Active capacitance pen with self-calibration function and control system thereof
The active capacitive pen with self-calibration function uses a multimodal sensing layer and a dynamic control layer to achieve real-time calibration, solving the problem of tilted writing and offset of the active capacitive pen after long-term use, ensuring accurate handwriting and suppressing screen noise interference.
Patent Information
- Application Number
- CN202510786131.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-12
- Publication Date
- 2025-09-16
AI Technical Summary
Existing active capacitive pens are prone to tilt and writing deviation after long-term use. There is a coordinate offset between the pen tip and the screen detection point. They are also easily affected by changes in user holding posture, pen tip wear, screen curvature and environmental electromagnetic interference. There is a lack of an effective calibration mechanism to eliminate positioning offset and writing distortion.
The active capacitive stylus with self-calibration function includes a pen tip electrode, a self-calibration unit, a control chip, a Bluetooth communication unit, a protective mechanism and a support mechanism. It achieves real-time calibration through a multimodal sensing layer, a signal conditioning layer and a dynamic control layer, and combines a closed-loop system to eliminate positioning offset and writing distortion, and suppress screen noise interference.
Real-time calibration is achieved during use, eliminating positioning offset and writing distortion caused by changes in user holding posture, pen tip wear and environmental electromagnetic interference, ensuring accurate handwriting and effectively avoiding signal conflicts and delays.
Smart Images
Figure CN120653152A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of active capacitive pens, and in particular to an active capacitive stylus with a self-calibration function and a control system thereof. Background Art
[0002] An active capacitive stylus is a high-precision input device that interacts with a touchscreen through built-in circuitry. Compared to passive capacitive pens (which only simulate finger touch), it offers advantages such as pressure sensitivity, tilt detection, and low latency. It is widely used in areas such as drawing, note-taking, and design.
[0003] With the popularity of touch devices, active capacitive pens have become core tools for drawing, note-taking and other scenarios due to their high-precision positioning and pressure-sensitive tilt recognition capabilities. The essence of its technology is to achieve coordinate positioning by transmitting a modulated signal through the pen tip and coupling it with the capacitive screen. However, existing active capacitive pens will have the problem of tilted writing offset after long-term use. When the pen body is tilted, there is a coordinate offset between the physical contact point of the pen tip and the screen detection point, resulting in a deviation between the handwriting trajectory and the actual landing point, requiring the user to manually calibrate the signal interference and clock inaccuracy: the circuit space inside the pen is compact, and the communication module is easily interfered by the shielding ring grounding line, causing short circuit failure. The external crystal oscillator does not match the parasitic capacitance with the load capacitance, resulting in clock frequency offset and signal loss. Therefore, there is a lack of solutions that can effectively eliminate positioning offset and writing distortion introduced by factors such as changes in user holding posture, pen tip wear, screen curvature and environmental electromagnetic interference. There is also a lack of solutions that can effectively avoid signal conflicts and delays and suppress screen noise interference. Summary of the Invention
[0004] The present invention aims to provide an active capacitive pen with self-calibration function and its control system, which is mainly used to solve the problems that the existing technology lacks the ability to effectively eliminate positioning offset and writing distortion introduced by factors such as changes in user holding posture, pen tip wear, screen curvature and environmental electromagnetic interference, and lacks the ability to effectively avoid signal conflicts and delays and suppress screen noise interference.
[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:
[0006] An active capacitive stylus with self-calibration function includes a capacitive stylus body, a pen tip electrode, a self-calibration unit, a control chip, a Bluetooth communication unit, a protective mechanism, and a support mechanism. The pen tip electrode is arranged at the rightmost end of the capacitive stylus body and is used to couple with the capacitive screen of a touch device. The self-calibration unit is arranged inside the capacitive stylus body and is used to detect in real time the offset of the physical parameters when the pen tip contacts the capacitive screen and generate calibration parameters. The control chip is arranged in the middle of the capacitive stylus body and is used to dynamically adjust the transmission signal of the pen tip electrode according to the calibration parameters. The Bluetooth communication unit is arranged on the left side of the control chip and is used to transmit the calibration parameters and pen body status data to the touch device. The protective mechanism is arranged on the outside of the left end of the capacitive stylus body and is in contact with the outer wall of the capacitive stylus body. The support mechanism can The rotating part is arranged on the outside of the protective mechanism, and an elastic limiter is movably arranged on the outside of the support mechanism, and one end of the elastic limiter is in contact with one side of the support mechanism. The self-calibration unit also includes a multimodal sensing layer, a signal conditioning layer, a dynamic control layer and a communication interface layer. The multimodal sensing layer is arranged on the left side of the pen tip motor, and is used to capture the physical state of the pen body in real time, and provide original data input for calibration. The signal conditioning layer is arranged on the left side of the multimodal sensing layer, and is used to improve the signal-to-noise ratio of the sensing data, and provide reliable input for calibration decisions. The dynamic control layer is arranged on the left side of the signal conditioning layer, and is used to convert the calibration parameters into physical adjustment actions to realize real-time compensation of the pen tip. The communication interface layer is arranged on the right side of the control chip, and is used to establish a two-way data channel between the pen tip and the touch device to realize closed-loop calibration.
[0007] An active capacitive stylus control system with self-calibration function includes the following steps:
[0008] S1. Contact detection and triggering: The pressure distribution can be measured through the annular pressure-sensitive sensor array. When the pressure is greater than 0.1 Newton, the self-calibration process is triggered, and the shape memory alloy spring will produce initial expansion and contraction.
[0009] S2. Multimodal data acquisition: A three-axis MEMS gyroscope is used to collect three-axis attitude angles, a piezoelectric sensor array is used to detect pressure gradients, and a Hall effect displacement sensor is used to measure the pen tip extension and retraction. An electromagnetic field detector is used to capture the screen drive frequency.
[0010] S3, signal conditioning processing: The signal is amplified by a low-noise amplifier and band-pass filtered by an anti-aliasing filter, while the 24-bit Σ-Δ ADC digitizes the signal and imports it into the control chip for calibration parameter calculation.
[0011] S4, dynamic control execution: the parameter programmable DAC converts the parameters into control voltage, and the real-time clock synchronizer synchronizes the screen refresh cycle;
[0012] S5, communication transmission and closed-loop feedback correction: send data packets and receive errors through the BLE five-point zero RF module, then correct the model again through the control chip, and finally update the control shape memory alloy spring
[0013] Working principle and beneficial effects of the present invention:
[0014] 1. Working principle: The pen tip electrode is used to couple with the capacitive screen of the touch device; the self-calibration unit is used to detect the physical parameter offset when the pen tip contacts the capacitive screen in real time and generate calibration parameters; the control chip is used to dynamically adjust the transmission signal of the pen tip electrode according to the calibration parameters; the Bluetooth communication unit is used to transmit the calibration parameters and pen body status data to the touch device; the multimodal sensing layer is used to capture the physical state of the pen body in real time and provide raw data input for calibration; the signal conditioning layer is used to improve the signal-to-noise ratio of the sensing data and provide reliable input for calibration decisions; the dynamic control layer is used to convert the calibration parameters into physical adjustment actions to achieve real-time compensation of the pen tip; the communication interface layer is used to establish a two-way data channel between the pen tip and the touch device to achieve closed-loop calibration; in addition, the protective mechanism is fitted with the outer wall of the capacitive pen body so that the protective mechanism can be mounted on both ends of the capacitive pen body. When it is mounted on the left end of the capacitive pen body, it rotates toward the upper left of the capacitive pen body. Support mechanism, during this process, the support mechanism will pass through the elastic limiter when rotating. Due to the elasticity of the elastic limiter, the support mechanism drives the elastic limiter to move toward the outside of the capacitive pen body, thereby making way for the elastic limiter to the support mechanism. When the support mechanism passes through the elastic limiter, due to the reaction force of the elastic limiter, the elastic limiter is reset, so that one end of the reset elastic limiter contacts one side of the support mechanism, thereby limiting and fixing the support mechanism after rotation. In this way, through the support of the support mechanism, the capacitive pen body can be placed on the desktop at an inclined angle, and a gap is left between the capacitive pen body and the desktop, which is convenient for the user to pick up and use later. At the same time, it can prevent the round or D-shaped capacitive pen body from rolling and falling, thereby improving the convenience and safety of use. When the protective mechanism is sleeved on the outside of the pen tip of the capacitive pen body, the protective mechanism can support and protect the pen tip to prevent the pen tip from accidentally falling to the ground and being damaged.
[0015] 2.Beneficial effects:
[0016] (1) Through the communication interface layer, calibration parameters, pen body status data and device feedback errors are transmitted bidirectionally. Through the multimodal sensing layer, signal conditioning layer, dynamic control layer and control chip, the closed-loop system starts working at the moment of contact, effectively eliminating positioning offset and writing distortion introduced by factors such as changes in user holding posture, pen tip wear, screen curvature and environmental electromagnetic interference, ensuring that the handwriting is always accurate. The screen drive frequency is captured through the electromagnetic field detector, and combined with the real-time clock synchronizer, the pen tip signal emission is accurately synchronized with the screen refresh cycle, effectively avoiding signal conflicts and delays, and significantly suppressing screen noise interference.
[0017] (2) The rubber sleeve makes it easy to put the protective sleeve on both ends of the capacitive pen body. When not in use, it can be put on the left end of the capacitive pen body, and the outer wall of the adjacent guide rod can be in contact with one side of the support plate after rotation through the force of the tension spring, thereby limiting the position of the support plate, so that the support plate remains in a state of rotation toward the upper left of the capacitive pen body. Through the two support plates, the capacitive pen body can be placed on the desktop at an inclined angle, and a gap is left between the capacitive pen body and the desktop, which is convenient for users to pick up and use later. At the same time, it can prevent the round or D-shaped capacitive pen body from rolling and falling, thereby improving the convenience and safety of use. When in use, it can be put on the outside of the pen tip of the capacitive pen body. At this time, the outside of the pen tip is in contact with several baffles, thereby supporting and protecting the pen tip, and preventing the pen tip from accidentally falling to the ground and being damaged.
[0018] Preferably, the pen tip electrode includes a conical metal core, an annular pressure-sensitive sensor array, a shape memory alloy spring and a hollow metal mesh. The conical metal core is installed at the rightmost end inside the capacitive pen body, and the outer side of the conical metal core is provided with a sleeve close to the annular pressure-sensitive sensor array. A shape memory alloy spring is installed at one end of the conical metal core, and one end of the shape memory alloy spring is fixedly connected to the inner wall of the capacitive pen body. The outer side of the annular pressure-sensitive sensor array is provided with a hollow metal mesh; the pressure distribution of the conical metal core can be measured by the annular pressure-sensitive sensor array. When the pressure is greater than zero point one Newton, the self-calibration process is triggered. At this time, the shape memory alloy spring produces initial expansion and contraction. At this time, due to the action of the hollow metal mesh, electromagnetic interference is suppressed, and at the same time, pressure is allowed to be transmitted to the annular pressure-sensitive sensor array.
[0019] Preferably, the multimodal sensing layer includes a three-axis MEMS gyroscope, a piezoelectric sensor array, a Hall displacement sensor and an electromagnetic field detector. The Hall displacement sensor is installed on the left side of the pen tip electrode, and a three-axis MEMS gyroscope is installed inside the capacitive pen body near the left side of the Hall displacement sensor. A piezoelectric sensor array is installed inside the capacitive pen body near the left side of the three-axis MEMS gyroscope, and an electromagnetic field detector is installed inside the capacitive pen body near the left side of the piezoelectric sensor array. The three-axis attitude angle is collected by the three-axis MEMS gyroscope, and the pressure gradient is detected by the piezoelectric sensor array. The pen tip extension and contraction amount is measured in conjunction with the Hall displacement sensor, and the electromagnetic field detector can capture the screen driving frequency.
[0020] Preferably, the signal conditioning layer includes a low-noise amplifier, an anti-aliasing filter and a twenty-four-bit Σ-ΔADC. The low-noise amplifier is installed on the left side of the multimodal sensing layer, an anti-aliasing filter is installed inside the capacitive pen body near the low-noise amplifier, and a twenty-four-bit Σ-ΔADC is installed inside the capacitive pen body near the left side of the anti-aliasing filter; bandpass filtering is performed through the low-noise amplifier gain signal and the anti-aliasing filter, and the twenty-four-bit Σ-ΔADC digitally converts the digital signal and imports it into the control chip for calibration parameter calculation and processing.
[0021] Preferably, the dynamic control layer includes a parameter programmable DAC, a real-time clock synchronizer and a self-triggering logic circuit. The parameter programmable DAC is installed on the left side of the signal conditioning layer, and the real-time clock synchronizer is installed inside the capacitive pen body near the parameter programmable DAC. The self-triggering logic circuit is installed inside the capacitive pen body near the left side of the real-time clock synchronizer; the parameter programmable DAC converts parameters into control voltage, and the real-time clock synchronizer can synchronize the screen refresh cycle, and cooperates with the self-triggering logic circuit to immediately start the high-speed calibration mode when a dynamic mutation (such as a sudden change in pressure) is detected.
[0022] Preferably, the communication interface layer includes a BLE five-point zero RF module, which is installed on the right side of the control chip; data packets are sent and errors are received through the BLE five-point zero RF module, and then the model is corrected again through the control chip, and finally the control shape memory alloy spring is updated, and in conjunction with the Bluetooth communication unit, calibration parameters and pen body status data can be transmitted to the touch device.
[0023] Preferably, the protective mechanism includes a protective sleeve, a rubber sleeve and a baffle, the protective sleeve is mounted on the left end of the capacitive pen body, the inner wall of the protective sleeve is fixedly connected to the rubber sleeve near the opening, the inner wall of the protective sleeve is fixedly connected to one side of the rubber sleeve, and the baffles are equidistantly arranged in a circular array; when using the protective sleeve, the protective sleeve can be mounted on the outside of the pen tip of the capacitive pen body, at this time the outside of the pen tip contacts the several baffles, and the rubber sleeve contacts the outer wall of the right end of the capacitive pen body, so as to support and protect the pen tip and prevent the pen tip from accidentally falling to the ground and being damaged.
[0024] Preferably, the support mechanism includes a support plate, and the outer wall of the protective cover is fixedly connected to two mounting seats. Two support plates are provided, and one end of the two support plates is rotatably connected to the inside of the two mounting seats respectively; through the two support plates, the capacitive pen body can be placed on the desktop at an inclined angle, and a gap is left between the capacitive pen body and the desktop, which is convenient for users to pick up and use later, and at the same time can prevent the round or D-shaped capacitive pen body from rolling and falling, thereby improving convenience and safety of use.
[0025] Preferably, the elastic limiting member includes a connecting rod, a mounting hole, a tension spring, a moving rod, a connecting plate and a guide rod, wherein a plurality of connecting rods are provided, and one end of the adjacent connecting rods is fixedly connected to both sides of the mounting seat, a mounting hole is opened on one side of the connecting rod, and a tension spring is fixedly connected to one side of the inner wall of the mounting hole, and one end of the tension spring is fixedly connected to the moving rod, and the outer wall of one end of the moving rod is fitted with the inner wall of the mounting hole, and the other end of the moving rod is fixedly connected to the connecting plate, and the inner side of the connecting plate is fixedly connected to the guide rod, and the support plate is pulled toward the left end of the capacitive pen body so that the left end of the support plate is in the mounting position. The mounting seat rotates inside, and when the support plate rotates to contact one end of the guide rod, since one end of the guide rod is set to a rounded corner, the one end of the guide rod is squeezed and moves toward the outside of the mounting seat. At this time, the guide rod drives the connecting plate to move, and the connecting plate drives the moving rod to move inside the mounting hole, and then the moving rod drives the tension spring to stretch. When the support plate passes through one end of the guide rod, the right end of the support plate rotates toward the upper left of the capacitive pen body. Due to the reaction force of the tension spring, the adjacent guide rod can be reset, so that the outer wall of one end of the guide rod contacts one side of the rotated support plate, thereby limiting the position of the support plate. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 This is a three-dimensional structural diagram of an active capacitive stylus with self-calibration function according to the present invention;
[0027] Figure 2 This is a bottom view of an active capacitive stylus with self-calibration function according to the present invention;
[0028] Figure 3 This is a module diagram of an active capacitive stylus with self-calibration function according to the present invention;
[0029] Figure 4 This is a structural diagram of the support plate of an active capacitive stylus with self-calibration function in the patent of the present invention;
[0030] Figure 5 This is a cross-sectional view of the connecting rod of an active capacitive stylus with self-calibration function according to the present invention;
[0031] Figure 6 This is a diagram of the baffle structure of an active capacitive stylus with self-calibration function in the patent of the present invention;
[0032] Figure 7 This is a right view of the protective cover of the active capacitive stylus with self-calibration function in the patent of the present invention;
[0033] Figure 8 This is a flow chart of the control system of an active capacitive stylus with self-calibration function according to the patent of this invention.
[0034] The reference numerals in the drawings of the specification include: 1. capacitive stylus body;
[0035] 2. Pen tip electrode; 201. Conical metal core; 202. Ring-shaped pressure-sensitive sensor array; 203. Shape memory alloy spring; 204. Hollow metal mesh;
[0036] 3. Multimodal sensing layer; 301. Three-axis MEMS gyroscope; 302. Piezoelectric sensor array; 303. Hall displacement sensor; 304. Electromagnetic field detector;
[0037] 4. Signal conditioning layer; 401. Low noise amplifier; 402. Anti-aliasing filter; 403. 24-bit Σ-Δ ADC
[0038] 5. Dynamic control layer; 501. Parameter programmable DAC; 502. Real-time clock synchronizer; 503. Self-triggering logic circuit
[0039] 6. Communication interface layer; 601. BLE five-point zero radio frequency module (601);
[0040] 7. Control chip; 8. Bluetooth communication unit;
[0041] 9. Protective mechanism; 901. Protective cover; 902. Rubber cover; 903. Baffle;
[0042] 10. Support mechanism; 1001. Connecting rod; 1002. Mounting hole; 1003. Tension spring; 1004. Moving rod; 1005. Connecting plate; 1006. Guide rod; 1007. Mounting seat; 1008. Support plate. DETAILED DESCRIPTION
[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0044] Example 1, as Figure 1-Figure 7As shown, an active capacitive stylus with self-calibration function is split and integrated according to the functional differences of claims 1 to 9 in the claims. It includes a capacitive stylus body 1, a pen tip electrode 2, a self-calibration unit, a control chip 7, a Bluetooth communication unit 8, a protective mechanism 9 and a support mechanism 10. The pen tip electrode 2 is arranged at the rightmost end of the capacitive stylus body 1 and is used to couple with the capacitive screen of the touch device. The pen tip electrode 2 includes a conical metal core 201, an annular pressure-sensitive sensor array 202, a shape memory alloy spring 203 and a hollow metal mesh 204. The conical metal core 201 is installed at the rightmost end inside the capacitive stylus body 1. The outer side of the conical metal core 201 is provided with a sleeve close to the annular pressure-sensitive sensor array 202. One end of the conical metal core 201 is provided with a shape memory alloy spring 203. 03, one end of the shape memory alloy spring 203 is fixedly connected to the inner wall of the capacitive pen body 1, the outer side of the annular pressure-sensitive sensor array 202 is provided with a hollow metal mesh 204, the self-calibration unit is arranged inside the capacitive pen body 1, and is used to detect the physical parameter offset when the pen tip contacts the capacitive screen in real time, and generate calibration parameters, the control chip 7 is arranged in the middle of the capacitive pen body 1, and is used to dynamically adjust the transmission signal of the pen tip electrode according to the calibration parameters, the Bluetooth communication unit 8 is arranged on the left side of the control chip 7, and is used to transmit the calibration parameters and pen body status data to the touch device; wherein the self-calibration unit also includes a multimodal sensing layer 3, a signal conditioning layer 4, and a dynamic control layer. Layer 5 and communication interface layer 6, the multimodal sensing layer 3 is arranged on the left side of the pen tip motor 2, and is used to capture the physical state of the pen body in real time and provide raw data input for calibration. The multimodal sensing layer 3 includes a three-axis MEMS gyroscope 301, a piezoelectric sensing array 302, a Hall displacement sensor 303 and an electromagnetic field detector 304. The Hall displacement sensor 303 is installed on the left side of the pen tip electrode 2. The three-axis MEMS gyroscope 301 is installed on the left side of the Hall displacement sensor 303 inside the capacitive pen body 1. The piezoelectric sensing array 302 is installed on the left side of the three-axis MEMS gyroscope 301 inside the capacitive pen body 1. An electromagnetic field detector 304 is installed inside the capacitive stylus body 1, near the left side of the piezoelectric sensor array 302. A signal conditioning layer 4 is provided on the left side of the multimodal sensing layer 3 and is used to improve the signal-to-noise ratio of the sensing data and provide reliable input for calibration decisions. The signal conditioning layer 4 includes a low-noise amplifier 401, an anti-aliasing filter 402, and a 24-bit Σ-Δ ADC 403. The low-noise amplifier 401 is installed on the left side of the multimodal sensing layer 3. An anti-aliasing filter 402 is installed inside the capacitive stylus body 1, near the side of the low-noise amplifier 401. A 24-bit Σ-Δ ADC 403 is installed inside the capacitive stylus body 1, near the left side of the anti-aliasing filter 402.The dynamic control layer 5 is set on the left side of the signal conditioning layer 4 and is used to convert the calibration parameters into physical adjustment actions to achieve real-time compensation at the pen end. The dynamic control layer 5 includes a parameter programmable DAC 501, a real-time clock synchronizer 502 and a self-triggering logic circuit 503. The parameter programmable DAC 501 is installed on the left side of the signal conditioning layer 4. The real-time clock synchronizer 502 is installed on the side of the parameter programmable DAC 501 inside the capacitive pen body 1. The self-triggering logic circuit 503 is installed on the left side of the real-time clock synchronizer 502 inside the capacitive pen body 1. 3; The communication interface layer 6 is arranged on the right side of the control chip 7 and is used to establish a two-way data channel between the pen tip and the touch device to achieve closed-loop calibration. The communication interface layer 6 includes a BLE five-point zero radio frequency module 601, which is installed on the right side of the control chip 7; When the user touches the tip of the capacitive pen with an external device, the pressure distribution of the conical metal core 201 can be measured through the annular pressure-sensitive sensor array 202. When the pressure is greater than 0.1 Newton, the self-calibration process is triggered. At this time, the shape memory alloy spring 203 produces initial expansion and contraction. At this time, due to The hollow metal mesh 204 suppresses electromagnetic interference while allowing pressure to be transmitted to the annular pressure-sensitive sensor array 202. The three-axis attitude angle is then collected by the three-axis MEMS gyroscope 301, and the pressure gradient is detected by the piezoelectric sensor array 302. The Hall displacement sensor 303 is used to measure the extension and retraction of the pen tip. The electromagnetic field detector 304 captures the screen drive frequency, and the signal is amplified by the low-noise amplifier 401 and band-pass filtered by the anti-aliasing filter 402. The 24-bit Σ-Δ ADC 403 digitizes and imports the digital signal into the control chip 7. Calibration parameters are calculated and processed internally. The programmable DAC 501 converts the parameters into control voltages, while the real-time clock synchronizer 502 synchronizes the screen refresh cycle. In conjunction with the self-triggering logic circuit 503, when a sudden dynamic change (such as a sudden change in pressure) is detected, the high-speed calibration mode is immediately activated. Data packets are sent and errors are received via the BLE five-point zero RF module 601. The model is then corrected again via the control chip 7. Finally, the shape memory alloy spring 203 is updated and controlled. In conjunction with the Bluetooth communication unit 8, calibration parameters and pen body status data can be transmitted to the touch device.
[0045] The protective mechanism 9 is arranged on the outside of the left end of the capacitive pen body 1, and the protective mechanism 9 includes a protective sleeve 901, a rubber sleeve 902 and a baffle 903. The protective sleeve 901 is sleeved on the left end of the capacitive pen body 1, and the inner wall of the protective sleeve 901 is fixedly connected to the rubber sleeve 902 near the opening. The inner wall of the protective sleeve 901 is fixedly connected to one side of the rubber sleeve 902, and the baffles 903 are equidistantly arranged in a circular array; and the protective mechanism 9 is fitted with the outer wall of the capacitive pen body 1, and the support mechanism 10 is rotatably arranged on the outside of the protective mechanism 9, and the support mechanism 10 includes a support plate 1008. The outer wall of the protective sleeve 901 is fixedly connected to two mounting seats 1007, and there are two support plates 1008. One end of the two support plates 1008 is rotatably connected to the inside of the two mounting seats 1007, and the support mechanism 10 An elastic limiter is movably provided on the outside, and one end of the elastic limiter contacts one side of the support mechanism 10; the elastic limiter includes a connecting rod 1001, a mounting hole 1002, a tension spring 1003, a moving rod 1004, a connecting plate 1005 and a guide rod 1006, and a plurality of connecting rods 1001 are provided, and one end of adjacent connecting rods 1001 is fixedly connected to both sides of the mounting seat 1007, a mounting hole 1002 is provided on one side of the connecting rod 1001, a tension spring 1003 is fixedly connected to one side of the inner wall of the mounting hole 1002, and one end of the tension spring 1003 is fixedly connected to the moving rod 1004, and the outer wall of one end of the moving rod 1004 is fitted with the inner wall of the mounting hole 1002, and the other end of the moving rod 1004 is fixedly connected to the connecting plate 1005, and the inner side of the connecting plate 1005 is fixedly connected to the guide rod 1006;In the initial state, the support plate 1008 is located inside the mounting seat 1007. Due to the action of the rubber sleeve 902, the protective sleeve 901 can be sleeved on both ends of the capacitive stylus body 1. When the protective sleeve 901 is not in use, the protective sleeve 901 can be sleeved on the left end of the capacitive stylus body 1. Due to the action of the rubber sleeve 902, the outer wall of the capacitive stylus body 1 squeezes the rubber sleeve 902, thereby limiting the position of the protective sleeve 901 and pulling the support plate 1008 toward the left end of the capacitive stylus body 1. The left end of the support plate 1008 rotates inside the mounting seat 1007. When the support plate 1008 rotates to contact one end of the guide rod 1006, since one end of the guide rod 1006 is set to a rounded corner, the one end of the guide rod 1006 is squeezed and moves toward the outside of the mounting seat 1007. At this time, the guide rod 1006 drives the connecting plate 1005 to move, and the connecting plate 1005 drives the moving rod 1004 to move inside the mounting hole 1002, and then the moving rod 1004 drives the tension spring 100 3 stretches. When the support plate 1008 passes through one end of the guide rod 1006, the right end of the support plate 1008 rotates toward the upper left of the capacitive stylus body 1. Due to the reaction force of the tension spring 1003, the adjacent guide rod 1006 can be reset, so that the outer wall of one end of the guide rod 1006 contacts the side of the rotated support plate 1008, thereby limiting the position of the support plate 1008. Through the two support plates 1008, the capacitive stylus body 1 can be placed on the desktop at an inclined angle, and a gap is left between the capacitive stylus body 1 and the desktop, which is convenient for users to pick up and use later. At the same time, it can prevent the round or D-shaped capacitive stylus body 1 from rolling and falling, improving the convenience and safety of use. When using the protective cover 901, the protective cover 901 can be placed on the outside of the pen tip of the capacitive stylus body 1. At this time, the outside of the pen tip contacts the several baffles 903, and the rubber cover 902 contacts the outer wall of the right end of the capacitive stylus body 1, thereby supporting and protecting the pen tip and preventing the pen tip from accidentally falling to the ground and being damaged.
[0046] Example 2, as Figure 8 As shown, an active capacitive stylus control system with self-calibration function is further described with respect to claim 10, comprising the following steps:
[0047] S1. Contact detection and triggering: The pressure distribution can be measured by the annular pressure-sensitive sensor array 202. When the pressure is greater than 0.1 Newton, the self-calibration process is triggered, and the shape memory alloy spring 203 generates initial expansion and contraction.
[0048] S2. Multimodal data acquisition: The three-axis MEMS gyroscope 301 is used to collect the three-axis attitude angle, and the piezoelectric sensor array 302 is used to detect the pressure gradient. The Hall displacement sensor 303 is used to measure the extension and retraction of the pen tip. The electromagnetic field detector 304 can capture the screen driving frequency.
[0049] S3, signal conditioning processing: The signal is amplified by the low noise amplifier 401 and bandpass filtered by the anti-aliasing filter 402, while the 24-bit Σ-Δ ADC 403 digitally converts the signal and imports it into the control chip 7 for calibration parameter calculation processing;
[0050] S4, dynamic control execution: the parameter programmable DAC 501 converts the parameter into a control voltage, and the real-time clock synchronizer 502 synchronizes the screen refresh cycle;
[0051] S5, communication transmission and closed-loop feedback correction: send data packets and receive errors through the BLE five-point zero radio frequency module 601, then correct the model again through the control chip 7, and finally update the control shape memory alloy spring 203.
[0052] From the above, it can be seen that the specific implementation of the present invention is as follows: when the user touches the tip of the capacitive pen with an external device, the pressure distribution of the conical metal core 201 can be measured through the annular pressure-sensitive sensor array 202. When the pressure is greater than 0.1 Newton, the self-calibration process is triggered. At this time, the shape memory alloy spring 203 produces initial expansion and contraction. At this time, due to the effect of the hollow metal mesh 204, electromagnetic interference is suppressed, and at the same time, pressure is allowed to be transmitted to the annular pressure-sensitive sensor array 202. Then, the three-axis attitude angle is collected through the three-axis MEMS gyroscope 301, and the pressure gradient is detected by the piezoelectric sensor array 302. The expansion and contraction of the pen tip is measured in conjunction with the Hall displacement sensor 303, and the electromagnetic field detector 304 can capture the screen driving frequency and amplify it through low noise. The gain signal of the detector 401 and the anti-aliasing filter 402 perform bandpass filtering, while the 24-bit Σ-Δ ADC 403 digitally converts the digital signal and imports it into the control chip 7 for calibration parameter calculation and processing. The parameter programmable DAC 501 converts the parameter into a control voltage, and the real-time clock synchronizer 502 can synchronize the screen refresh cycle. In conjunction with the self-triggering logic circuit 503, when a dynamic mutation (such as a sudden change in pressure) is detected, the high-speed calibration mode is immediately activated. The data packet is sent and the error is received through the BLE five-point zero radio frequency module 601. Then, the model is corrected again through the control chip 7. Finally, the shape memory alloy spring 203 is updated and controlled. In conjunction with the Bluetooth communication unit 8, the calibration parameters and pen body status data can be transmitted to the touch device.
[0053] In summary, calibration parameters, pen body status data, and device feedback errors are bidirectionally transmitted through the communication interface layer 6. Furthermore, through the multimodal sensing layer 3, signal conditioning layer 4, dynamic control layer 5, and control chip 7, a closed-loop system begins operating at the moment of contact. This effectively eliminates positioning offsets and writing distortions introduced by factors such as changes in user grip posture, pen tip wear, screen curvature, and environmental electromagnetic interference, ensuring consistent handwriting accuracy. Furthermore, the screen drive frequency is captured by the electromagnetic field detector 304. Combined with the real-time clock synchronizer 502, the pen tip signal emission is precisely synchronized with the screen refresh cycle, effectively avoiding signal conflicts and delays and significantly suppressing screen noise interference.
[0054] In addition, in the initial state, the support plate 1008 is located inside the mounting seat 1007. Due to the action of the rubber sleeve 902, the protective sleeve 901 can be sleeved on both ends of the capacitive pen body 1. When the protective sleeve 901 is not in use, the protective sleeve 901 can be sleeved on the left end of the capacitive pen body 1. Due to the action of the rubber sleeve 902, the outer wall of the capacitive pen body 1 squeezes the rubber sleeve 902, thereby limiting the position of the protective sleeve 901 and pulling the support plate 1008 toward the left end of the capacitive pen body 1. 08, so that the left end of the support plate 1008 rotates inside the mounting seat 1007. When the support plate 1008 rotates to contact one end of the guide rod 1006, since one end of the guide rod 1006 is set to a rounded corner, the one end of the guide rod 1006 is squeezed and moves toward the outside of the mounting seat 1007. At this time, the guide rod 1006 drives the connecting plate 1005 to move, and the connecting plate 1005 drives the moving rod 1004 to move inside the mounting hole 1002, and then the moving rod 1004 drives the tension spring 1 003 is stretched. When the support plate 1008 passes through one end of the guide rod 1006, the right end of the support plate 1008 rotates toward the upper left of the capacitive pen body 1. Due to the reaction force of the tension spring 1003, the adjacent guide rod 1006 can be reset, so that the outer wall of one end of the guide rod 1006 contacts one side of the rotated support plate 1008, thereby limiting the position of the support plate 1008. Through the two support plates 1008, the capacitive pen body 1 can be placed on the desktop at an inclined angle, and a gap is left between the capacitive pen body 1 and the desktop, which is convenient for the user to take and use later. At the same time, it can prevent the round or D-shaped capacitive pen body 1 from rolling and falling, thereby improving the convenience and safety of use. When using the protective cover 901, the protective cover 901 can be put on the outside of the pen tip of the capacitive pen body 1. At this time, the outside of the pen tip contacts several baffles 903, and the rubber cover 902 contacts the outer wall of the right end of the capacitive pen body 1, thereby supporting and protecting the pen tip to prevent the pen tip from accidentally falling to the ground and being damaged.
[0055] The above is only an embodiment of the present invention, and the common knowledge such as the specific structure and characteristics of the scheme is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.
Claims
1. An active capacitive stylus with self-calibration function, characterized in that: The invention comprises a capacitive pen body (1), a pen tip electrode (2), a self-calibration unit, a control chip (7), a Bluetooth communication unit (8), a protective mechanism (9) and a support mechanism (10), wherein the pen tip electrode (2) is arranged at the rightmost end of the capacitive pen body (1) and is used to couple with the capacitive screen of a touch device, the self-calibration unit is arranged inside the capacitive pen body (1) and is used to detect in real time the offset of the physical parameter when the pen tip contacts the capacitive screen and to generate calibration parameters, the control chip (7) is arranged in the middle of the capacitive pen body (1) and is used to dynamically adjust the transmission signal of the pen tip electrode according to the calibration parameters, the Bluetooth communication unit (8) is arranged on the left side of the control chip (7) and is used to transmit the calibration parameters and pen body status data to the touch device, the protective mechanism (9) is arranged outside the left end of the capacitive pen body (1), and the protective mechanism (9) is in contact with the outer wall of the capacitive pen body (1), and the support mechanism (10) (10) is rotatable. The self-calibration unit further comprises a multimodal sensing layer (3), a signal conditioning layer (4), a dynamic control layer (5), and a communication interface layer (6). The multimodal sensing layer (3) is arranged on the left side of the pen tip motor (2) and is used to capture the physical state of the pen body in real time and provide raw data input for calibration. The signal conditioning layer (4) is arranged on the left side of the multimodal sensing layer (3) and is used to improve the signal-to-noise ratio of the sensing data and provide reliable input for calibration decision. The dynamic control layer (5) is arranged on the left side of the signal conditioning layer (4) and is used to convert the calibration parameters into physical adjustment actions to achieve real-time compensation of the pen tip. The communication interface layer (6) is arranged on the right side of the control chip (7) and is used to establish a two-way data channel between the pen tip and the touch device to achieve closed-loop calibration.
2. The active capacitive stylus pen with self-calibration function according to claim 1, characterized in that: The pen tip electrode (2) comprises a conical metal core (201), an annular pressure-sensitive sensor array (202), a shape memory alloy spring (203) and a hollow metal mesh (204); the conical metal core (201) is mounted at the rightmost end inside the capacitive pen body (1); the outer side of the conical metal core (201) is provided with a sleeve close to the annular pressure-sensitive sensor array (202); one end of the conical metal core (201) is provided with a shape memory alloy spring (203); one end of the shape memory alloy spring (203) is fixedly connected to the inner wall of the capacitive pen body (1); and the outer side of the annular pressure-sensitive sensor array (202) is provided with a hollow metal mesh (204).
3. The active capacitive stylus pen with self-calibration function according to claim 1, characterized in that: The multimodal sensing layer (3) comprises a three-axis MEMS gyroscope (301), a piezoelectric sensing array (302), a Hall displacement sensor (303) and an electromagnetic field detector (304); the Hall displacement sensor (303) is mounted on the left side of the pen tip electrode (2); the three-axis MEMS gyroscope (301) is mounted inside the capacitive pen body (1) near the left side of the Hall displacement sensor (303); the piezoelectric sensing array (302) is mounted inside the capacitive pen body (1) near the left side of the three-axis MEMS gyroscope (301); and the electromagnetic field detector (304) is mounted inside the capacitive pen body (1) near the left side of the piezoelectric sensing array (302).
4. The active capacitive stylus pen with self-calibration function according to claim 1, characterized in that: The signal conditioning layer (4) comprises a low-noise amplifier (401), an anti-aliasing filter (402) and a twenty-four-bit Σ-Δ ADC (403); the low-noise amplifier (401) is mounted on the left side of the multimodal sensing layer (3); the anti-aliasing filter (402) is mounted on a side of the capacitive stylus body (1) close to the low-noise amplifier (401); and the twenty-four-bit Σ-Δ ADC (403) is mounted on a side of the capacitive stylus body (1) close to the left side of the anti-aliasing filter (402).
5. The active capacitive stylus with self-calibration function according to claim 1, characterized in that: The dynamic control layer (5) comprises a parameter programmable DAC (501), a real-time clock synchronizer (502) and a self-triggering logic circuit (503); the parameter programmable DAC (501) is installed on the left side of the signal conditioning layer (4); the real-time clock synchronizer (502) is installed on the inside of the capacitive pen body (1) near the parameter programmable DAC (501); and the self-triggering logic circuit (503) is installed on the left side of the real-time clock synchronizer (502) inside the capacitive pen body (1).
6. The active capacitive stylus with self-calibration function according to claim 1, characterized in that: The communication interface layer (6) includes a BLE five-point zero radio frequency module (601), and the BLE five-point zero radio frequency module (601) is installed on the right side of the control chip (7).
7. The active capacitive stylus pen with self-calibration function according to claim 1, characterized in that: The protective mechanism (9) comprises a protective sleeve (901), a rubber sleeve (902) and a baffle (903); the protective sleeve (901) is sleeved on the left end of the capacitive stylus body (1); the inner wall of the protective sleeve (901) is fixedly connected to the rubber sleeve (902) near the opening; the inner wall of the protective sleeve (901) is fixedly connected to one side of the rubber sleeve (902); and the baffles (903) are equidistantly arranged in a circular array.
8. The active capacitive stylus with self-calibration function according to claim 7, characterized in that: The support mechanism (10) comprises a support plate (1008), the outer wall of the protective sleeve (901) is fixedly connected to two mounting seats (1007), two support plates (1008) are provided, and one end of the two support plates (1008) is rotatably connected to the inside of the two mounting seats (1007).
9. The active capacitive stylus with self-calibration function according to claim 8, characterized in that: The elastic limiting component comprises a connecting rod (1001), a mounting hole (1002), a tension spring (1003), a moving rod (1004), a connecting plate (1005) and a guide rod (1006). A plurality of connecting rods (1001) are provided, and one end of adjacent connecting rods (1001) is fixedly connected to both sides of a mounting seat (1007). A mounting hole (1002) is provided on one side of the connecting rod (1001), and a tension spring (1003) is fixedly connected to one side of an inner wall of the mounting hole (1002). One end of the tension spring (1003) is fixedly connected to the moving rod (1004). The outer wall of one end of the moving rod (1004) is in contact with the inner wall of the mounting hole (1002). The other end of the moving rod (1004) is fixedly connected to the connecting plate (1005), and the inner side of the connecting plate (1005) is fixedly connected to the guide rod (1006).
10. An active capacitive stylus control system with self-calibration function, characterized in that: The steps include: S1. Contact detection and triggering: The pressure distribution can be measured by the annular pressure-sensitive sensor array (202). When the pressure is greater than 0.1 Newton, the self-calibration process is triggered, and the shape memory alloy spring (203) generates initial expansion and contraction; S2. Multimodal data acquisition: The three-axis attitude angle is collected by the three-axis MEMS gyroscope (301), and the pressure gradient is detected by the piezoelectric sensor array (302). The pen tip extension and retraction amount is measured in conjunction with the Hall displacement sensor (303), and the electromagnetic field detector (304) can capture the screen driving frequency; S3, signal conditioning processing: the signal is amplified by a low noise amplifier (401) and bandpass filtered by an anti-aliasing filter (402), while a 24-bit Σ-Δ ADC (403) performs digital conversion and imports the digital signal into the control chip (7) for calibration parameter calculation processing; S4, dynamic control execution: the parameter programmable DAC (501) converts the parameter into a control voltage, and the real-time clock synchronizer (502) synchronizes the screen refresh cycle; S5, communication transmission and closed-loop feedback correction: send data packets and receive errors through the BLE five-point zero radio frequency module (601), then correct the model again through the control chip (7), and finally update the control shape memory alloy spring (203).