to perform analog-to-digital conversion on the first amplified signal and output a first digital signal to the pen controller. The second amplifier circuit, connected to the coupling structure, is used to amplify the second uplink signal and output the second amplified signal. The second analog-to-digital converter is connected to the second amplifier circuit and the pen controller, and is used to perform analog-to-digital conversion on the second amplified signal and output a second digital signal to the pen controller; The pen controller is used to perform calculations on the first digital signal and the second digital signal to determine the original uplink signal output by the touch screen.

5. The pen chip according to claim 4, wherein, The active pen also includes a gain adjustment circuit. The first end of the gain adjustment circuit is connected to the coupling structure, and the second end of the gain adjustment circuit is connected to the second amplifier circuit. It is used to adjust the gain of the second uplink signal and output the adjusted second uplink signal to the second amplifier circuit.

6. The pen chip according to claim 3 or 5, wherein, The gain adjustment circuit includes an adjustment capacitor, an adjustment resistor, or an adjustment unit, wherein the adjustment unit includes an adjustment capacitor and an adjustment resistor connected in series or in parallel.

7. The pen chip according to claim 3 or 5, wherein, The gain adjustment circuit may be located inside the pen chip or outside the pen chip.

8. The pen chip according to any one of claims 2-5, wherein, The pen chip also includes a pen controller, a pen driver circuit, and a multiplexer; The multiplexer is simultaneously connected to the pen electrode and the coupling structure, and is also connected to the pen receiving circuit or the pen driving circuit. The pen controller is connected to the multiplexer and is used to control the second end of the multiplexer to connect to the pen receiving circuit or the pen driving circuit. When the second end of the multiplexer is connected to the pen driving circuit, the pen driving circuit is also controlled to simultaneously output a first driving signal to the pen electrode and output a second driving signal to the coupling structure, so that the coupling structure isolates the crosstalk signal between the active pen and the hand.

9. The pen chip according to claim 8, wherein, The multiplexer includes a first converter and a second converter; The first converter is connected to both the pen electrode and the coupling structure, and is also connected to the pen receiving circuit; The second converter is connected to both the pen electrode and the coupling structure, and is also connected to the pen driving circuit; The pen controller is connected to the first converter and the second converter, and is used to control one of the first converter and the second converter to be turned on and the other to be turned off.

10. The pen chip according to claim 8, wherein, The pen driving circuit includes a first driving circuit and a second driving circuit. The first terminal of the first driving circuit is connected to the pen controller, and the second terminal of the first driving circuit is connected to the pen electrode through the multiplexer, for outputting a first driving signal to the pen electrode based on the first control signal output by the pen controller. The first end of the second driving circuit is connected to the pen controller, and the second end of the second driving circuit is connected to the coupling structure through the multiplexer. It is used to output a second driving signal to the coupling structure based on the second control signal output by the pen controller, so that the coupling structure isolates the crosstalk signal between the active pen and the hand. The pen controller is used to control the multiplexer to connect the first driving circuit and the pen electrode, and to connect the second driving circuit and the coupling structure, and to output a first control signal and a 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.

11. The pen chip according to claim 10, 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.

12. The pen chip according to claim 11, 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 a second coefficient corresponding to the multiple first driving signals, wherein the value of the second coefficient is in the range of 0-20%, and the second coefficients corresponding to the multiple first driving signals are different values.

13. The pen chip according to claim 12, 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.

14. The pen chip according to claim 12, 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.

15. The pen chip according to claim 12, wherein, The first coefficient has a value range of 3%-10%; the second coefficient has a value range of 3%-10%.

16. The pen chip according to claim 11, 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.

17. The pen chip according to claim 11, 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.

18. An active pen, wherein, The device includes a pen housing, a pen electrode disposed on the pen housing, and a coupling 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 1-17, wherein the pen chip is disposed within the pen housing and the pen chip is connected to the pen electrode and the coupling structure.

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