Pen chip and active pen

Abstract

The utility model discloses a pen chip and an active pen, the active pen comprises a pen shell, a pen electrode arranged on the pen shell and a coupling structure arranged in the pen shell, and the pen electrode is used for coupling with a screen electrode on a touch screen; the pen chip is arranged in the pen shell, and the pen chip is connected with the pen electrode and the coupling structure and used for processing a first uplink signal received by the pen electrode and a second uplink signal received by the coupling structure and determining an original uplink signal output by the touch screen. The pen chip can compensate the attenuated first uplink signal by using the second uplink signal to determine the original uplink signal output by the touch screen so as to ensure the accuracy of the active pen identifying the original uplink signal output by the touch screen.

Description

Technical Field

[0001] This utility model relates to the field of touch system technology, and in particular to a pen chip and an active pen. Background Technology

[0002] Existing touch systems consist of an active pen and a touchscreen. The active pen and touchscreen operate based on a certain communication protocol. During operation, a coupling capacitor exists between the active pen and the touchscreen, through which signals are transmitted. When a user holds the active pen close to or touches the touchscreen—for example, when the user holds the active pen to tap the touchscreen, hovers it at a certain height on the touchscreen, or writes—the hand also approaches or touches the touchscreen. This causes the touchscreen's screen electrodes to send an uplink signal (also known in the industry as an uplink signal) to the active pen's electrodes. The hand couples a relatively large uplink signal, which is then coupled to the active pen system ground through parasitic capacitance (since the hand is also holding the active pen). In this situation, the uplink signal received by the active pen's electrodes from the reference active pen system ground is significantly attenuated, affecting the accuracy of the active pen's uplink signal recognition. Summary of the Invention

[0003] This utility model provides a pen chip and an active pen to solve the problem of significant attenuation of the uplink signal received by the pen electrode of the active pen.

[0004] This utility model embodiment provides a pen chip applicable to an active pen. 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 a touch screen. The pen chip is disposed within the pen housing and is connected to the pen electrode and the coupling structure. It is used to process a first uplink signal received by the pen electrode and a second uplink signal received by the coupling structure to determine the original uplink signal output by the touch screen.

[0005] This utility model provides an active pen, including a pen shell, a pen electrode disposed on the pen shell, and a coupling structure disposed within the pen shell, wherein the pen electrode is coupled to a screen electrode on a touch screen; it also includes the aforementioned pen chip, wherein the pen chip is disposed within the pen shell and is connected to the pen electrode and the coupling structure.

[0006] This utility model embodiment provides 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 a first uplink signal received by the pen electrode and a second uplink signal received by the coupling structure. The second uplink signal is used to compensate for the attenuation of the first uplink signal, thereby determining the original uplink signal output by the touch screen, so as to ensure the accuracy of the active pen in recognizing the original uplink signal output by the touch screen. Attached Figure Description

[0007] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 This is a schematic diagram of the structure of an active pen in one embodiment of the present invention;

[0009] Figure 2 This is a schematic diagram illustrating the communication between the stylus and the touchscreen.

[0010] Figure 3 This is a schematic diagram of a typical active pen structure;

[0011] Figure 4 yes Figure 3 The figure shows a typical physical capacitive coupling model of a touch system formed by an active stylus and a touch screen.

[0012] Figure 5 yes Figure 1 The diagram shows an optimized physical capacitive coupling model of the touch system formed by the active stylus and the touchscreen.

[0013] Figure 6 yes Figure 3 Typical schemes shown and Figure 1 A comparison diagram of the output signals of the pen receiving circuit in the optimized scheme shown;

[0014] Figure 7 yes Figure 1 The diagram shows the first circuit diagram of the active pen.

[0015] Figure 8 yes Figure 1 The diagram shows the second circuit of the active pen.

[0016] Figure 9 yes Figure 1 The diagram shows the third circuit of the active pen.

[0017] Figure 10 yes Figure 1 The diagram shows the third circuit of the active pen.

[0018] Figure 11 When your hand is on the touchscreen, Figure 3 The figure shows a typical physical capacitive coupling model of a touch system formed by an active stylus and a touch screen.

[0019] Figure 12 When your hand is not on the touchscreen Figure 3The figure shows a typical physical capacitive coupling model of a touch system formed by an active stylus and a touch screen.

[0020] Figure 13 When your hand is on the touchscreen, Figure 1 The diagram shows a physical capacitive coupling model of the touch system formed by the active pen and the touch screen.

[0021] Figure 14 This is a schematic diagram of the second driving signal and the first driving signal in an embodiment of the present invention;

[0022] Figure 15 This is a schematic diagram of the envelope of hand-held crosstalk signals at different detection frequencies.

[0023] In the diagram: 10. Active pen; 11. Pen casing; 12. Pen electrode; 121. Main electrode; 122. Sub-electrode; 13. Coupling structure; 14. Pen chip; 141. Pen receiving circuit; 1411. Superimposed amplifier circuit; 1412. Superimposed analog-to-digital converter; 1413. First amplifier circuit; 1414. First analog-to-digital converter; 1415. Second amplifier circuit; 1416. Second analog-to-digital converter; 142. Pen controller; 143. Pen driving circuit; 1431. First driving circuit; 432. Second driving circuit; 144. Multiplexer; 1441. First converter; 1442. Second converter; 15. Power supply; 16. Power management module; 17. Gain adjustment circuit; 20. Touch screen; 21. Screen electrode; 211. Driving electrode; 212. Sensing electrode; 22. Screen chip; 221. Screen driving circuit; 222. Screen receiving circuit; 223. Screen controller; 224. Switch module; 2241. First switch selector; 2242. Second switch selector. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0025] It should be understood that this invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this invention to those skilled in the art. In the drawings, for clarity, the dimensions of layers and regions, as well as their relative dimensions, may be exaggerated. The same reference numerals denote the same elements throughout.

[0026] To fully understand this utility model, detailed structures and steps will be presented in the following description to illustrate the technical solution proposed by this utility model. Preferred embodiments of this utility model are described in detail below; however, in addition to these detailed descriptions, this utility model may have other embodiments.

[0027] This utility model embodiment provides a pen chip 14, applicable to an active pen 10, such as... Figure 1 As shown, the active pen 10 includes a pen housing 11, a pen electrode 12 disposed on the pen housing 11, and a coupling structure 13 disposed inside the pen housing 11. The pen electrode 12 is used to couple with the screen electrode 21 on the touch screen 20. The pen chip 14 is disposed inside the pen housing 11 and is connected to the pen electrode 12 and the coupling structure 13. The pen chip 14 is used to process the first uplink signal received by the pen electrode 12 and the second uplink signal received by the coupling structure 13 to determine the original uplink signal output by the touch screen 20.

[0028] The pen electrode 12 is an electrode disposed on the active pen 10. There can be one or more pen electrodes 12, which can be determined according to the actual situation. The coupling structure 13 is a structure used to realize signal coupling. For example, the coupling structure 13 can be a structure made of conductive material for realizing signal coupling.

[0029] The original uplink signal refers to the uplink signal output by the touchscreen 20. The first uplink signal refers to the uplink signal received by the pen electrode 12, specifically the uplink signal transmitted through the coupling capacitor between the pen electrode 12 and the screen electrode 21. This first uplink signal is the original uplink signal after attenuation during transmission. The second uplink signal refers to the uplink signal received by the coupling structure 13. Here, the uplink signal refers to the signal transmitted from the touchscreen 20 to the active pen 10.

[0030] Figure 2 The diagram illustrates the touch system of the active stylus 10 and the touchscreen 20. This touch system is used only to illustrate its working principle and does not limit the specific design form. Figure 2 As shown, the touchscreen 20 includes a screen body (not shown), screen electrodes 21, and a screen chip 22. The screen electrodes 21 are disposed on the screen body and used for coupling with the pen electrodes 12 on the active pen 10. The screen chip 22 is disposed outside the screen body and electrically connected to the screen electrodes 21. In this example, the screen chip 22 is disposed on a circuit board outside the screen body; the circuit board can be a flexible printed circuit board or a rigid printed circuit board. The screen electrodes 21 include driving electrodes 211 (…). Figure 2 D0-D3) and sensing electrode 212 ( Figure 2As can be understood from S0-S3, the touch screen 20 may include multiple sets of driving electrodes 211 and sensing electrodes 212 as shown in the examples. In this example, the screen chip 22 includes a screen driving circuit 221, a screen receiving circuit 222, and a screen controller 223. The screen controller 223 is a logic controller disposed on the touch screen 20, specifically a microcontroller (Micro Controller Unit, abbreviated as MCU) disposed within the touch screen 20.

[0031] Furthermore, the touch screen 20 or screen chip 22 also includes a switch module 224 disposed on the circuit board. The switch module 224 includes a first switch selector 2241 and a second switch selector 2242. The first switch selector 2241 is used to connect the screen driving circuit 221 and multiple driving electrodes 211, and can control the on / off state of the driving electrodes 211 of the corresponding channel under the control of the screen controller 223. The second switch selector 2242 is used to connect the screen receiving circuit 222 and multiple sensing electrodes 212, and can control the on / off state of the sensing electrodes 212 of the corresponding channel under the control of the screen controller 223. The first switch selector 2241 and the second switch selector 2242 are connected, and under the control of the screen controller 223, the driving electrodes 211 can be connected to the screen receiving circuit 222 through the first switch selector 2241 and the second switch selector 2242, so that the touch screen 20 can cooperate with the active pen 10 to complete the detection function. When the active pen 10 approaches or touches the touch screen 20, the pen electrode 12 on the active pen 10 is coupled to the screen electrode 21 on the touch screen 20, and the active pen 10 and the touch screen 20 can communicate with each other through this coupling capacitor.

[0032] See Figure 3 A typical active pen 10 includes a pen housing 11, a pen electrode 12 disposed on the pen housing 11, and a pen chip 14 disposed inside the pen housing 11. The pen chip 14 is connected to the pen electrode 12, and a pen receiving circuit 141 is disposed within the pen chip 14. The pen receiving circuit 141 is connected to the pen electrode 12. After receiving a first uplink signal, the pen electrode 12 sends the received first uplink signal to the pen receiving circuit 141. That is, the active pen 10 provided in this embodiment of the present invention has a coupling structure 13 connected to the pen chip 14, while the typical solution does not have a coupling structure 13.

[0033] See Figure 4Based on the physical capacitive coupling model established by a typical active pen 10 and touch screen 20, the principle of attenuation of the uplink signal received by the active pen 10 after the hand touches the touch screen 20 is explained using the pen electrode 12 of an active pen 10. There is a coupling capacitance C1 between the pen electrode 12 of the active pen 10 and the screen electrode 21 of the touch screen 20. Simultaneously, there is a coupling capacitance C2 between the hand and the screen electrode 21 of the touch screen 20. Since the hand is holding the active pen 10, there is a coupling capacitance C3 between the hand and the active pen system. Additionally, there are two paths between the hand and the touch screen system: one is a direct coupling capacitance C6, and the other is an indirect coupling through the coupling capacitance C4 between the hand and ground and the coupling capacitance C7 between ground and the touch screen system ground. There is a coupling capacitance C5 between the active pen system ground and ground, and a coupling capacitance C8 between the active pen system and the touch screen system. Here, it is assumed that the pen electrode 12 of the active pen 10 is suspended at a height of 10mm above the touch screen 20. Typical capacitance values ​​for C1 to C8 are: C1 (40fF), C2 (50pF), C3 (100pF), C4 (68pF), C5 (7pF), and C6 (12pF). The coupling capacitors C7 (40pF) and C8 (1pF) may vary depending on the specific screen and pen design, but this does not affect the explanation of the principle here.

[0034] The screen electrode 21 of the touch screen 20 is powered by an AC voltage source (i.e. Figure 2 The screen driver circuit 221 drives the AC voltage source through coupling capacitor C1, active pen system ground, and earth back to the touch screen system ground. When a hand touches or approaches the touch screen 20, the AC voltage source simultaneously returns through coupling capacitors C2 and C6 at the hand contact position (i.e., Figure 4 A relatively large voltage signal Vb (referencing the touchscreen system ground) is generated at point B. Since point B is coupled to the active pen system ground through a large coupling capacitor C3, the voltage of the active pen system ground (also referencing the touchscreen system ground) is close to the voltage Vb at point B. Assuming... Figure 4 The voltage at point A is Va (Va is the voltage of the AC voltage source built into the touchscreen 20, referenced to the touchscreen system ground). Therefore, the equivalent signal at point A received by the pen receiving circuit 141, referencing the active pen system ground, is Va-Vb (assuming they are in phase; in reality, due to parasitic resistance and capacitance on the return path, there will be a slight phase difference). This is the fundamental reason why the uplink signal received by the active pen 10 attenuates when the hand touches the touchscreen 20. Assuming the hand moves away from the touchscreen 20, then... Figure 4 The coupling capacitor C2 will decrease sharply to close to 0, which is equivalent to the circuit being open. Then the voltage Vb at point B is close to 0V. The equivalent voltage at point A received by the pen receiving circuit 141 of the reference active pen system ground is close to Va, which can be considered to be basically without attenuation.

[0035] See Figure 1The active pen 10 shown has a coupling structure 13 inside for coupling the second uplink signal from the hand. The coupling structure 13 can be directly connected to the pen chip 14 of the active pen 10. The pen chip 14 has a pen receiving circuit 141 inside. The coupling structure 13 can be coupled to the input terminal of the pen receiving circuit 141, or it can be coupled to the input terminal of the pen receiving circuit 141 through a capacitor, a resistor, a switch, or other components. The coupling structure 13 sends the received second uplink signal to the pen receiving circuit 141 to compensate for the first uplink signal received by the pen electrode 12, thereby determining the original uplink signal with basically no attenuation.

[0036] See Figure 5 , combined Figure 1 The physical capacitive coupling model established by the active pen 10 and the touch screen 20 in the optimization scheme shown is only used for principle explanation, and some actual non-critical parasitic paths are not shown. Figure 5 The intermediate coupling structure 13 is connected to the gain adjustment circuit 17 (which may be, but is not limited to, the following). Figure 5 The regulating capacitor C9 shown is coupled to the input terminal of the pen receiver circuit 141. A capacitance value of 10pF to 20pF is recommended for C9. Figure 5 As shown, since the active pen 10 has a coupling structure 13, there is an additional parasitic capacitance C10 between the coupling structure 13 and the active pen system ground. The typical capacitance value of the parasitic capacitance C10 is 50pF to 100pF. There is also a parasitic capacitance C11 between the active pen system ground and the touch screen system ground. The typical capacitance value of the parasitic capacitance C11 is 1pF to 2pF. Figure 5 The capacitance values ​​for the other capacitors are as given above: C1 (40pF), C2 (50pF), C3 (100pF), C4 (68pF), C5 (7pF), C6 (12pF), C7 (40pF), and C8 (1pF). The capacitance values ​​depend on factors such as the structural design of the active pen 10 and the touchscreen 20; this solution does not restrict the specific values. Figure 5As shown in the physical capacitive coupling model of the touch system, when a hand touches the touchscreen 20, the pen receiving circuit 141 can simultaneously detect the first uplink signal coupled to the pen electrode 12 through the screen electrode 21 and the second uplink signal coupled by the hand through the coupling structure 13. This allows the pen chip 14 to determine the original uplink signal output by the touchscreen 20 based on the first and second uplink signals. Understandably, when a hand touches or approaches the touchscreen 20, the original uplink signal output by the touchscreen 20 is attenuated, causing the pen electrode 12 to output the attenuated first uplink signal to the pen chip 14. Because the hand touches the touchscreen 20, the attenuated portion of the signal can be sent to the pen chip 14 through the coupling structure 13 within the active pen 10. That is, the coupling structure 13 can send the second uplink signal to the pen chip 14, allowing the pen chip 14 to determine the essentially unattenuated original uplink signal output by the touchscreen 20 based on the first and second uplink signals. This helps ensure the accuracy of the pen chip 14 in determining the strength of the uplink signal output by the touchscreen 20.

[0037] See Figure 6 When the original uplink signal output by the touch screen 20 is the same, the pen electrode 12 of the active pen 10 has the same floating height, and the pen receiving circuit 141 built into the active pen 10 is the same, the signal will be received by the pen receiving circuit 141 built into the active pen 10. Figure 1 The optimized pen chip 14 and shown Figure 3 In the typical scheme shown, the pen receiving circuit 141 in the pen chip 14 detects and processes the received uplink signal. The signal strength of the output signal after the optimized scheme is more than twice that of the output signal after the existing scheme. That is, the optimized scheme has almost no signal attenuation, which helps to ensure the accuracy of the pen chip 14.

[0038] In one embodiment, such as Figure 7 As shown, the pen chip 14 includes a pen receiving circuit 141, which includes a superposition amplifier circuit 1411 and a superposition analog-to-digital converter 1412. The superposition amplifier circuit 1411 is connected to both the pen electrode 12 and the coupling structure 13, 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 superposition analog-to-digital converter 1412 is connected to the superposition amplifier circuit 1411 and is used to perform analog-to-digital conversion on the superposition amplified signal to determine the original uplink signal output by the touch screen 20.

[0039] The pen receiving circuit 141 is a circuit disposed on the pen chip 14 for receiving uplink signals. The superposition amplifier circuit 1411 is a circuit for amplifying the superimposed analog signals. The superposition analog-to-digital converter 1412 is a circuit for converting the analog signals output by the superposition amplifier circuit 1411 into digital signals.

[0040] The pen controller 142 is a logic controller mounted on the active pen 10, specifically a microcontroller (MCU) located within the active pen 10. The MCU serves as the core of the pen's computation and control, acting as the final execution unit for information processing and program execution. It primarily controls the operation of the circuits and electrical components mounted on the active pen 10. Understandably, the pen controller 142 can be located either within or outside the pen chip 14; this embodiment is described using the example of it being located within the pen chip 14. Furthermore, the active pen 10 also includes a power supply 15 and a power management module 16. The power management module 16 is connected to the power supply 15 and to the pen controller 142 to control the power supply 15 to provide power to the pen controller 142 and other connected devices.

[0041] As an example, the pen chip 14 includes a pen receiving circuit 141, which includes a superposition amplifier circuit 1411 and a superposition analog-to-digital converter 1412. The first input terminal of the superposition amplifier circuit 1411 is connected to both the pen electrode 12 and the coupling structure 13, and the second input terminal is connected to the common-mode voltage terminal VCM. This allows the superposition of the first uplink signal received by the pen electrode 12 and the second uplink signal received by the coupling structure 13, resulting in a superposition signal input to the superposition amplifier circuit 1411. This allows the superposition amplifier circuit 1411 to amplify the superposition of the first and second uplink signals and output a superposition amplified signal. Here, the superposition amplified signal is the amplified signal resulting from the superposition of the two uplink signals. The superposition analog-to-digital converter 1412 is connected to the superposition amplifier circuit 1411 and can perform analog-to-digital conversion on the superposition amplified signal to determine the original uplink signal output by the touchscreen 20.

[0042] In this example, the pen chip 14 also includes a pen controller 142 connected to the pen receiving circuit 141. The pen controller 142 is connected to 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. Its logic control process is similar to that of a typical pen controller 142, and will not be described in detail here.

[0043] In this example, the superimposed amplifier circuit 1411 may include a trans-impedance amplifier (TIA), a first resistor R1, a second resistor Rf, and a first capacitor Cf. The first input terminal of the trans-impedance amplifier is connected to both the pen electrode 12 and the coupling structure 13 via the first resistor R1, and the second input terminal 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 terminal and the output terminal of the trans-impedance amplifier, respectively. The two ends of the first capacitor Cf are connected to the first input terminal and the output terminal of the trans-impedance amplifier, respectively. In this example, the first resistor R1, the second resistor Rf, and the first capacitor Cf are built-in components of the superimposed amplifier circuit 1411 used to adjust the gain of the trans-impedance amplifier. The gain adjustment process is prior art and will not be described in detail here.

[0044] In one embodiment, such as Figure 5 and Figure 7 As shown, the active pen 10 also includes a gain adjustment circuit 17. The first end of the gain adjustment circuit 17 is connected to the coupling structure 13, and the second end of the gain adjustment circuit 17 is connected to the superposition amplifier circuit 1411. It is used to adjust the gain of the second uplink signal and output the adjusted second uplink signal to the superposition amplifier circuit 1411.

[0045] like Figure 5 and Figure 7 As shown, the coupling structure 13 is connected to the gain adjustment circuit 17 (which may employ, but is not limited to, other methods). Figure 5 The adjusting capacitor C9 shown is coupled to the input terminal of the pen receiving circuit 141 (i.e., the first input terminal of the superposition amplifier circuit 1411). A capacitance value of 10pF to 20pF is recommended for C9. A gain adjustment circuit 17 is placed between the coupling structure 13 and the superposition amplifier circuit 1411. This gain adjustment circuit 17 adjusts the gain of the second uplink signal received by the coupling structure 13 to enhance the signal strength of the second uplink signal. The adjusted second uplink signal is then output to the superposition amplifier circuit 1411, allowing the superposition amplifier circuit 1411 to amplify the signal resulting from the superposition of the first uplink signal and the adjusted second uplink signal, thereby ensuring the signal strength and quality of the superposition amplified signal output by the superposition amplifier circuit 1411. Generally, the signal strength of the first uplink signal is much greater than that of the second uplink signal. Therefore, a gain adjustment circuit 17 is placed between the coupling structure 13 and the superposition amplifier circuit 1411 to adjust the gain of the second uplink signal, thus ensuring the signal strength and quality of the adjusted second uplink signal.

[0046] Furthermore, in the superimposed amplifier circuit 1411, there are a transimpedance amplifier TIA, a first resistor R1, a second resistor Rf, and a first capacitor Cf. The first input terminal of the transimpedance amplifier is connected to both the pen electrode 12 and the coupling structure 13 through the first resistor R1, and the second input terminal of the transimpedance amplifier is connected to the common-mode voltage terminal VCM. The two ends of the second resistor Rf are connected to the first input terminal and the output terminal of the transimpedance amplifier, respectively. When the two ends of the first capacitor Cf are connected to the first input terminal and the output terminal of the transimpedance amplifier, respectively, the gain adjustment circuit 17 is disposed between the coupling structure 13 and the first resistor R1. The gain adjustment circuit 17 works in conjunction with the first resistor R1, the second resistor Rf, and the first capacitor Cf to adjust the gain of the second uplink signal.

[0047] In one embodiment, such as Figure 8 As shown, the pen chip 14 includes a pen receiving circuit 141, which is connected to a pen controller 142. The pen receiving circuit 141 includes a first amplifier circuit 1413, a first analog-to-digital converter 1414, a second amplifier circuit 1415, and a second analog-to-digital converter 1416. The first amplifier circuit 1413, connected to the pen electrode 12, amplifies the first uplink signal and outputs a first amplified signal. The first analog-to-digital converter 1414, connected to the first amplifier circuit 1413 and the pen controller 142, processes the first amplified signal... The system performs an analog-to-digital conversion to output a first digital signal to the pen controller 142; a second amplifier circuit 1415, connected to the coupling structure 13, amplifies the second uplink signal and outputs a second amplified signal; a second analog-to-digital converter 1416, connected to the second amplifier circuit 1415 and the pen controller 142, performs analog-to-digital conversion on the second amplified signal and outputs a second digital signal to the pen controller 142; the pen controller 142 performs calculations on the first and second digital signals to determine the original uplink signal output by the touch screen 20.

[0048] The first amplifier circuit 1413 is connected to the pen electrode 12, and the second amplifier circuit 1415 is connected to the coupling structure 13. Both amplifier circuits are used to amplify the signal. The first analog-to-digital converter 1414 is connected to the first amplifier circuit 1413, and the second analog-to-digital converter 1416 is connected to the second amplifier circuit 1415. The analog-to-digital converter is used to convert analog signals into digital signals.

[0049] 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 amplifier circuit 1413, a first analog-to-digital converter 1414, a second amplifier circuit 1415, and a second analog-to-digital converter 1416. The first input terminal of the first amplifier circuit 1413 is connected to the pen electrode 12, the second input terminal of the first amplifier circuit 1413 is connected to the common-mode voltage terminal VCM, and the output terminal of the first amplifier circuit 1413 is connected to the first analog-to-digital converter 1414. It amplifies the first uplink signal and outputs a first amplified signal to the first analog-to-digital converter 1414. This first amplified signal is the amplified version of the first uplink signal. The first analog-to-digital converter 1414 is connected to the first amplifier circuit 1413 and the pen controller 142, and performs analog-to-digital conversion on the first amplified signal, outputting a first digital signal to the pen controller 142. This first digital signal is the digital signal corresponding to the first amplified signal. The first input terminal of the second amplifier circuit 1415 is connected to the coupling structure 13, the second input terminal of the second amplifier circuit 1415 is connected to the common-mode voltage terminal VCM, and the output terminal of the second amplifier circuit 1415 is connected to the second analog-to-digital converter 1416. This second amplifier circuit amplifies the second uplink signal and outputs a second amplified signal to the second analog-to-digital converter 1416. This second amplified signal is the amplified version of the second uplink signal. The second analog-to-digital converter 1416 is connected to the second amplifier circuit 1415 and the pen controller 142. This second analog-to-digital converter performs analog-to-digital conversion on the second amplified signal and outputs a second digital signal to the pen controller 142. This second digital signal is the digital signal corresponding to the second amplified signal. The pen controller 142 is simultaneously connected to the first analog-to-digital converter 1414 and the second analog-to-digital converter 1416. This pen controller performs calculations on the first and second digital signals, superimposing them to determine the original uplink signal output by the touchscreen 20. This signal is then used for subsequent logic control based on the original uplink signal. The logic control process is similar to that of a typical pen controller 142 and will not be described in detail here.

[0050] In this example, both the first amplifier circuit 1413 and the second amplifier circuit 1415 include a transimpedance amplifier TIA, a first resistor R1, a second resistor Rf, and a first capacitor Cf. The first input terminal of the transimpedance amplifier in the first amplifier circuit 1413 is connected to the pen electrode 12 through the first resistor R1, and the first input terminal of the transimpedance amplifier in the second amplifier circuit 1415 is connected to the coupling structure 13 through the first resistor R1. The connection relationships of other structures are the same as in the above embodiment, and will not be described in detail here to avoid repetition.

[0051] In one embodiment, such as 5 and Figure 8As shown, the pen receiving circuit 141 also includes a gain adjustment circuit 17. The first end of the gain adjustment circuit 17 is connected to the coupling structure 13, and the second end of the gain adjustment circuit 17 is connected to the second amplifier circuit 1415. It is used to adjust the gain of the second uplink signal and output the adjusted second uplink signal to the second amplifier circuit 1415.

[0052] As an example, the coupling structure 13 is coupled to the input terminal of the pen receiving circuit 141 via a gain adjustment circuit 17, specifically to the first input terminal of the second amplifier circuit 1415. The gain adjustment circuit 17 adjusts the gain of the second uplink signal received by the coupling structure 13 to enhance its signal strength. The adjusted second uplink signal is then output to the second amplifier circuit 1415, which amplifies the signal and outputs the amplified signal to the second analog-to-digital converter 14161. Generally, the signal strength of the first uplink signal is much greater than that of the second uplink signal. Therefore, a gain adjustment circuit 17 is provided between the coupling structure 13 and the second amplifier circuit 1415 to adjust the gain of the second uplink signal, thus enhancing its performance.

[0053] In one embodiment, the gain adjustment circuit 17 includes an adjustment capacitor C9, an adjustment resistor, or an adjustment unit, wherein the adjustment unit includes an adjustment capacitor C9 and an adjustment resistor connected in series or in parallel.

[0054] As an example, such as Figure 5 , Figure 7 and Figure 8 As shown, the gain adjustment circuit 17 may consist only of an adjustment capacitor C9, with its two ends connected to the coupling structure 13 and the amplifier circuit connected to the coupling structure 13, respectively. For example, in one embodiment, the adjustment capacitor C9 may be placed between the coupling structure 13 and the superimposed amplifier circuit 1411. In another embodiment, the adjustment capacitor C9 may be placed between the coupling structure 13 and the second amplifier circuit 1415. The adjustment capacitor C9 may cooperate with the built-in components of the superimposed amplifier 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.

[0055] As an example, such as Figure 9As shown, the gain adjustment circuit 17 may consist only of an adjustment resistor R2, with its two ends connected to the coupling structure 13 and the amplifier circuit connected to the coupling structure 13, respectively. For example, in one embodiment, the adjustment resistor R2 may be placed between the coupling structure 13 and the superimposed amplifier circuit 1411. In another embodiment, the adjustment resistor R2 may be placed between the coupling structure 13 and the second amplifier circuit 1415. This adjustment resistor may cooperate with the built-in components of the superimposed amplifier 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.

[0056] As an example, such as Figure 10 As shown, the gain adjustment circuit 17 may include an adjustment unit, which includes a series or parallel adjustment capacitor C9 and an adjustment resistor R2. The two ends of the adjustment unit are connected to the coupling structure 13 and the amplifier circuit connected to the coupling structure 13, respectively. For example, in one embodiment, the adjustment unit may be located between the coupling structure 13 and the superimposed amplifier circuit 1411; in another embodiment, the adjustment unit may be located between the coupling structure 13 and the second amplifier circuit 1415. This adjustment unit can cooperate with the built-in components of the superimposed amplifier 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] In one embodiment, the gain adjustment circuit 17 is disposed inside the pen chip 14, or the gain adjustment circuit 17 is disposed outside the pen chip 14.

[0058] As an example, the gain adjustment circuit 17 can be located within the pen chip 14 (e.g., Figure 8 (As shown), it can also be set outside the pen chip 14 (such as...) Figure 7 , Figure 9 and Figure 10 As shown in the figure, its specific location can be determined independently according to the actual situation.

[0059] In one embodiment, such as Figure 9As shown, the pen chip 14 also includes a pen controller 142, a pen driver circuit 143, and a multiplexer 144. The multiplexer 144 is connected to both the pen electrode 12 and the coupling structure 13, and is also connected to either the pen receiving circuit 141 or the pen driver circuit 143. The pen controller 142 is connected to the multiplexer 144 and is used to control the second end of the multiplexer 144 to connect to either the pen receiving circuit 141 or the pen driver circuit 143. When the second end of the multiplexer 144 is connected to the pen driver circuit 143, the pen driver circuit 142 is also controlled to simultaneously output a first driving signal to the pen electrode 121 and a second driving signal to the coupling structure 13, so that the coupling structure 13 isolates the crosstalk signal between the active pen 10 and the hand.

[0060] The multiplexer 144 (MUX) is a device used to switch the connection states between multiple inputs and multiple outputs. The first drive signal is the drive signal output by the pen drive circuit 143 to the pen electrode 12, and it is a drive signal free from crosstalk interference. The second drive signal is the drive signal output by the pen drive circuit 143 to the coupling structure 13.

[0061] As an example, the pen chip 14 also includes a pen driver circuit 143 and a multiplexer 144. The multiplexer 144 is connected to both the pen electrode 12 and the coupling structure 13. The multiplexer 144 is also connected to either the pen receiving circuit 141 or the pen driver circuit 143. The pen controller 142 is also 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 simultaneously connected to the pen receiving circuit 141, so that the pen electrode 12 and the coupling structure 13 simultaneously output a first uplink signal and a second uplink signal to the pen receiving circuit 141, so that the original uplink signal without attenuation output by the touch screen 20 can be determined based on the first uplink signal and the second uplink signal. Alternatively, the pen controller 142 outputs a control signal to control the pen electrode 12 and the coupling structure 13 to be simultaneously connected to the pen driver circuit 143, so that the pen driver circuit 143 simultaneously outputs a first driving signal to the pen electrode 121 and a second driving signal to the coupling structure 13, so that the coupling structure 13 can isolate the crosstalk signal between the active pen 10 and the hand.

[0062] See Figure 11 and Figure 12 The following is combined Figure 3The physical capacitive coupling model of the touch system formed by the typical active pen 10 and the touch screen 20 is shown. The principle of crosstalk between the active pen 10 and the hand on the touch screen 20 is explained using the pen electrode 12 of the active pen 10. When the hand holds the stylus 10 and its electrode 12 approaches or contacts the sensing electrode S1 of the touchscreen 20, and the hand contacts the sensing electrode S1 of the touchscreen 20, both the stylus electrode 12 and the hand form capacitive coupling with the sensing electrode S1 of the touchscreen 20. That is, there is a coupling capacitance C1 between the stylus electrode 12 of the stylus 10 and the sensing electrode S1 of the touchscreen 20. At the same time, there is a coupling capacitance C5 between the hand and the sensing electrode S1 of the touchscreen 20. Since the hand is holding the stylus 10, there is a coupling capacitance C2 between the hand and the stylus system. In addition, there are two paths between the hand and the touchscreen system: one is a direct coupling capacitance C7, and the other is an indirect coupling through the coupling capacitance C3 between the hand and ground and the coupling capacitance C4 between ground and the touchscreen system ground. There is also a coupling capacitance C6 between the stylus system and the touchscreen system. Typical capacitance values ​​for C1-C7 are C1 (40fF), C2 (200pF), C3 (80pF), and C4 (8pF). C5 (1pF), C6 (3pF), and C7 (2pF) are capacitors that may vary depending on the specific screen and pen design, but this does not affect the explanation of the principle here.

[0063] See Figure 11 When the hand holds the pen electrode 12 of the active pen 10 close to or touches the sensing electrode S1 of the touch screen 20, and the hand touches the sensing electrode S1 of the touch screen 20, the pen controller 142 controls the pen driving circuit 143 (i.e., voltage source AC1) to output a first driving signal. This first driving signal is transmitted sequentially through the path of "active pen system ground - voltage source AC1 - pen electrode 12 - coupling capacitor C1 - sensing electrode S1 - touch screen system ground - ground - hand - active pen system ground". That is, this path can transmit the capacitive projection signal between the active pen 10 and the touch screen 20. In this process, because When the hand contacts the sensing electrode S1, a coupling capacitor C5 exists between the hand and the sensing electrode S1 of the touch screen 20. This also creates a path for transmitting the capacitive projection signal (i.e., crosstalk signal) between the hand and the touch screen 20: "active pen system ground - coupling capacitor C2 - coupling capacitor C5 - parasitic resistance R0 of sensing electrode S1 - touch screen system ground". Since the current flows in opposite directions at the coupling capacitor C2 for the capacitive projection signals transmitted through the two paths, the capacitive projection signal between the hand and the sensing electrode S1 and the capacitive projection signal between the active pen 10 and the sensing electrode S1 are inverse signals. That is, when the hand is on the sensing electrode S1 of the touch screen 20, a crosstalk signal that is inversely related to the first driving signal will pass through the coupling capacitor C5 and the parasitic resistance R0 of the sensing electrode S1, interfering with the first driving signal of the active pen 10 corresponding to the sensing electrode S1, thus affecting the original signal quantity of the active pen 10.

[0064] See Figure 12 When the hand holds the pen electrode 12 of the active pen 10 close to or touches the sensing electrode S1 of the touch screen 20, and the hand does not touch the sensing electrode S1 of the touch screen 20, the pen electrode 12 of the active pen 10 and the sensing electrode S1 of the touch screen 20 are coupled by a coupling capacitor C1 because the pen electrode 12 is close to or touches the sensing electrode S1; the hand does not touch the sensing electrode S1 of the touch screen 20 and there is no coupling capacitor C5 between the hand and the sensing electrode S1; the hand holds the active pen 10 and there is a coupling capacitor C2 between the hand and the active pen system ground. During this process, the pen controller 142 controls the pen driving circuit 143 (voltage source AC1) to output a first driving signal. The first driving signal is transmitted sequentially through the path of "active pen system ground - voltage source AC1 - pen electrode 12 - coupling capacitor C1 - sensing electrode S1 - touch screen system ground - ground - hand - active pen system ground". Since there is no coupling capacitor C5 between the hand and the sensing electrode S1, there will be no crosstalk signal transmitted through the path "active pen system ground - coupling capacitor C2 - coupling capacitor C5 - parasitic resistance R0 of sensing electrode S1 - touch screen system ground". That is, when the hand is not in contact with the sensing electrode S1 of the touch screen 20, there is no crosstalk signal opposite to the first driving signal that passes through the coupling capacitor C5 and the parasitic resistance R0 of the sensing electrode S1 and interferes with the first driving signal of the active pen 10 corresponding to the sensing electrode S1, thus affecting the original signal quantity of the active pen 10.

[0065] Depend on Figure 11 and Figure 12 As shown in the physical capacitive coupling model, the fundamental reason for the crosstalk signal between the hand and the touch screen 20 is that there is a coupling capacitor C2 between the hand and the sensing electrode S1, which allows the crosstalk signal to be transmitted through the path of "active pen system ground - coupling capacitor C2 between the hand and the active pen system ground - coupling capacitor C5 between the hand and the sensing electrode S1 - parasitic resistance R0 of the sensing electrode S1 - touch screen system ground". The active pen 10 in this embodiment of the present invention includes not only a pen shell 11 and a pen electrode 12 disposed on the pen shell 11, but also a coupling structure 13 and a pen driving circuit 143 disposed within the pen shell 11. The pen driving circuit 143 is connected to both the pen controller 142 and the coupling structure 13. Based on the control signal output by the pen controller 142, it can output a second driving signal to the coupling structure 13, so that the coupling structure 13 eliminates or greatly reduces the direct coupling between the hand and the active pen system ground. Specifically, it eliminates or reduces the coupling capacitance C2 between the hand and the active pen system ground, so that the path "active pen system ground - coupling capacitance C2 between the hand and the active pen system ground - coupling capacitance C5 between the hand and the sensing electrode S1 - parasitic resistance R0 of the sensing electrode S1 - touch screen system ground" cannot transmit signals, thereby achieving the purpose of eliminating and isolating crosstalk signals between the active pen 10 and the hand.

[0066] See Figure 13 When the active pen 10 approaches or touches the touch screen 20, the pen electrode 12 on the active pen 10 is coupled to the screen electrode 21 on the touch screen 20. The first driving signal output by the active pen 10 to the touch screen 20 through the pen driving circuit 143 is transmitted sequentially through the path of "active pen system ground - voltage source AC1 - pen electrode 12 - coupling capacitor C1 - sensing electrode S1 - touch screen system ground - ground - hand - active pen system ground". During this process, if the hand 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. This crosstalk signal is transmitted through the path of "active pen system ground - coupling capacitor C2 between the hand and the active pen system ground - coupling capacitor C5 between the hand and the sensing electrode S1 - parasitic resistance R0 of the sensing electrode S1 - touch screen system ground". In order to eliminate this crosstalk signal, when the pen controller 142 outputs the first driving signal to the pen electrode 12l through the pen driving circuit 143, it can simultaneously output the second driving signal to the coupling structure 13 through the pen driving circuit 143 to drive the coupling structure 13 to work, so that it forms a coupling capacitor C2 that eliminates or greatly reduces the coupling capacitor C2 between the hand and the active pen system ground, thereby interrupting 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", thereby achieving the purpose of eliminating and isolating the crosstalk signal between the active pen 10 and the hand. In this example, the pen controller 142 outputs a first driving signal and a second driving signal simultaneously, so that the electric field formed by the first driving signal and the second driving signal occurs simultaneously, thereby isolating the crosstalk signal that occurs simultaneously with the first driving signal, so as to effectively eliminate the crosstalk signal.

[0067] In one embodiment, such as Figure 10 As shown, the multiplexer 144 includes a first converter 1441 and a second converter 1442; the first converter 1441 is connected to both the pen electrode 12 and the coupling structure 13, and is also connected to the pen receiving circuit 141; the second converter 1442 is connected to both the pen electrode 12 and the coupling structure 13, and is also connected to the pen driving circuit 143; the pen controller 142 is connected to the first converter 1441 and the second converter 1442, and is used to control either the first converter 1441 or the second converter 1442 to be turned on and the other to be turned off.

[0068] 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.

[0069] As an example, the first terminal of the first converter 1441 is connected to both the pen electrode 12 and the coupling structure 13, and the second terminal of the first converter 1441 is connected to the pen receiving circuit 141. The first converter 1441 is also connected to the pen controller 142. Based on the control signal output by the pen controller 142, the pen receiving circuit 141 can be controlled to be connected to both the pen electrode 12 and the coupling structure 13 simultaneously, so that the pen receiving circuit 141 can simultaneously receive the first uplink signal received by the pen electrode 12 and the second uplink signal received by the coupling structure 13, so as to determine the basically attenuated 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 converter 1442 is connected to both the pen electrode 12 and the coupling structure 13. The second end of the second converter 1442 is connected to the pen driving circuit 143. The second converter 1442 is also connected to the pen controller 142. Based on the control signal output by the pen controller 142, the pen driving circuit 143 can be controlled to be connected to both the pen electrode 12 and the coupling structure 13 at the same time, so that the pen driving circuit 143 can simultaneously control the pen electrode 121 to output a first driving signal and the coupling structure 13 to output a second driving signal, so that the coupling structure 13 isolates the crosstalk signal between the active pen 10 and the hand.

[0070] In this example, the pen controller 142 is connected to the first converter 1441 and the second converter 1442, and can control either the first converter 1441 or the second converter 1442 to be turned on and the other to be turned off. Specifically, it can control the first converter 1441 to be turned on and the second converter 1442 to be turned off, so that the pen electrode 12 and the coupling structure 13 can simultaneously output the first uplink signal and the second uplink signal to the pen receiving circuit 141; or, it can control the first converter 1441 to be turned off and the second converter 1442 to be turned on, so that the pen driving circuit 143 can output the first driving signal to the pen electrode 121 and the second driving signal to the coupling structure 13.

[0071] In one embodiment, such as Figure 9As shown, the pen driving circuit 143 includes a first driving circuit 1431 and a second driving circuit 1432. The first terminal of the first driving circuit 1431 is connected to the pen controller 142, and the second terminal of the first driving circuit 1431 is connected to the pen electrode 12 through a multiplexer 144. It is used to output a first driving signal to the pen electrode 121 based on the first control signal output by the pen controller 142. The first terminal of the second driving circuit 1432 is connected to the pen controller 142, and the second terminal of the second driving circuit 1432 is connected to the coupling structure 13 through the multiplexer 144. It is used to output a second driving signal to the coupling structure 13 based on the second control signal output by the pen controller 142, so that the coupling structure 13 isolates the crosstalk signal between the active pen 10 and the hand. The pen controller 142 is used 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. It outputs the first control signal and the second control signal simultaneously, so that the first driving circuit 1431 and the second driving circuit 1432 simultaneously output the first driving signal and the second driving signal.

[0072] The first driving circuit 1431 is connected to the pen electrode 12 and is used to drive the pen electrode 12 to work. The first control signal is a signal used to control the operation of the first driving circuit 1431. The first driving signal is the driving signal output by the first driving circuit 1431 to the pen electrode 12, and it is a driving signal that is not interfered with by crosstalk signals. In this example, the first driving circuit 1431 can specifically output the first driving signal to the pen electrode 121 based on the first control signal output by the pen controller 142, control the pen electrode 12 to work, so that the pen electrode 12 is coupled with the screen electrode 21 on the touch screen 20, so that the active pen 10 and the touch screen 20 can communicate.

[0073] The second driving circuit 1432 is connected to the coupling structure 13 and is used to drive the coupling structure 13 to operate. The second control signal is a signal used to control the operation of the second driving circuit 1432. The second driving signal is the 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 a second driving signal to the coupling structure 13 based on the second control signal output by the pen controller 142, so that the coupling structure 13 isolates the crosstalk signal between the active pen 10 and the hand.

[0074] The first driving circuit 1431 and the second driving circuit 1432 can be circuits that reuse some of the components.

[0075] See Figure 13When the active pen 10 approaches or touches the touch screen 20, the pen electrode 12 on the active pen 10 couples with the screen electrode 21 on the touch screen 20. The first driving signal output by the active pen 10 to the touch screen 20 is transmitted sequentially through the path of "active pen system ground - voltage source AC1 - pen electrode 12 - coupling capacitor C1 - sensing electrode S1 - touch screen system ground - ground - hand - active pen system ground". During this process, if the hand comes into contact with the sensing electrode S1 on the touch screen 20, a crosstalk signal affecting the first driving signal will be formed between the hand and the active pen 10. This crosstalk signal is transmitted through the path of "active pen system ground - coupling capacitor C2 between 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, when the pen controller 142 outputs the first driving signal to the first driving circuit 1431 (voltage source AC1), it can simultaneously output the second driving signal to the second driving circuit 1432 (voltage source AC2) to drive the coupling structure 13 to work, so that it can eliminate or greatly reduce the coupling capacitor C2 between the hand and the active pen system ground, so that 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" is interrupted, thereby achieving the purpose of eliminating and isolating the crosstalk signal between the active pen 10 and the hand. In this example, the pen controller 142 outputs a first driving signal and a second driving signal simultaneously, so that the electric field formed by the first driving signal and the second driving signal occurs simultaneously, thereby isolating the crosstalk signal that occurs simultaneously with the first driving signal, so as to effectively eliminate the crosstalk signal.

[0076] Referring to Table 1, when the pen electrode 12 of a typical active pen 10 is close to or in contact with the sensing electrode ch16, and the hand touches the sensing electrode ch14, the active pen 10 forms a capacitive projection signal envelope centered on the sensing electrode ch16 to transmit the first driving signal. At this time, the crosstalk signal is transmitted through the coupling capacitance between the hand and the active pen system ground - the coupling capacitance between the hand and the sensing electrode ch14 - the parasitic resistance corresponding to the sensing electrode ch14, causing the hand to interfere with the capacitive projection signal envelope centered on the sensing electrode ch14. Specifically, the encoded value corresponding to the sensing electrode ch14 is much larger than the encoded values ​​corresponding to the adjacent sensing electrodes ch13 and ch15. In this way, the capacitive projection signal envelope of the active pen 10 is destroyed, affecting the accuracy of the communication between the active pen 10 and the touch screen 20.

[0077] Table 1. Signal envelope formed by a typical active pen.

[0078]

[0079] Referring to Table 2, in this embodiment of the present invention, when the pen electrode 12 of the active pen 10 approaches 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, which is used to transmit the first driving signal. At this time, the crosstalk signal is transmitted through "the coupling capacitance between the hand and the active pen system ground - the coupling capacitance between the hand and the sensing electrode ch14 - the parasitic resistance corresponding to the sensing electrode ch14". Since the pen controller 142 controls the first driving circuit 1431 to output the first driving signal to the pen electrode 121 at the same time, it also controls the second driving circuit 143. 2. A second driving signal is output to the coupling structure 13 to eliminate the coupling capacitance between the hand and the sensing electrode ch14, thereby interrupting the transmission path of the crosstalk signal and eliminating the crosstalk signal. The final output of the encoding value corresponding to the sensing electrode ch14 is between the encoding value corresponding to the sensing electrode ch13 and the encoding value corresponding to the sensing electrode ch15. Furthermore, with the sensing electrode ch16 as the center, the encoding values ​​corresponding to the sensing electrodes 212 on both sides decrease sequentially, so that the capacitance projection signal formed with the sensing electrode ch16 as the center is basically unaffected by the capacitance projection signal formed between the hand and the touch screen 20.

[0080] Table 2. Signal envelope formed by the active pen in this embodiment of the present invention.

[0081]

[0082] In this example, when it is necessary to control the active pen 1 to output a drive signal to the touch screen 2, the pen controller 142 needs to output a control signal to the multiplexer 144 so that the multiplexer 144 connects the first drive circuit 1431 and the pen electrode 12, and connects the second drive circuit 1432 and the coupling structure 13. This allows the pen controller 142 to simultaneously output the first drive signal and the second drive signal through the first drive circuit 1431 and the second drive circuit 1432, so that the electric field formed by the first drive signal and the second drive signal occurs simultaneously. This allows the crosstalk signal that occurs simultaneously with the first drive signal to be isolated, thereby effectively eliminating the crosstalk signal.

[0083] In one embodiment, the signal parameters of the second driving signal are related to the signal parameters of a single first driving signal, or the second driving signal is related to the signal parameters of multiple first driving signals that are output simultaneously.

[0084] 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. Simultaneously, the pen controller 142 controls the second driving circuit 1432 to correlate the second driving signal received by the coupling structure 13 with the single first driving signal. Alternatively, at the same time, the pen controller 142 can control the first driving circuit 1431 to simultaneously output multiple first driving signals to multiple pen electrodes 12. In this case, the pen controller 142 controls the signal parameters of the second driving signal received by the second driving circuit 1432 and the simultaneously output multiple first driving signals to the coupling structure 13. In this example, the signal parameters include, but are not limited to, frequency, phase, and amplitude.

[0085] In one embodiment, the second driving signal and the first driving signal have the same frequency and phase; the amplitude of the second driving signal is the product of the amplitude of the target driving signal and a first coefficient, the first coefficient being in the range of 0-20%, the target driving signal being a single first driving signal or a signal superimposed from multiple first driving signals; or, the amplitude of the second driving signal is the amplitude after weighting the amplitudes of multiple first driving signals and the second coefficients corresponding to the multiple first driving signals, the second coefficient being in the range of 0-20%.

[0086] As an example, such as Figure 14As shown, the frequency of the second driving signal is the same as that of the first driving signal, so that the second driving signal and the first driving signal are in the same bandwidth, allowing the touch screen 20 to recognize the two signals in the same bandwidth. Since the phase of the crosstalk signal formed between the active pen 10 and the hand is opposite to the phase of the first driving signal, the phase of the second driving signal is configured to be the same as the phase of the first driving signal, so that the phase of the second driving signal is opposite to the phase of the crosstalk signal. This allows the output second driving signal to eliminate or greatly reduce the direct coupling between the hand and the active pen system, thereby allowing the coupling structure 13 to isolate the crosstalk signal between the active pen 10 and the hand. Since the crosstalk signal formed between the active pen 10 and the hand is transmitted through the coupling capacitance between the hand and the touch screen 20 and the screen electrode 21 where its projection is located, given that the screen electrode 21 on the touch screen 20 is fixed, the amplitude (energy) of the crosstalk signal depends on the coupling capacitance between the hand and the touch screen 20, specifically on factors such as the distance between the hand and the touch screen 20, the projection area, and the relative permittivity. These factors are combined to determine the corresponding adjustment coefficient. The adjustment coefficient can be either a first coefficient or a second coefficient. The first coefficient is used to limit the amplitude scaling ratio between the second drive signal and the target drive signal. The first coefficient can be a preset fixed value or a dynamic value determined according to the actual situation. The second coefficient is used to limit the amplitude scaling ratio between the second drive signal and each first drive signal. The second coefficient can be a preset fixed value or a dynamic value determined according to the actual situation.

[0087] In one example, the amplitude of the second driving signal is the product of the amplitude of the target driving signal and the first coefficient. The first coefficient ranges from 0 to 20%. The target driving signal is either a single first driving signal or a signal resulting from the superposition of multiple first driving signals. Assuming the amplitude of the i-th first driving signal is Si, the amplitude of the target driving signal is Sm, the amplitude of the second driving signal is Sd, and the first coefficient is k1, since the target driving signal is either a single first driving signal or a signal resulting from the superposition of multiple first driving signals, then Sm = Then the amplitude of the second driving signal Sd = k1 * Sm = k1 * This allows for the superposition of the amplitudes of multiple first driving signals. The product of the superimposed amplitude and the first coefficient helps ensure that the amplitude of the finally determined second driving signal can effectively eliminate crosstalk signals.

[0088] In another example, the amplitude of the second driving signal is the weighted amplitude of multiple first driving signals and their corresponding second coefficients. The second coefficients range from 0% to 20%. Assuming the amplitude of the i-th first driving signal is Si, the amplitude of the second driving signal is Sd, and the second coefficient corresponding to the i-th first driving signal is ki, then the amplitude of the second driving signal Sd = The parameter ki is used to perform weighted processing on the amplitudes of multiple first driving signals and their second coefficients, and to determine the amplitude of the second driving signal based on the weighted amplitude. In this example, the amplitudes corresponding to the multiple first driving signals and at least one of the corresponding second coefficients are different. Specifically, the amplitudes can be the same but the second coefficients are different, or the amplitudes can be different but the second coefficients are the same, or both the amplitudes and the second coefficients can be different. This can be adjusted according to the actual situation. Weighted processing based on the amplitudes and second coefficients of the multiple first driving signals helps to ensure that the amplitude of the finally determined second driving signal can effectively eliminate crosstalk signals.

[0089] In one embodiment, the first coefficient is negatively correlated with the first suspension height; the first suspension height is the height between the electrode apex of the active pen 10 facing the touch screen 20 and the touch screen 20.

[0090] As an example, when the amplitude of the second driving signal is the product of the amplitude of the target driving signal and the first coefficient, the first coefficient is negatively correlated with the first floating height between the electrode vertex of the active pen 10 facing the touch screen 20 and the touch screen 20. That is, the lower the first floating height, the closer the active pen 10 is to the touch screen 20, and the greater the crosstalk signal it may generate. Therefore, its corresponding first coefficient needs to be larger, thereby making the amplitude of the corresponding second driving signal larger. Conversely, the higher the first floating height, the farther the active pen 10 is from the touch screen 20, and the smaller the crosstalk signal it generates. Therefore, its corresponding first coefficient needs to be smaller, thereby making the amplitude of the corresponding second driving signal smaller. In this example, the negative correlation between the first coefficient and the first floating height can be linear or non-linear, and can be determined independently according to the actual situation. In this example, after determining the first suspension height, the pen controller 142 can dynamically determine the corresponding first coefficient by querying a pre-set first height coefficient mapping table based on the first suspension height. Based on the product of the target driving signal (at least one first driving signal superimposed) and the first coefficient, a second driving signal is determined. The second driving circuit 1432 is then controlled to output the second driving signal to the coupling structure 13, thereby isolating the active pen 10 from the hand. Here, the first height coefficient mapping table is a pre-set data table reflecting the mapping relationship between the first suspension height and the first coefficient.

[0091] In one embodiment, the second coefficient corresponding to each first driving signal is negatively correlated with the second floating height of the pen electrode 12 corresponding to each first driving signal; and / or, the amplitude corresponding to each first driving signal is positively correlated with the second floating height of the pen electrode 12 corresponding to each first driving signal; the second floating height of the pen electrode 12 is the height between the point of the pen electrode 12 closest to the touch screen 20 and the touch screen 20.

[0092] As an example, when the amplitude of the second driving signal is the weighted amplitude of multiple first driving signals and the second coefficients corresponding to the multiple first driving signals, the second coefficient corresponding to each first driving signal is negatively correlated with the second floating height of the pen electrode 12 corresponding to each first driving signal. The amplitudes corresponding to each first driving signal can be the same or different, and can be determined according to the actual situation. That is to say, the lower the second floating height of each pen electrode 12, the closer the pen electrode 12 is to the touch screen 20. At this time, the crosstalk signal between the active pen 10 and the hand is greater, so its corresponding second coefficient needs to be larger; conversely, the higher the second floating height of each pen electrode 12, the farther the pen electrode 12 is from the touch screen 20. At this time, the crosstalk signal between the active pen 10 and the hand is smaller, so its corresponding first coefficient needs to be smaller.

[0093] In this example, the pen controller 142 can determine the second levitation height of each pen electrode 12, and dynamically determine its corresponding second coefficient by querying a pre-set second height coefficient mapping table based on the second levitation height. The pen controller 142 can also determine the amplitude of the first driving signal corresponding to each pen electrode 12 according to actual conditions, perform weighted processing on the amplitudes of the first driving signals corresponding to multiple pen electrodes 12 and their second coefficients, determine the second driving signal, and control the second driving circuit 1432 to output the second driving signal to the coupling structure 13, so that the coupling structure 13 isolates the crosstalk signal between the active pen 10 and the hand. The second height coefficient mapping table is a pre-set data table reflecting the mapping relationship between the second levitation height and the second coefficient.

[0094] For example, when the active pen 10 includes two pen electrodes 12, namely a main electrode 121 and a secondary electrode 122, and the amplitude of the first driving signal of the main electrode 121 is 40V and the amplitude of the first driving signal of the secondary electrode 122 is 30V, the second floating height h1 of the main electrode 121 (i.e., the height between the point of the main electrode 121 closest to the touch screen 20 and the touch screen 20) can be dynamically determined. Based on the second floating height h1, the second height coefficient mapping table is consulted to determine the second coefficient K21 corresponding to the main electrode 121; and the second floating height of the secondary electrode 122 is dynamically determined. The second floating height h2 (i.e., the height between the point of the secondary electrode 122 closest to the touch screen 20 and the touch screen 20) is used to query the second height coefficient mapping table to determine the second coefficient corresponding to the secondary electrode 122 as K22. Then, the amplitude of the first driving signal corresponding to the main electrode 121 and the secondary electrode 122 is weighted and processed to dynamically determine the amplitude of the second driving signal, that is, the amplitude of the second driving signal = 40V*K21 + 30V*K22, which helps to ensure that the amplitude of the finally determined second driving signal can effectively eliminate crosstalk signals.

[0095] As another example, when the pen controller 142 outputs the first driving signal and the second driving signal, the amplitude of each first driving signal is positively correlated with the second floating height of the pen electrode 12 corresponding to each first driving signal. The lower the second floating height of each pen electrode 12, the closer the pen electrode 12 is to the touch screen 20, and the smaller its driving energy. Therefore, the amplitude of the first driving signal output by the pen electrode 12 is smaller to save energy. The higher the second floating height of each pen electrode 12, the farther the pen electrode 12 is from the touch screen 20, and the greater its driving energy. The amplitude of the first driving signal output by the pen electrode 12 is larger. The second coefficients corresponding to each first driving signal can be the same or different. For example, in an active pen 10 that includes two pen electrodes 12, namely a main electrode 121 and a secondary electrode 122, the second coefficients of the main electrode 121 and the secondary electrode 122 can be predetermined based on their positions, shapes, and materials. Alternatively, the corresponding second coefficients can be determined based on their corresponding second floating heights or other measured data.

[0096] In this example, the pen controller 142 can determine the second floating height of each pen electrode 12, and dynamically determine the amplitude of the first driving signal of each pen electrode 12 based on the second floating height. For example, the amplitude of the first driving signal of each pen electrode 12 can be determined by looking up a table or other preset methods. Then, the second coefficient corresponding to each first driving signal is determined. Finally, the second driving signal is determined by weighting the amplitude of the first driving signal corresponding to multiple pen electrodes 12 and its second coefficient, and the second driving signal is output to the second driving circuit 1432 to control the operation of the coupling structure 13 and isolate the crosstalk signal between the active pen 10 and the hand.

[0097] For example, when the pen controller 142 outputs the first driving signal and the second driving signal, it can make the amplitude of multiple first driving signals the same, and the second coefficients corresponding to the multiple first driving signals are negatively correlated with their corresponding second floating heights. Weighted processing is performed based on the amplitudes and second coefficients corresponding to the multiple first driving signals, making the control process simple and convenient. Alternatively, it can make the amplitude of multiple first driving signals positively correlated with their corresponding second floating heights, and the second coefficients of the multiple first driving signals are the same or different. Weighted processing is performed based on the amplitudes and second coefficients corresponding to the multiple first driving signals, making the control process simple and convenient, and enabling targeted elimination of crosstalk signals corresponding to each first driving signal.

[0098] In one embodiment, the first coefficient ranges from 3% to 10%; the second coefficient ranges from 3% to 10%.

[0099] As an example, the amplitude of the second driving signal is configured to be 3%-10% of the amplitude of the target driving signal. The range of the first coefficient is determined by simulation tests based on typical working conditions, so that it can effectively isolate crosstalk signals between the active pen 10 and the hand without causing energy waste.

[0100] As another example, when the amplitude of the second driving signal is the weighted amplitude of multiple first driving signals and the second coefficients corresponding to the multiple first driving signals, the second coefficient corresponding to each first driving signal is limited to 3%-10%. The value range of the second coefficient is a numerical range determined based on simulation experiments under typical working conditions. In this example, the amplitudes corresponding to the multiple first driving signals can be the same or different, and the second coefficients corresponding to the multiple first driving signals can also be the same or different. This ensures that the amplitude of the weighted second driving signal can effectively isolate crosstalk signals between the active pen 10 and the hand without causing energy waste.

[0101] In one embodiment, the second driving signal and the first driving signal have different frequencies so that the touch screen 20 can detect the first measured signal and the second measured signal. Based on the first measured signal and the second measured signal, the first driving signal output by the active pen 10 is determined. The first measured signal is the signal coupled to the touch screen 20 by the first driving signal, and the second measured signal is the signal coupled to the touch screen 20 by the second driving signal.

[0102] The first measured signal is the signal coupled to the touchscreen 20 by the first driving signal. Specifically, it refers to the signal transmitted to the touchscreen 20 through the coupling capacitor between the pen electrode 12 and the screen electrode 21, and is the encoded signal after the first driving signal has been interfered with by crosstalk signals. The second measured signal is the signal coupled to the touchscreen 20 by the second driving signal. Specifically, it refers to the signal transmitted to the touchscreen 20 through the coupling capacitor between the hand and the touchscreen 20, and is the driving signal after the second driving signal has been interfered with by crosstalk signals.

[0103] As an example, the pen controller 142 outputs a first driving signal and a second driving signal at different frequencies to ensure that the first driving signal and the second driving signal are within different bandwidths. This allows the touch screen 20 to collect the first measured signal and the second measured signal at different frequencies when the active pen 10 approaches or touches the touch screen 20. The first measured signal can be understood as the actual detected signal after the first driving signal has been interfered with by a crosstalk signal, and the second measured signal can be understood as the actual detected signal after the second driving signal has been interfered with by a crosstalk signal. Then, based on the built-in signal compensation algorithm, the signal characteristics of the first measured signal and the second measured signal can be compensated to identify the compensated signal characteristics as the first driving signal output by the active pen 10 without crosstalk interference, thereby significantly improving the signal-to-noise ratio of the first driving signal of the active pen 10.

[0104] As an example, the multiple first driving signals are the first driving signal received by the main electrode 121 and the first driving signal received by the sub-electrode 122, respectively.

[0105] Alternatively, the multiple first driving signals are the first driving signal received by the main electrode 121, the first driving signal received by the secondary electrode 122, and the first driving signal received by the pen tail electrode (not shown in the figure);

[0106] The main electrode 121 and the auxiliary electrode 122 are disposed on the pen tip of the active pen 10, and the pen tail electrode is disposed on the pen tail of the active pen 10.

[0107] As an example, when the active pen 10 has two pen electrodes 12, which are respectively the main electrode 121 and the auxiliary electrode 122 on the pen tip of the active pen 10, the pen controller 142 can control the first driving circuit 1431 to simultaneously output two first driving signals. These two first driving signals are the first driving signal received by the main electrode 121 and the first driving signal received by the auxiliary electrode 122, respectively. In one possible implementation, the second driving signal has the same frequency and phase as the two first driving signals. The amplitude of the second driving signal can be the product of the target driving signal superimposed from the two first driving signals and the first coefficient. Alternatively, the amplitude of the second driving signal can be the weighted amplitude of the first driving signal corresponding to the main electrode 121, the second coefficient corresponding to the main electrode 121, the first driving signal corresponding to the auxiliary electrode 122, and the second coefficient corresponding to the auxiliary electrode 122. In another possible implementation, the two simultaneously output first driving signals have the same frequency, but the second driving signal has a different frequency from the two first driving signals, and its amplitude can be the same or different.

[0108] As an example, the active pen 10 has three pen electrodes 12, namely the main electrode 121 and the secondary electrode 122 on the pen tip, and the pen tail electrode on the pen tail. At the same time, the pen controller 142 can control the first driving circuit 1431 to simultaneously output three first driving signals. These three first driving signals are the first driving signal received by the main electrode 121, the first driving signal received by the secondary electrode 122, and the first driving signal received by the pen tail electrode, respectively. In one possible implementation, the second driving signal has the same frequency and phase as the three first driving signals. The amplitude of the second driving signal can be the product of the target driving signal superimposed from the three first driving signals and the first coefficient. Alternatively, the amplitude of the second driving signal can be the weighted amplitude of the first driving signal corresponding to the main electrode 121, the second coefficient corresponding to the main electrode 121, the first driving signal corresponding to the secondary electrode 122, the second coefficient corresponding to the secondary electrode 122, the first driving signal corresponding to the pen tail electrode, and the second coefficient corresponding to the pen tail electrode. In another possible implementation, the three first drive signals output simultaneously have the same frequency, but the second drive signal has a different frequency from the three first drive signals, and its amplitude can be the same or different.

[0109] This utility model provides an active pen 10, including a pen shell 11, a pen electrode 12 disposed on the pen shell 11, and a coupling structure 13 disposed inside the pen shell 11. The pen electrode 12 is coupled to a screen electrode 21 on a touch screen 20. It also includes a pen chip 14 as described in the above embodiment. The pen chip 14 is disposed inside the pen shell 11 and is connected to the pen electrode 12 and the coupling structure 13.

[0110] In this example, a coupling structure 13 is added to the active pen 10 and disposed within the pen shell 11. 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 simultaneously receive the first uplink signal received by the pen electrode 12 and the second uplink signal received by the coupling structure 13. The first and second uplink signals are processed to determine the essentially unattenuated original uplink signal output by the touch screen 20, thereby ensuring the accuracy of the received uplink signal. Alternatively, when the active pen 10 outputs a drive signal to the touch screen, the pen drive circuit 143 can be controlled to simultaneously output the first drive signal to the pen electrode 121 and the second drive signal to the coupling structure 13. This allows the coupling structure 13 to eliminate or greatly reduce the direct coupling between the hand and the active pen system ground, thereby achieving the purpose of eliminating and isolating crosstalk signals between the active pen 10 and the hand.

[0111] In one embodiment, the pen casing 11 has a gripping area; the coupling structure 13 is disposed within the gripping area.

[0112] As an example, the pen casing 11 has a grip area, which is an area for the user's hand to hold. This grip area can be a humanoid grip position for the pen, ensuring a better grip experience and reducing hand fatigue for the active pen 10. In this example, when a grip area is provided on the grip area, the coupling structure 13 can be placed within the grip area. The coupling structure 13 can both receive the second uplink signal and isolate crosstalk signals between the active pen 10 and the hand, eliminating the need to place the coupling structure 13 in other locations on the active pen 10, thus helping to save on the manufacturing cost of the coupling structure 13.

[0113] In one embodiment, when the coupling structure 13 includes a conductive spacer, the conductive spacer is assembled inside the pen shell 11; or, when the coupling structure 13 includes a conductive coating, the conductive coating is applied to the inner wall of the pen shell 11; or, when the coupling structure 13 includes a conductive component, the conductive component is disposed on the pen shell 11.

[0114] As an example, the coupling structure 13 can be a conductive spacer, which is a conductive structural component independent of the pen housing 11. For example, it can be made of aluminum, copper, or other conductive materials to form a conductive spacer that can be detachably installed in the pen housing 11. As long as the conductive spacer can achieve its conductive function and can be installed inside the pen housing 11, it can take any form. In this example, the conductive spacer is assembled inside the pen housing 11 and grounded with the active pen system, such that the outer wall of the conductive spacer is in contact with or spaced from the inner wall of the pen housing 11. The conductive spacer is electrically connected to the second drive circuit 1432 disposed inside the pen housing 11, so that it can both receive the second uplink signal and isolate the crosstalk signal between the active pen 10 and the hand. In this example, the conductive spacer is assembled inside the pen housing 11, specifically disposed on the pen body of the pen housing 11. The outer wall of the conductive spacer can be in contact with or spaced from the inner wall of the pen body. A non-conductive component can be placed between the two, or no non-conductive component can be placed.

[0115] As an example, the coupling structure 13 can be a conductive coating, which is formed by applying a conductive coating (including but not limited to conductive paint) to the inner wall of the pen shell 11. In this example, the conductive coating is electrically connected to the second driving circuit 1432 disposed inside the pen shell 11, so that it can receive the second uplink signal and isolate crosstalk signals between the active pen 10 and the hand. Since the conductive coating is applied to the inner wall of the pen shell 11, the conductive coating and the pen shell 11 are integrated into one structure, resulting in a simple overall structure that is easy to manufacture.

[0116] As an example, the coupling structure 13 can also be a conductive component disposed on the pen shell 11. This conductive component refers to a conductive part on the pen shell 11, which can be the entire structure of the pen shell 11 or a portion thereof. For example, when the pen shell 11 is a conductive housing made of conductive material, the coupling structure 13 can be the conductive housing itself; or, for example, when the pen shell 11 includes an insulating housing and a conductive element embedded in the insulating housing, the coupling structure 13 can be the conductive element embedded in the insulating housing, so that it can both receive the second uplink signal and isolate crosstalk signals between the active pen 10 and the hand.

[0117] In one embodiment, the pen casing 11 includes a pen body and a pen tip disposed at one end of the pen body; a pen electrode 12 is disposed on the pen tip, and at least a portion of the pen electrode 12 extends out of the pen tip.

[0118] As an example, the pen casing 11 includes a pen body and a pen tip disposed at one end of the pen body, with a gripping area provided on the pen body. A pen electrode 12 is disposed on the pen tip, and at least a portion of the pen electrode 12 extends beyond the pen tip, allowing the user to control the pen electrode 12 on the pen tip to approach or contact the touchscreen 20, thereby coupling the pen electrode 12 with the screen electrode 21 on the touchscreen 20, and enabling the active pen 10 to transmit signals with the touchscreen 20. Generally, a pen controller 142 and a first driving circuit 1431 are disposed within the pen body. The pen controller 142 is connected to the first driving circuit 1431, and the first driving circuit 1431 is connected to the pen electrode 12 disposed on the pen tip, so that the pen controller 142 can output a first driving signal to the first driving circuit 1431, causing the first driving circuit 1431 to control the pen electrode 12 to operate. Since the coupling structure 13 mainly transmits signals through the coupling capacitance formed by the contact between the hand and the active pen 1, its position is related to the hand's grip position on the active pen 10. Since the grip position on the active pen 10 is generally located on the pen body, the coupling structure 13 is positioned at the grip position on the pen body. Furthermore, the coupling structure 13 needs to be electrically connected to the pen controller 142 via the second driving circuit 1432. If it were located on the outside of the pen body, connection holes or other connection structures would need to be made on the pen body, leading to complex manufacturing processes, low production efficiency, and high costs. Therefore, placing the coupling structure 13 and the second driving circuit 1432 inside the pen body gives the active pen 10 advantages such as simple structure, high manufacturing efficiency, and low cost.

[0119] In one embodiment, the pen tip is provided with an assembly hole; the pen electrode 12 includes a main electrode 121 and a secondary electrode 122; one end of the main electrode 121 is disposed inside the pen housing 11, and the other end of the main electrode 121 extends out of the pen housing 11 through the assembly hole for positioning detection; the secondary electrode 122 is disposed inside the pen housing 11 and sleeved outside the main electrode 121 for tilt angle detection.

[0120] As an example, the pen tip has a mounting hole along the axial direction of the active pen 10 for mounting the pen electrode 12, such that a portion of the pen electrode 12 extends out of the pen tip, and the other portion is connected to the first drive circuit 1431 located inside the pen body. The pen tip here is generally tapered, with the larger end of the tapered tip connected to the pen body and the smaller end of the tapered tip having the mounting hole. The pen electrode 12 includes a main electrode 121 and a secondary electrode 122 connected to the first drive circuit 1431. The main electrode 121 is used to implement the positioning detection function, and the secondary electrode 122 is used to implement the tilt angle detection function. In this example, one end of the main electrode 121 is disposed inside the pen housing 11 and connected to the first driving circuit 1431, and the other end of the main electrode 121 extends out of the pen housing 11 through the mounting hole; the secondary electrode 122 is disposed inside the pen housing 11 and sleeved outside the main electrode 121. Specifically, the secondary electrode 122 is disposed in the gap between the main electrode 121 and the pen tip, and the secondary electrode 122 is connected to the first driving circuit 1431, so that at any time when the active pen 10 approaches or contacts the touch screen 20, the main electrode 121 and the secondary electrode 122 can couple with the screen electrode 21 on the touch screen 20, so that the active pen 10 and the touch screen 20 can communicate to ensure the realization of the positioning detection function and the tilt angle detection function.

[0121] In this example, the main electrode 121 includes a cylindrical body and a touch portion extending axially from one end of the cylindrical body. The cylindrical body passes through the mounting hole of the pen tip. The touch portion can be a cone, hemisphere, fan, or other shape, which can be customized according to user needs. The secondary electrode 122 includes a cone-shaped body with a through hole, so that the cone-shaped body can be fitted over the cylindrical body of the main electrode 121. The cone-shaped design of the secondary electrode 122 makes its signal envelope more stable.

[0122] This utility model embodiment provides a screen chip 22, suitable for connection to screen electrodes 21 on a touch screen 20. The screen electrodes 21 are used to couple with pen electrodes 12 on an active pen 10. The screen chip 22 includes a screen receiving circuit 222 and a screen controller 223. The screen receiving circuit 222 is connected to both the screen electrodes 21 and the screen controller 223, and is used to send the measured signal detected by the screen electrodes 21 to the screen controller 223. The screen controller 223 is used to determine the measured signal as the first driving signal output by the active pen 10 when the measured signal is a single-frequency signal; when the measured signal contains a first measured signal and a second measured signal with different frequencies, it compensates the first measured signal based on the second measured signal to determine the first driving signal output by the active pen 10. The first measured signal is the signal coupled to the touch screen 20 by the first driving signal, and the second measured signal is the signal coupled to the touch screen 20 by the second driving signal.

[0123] Figure 2The diagram illustrates a touch system consisting of an active pen 10 and a touchscreen 20. This touch system is used only to illustrate the crosstalk principle described above and does not limit the specific design form. Figure 2 As shown, the touchscreen 20 includes a screen body, screen electrodes 21, and a screen chip 22. The screen electrodes 21 are disposed on the screen body and are used for coupling with the pen electrodes 12 on the active pen 10. The screen chip 22 is disposed outside the screen body and is electrically connected to the screen electrodes 21. In this example, the screen chip 22 is disposed on a circuit board outside the screen body. This circuit board can be a flexible printed circuit board or a rigid printed circuit board. The screen electrodes 21 include driving electrodes 211 (…). Figure 2 D0-D3) and sensing electrode 212 ( Figure 2 As can be understood from S0-S3, the touchscreen 20 may include multiple sets of driving electrodes 211 and sensing electrodes 212 as shown in the examples. In this example, the screen chip 22 includes a screen driving circuit 221, a screen receiving circuit 222, and a screen controller 223. The screen controller 223 is a logic controller disposed on the touchscreen 20, specifically a microcontroller unit (MCU) disposed within the touchscreen 20. The screen driving circuit 221 is connected to both the driving electrode 211 and the screen controller 223, and is used to control the driving electrode 211 to work according to the screen driving signal output by the screen controller 223. The screen receiving circuit 222 is connected to both the sensing electrode 212 and the screen controller 223, and is used to acquire and demodulate the measured signal output by the sensing electrode 212, and output the processed signal to the screen controller 223.

[0124] As an example, when the active pen 10 approaches or touches the touch screen 20, the active pen 10 is coupled to the screen electrode 21 through the pen electrode 12, so that the screen electrode 21 on the touch screen 20 can send the detected measured signal to the screen controller 223. Specifically, this includes the following two schemes:

[0125] The first solution is as follows: When the first driving signal and the second driving signal output by the pen controller 142 have the same frequency, specifically when the frequency and phase of the second driving signal and the first driving signal are the same, the measured signal sensed by the screen electrode 21 on the touch screen 20 is a single frequency signal. The screen controller 223 can directly determine the measured signal as the first driving signal output by the pen electrode 12 so as to perform subsequent control operations based on the first driving signal.

[0126] The second approach is as follows: When the first driving signal and the second driving signal output by the pen controller 142 have different frequencies, the measured signal sensed by the screen electrode 21 on the touch screen 20 includes the first measured signal and the second measured signal with different frequencies. Here, the first driving signal is transmitted to the touch screen 20 through the coupling capacitor between the pen electrode 12 and the screen electrode 21, and the second measured signal is transmitted to the touch screen 20 through the coupling capacitor between the hand and the touch screen 20. After receiving the first measured signal and the second measured signal with different frequencies, the screen controller 223 can perform signal feature compensation processing on the two signals based on the built-in signal compensation algorithm, so as to identify the signal feature after compensation as the first driving signal output by the active pen 10 without crosstalk interference, so that the signal-to-noise ratio of the first driving signal of the active pen 10 can be greatly improved.

[0127] In one embodiment, the first driving signal is the sum of the first measured signal and the compensation signal; the compensation signal is the product of the second measured signal and the third coefficient.

[0128] The compensation signal is used to compensate the first measured signal. The third coefficient is used to adjust the second measured signal, specifically a coefficient less than 1.

[0129] As an example, assuming the first measured signal is S1, the second measured signal is S2, and the third coefficient is k3, the screen controller 223 compensates for the first measured signal based on the second measured signal, determining the first driving signal output by the active pen 10 as S1 + k3 * S2. This achieves compensation of the first measured signal using the second measured signal, determining a second driving signal free from crosstalk, thus ensuring a significant improvement in the signal-to-noise ratio of the first driving signal recognized by the touchscreen 20. The first and second measured signals have different frequencies, such as... Figure 15As shown, when a hand touches the screen electrode 21 (i.e., the same sensor channel) that projects the same direction as the pen electrode 12 of the active pen 10, two frequency signal envelopes will be generated within the screen electrode 21. The envelopes of the two frequency signals are similar, and the crosstalk effect of the hand can be compensated by the third coefficient k3. Assuming that at 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, then the first measured signal that the touch screen 20 can detect is the S1 signal, where S1 = raw1 - raw2, and raw1 = S1 + raw2; the S1 signal is the first measured signal after crosstalk of the first driving signal corresponding to the f1 frequency. At frequency f2, the crosstalk signal between the active pen 10 and the hand is raw3. The second measured signal that the touch screen 20 can detect is the S2 signal. The S2 signal is the second measured signal after crosstalk of the second driving signal corresponding to frequency f2. Since the crosstalk signals raw2 and raw3 at frequency f1 and frequency f2 have similar signal characteristics, they can be compensated by the crosstalk signal at frequency f2. The compensated first driving signal is raw1-raw2+k3*raw3. That is, the compensated signal is the crosstalk-free signal output by the active pen 10, i.e., the first driving signal, which greatly improves the signal-to-noise ratio of the first driving signal of the active pen 10.

[0130] This utility model provides a touch screen 20, including a screen body, a screen electrode 21, and a screen chip 22 as described in the above embodiment; the screen electrode 21 is disposed on the screen body and is used to couple with the pen electrode 12 on the active pen 10; the screen chip 22 is disposed outside the screen body and is electrically connected to the screen electrode 21.

[0131] like Figure 2 As shown, the touch screen 20 includes a screen body, screen electrodes 21, and screen chip 22. The screen electrodes 21 are disposed on the screen body and are used to couple with the pen electrodes 12 on the active pen 10. The screen chip 22 is disposed outside the screen body and is electrically connected to the screen electrodes 21. The screen chip 22 includes a screen driving circuit 221, a screen receiving circuit 222, and a screen controller 223. When the active pen 10 approaches or touches the touch screen 20, the active pen 10 couples with the screen electrodes 21 through the pen electrodes 12, so that the screen electrodes 21 on the touch screen 20 can send the measured signal they detect to the screen controller 223, so that the screen controller 223 can determine the first driving signal output by the active pen 10 without crosstalk interference based on the measured signal it receives, so that the signal-to-noise ratio of the first driving signal of the active pen 10 can be greatly improved.

[0132] This utility model embodiment provides a touch system, including the active pen 10 and the touch screen 20 in the above embodiment; the pen electrode 12 on the active pen 10 is coupled to the screen electrode 21 on the touch screen 20.

[0133] In this example, a coupling structure 13 is added to the active pen 10 and disposed inside the pen shell 11. 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 simultaneously receive the first uplink signal received by the pen electrode 12 and the second uplink signal received by the coupling structure 13, and process the first uplink signal and the second uplink signal to determine the original uplink signal with basically no attenuation output by the touch screen 20, so as to ensure the accuracy of the received uplink signal.

[0134] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.

Claims

1. A refill for use in a ballpoint pen, characterized in that The active pen comprises a pen shell, a pen electrode arranged on the pen shell and a coupling structure arranged in the pen shell, the pen electrode being used to couple with a screen electrode on a touch screen; The pen chip is arranged in the pen shell, the pen chip being connected with the pen electrode and the coupling structure, and being used to process a first uplink signal received by the pen electrode and a second uplink signal received by the coupling structure, and determine an original uplink signal output by the touch screen.

2. The pen chip of claim 1, wherein, The pen chip comprises a pen receiving circuit, the pen receiving circuit comprising a superposition amplifier circuit and a superposition analog-to-digital converter; The superposition amplifier circuit is connected with the pen electrode and the coupling structure simultaneously, and is used to amplify and process a signal obtained by superimposing the first uplink signal and the second uplink signal, and output a superposition amplified signal; The superposition analog-to-digital converter is connected with the superposition amplifier circuit, and is used to perform analog-to-digital conversion on the superposition amplified signal, and determine the original uplink signal output by the touch screen.

3. The pen chip of claim 2, wherein, The active pen further comprises a gain adjustment circuit, a first end of the gain adjustment circuit being connected with the coupling structure, and a second end of the gain adjustment circuit being connected with the superposition amplifier circuit, and the gain adjustment circuit being used to perform gain adjustment on the second uplink signal, and output an adjusted second uplink signal to the superposition amplifier circuit.

4. The pen chip of claim 1, wherein, The pen chip comprises a pen receiving circuit, the pen receiving circuit being used to connect a pen controller, and the pen receiving circuit comprising a first amplifier circuit, a first analog-to-digital converter, a second amplifier circuit and a second analog-to-digital converter; The first amplifier circuit is connected with the pen electrode, and is used to amplify and process the first uplink signal, and output a first amplified signal; The first analog-to-digital converter is connected with 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 is connected with the coupling structure, and is used to amplify and process the second uplink signal, and output a second amplified signal; The second analog-to-digital converter is connected with 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 operation processing on the first digital signal and the second digital signal, and determine the original uplink signal output by the touch screen.

5. The pen chip of claim 4, wherein, The active pen further comprises a gain adjustment circuit, a first end of the gain adjustment circuit being connected with the coupling structure, and a second end of the gain adjustment circuit being connected with the second amplifier circuit, and the gain adjustment circuit being used to perform gain adjustment on the second uplink signal, and output an adjusted second uplink signal to the second amplifier circuit.

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

7. The pen chip according to claim 3 or 5, characterized by The gain adjustment circuit is arranged in the pen chip, or the gain adjustment circuit is arranged outside the pen chip.

8. The pen chip according to any one of claims 2 to 5, wherein, The pen chip further comprises a pen controller, a pen driving circuit and a multiplexer; The multiplexer is connected with the pen electrode and the coupling structure simultaneously, and is connected with the pen receiving circuit or the pen driving circuit; The pen controller is connected with the multiplexer, and is configured to control the second end of the multiplexer to be connected with the pen receiving circuit or the pen driving circuit, and when the second end of the multiplexer is connected with the pen driving circuit, the pen controller is further configured to control the pen driving circuit to output the first driving signal to the pen electrode and the second driving signal to the coupling structure simultaneously, so that the coupling structure isolates the crosstalk signal between the active pen and the hand.

9. The pen chip of claim 8, wherein, The multiplexer comprises a first switch and a second switch; The first switch is connected with the pen electrode and the coupling structure simultaneously, and is connected with the pen receiving circuit; The second switch is connected with the pen electrode and the coupling structure simultaneously, and is connected with the pen driving circuit; The pen controller is connected with the first switch and the second switch, and is configured to control one of the first switch and the second switch to be turned on and the other to be turned off.

10. The pen chip of claim 8, wherein, The pen driving circuit comprises a first driving circuit and a second driving circuit; The first end of the first driving circuit is connected with the pen controller, and the second end of the first driving circuit is connected with the pen electrode through the multiplexer, and is configured to output the 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 with the pen controller, and the second end of the second driving circuit is connected with the coupling structure through the multiplexer, and is configured to output the 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 connected with the first driving circuit and the pen electrode through the multiplexer, and is connected with the second driving circuit and the coupling structure, and is configured to output the first control signal and the second control signal simultaneously, so that the first driving circuit and the second driving circuit output the first driving signal and the second driving signal simultaneously.

11. A stylus, characterized by The pen comprises a pen shell, a pen electrode arranged on the pen shell, and a coupling structure arranged in the pen shell, the pen electrode is coupled with a screen electrode on a touch screen; The pen further comprises the pen chip according to any one of claims 1-10, the pen chip is arranged in the pen shell, and the pen chip is connected with the pen electrode and the coupling structure.

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