A pressure touchpad of a finger substitute pressure-sensitive active pen

Abstract

The application relates to the field of human-computer interaction and touch input technology, and discloses a pressure touch plate of a finger-replacing pressure-sensitive active pen, which comprises a touch sensing layer, a pressure sensing layer and a signal processing module, wherein: the touch sensing layer detects the coordinate position of a finger on the surface of the touch plate through a capacitive sensing technology; the pressure sensing layer detects the pressure applied on the surface of the touch plate through a piezoresistive or piezoelectric pressure sensor; and the signal processing module generates a drawing or writing command according to the coordinate information output by the touch sensing layer and the pressure value output by the pressure sensing layer, and adjusts the thickness of a pen trace or a drawing effect. Through the dynamic data fusion algorithm of the signal processing module combined with the touch sensing layer and the pressure sensing layer, the function of a finger as a handwriting pen is realized, an additional physical handwriting pen is not needed, a user can perform a drawing or writing operation on the touch plate, and parameters can be dynamically adjusted, the portability is improved, and various requirements such as daily writing and design drawing are met.

Description

Technical Field

[0001] This invention relates to the field of human-computer interaction and touch input technology, specifically a pressure touchpad that replaces a pressure-sensitive active pen with a finger. Background Technology

[0002] With the rapid development of information technology and human-computer interaction technology, touchpads, as an important input device, are widely used in portable electronic devices such as laptops and tablets. Traditional touchpads mainly rely on capacitive sensing technology to detect the touch position of fingers, offering high accuracy and response speed, and enabling functions such as cursor movement and gesture recognition. However, as users' demands for device portability and multifunctionality continue to increase, touchpads gradually need to meet more complex interaction requirements, such as enabling drawing and writing functions without the need for an additional stylus, to adapt to diverse application scenarios in modern offices, education, and design.

[0003] In existing technologies, touchpads on the market typically possess basic single-point or multi-point touch functionality, detecting touch coordinates through capacitive sensing to perform mouse-like operations. Additionally, some touchpad devices support more precise drawing and writing operations via an external stylus. However, this design requires users to purchase and carry a separate stylus, increasing complexity and equipment cost. Furthermore, existing touchpads are functionally limited, mostly unable to sense pressure applied by fingers, thus hindering the ability to adjust pen stroke thickness based on pressure, limiting their application in graphic design and creative work scenarios.

[0004] The main problem with existing touchpads lies in their functional limitations, particularly in their inability to directly achieve stylus-like functions using fingers. This not only increases reliance on peripherals but also restricts the user's freedom of operation in drawing and writing scenarios. More importantly, existing touchpads cannot dynamically adjust parameters such as stroke thickness and transparency, resulting in an unnatural drawing and writing experience that fails to meet users' demands for higher precision and dynamic effects. Therefore, a pressure-sensitive touchpad is needed that can replace stylus functionality with fingers, capable of detecting touch coordinates and sensing the pressure applied by the finger, thereby enabling dynamic adjustment of drawing strokes and meeting the requirements of portability and multifunctionality. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a pressure touchpad that replaces a pressure-sensitive active pen with a finger, solving the problems that existing touchpads cannot directly achieve the function of a stylus with a finger and cannot dynamically adjust the thickness of drawing strokes.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a pressure-sensitive touchpad that replaces a pressure-sensitive stylus with a finger, comprising a touch-sensing layer, a pressure-sensing layer, and a signal processing module, wherein:

[0007] The touch sensing layer detects the coordinate position of a finger on the touchpad surface using capacitive sensing technology;

[0008] The pressure sensing layer detects the pressure applied to the touchpad surface using a piezoresistive or piezoelectric pressure sensor;

[0009] The signal processing module generates drawing or writing commands based on the coordinate information output by the touch sensing layer and the pressure value output by the pressure sensing layer, and adjusts the thickness of the strokes or the drawing effect.

[0010] Preferably, the touch sensing layer is an interleaved electrode array, and the touch sensing signal is collected by point-by-point scanning, supporting single-point touch and multi-point touch functions, while simultaneously detecting the coordinate position and touch area of ​​multiple touch points.

[0011] Preferably, the pressure sensing layer includes one or more independent pressure sensing areas. The pressure applied at any position on the touchpad is calculated by a corresponding algorithm, and the pressure value is transmitted to the signal processing module. The signal processing module generates corresponding drawing commands based on the pressure distribution of each area.

[0012] Preferably, the signal processing module switches the touchpad's working mode based on a preset pressure threshold, including a normal touch mode and a stylus mode. When the pressure value is greater than the preset threshold, the touchpad switches to stylus mode.

[0013] Preferably, the signal processing module can generate a composite drawing signal based on the synchronization signals of the touch sensing layer and the pressure sensing layer, specifically including:

[0014] The drawing trajectory is determined based on the touch position signal;

[0015] The thickness, transparency, or hardness of the strokes are dynamically adjusted based on the pressure signal.

[0016] Preferably, the touch sensing layer and the pressure sensing layer are coplanarly integrated, and the signal acquisition circuit is isolated from external interference signals by a shielding layer.

[0017] Preferably, the signal processing module includes a pressure mapping algorithm that can map pressure values ​​to the thickness of strokes in drawing, specifically:

[0018] Low pressure values ​​are mapped to fine lines;

[0019] High pressure values ​​are mapped to thick strokes;

[0020] The pressure mapping relationship can be adjusted or preset according to user needs.

[0021] Preferably, the signal processing module has a built-in smoothing algorithm that performs real-time filtering on the acquired pressure signal to eliminate noise caused by operational jitter.

[0022] Preferably, the touchpad includes a standardized interface for connecting to external devices and provides signal access to the touch sensing layer and pressure sensing layer through the interface, allowing external devices to customize the style and effect of drawing or writing through the developer API interface.

[0023] Preferably, the signal processing module uses an adaptive adjustment algorithm to correct the signal of the pressure sensing layer based on environmental parameters.

[0024] This invention provides a pressure-sensitive touchpad that replaces a pressure-sensitive stylus with a finger. It offers the following advantages:

[0025] 1. This invention enables the use of a finger as a stylus by utilizing the collaborative work of a touch-sensing layer and a pressure-sensing layer, combined with a dynamic data fusion algorithm in the signal processing module. Without the need for an additional physical stylus, users can draw or write on the touchpad and dynamically adjust parameters such as stroke thickness and transparency, thereby improving portability, reducing reliance on external devices, and meeting various needs such as daily writing and design drawing.

[0026] 2. This invention features two working modes: a normal touch mode and a stylus mode, dynamically switching between them based on the pressure value detected by the pressure-sensing layer. When the detected pressure value exceeds a threshold, the touchpad automatically enters stylus mode, supporting precise drawing and writing; when the pressure value is low, it switches back to normal touch mode, supporting everyday mouse functions. This mode-switching mechanism enhances the touchpad's versatility and user experience.

[0027] 3. By detecting the pressure applied by the finger through a pressure-sensing layer and combining it with the pressure mapping algorithm of the signal processing module, this invention can dynamically adjust the thickness, transparency, or hardness of the strokes, thereby simulating the effect of a realistic stylus. A light touch generates fine strokes, while heavy pressure generates thick strokes, making drawing and writing more natural and fluid. This feature is particularly suitable for professional drawing, signature, and creative design scenarios.

[0028] 4. The touch sensing layer of this invention employs high-resolution capacitive sensing technology, combined with a crisscrossing electrode array design, to achieve precise touch coordinate detection; the pressure sensing layer accurately senses pressure values ​​through flexible piezoresistive or piezoelectric materials and supports independent detection of multiple areas, ensuring the accuracy of pressure distribution. The collaborative design of the two sensor layers significantly improves the overall detection accuracy of the touchpad.

[0029] 5. The present invention adopts a coplanar integrated design, which integrates the touch sensing layer and the pressure sensing layer on the same plane. The design of flexible circuit and shielding layer effectively reduces the internal connection complexity and significantly reduces the overall thickness of the touch panel. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the pressure touch panel of the present invention;

[0031] Figure 2 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Please see the appendix Figure 1 -Appendix Figure 2 This invention provides a pressure touchpad that replaces a pressure-sensitive stylus with a finger, comprising:

[0034] 1. Touch sensing layer

[0035] The touch sensing layer detects the coordinate position of a finger on the touchpad surface using capacitive sensing technology, providing precise trajectory data for subsequent drawing or writing commands. This module works in conjunction with the pressure sensing layer to support precise multi-touch, stylus mode switching, and dynamic drawing functions. Connected to the signal processing module, the touch sensing layer captures touch positions in real time by scanning changes in the capacitance of the electrode array, meeting the touchpad's requirements for high precision and real-time performance.

[0036] In this embodiment, the touch sensing layer is formed by an alternating array of horizontal and vertical electrodes to create a two-dimensional coordinate array. This alternating electrode array design effectively covers the entire touchpad surface and provides an independent capacitive sensing unit for each touch point.

[0037] The capacitance value between each electrode node is detected by the change in capacitance when the finger touches it, thereby determining the specific location of the touch point.

[0038] When a finger approaches or touches the touchpad surface, it changes the electric field distribution between the finger and the electrodes, causing a change in the node capacitance value.

[0039] Capacitance C ij The change is related to the position and area of ​​the touch point, and its calculation formula is:

[0040] ;

[0041] in, Where is the dielectric constant. The effective area of ​​the electrode covered by the finger. This refers to the distance between the finger and the electrode. When the finger makes contact... Reduced, leading to With this increase, touch signals are easier to detect.

[0042] The capacitive signal of the touch sensing layer is acquired by scanning point by point, and the scanning frequency can be set to the 1ms level to ensure the real-time performance and continuity of the signal.

[0043] The signal acquisition circuit converts the analog capacitance change signal into a digital signal through an analog-to-digital converter (ADC) and transmits it to the signal processing module in real time.

[0044] The touch sensing layer supports single-point touch and multi-point touch functions, and can simultaneously detect the XY coordinate position of multiple touch points and the area covered by the finger.

[0045] The signal processing module processes signals from multiple touch points and calculates the independent trajectory of each touch point, making it suitable for complex gesture operation scenarios, such as zooming in, zooming out, and rotating.

[0046] To improve the stability of touch signals, the touch sensing layer is equipped with an anti-interference design, which reduces the impact of external electromagnetic interference by optimizing the material and arrangement of the electrodes.

[0047] Even in high humidity or high temperature environments, the touch signal remains stable, and the touchpad sensitivity is unaffected.

[0048] The sensitivity, scanning frequency, and electrode node layout of the touch sensing layer can be adjusted through software configuration to suit different usage scenarios.

[0049] The sensitivity adjustment range is set to 1 to 10 levels, and the scanning frequency range is 500Hz to 2000Hz.

[0050] Finger touch detection:

[0051] When a user touches the touchpad with their finger, the capacitance value of the electrode at the finger's location changes, and the touch sensing layer captures this change signal in real time.

[0052] Coordinate calculation:

[0053] The signal acquisition module scans the electrode array point by point to obtain the capacitance change of all nodes, and calculates the XY coordinates of the touch point based on the change.

[0054] Touch area determination:

[0055] The signal processing module analyzes the number of electrodes covered by the finger to estimate the area touched by the finger, providing reference data for subsequent drawing effects (such as changes in stroke thickness or transparency).

[0056] 2. Pressure-sensing layer

[0057] The pressure-sensitive layer detects the pressure applied by a finger to the touchpad surface, providing core data support for dynamically adjusting the thickness and transparency of drawing strokes. Working in conjunction with the touch-sensitive layer, the pressure-sensitive layer provides the foundation for stylus mode switching and complex drawing functions through precise pressure detection. The pressure-sensitive layer is designed with sensitivity, accuracy, and environmental adaptability in mind to meet the needs of various application scenarios.

[0058] The pressure sensing layer is made of flexible piezoresistive or piezoelectric material, which can sense the applied pressure and output a corresponding electrical signal.

[0059] The pressure sensing layer is divided into multiple independent detection areas, each of which independently collects pressure signals, thereby enabling the detection of pressure distribution on the touchpad surface.

[0060] Piezoresistive pressure sensor:

[0061] In piezoresistive design, the resistance of the material changes with pressure, and the relationship can be expressed as:

[0062] ;

[0063] in, Let be the initial resistance value, α be the sensitivity coefficient, and P be the applied pressure. As the pressure increases, the resistance value decreases, and the signal acquisition module converts the changing resistance value into a voltage signal for further processing.

[0064] Piezoelectric pressure sensors: In piezoelectric designs, a material generates a voltage signal when subjected to pressure, the intensity of which is proportional to the applied pressure. The signal acquisition module amplifies and digitizes the voltage signal using an amplifier circuit for subsequent signal processing.

[0065] The pressure sensing layer is divided into multiple independent pressure detection areas, each with its own independent signal acquisition channel.

[0066] This partitioned design supports the detection of pressure distribution on the touchpad surface, enabling complex drawing functions such as dynamic pen stroke effects driven by multi-point pressure distribution.

[0067] The pressure signal is detected in real time by the signal acquisition circuit and transmitted to the signal processing module.

[0068] The signal acquisition frequency is adjustable, with a typical value of 1kHz, which can meet the real-time requirements for rapid plotting.

[0069] The signal acquisition module uses a low-noise amplifier circuit to enhance signal sensitivity and converts analog signals into digital signals through an analog-to-digital converter (ADC).

[0070] The output signal of the pressure-sensing layer is correlated with the thickness of the drawing strokes through a preset mapping relationship:

[0071] ;

[0072] Where S represents the stroke thickness and β represents the mapping coefficient. The signal processing module can dynamically adjust the mapping relationship according to user needs.

[0073] The sensitivity of the pressure sensing layer can be optimized by adjusting the material properties and circuit parameters, with a sensitivity range of 10g to 500g.

[0074] The linear range of the pressure sensing layer is designed to be from 0g to 1kg. Pressure exceeding this range will trigger an overload protection mechanism to protect the sensing layer from damage.

[0075] The pressure sensing layer is designed with flexible materials, giving it good environmental adaptability. The detection accuracy of the pressure signal does not decrease significantly in high humidity or high temperature environments.

[0076] To further enhance reliability, the signal processing module incorporates an environmental correction algorithm that dynamically compensates for the pressure signal based on temperature and humidity data. The correction formula is as follows:

[0077] ;

[0078] Wherein, γ is the correction coefficient, which is calculated in real time by the temperature and humidity sensor.

[0079] Pressure signal acquisition

[0080] When a finger applies pressure to the touchpad surface, the resistance or voltage value of the pressure-sensing layer changes with the pressure, generating a corresponding signal.

[0081] The signal acquisition module collects pressure data at a sampling frequency of 1ms and transmits it to the signal processing module.

[0082] Pressure distribution calculation

[0083] The multi-zone detection design supports the simultaneous acquisition of signals from multiple pressure zones. The signal processing module calculates the overall pressure distribution on the touchpad surface based on the pressure value of each zone.

[0084] Drawing command generation

[0085] The signal processing module maps the pressure value to the thickness or transparency of the drawing strokes, and combines this with the coordinate information of the touch sensing layer to generate a complete drawing command.

[0086] High-sensitivity pressure detection: The pressure sensing layer can detect minute pressure changes, adapting to operational needs ranging from light touch to heavy pressure.

[0087] Dynamic pressure distribution: The multi-zone independent detection design supports real-time analysis of the pressure distribution on the touchpad surface, making it suitable for complex drawing applications.

[0088] Strong environmental adaptability: The pressure sensing layer can still work stably in harsh environments such as high temperature and high humidity, and the detection accuracy can be further improved by combining with environmental correction algorithms.

[0089] Highly scalable: The output signal can interact with external devices through a standardized interface and supports user-defined pressure mapping relationships.

[0090] 3. Signal Processing Module

[0091] The signal processing module receives signals from the touch and pressure sensing layers and generates accurate drawing or writing commands by fusing touch coordinate information with pressure data. It performs multiple functions, including data acquisition, mode switching, signal fusion, pressure mapping, and noise processing, providing the touchpad with stylus functionality, dynamic stroke adjustment, and high-stability operation support. The signal processing module is designed to closely integrate the output characteristics of the touch and pressure sensing layers and ensures real-time performance and accuracy through optimized algorithms.

[0092] Data acquisition function

[0093] The signal processing module receives the coordinate information of the touch sensing layer and the pressure data of the pressure sensing layer through a high-speed signal acquisition circuit.

[0094] Touch data acquisition: The touch sensing layer electrode array is scanned point by point to obtain the XY coordinates and coverage area of ​​the touch point. The scanning frequency is adjustable, with a typical value of 1ms.

[0095] Pressure data acquisition: Pressure values ​​are acquired from multiple detection areas of the pressure sensing layer, and the analog signals are converted into digital signals by an analog-to-digital converter (ADC) for subsequent processing.

[0096] The signal processing module dynamically switches the touchpad's operating mode based on the pressure value, including normal touch mode and stylus mode.

[0097] Pressure threshold determination: When the pressure value P exceeds the preset threshold P th When the touchpad switches to stylus mode, the mode switching logic is as follows:

[0098] ;

[0099] The stylus mode supports higher precision and dynamic stroke adjustment, making it suitable for drawing and writing scenarios.

[0100] The signal processing module fuses the coordinate data of the touch sensing layer and the pressure data of the pressure sensing layer to generate a composite drawing signal.

[0101] Touch trajectory generation: Calculate the drawing trajectory based on the coordinate information of the touch sensing layer.

[0102] Pressure-driven effect: The thickness, transparency, or hardness of the strokes is dynamically adjusted based on the pressure value of the pressure-sensing layer. The formula for the stroke effect is as follows:

[0103] ;

[0104] Where S is the stroke thickness and β is the mapping coefficient.

[0105] The pressure mapping algorithm is used to convert pressure values ​​(PPP) into stroke parameters in drawing commands. The mapping relationship can be customized by the user or automatically adjusted through preset parameters.

[0106] Low pressure mapping: Light pressure corresponds to fine lines, suitable for delicate operations;

[0107] High pressure mapping: High pressure corresponds to thick strokes, suitable for large-area fill drawing.

[0108] The mapping formula is expandable; for example, it can incorporate transparency adjustments.

[0109] ;

[0110] Where T is the transparency and γ is the transparency mapping coefficient.

[0111] Noise processing function

[0112] To ensure the stability of pressure data, the signal processing module has a built-in smoothing algorithm to filter the acquired pressure signals in real time.

[0113] Low-pass filtering algorithm: eliminates high-frequency noise and optimizes the continuity of the plotting trajectory. The smoothing formula is:

[0114] ;

[0115] Where D(t) is the current pressure value and α is the smoothing factor.

[0116] Interface output function

[0117] The signal processing module connects to external devices via standardized interfaces (such as USB or wireless transmission protocols). The generated composite drawing signals can be transmitted to external devices in real time for use by drawing or writing applications.

[0118] The interface supports a developer API, allowing external devices to access touch and pressure data for customized drawing functions.

[0119] Signal Acquisition and Fusion

[0120] When a finger touches the touchpad, the touch sensing layer provides coordinate data, and the pressure sensing layer outputs pressure values.

[0121] The signal processing module synchronously acquires two types of signals at a frequency of 1ms and performs fusion processing according to a preset algorithm.

[0122] Mode switching and drawing command generation

[0123] When the pressure exceeds the threshold, the touchpad switches to stylus mode.

[0124] The signal processing module combines coordinate data with pressure values ​​to generate a composite drawing signal, adjusting the stroke thickness and transparency.

[0125] Real-time output

[0126] The processed drawing signal is transmitted to an external device in real time via an interface, driving the drawing software to achieve the corresponding effect.

[0127] Coplanar integration aims to integrate the touch sensing layer and pressure sensing layer on the same plane, achieving a high degree of integration between touch and pressure sensing. This design effectively reduces the thickness of the touchpad, improves the accuracy and stability of signal acquisition, and simplifies the overall manufacturing process. Through coplanar integration, the touchpad can better adapt to the thinner and lighter requirements of modern portable devices, while enhancing anti-interference capabilities and improving the user experience.

[0128] The touch sensing layer and the pressure sensing layer are integrated on the same substrate material in a coplanar manner, and the two layers are connected by a flexible circuit to form an integrated sensing unit.

[0129] The coplanar design employs a multi-layered composite structure, with a wear-resistant surface layer, a sensing layer in the middle, and a shielding layer at the bottom. The sensing layer is fabricated using standard photolithography processes to ensure uniform distribution of electrodes and sensors.

[0130] Touch sensing circuit: The electrode array of the touch sensing layer is arranged in a crisscross pattern to form a two-dimensional coordinate system, which is connected to the signal acquisition circuit.

[0131] Pressure sensing circuit: The sensor units of the pressure sensing layer are distributed in different areas of the touch panel, and each unit is independently connected to the signal acquisition circuit.

[0132] Circuit integration method: The signals from the touch sensing layer and the pressure sensing layer are transmitted to the signal processing module through a shared flexible cable, which simplifies the circuit connection design and reduces the interconnection complexity.

[0133] To avoid mutual interference between touch sensing signals and pressure sensing signals, the coplanar integrated design places a shielding layer between the touch sensing layer and the pressure sensing layer.

[0134] Features of the shielding layer: The shielding layer is made of conductive material, which can effectively isolate interference from different signal paths and prevent external electromagnetic waves from affecting the signal.

[0135] Electromagnetic compatibility: The shielding layer is designed to meet electromagnetic compatibility (EMC) standards, ensuring the stability of the touchpad in high-interference environments.

[0136] The coplanar integrated design significantly reduces the overall thickness of the touchpad, keeping the total thickness of the touchpad within 3 millimeters, meeting the demand for a thin and light structure in portable devices.

[0137] To further reduce the thickness of the structure, the thickness of the sensing layer and the shielding layer is controlled by optimizing the material selection, with the sensing layer having a thickness of 0.2 mm and the shielding layer having a thickness of 0.1 mm.

[0138] Material selection: The substrate material is a flexible polyimide film, which has high heat resistance and mechanical strength, making it suitable for large-scale production.

[0139] Process flow: The sensing layer and the shielding layer are processed by roll-to-roll photolithography, which is highly precise and efficient; the flexible circuit is connected to the sensing layer by thermoforming to ensure reliable contact.

[0140] Quality control: Each touchpad undergoes three electrical performance tests during the production process to ensure the sensing accuracy and stability of the integrated layer.

[0141] The touchpad surface is covered with a wear-resistant and non-slip material to protect the sensing layer from physical damage and enhance the tactile experience for users.

[0142] The surface material has hydrophobic properties, preventing liquids from entering the sensing layer, and is also easy to clean.

[0143] Environmental adaptability

[0144] The coplanar touchpad can adapt to different temperature and humidity environments, with an operating temperature range of -10℃ to 60℃ and a humidity range of 10% to 90%RH.

[0145] In high humidity environments, the shielding layer prevents leakage of the sensing signal, while the flexible material of the pressure sensing layer has good moisture resistance.

[0146] Signal detection: When a user's finger touches the touchpad, the touch sensing layer detects the touch position in real time, and the pressure sensing layer detects the applied pressure value simultaneously.

[0147] The shielding layer isolates touch signals from pressure signals, ensuring their independence.

[0148] Signal transmission: The signals from the touch sensing layer and the pressure sensing layer are transmitted to the signal processing module through a shared flexible cable, with no significant signal delay.

[0149] Comprehensive processing: The signal processing module generates composite drawing commands based on touch and pressure signals and outputs them to external devices in real time.

[0150] 5. Standardized Interface

[0151] A standardized interface enables seamless connection between the touchpad and external devices, supporting signal transmission, function expansion, and user-customized operations. The interface design ensures the touchpad's versatility and adaptability while providing developers with a convenient way to call the API, enhancing the scalability of this invention. By providing an open developer API, users can flexibly configure the touchpad's parameters and functions according to their needs.

[0152] Interface Types and Compatibility

[0153] Wired interface: Uses USB 2.0 or USB-C interface to provide high-bandwidth signal transmission capability, ensuring that touchpad data can be transmitted to external devices in real time.

[0154] Wireless interface: Supports Bluetooth 5.0 and Wi-Fi 6 standards to enable wireless connection between the touchpad and external devices, adapting to portable scenarios.

[0155] Compatibility: The interface design is compatible with mainstream operating systems (such as Windows, macOS and Linux), and users can use it directly without installing additional drivers.

[0156] Data transmission function

[0157] Touch signal transmission: The interface can transmit the coordinate information generated by the touch sensing layer in real time, and the resolution supports 1000 DPI.

[0158] Pressure signal transmission: The interface supports high-precision transmission of pressure values, with an accuracy of up to 0.1 grams, and ensures no delay when transmitting large amounts of data.

[0159] Synchronization: Touch signals and pressure signals are transmitted with a unified timestamp to ensure the consistency of signal fusion.

[0160] Developer API

[0161] It provides an open developer API interface, allowing users to access touchpad touch data and pressure data, and customize functions according to specific needs.

[0162] API functionality:

[0163] Check the current working mode of the touchpad (normal touch mode or stylus mode).

[0164] Adjust the pressure sensitivity and threshold range.

[0165] Customize drawing commands, such as stroke thickness, transparency, and style.

[0166] API Documentation: Provides detailed API documentation, including sample code and development guidance, lowering the barrier to secondary development.

[0167] Configuration Function

[0168] Users can configure touchpad parameters through the interface, including touch sensitivity, pressure sensitivity, mode switching threshold, etc.

[0169] Configuration can be performed via terminal commands or a graphical interface, catering to the operating habits of users at different levels.

[0170] Safety and stability

[0171] Data encryption: Data transmitted via the wireless interface is encrypted using AES-256 to ensure the security of user data.

[0172] Anti-interference design: The interface signals adopt anti-interference coding technology, which can ensure signal stability in complex environments.

[0173] Error checking: A CRC check mechanism is introduced during transmission to ensure data integrity.

[0174] Extended application support

[0175] It supports plug-and-play functionality for various drawing and office software such as Photoshop, AutoCAD, and Microsoft Office.

[0176] It provides functional extensions for educational scenarios, such as support for virtual whiteboards and remote interactive operations.

[0177] Initial connection: The user connects the touchpad to an external device via USB or Bluetooth. Once the device detects the touchpad, it automatically loads the driver or calls the default interface.

[0178] Data access and configuration: Users can obtain touch coordinates and pressure values ​​by calling the touchpad's real-time data interface through the developer API.

[0179] Configure the touchpad sensitivity, mode switching threshold, or drawing command style as needed.

[0180] Real-time drawing operation: External devices receive data from the touchpad through an interface and map it to the drawing software to generate corresponding stroke effects.

[0181] 6. Environmental adaptive adjustment

[0182] Environmental adaptive adjustment is used to ensure the touchpad's performance stability under different environmental conditions. By monitoring environmental parameters (such as temperature and humidity) in real time, the signal processing module can dynamically correct deviations in touch and pressure signals to adapt to the needs of complex working environments.

[0183] Environmental parameter detection

[0184] The touchpad has a built-in temperature and humidity sensor for real-time monitoring of the working environment's temperature and humidity.

[0185] Temperature detection range: -10℃ to 60℃, accuracy: ±0.5℃.

[0186] Humidity detection range: 10%RH to 90%RH, accuracy: ±3%.

[0187] Signal correction algorithm

[0188] Touch signal calibration: When the temperature or humidity exceeds the normal range, the signal processing module calibrates the detection accuracy of the touch coordinates based on a preset environmental model. The calibration formula is as follows:

[0189] ;

[0190] Where X is the original coordinate value, ΔT is the temperature deviation, and α is the temperature correction coefficient.

[0191] Pressure signal correction: Pressure signal correction is based on a model that combines the effects of humidity and temperature.

[0192] ;

[0193] Where P is the original pressure value, ΔT and ΔH are the temperature and humidity deviations, respectively, and β and γ are correction coefficients.

[0194] Dynamic compensation: The signal processing module acquires environmental parameters once per second and updates the parameter values ​​of the correction model in real time.

[0195] The calibration process does not affect the user's operational smoothness, and the adjustment results take effect immediately.

[0196] User feedback function: When environmental parameters are detected to be outside the preset range, the touchpad will alert the user through a graphical interface or light prompts.

[0197] Users can choose to enable manual calibration mode to further optimize touchpad performance.

[0198] Long-term adaptive learning: The signal processing module has a built-in self-learning algorithm that optimizes the parameters of the correction model based on historical data, improving the stability of the touchpad in specific environments.

[0199] Environmental monitoring and correction: Temperature and humidity sensors detect environmental parameters in real time, and the signal processing module acquires the current temperature and humidity data.

[0200] When parameters are abnormal, the module automatically corrects the touch signal and pressure signal to ensure the accuracy of the output.

[0201] User feedback and adjustments: When environmental conditions change significantly, the touchpad prompts the user to check the working environment through the interface.

[0202] Users can manually adjust the touchpad's working mode or sensitivity based on the prompts.

[0203] Working Principle: Through the coordinated action of the touch sensing layer, pressure sensing layer, and signal processing module, precise detection of touch position and dynamic perception of applied pressure are achieved, thus enabling the finger to replace the function of a stylus. The touch sensing layer detects the touch coordinates of the finger using capacitive sensing technology, employing a crisscrossing electrode array structure to scan the touch signal point by point and acquire high-resolution touch data. The pressure sensing layer detects the magnitude of the pressure applied by the finger using flexible piezoresistive or piezoelectric materials and transmits this data to the signal processing module in real time. The signal processing module fuses the touch coordinates and pressure data to generate composite drawing commands, dynamically adjusting the thickness, transparency, or hardness of the strokes to achieve dynamic drawing or writing functions. When the pressure value exceeds a preset threshold, the touchpad automatically switches to stylus mode, supporting higher precision stroke control. To ensure the independence of touch and pressure signals, the touch sensing layer and pressure sensing layer adopt a coplanar integrated design and are equipped with a shielding layer to isolate signal interference. Through a built-in low-pass filter, the signal processing module can smooth the pressure signal and eliminate high-frequency noise. Furthermore, the signal processing module supports environmental adaptive adjustment, capable of correcting touch and pressure signals based on real-time changes in temperature and humidity, ensuring device stability under complex environmental conditions. Finally, all processed signals are transmitted to external devices through a standardized interface, and an open developer API is provided to support user configuration and functional expansion, making it widely applicable to various application scenarios such as graphic design, electronic signatures, and educational assistance.

[0204] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A pressure touchpad that replaces a pressure-sensitive stylus with a finger, characterized in that, include: The system comprises a touch-sensing layer, a pressure-sensing layer, and a signal processing module, wherein: The touch sensing layer detects the coordinate position of a finger on the touchpad surface using capacitive sensing technology; the touch sensing layer is an interleaved electrode array, and the touch sensing signal is collected by point-by-point scanning, supporting single-point touch and multi-point touch functions, while simultaneously detecting the coordinate position and touch area of ​​multiple touch points; The pressure sensing layer detects the pressure applied to the touchpad surface using a piezoresistive or piezoelectric pressure sensor. The pressure sensing layer is divided into multiple independent detection areas, each independently acquiring pressure signals, thereby detecting the pressure distribution on the touchpad surface. A corresponding algorithm calculates the pressure applied at any location on the touchpad and transmits the pressure value to the signal processing module. The touch sensing layer and the pressure sensing layer are integrated coplanarly on the same substrate material, connected by a flexible circuit to form an integrated sensing unit. The signal acquisition circuit is isolated from external interference signals by a shielding layer. The signal processing module generates drawing or writing commands based on the coordinate information output by the touch sensing layer and the pressure value output by the pressure sensing layer, and adjusts the thickness of the strokes or the drawing effect. The signal processing module generates corresponding drawing commands based on the pressure distribution in each area. The algorithm calculation formula is: R = R0(1 - α·P), where R is the resistance value, R0 is the initial resistance value, α is the sensitivity coefficient, and P is the applied pressure value. The signal processing module synchronously acquires touch signals and pressure signals, and performs fusion processing according to a preset algorithm. The signal processing module can generate composite drawing signals based on the synchronous signals from the touch sensing layer and the pressure sensing layer. The signal processing module uses an adaptive adjustment algorithm to correct the signal of the pressure sensing layer based on environmental parameters; wherein, the signal correction algorithm of the adaptive adjustment algorithm includes touch signal correction and pressure signal correction, and the adaptive adjustment algorithm also includes dynamic compensation, user feedback function, long-term adaptive learning, environmental monitoring and correction, and user feedback and adjustment. The touch signal correction is as follows: when the temperature or humidity exceeds the normal range, the signal processing module corrects the detection accuracy of the touch coordinates according to a preset environmental model. The correction formula is: X adjusted = X▪(1+α▪ΔT), where X adjusted To correct the coordinate values, X is the original coordinate value, ΔT is the temperature deviation, and α is the temperature correction coefficient; The pressure signal correction is based on a combined humidity and temperature influence model: P adjusted =P▪(1+β▪ΔT+γ▪ΔH), where P adjusted To correct the pressure value, P is the original pressure value, ΔT and ΔH are the temperature deviation and humidity deviation, respectively, and β and γ are correction coefficients; The dynamic compensation is as follows: the signal processing module acquires environmental parameters once per second and updates the parameter values ​​of the correction model in real time; The user feedback function is as follows: when environmental parameters are detected to exceed the preset range, the touchpad will remind the user through a graphical interface or light prompts. The user can choose to enable the manual calibration mode to further optimize the performance of the touchpad. The long-term adaptive learning is as follows: the signal processing module has a built-in self-learning algorithm that optimizes and corrects the parameters of the model based on historical data, thereby improving the stability of the touchpad in a specific environment; The environmental monitoring and correction are as follows: the temperature and humidity sensor detects environmental parameters in real time, and the signal processing module acquires the current temperature and humidity data; when the parameters are abnormal, the module automatically corrects the touch signal and pressure signal to ensure the accuracy of the output. The user feedback and adjustments are as follows: when environmental conditions change significantly, the touchpad prompts the user to check the working environment via the interface. Users can manually adjust the touchpad's operating mode or sensitivity based on the prompts.

2. A pressure touchpad that replaces a pressure-sensitive active pen with a finger, as described in claim 1, is characterized in that... The signal processing module switches the touchpad's operating mode based on a preset pressure threshold or a long press, including: normal touch mode and stylus mode. The switching modes include: When the pressure value exceeds the preset pressure threshold, the touchpad switches to stylus mode; Long press the touchpad to select and switch.

3. A pressure touchpad that replaces a pressure-sensitive active pen with a finger, as described in claim 1, is characterized in that... The signal processing module can generate a composite drawing signal based on the synchronization signals of the touch sensing layer and the pressure sensing layer, specifically including: The drawing trajectory is determined based on the touch position signal; The thickness, transparency, or hardness of the strokes are dynamically adjusted based on the pressure signal.

4. A pressure touchpad that replaces a pressure-sensitive active pen with a finger, as described in claim 1, is characterized in that... The signal processing module includes a pressure mapping algorithm that can map pressure values ​​to the thickness of strokes in drawing, specifically: Low pressure values ​​are mapped to fine lines; High pressure values ​​are mapped to thick strokes; The pressure value mapping relationship can be adjusted or preset according to user needs; The pressure value mapping relationship allows adjustment of pen tip size and color options.

5. A pressure touchpad that replaces a pressure-sensitive active pen with a finger, as described in claim 1, is characterized in that... The signal processing module has a built-in smoothing algorithm that filters the collected pressure signal in real time to eliminate noise caused by operational jitter.

6. A pressure touchpad that replaces a pressure-sensitive active pen with a finger, as described in claim 1, is characterized in that... The touchpad includes a standardized interface for connecting to external devices and provides signal access to the touch sensing layer and the pressure sensing layer through the standardized interface, allowing external devices to customize the style and effect of drawing or writing through the developer API interface.

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