Sensitivity test system and method for touchpad
By designing a touchpad sensitivity testing system with multiple modules, the existing system cannot accurately simulate user touch behavior and lack of dynamic calibration, and achieve high accuracy and reliability testing, adapt to changes in the production process and reduce costs.
Patent Information
- Application Number
- CN202411721710.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-03-21
AI Technical Summary
The existing touchpad testing system cannot accurately simulate the user's touch behavior, resulting in inaccurate test results, unable to fully evaluate the performance of the touchpad, and lacks dynamic calibration functions, so that the test parameters cannot be adjusted in real time to adapt to environmental changes and component differences.
A touch panel sensitivity testing system is designed, including a signal excitation source module, a differential to single-ended conversion module, a level transfer module, a voltage and current measurement path module, a data processing module and an automatic calibration module. Through the combination of these modules, accurate testing and dynamic calibration of touch panel sensitivity are achieved.
Through dynamic calibration and precise signal processing, the accuracy and reliability of touchpad sensitivity tests are improved, and can adapt to changes in the production process, ensuring that the touchpad provides consistent performance under various usage conditions, reducing production costs and rework rates.
Smart Images
Figure CN119667437A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of touch panel testing, and in particular to a touch panel sensitivity testing system and method. Background Art
[0002] A touchpad is a common input device widely used in laptops and some desktop computers. It allows users to control cursor movement, select items, and execute other commands by directly touching or sliding their fingers. A touchpad usually contains a sensing surface that can detect the position and movement of fingers, thereby achieving precise cursor control and gesture recognition. During the production process of a touchpad, it is crucial to test its sensitivity. The sensitivity test ensures that the touchpad can accurately respond to the user's touch and gestures, providing a smooth and intuitive user experience. The test system needs to be able to simulate different touch pressures and speeds to verify the performance of the touchpad under various usage conditions. The test system in the prior art cannot accurately simulate the user's touch behavior, resulting in inaccurate test results and an inability to fully evaluate the performance of the touchpad. During the production process, the sensitivity of the touchpad may change due to environmental changes and component differences. The existing system often lacks dynamic calibration functions and cannot adjust the test parameters in real time to adapt to these changes.
[0003] In order to solve the above problems, the present application proposes a touch panel sensitivity testing system and method. Summary of the invention
[0004] Based on the technical problems existing in the background technology, the present invention proposes a touch panel sensitivity testing system and method.
[0005] A touch panel sensitivity testing system proposed by the present invention comprises: Signal excitation source module: generates waveform signals for capacitance test and ITO resistance test; Differential to single-ended conversion module: converts differential signals into single-ended signals to adapt to subsequent processing; Level shifting module: adjusts the signal level to adapt to different signal modes; Voltage measurement path module: voltage measurement is achieved using a differential input amplifier; Current measurement path module: converts current to voltage through a programmable gain impedance amplifier and performs gain adjustment; Level conversion and single-ended to differential conversion module: perform level conversion and format conversion on the signal to meet ADC input requirements; Data processing module: uses high-resolution SAR ADC for digital sampling and subsequent data processing; Automatic calibration module: dynamically adjusts sensitivity parameters according to external touch changes to ensure the accuracy and linearity of the detection output position; The output of the signal excitation source module is connected to the differential to single-ended conversion module, the output of the differential to single-ended conversion module is connected to the level shifting module, the output of the level shifting module is respectively connected to the voltage measurement path module and the current measurement path module, the outputs of the voltage measurement path module and the current measurement path module are both connected to the level conversion and single-ended to differential conversion module, the output of the level conversion and single-ended to differential conversion module is connected to the data processing module, and the output of the data processing module is connected to the automatic calibration module to achieve closed-loop control.
[0006] As a further optimization solution of the present invention, the signal excitation source module includes: Digital signal processor: responsible for generating accurate test waveforms, including sine waves and square waves, for testing capacitors and ITO resistors; Direct digital synthesizer: provides stable frequency and phase control to generate high-quality test signals; Power Amplifier: Amplifies the signal generated by DSP or DDS to sufficient power level to drive the test of capacitors and ITO resistors.
[0007] As a further optimization solution of the present invention, the differential to single-ended conversion module includes: Differential signal receiver: receives the differential signal from the signal excitation source module; Balanced to unbalanced converter: converts differential signals to single-ended signals for subsequent signal processing; Output buffer: Provides driving capability for the converted single-ended signal to ensure that the signal can be stably transmitted to the next module.
[0008] As a further optimization solution of the present invention, the level shifting module includes: Level control unit: adjusts the signal level as needed to match the input requirements of subsequent modules; Voltage follower: provides distortion-free transmission of signals and realizes level adjustment at the same time; Output Level Detector: Monitors the level of the output signal to ensure it is within the expected range.
[0009] As a further optimization solution of the present invention, the voltage measurement path module includes: Differential input amplifier: receives and amplifies the differential voltage signal from the device under test; Filter: removes noise and unwanted frequency components from the signal to improve measurement accuracy; Analog-to-digital converter: Converts the amplified analog voltage signal into a digital signal for subsequent processing.
[0010] As a further optimization solution of the present invention, the current measurement path module includes: Current-to-voltage converter: converts the current through the device under test into a voltage signal; Programmable gain amplifier: adjust the gain according to the current to adapt to different measurement ranges; Impedance matching unit: ensures impedance matching between the amplifier and the device under test to reduce measurement errors.
[0011] As a further optimization solution of the present invention, the level conversion and single-ended to differential conversion module includes: Level converter: adjusts the level of single-ended signals to a level compatible with differential signals; Format converter: converts single-ended signals into differential signal formats to meet the input requirements of ADC; Signal Synchronizer: Ensures that the converted signal is synchronized with the system clock to avoid timing errors.
[0012] As a further optimization solution of the present invention, the data processing module includes: High-resolution SAR ADC: performs high-precision analog-to-digital conversion to obtain precise measurement data; Digital signal processor: processes the data converted by ADC, such as filtering and Fourier transform; Data buffer: Temporarily stores processed data for further analysis or output.
[0013] As a further optimization solution of the present invention, the automatic calibration module includes: Sensitivity detection unit: monitors the sensitivity changes of the touch panel and feeds the data back to the calibration algorithm; Calibration algorithm processor: dynamically adjusts sensitivity parameters based on data provided by the sensitivity detection unit; Parameter adjustment unit: According to the instructions of the calibration algorithm processor, adjust the sensitivity parameters of the system to achieve optimal performance.
[0014] A touch panel sensitivity testing method adopts the above-mentioned touch panel sensitivity testing system, and is characterized by comprising the following steps: Step 1: Use the signal excitation source module to generate waveform signals for capacitance test and ITO resistance test; Step 2: Convert the differential signal to a single-ended signal through a differential to single-ended conversion module to adapt to subsequent processing; Step 3: Adjust the signal level through the level shifting module to adapt to different signal modes; Step 4: Use the voltage measurement path module to achieve voltage measurement using a differential input amplifier; Step 5: Convert the current into voltage through a gain impedance amplifier in the current measurement path module and perform gain adjustment; Step 6: The level conversion and single-ended to differential conversion module converts the signal level and format to meet the ADC input requirements; Step 7: Use the data processing module to perform digital sampling and subsequent data processing; Step 8: Through the automatic calibration module, dynamically adjust the sensitivity parameters according to the external touch changes to ensure the accuracy and linearity of the detection output position.
[0015] The above technical solution of the present invention has the following beneficial technical effects: 1. Improve the accuracy and reliability of touch panel sensitivity testing through dynamic calibration and precise signal processing.
[0016] 2. By adjusting test parameters in real time, the system can adapt to changes in the production process, ensuring that the touch panel can provide consistent performance under various usage conditions.
[0017] 3. In addition, high-resolution ADCs and precise signal conversion improve the sensitivity and resolution of the test, making the test results more accurate. These improvements not only improve product quality, but also reduce production costs because rework and scrap rates caused by inaccurate testing are reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a module block diagram of a touch panel sensitivity testing system proposed by the present invention.
[0019] Figure 2 The present invention provides a flow chart of a touch panel sensitivity testing method. DETAILED DESCRIPTION
[0020] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.
[0021] like Figure 1 and Figure 2 As shown, a touch panel sensitivity testing system proposed by the present invention comprises: Signal excitation source module: generates waveform signals for capacitance test and ITO resistance test; Differential to single-ended conversion module: converts differential signals into single-ended signals to adapt to subsequent processing; Level shifting module: adjusts the signal level to adapt to different signal modes; Voltage measurement path module: voltage measurement is achieved using a differential input amplifier; Current measurement path module: converts current to voltage through a programmable gain impedance amplifier and performs gain adjustment; Level conversion and single-ended to differential conversion module: perform level conversion and format conversion on the signal to meet ADC input requirements; Data processing module: uses high-resolution SAR ADC for digital sampling and subsequent data processing; Automatic calibration module: dynamically adjusts sensitivity parameters according to external touch changes to ensure the accuracy and linearity of the detection output position; The output of the signal excitation source module is connected to the differential to single-ended conversion module, the output of the differential to single-ended conversion module is connected to the level shifting module, the output of the level shifting module is respectively connected to the voltage measurement path module and the current measurement path module, the outputs of the voltage measurement path module and the current measurement path module are both connected to the level conversion and single-ended to differential conversion module, the output of the level conversion and single-ended to differential conversion module is connected to the data processing module, and the output of the data processing module is connected to the automatic calibration module to achieve closed-loop control.
[0022] In this embodiment, the signal excitation source module includes: Digital signal processor: responsible for generating accurate test waveforms, including sine waves and square waves, for testing capacitors and ITO resistors; Direct digital synthesizer: provides stable frequency and phase control to generate high-quality test signals; Power Amplifier: Amplifies the signal generated by DSP or DDS to sufficient power level to drive the test of capacitors and ITO resistors.
[0023] It should be noted that: In the digital signal processor, the sine wave generation algorithm is as follows: ,in is the amplitude, f is the frequency, and t is the time; DSP is the core of the module and is responsible for generating the required test waveforms. It can be programmed to generate sine and square waveforms of specific frequencies and amplitudes. These waveforms are used to simulate the user's operation on the touch panel to test its capacitance and ITO resistance. The power amplifier receives the signal from the DSP or DDS and amplifies it to a sufficient power level to be able to effectively drive the capacitance and ITO resistance of the touch panel for testing.
[0024] In this embodiment, the differential to single-ended conversion module includes: Differential signal receiver: receives the differential signal from the signal excitation source module; Balanced to unbalanced converter: converts differential signals to single-ended signals for subsequent signal processing; Output buffer: Provides driving capability for the converted single-ended signal to ensure that the signal can be stably transmitted to the next module.
[0025] It should be noted that the differential signal demodulation formula is: , where V+ and V− are the two components of the differential signal.
[0026] In this embodiment, the level shifting module includes: Level control unit: adjusts the signal level as needed to match the input requirements of subsequent modules; Voltage follower: provides distortion-free transmission of signals and realizes level adjustment at the same time; Output Level Detector: Monitors the level of the output signal to ensure it is within the expected range.
[0027] It should be noted that: the level control unit adjusts the level of the signal according to the input requirements of the subsequent modules, which may include increasing or decreasing the amplitude of the signal to ensure that the signal matches the input range of the receiving module; A voltage follower is a type of buffer that provides distortion-free transmission of a signal while allowing level adjustment, which is critical to maintaining signal integrity.
[0028] In this embodiment, the voltage measurement path module includes: Differential input amplifier: receives and amplifies the differential voltage signal from the device under test; Filter: removes noise and unwanted frequency components from the signal to improve measurement accuracy; Analog-to-digital converter: Converts the amplified analog voltage signal into a digital signal for subsequent processing.
[0029] In this embodiment, the current measurement path module includes: Current-to-voltage converter: converts the current through the device under test into a voltage signal; Programmable gain amplifier: adjust the gain according to the current to adapt to different measurement ranges; Impedance matching unit: ensures impedance matching between the amplifier and the device under test to reduce measurement errors.
[0030] It should be noted that: in the current measurement path module, the impedance calculation formula is used to calculate the impedance matching problem when the current passing through the device under test is converted into a voltage signal. This involves the design of the current-to-voltage converter to ensure that the converter can effectively convert the current signal into a voltage signal while minimizing signal loss. In the level conversion and single-ended to differential conversion modules, the impedance calculation formula is used to ensure that when the signal is converted between single-ended and differential formats, the impedance characteristics of the system will not affect the integrity of the signal. This is especially important for the design of the signal synchronizer to ensure that the signal is synchronized with the system clock to avoid timing errors; Impedance calculation formula: ; ; ; ; .
[0031] In this embodiment, the level conversion and single-ended to differential conversion module includes: Level converter: adjusts the level of single-ended signals to a level compatible with differential signals; Format converter: converts single-ended signals into differential signal formats to meet the input requirements of ADC; Signal Synchronizer: Ensures that the converted signal is synchronized with the system clock to avoid timing errors.
[0032] In this embodiment, the data processing module includes: High-resolution SAR ADC: performs high-precision analog-to-digital conversion to obtain precise measurement data; Digital signal processor: processes the data converted by ADC, such as filtering and Fourier transform; Data buffer: Temporarily stores processed data for further analysis or output.
[0033] In this embodiment, the automatic calibration module includes: Sensitivity detection unit: monitors the sensitivity changes of the touch panel and feeds the data back to the calibration algorithm; Calibration algorithm processor: dynamically adjusts sensitivity parameters based on data provided by the sensitivity detection unit; Parameter adjustment unit: According to the instructions of the calibration algorithm processor, adjust the sensitivity parameters of the system to achieve optimal performance.
[0034] It should be noted that the signal excitation source module is responsible for generating waveform signals for capacitance testing and ITO resistance testing. This is achieved through a digital signal processor or a direct digital synthesizer, which can provide stable frequency and phase control to generate high-quality test signals. Subsequently, these signals are amplified to a sufficient power level through a power amplifier to drive the testing of capacitance and ITO resistance. The differential to single-ended conversion module converts the differential signal generated by the signal excitation source module into a single-ended signal to meet subsequent processing requirements. This conversion process usually involves a differential signal receiver and a balanced to unbalanced converter, which ensure that the signal maintains its integrity during the conversion process. The level shifting module adjusts the signal level to adapt to different signal modes. The level control unit, voltage follower and output level detector work together to ensure the accuracy of the signal level. The voltage measurement path module uses a differential input amplifier to achieve voltage measurement. The filter removes noise and unnecessary frequency components in the signal to improve the measurement accuracy. The analog-to-digital converter converts the amplified analog voltage signal into a digital signal for subsequent processing. The current measurement path module converts the current into voltage through a programmable gain impedance amplifier and adjusts the gain to adapt to different measurement ranges. The impedance matching unit ensures the impedance matching between the amplifier and the device under test to reduce measurement errors. The level conversion and single-ended to differential conversion modules perform level conversion and format conversion on the signal to meet the ADC input requirements. The level converter, format converter and signal synchronizer ensure that the signal is correctly transmitted between different modules to avoid timing errors. The data processing module uses a high-resolution SAR ADC for digital sampling and performs subsequent data processing, such as filtering and Fourier transform, to extract useful information and prepare for the final output. The automatic calibration module dynamically adjusts the sensitivity parameters according to the external touch changes to ensure the accuracy and linearity of the detection output position. The sensitivity detection unit monitors the sensitivity changes of the touch panel and feeds the data back to the calibration algorithm processor. The parameter adjustment unit adjusts the sensitivity parameters of the system according to the instructions of the calibration algorithm processor to achieve optimal performance.
[0035] A touch panel sensitivity testing method adopts the above-mentioned touch panel sensitivity testing system, and is characterized by comprising the following steps: Step 1: Use the signal excitation source module to generate waveform signals for capacitance test and ITO resistance test; Step 2: Convert the differential signal to a single-ended signal through a differential to single-ended conversion module to adapt to subsequent processing; Step 3: Adjust the signal level through the level shifting module to adapt to different signal modes; Step 4: Use the voltage measurement path module to achieve voltage measurement using a differential input amplifier; Step 5: Convert the current into voltage through a gain impedance amplifier in the current measurement path module and perform gain adjustment; Step 6: The level conversion and single-ended to differential conversion module converts the signal level and format to meet the ADC input requirements; Step 7: Use the data processing module to perform digital sampling and subsequent data processing; Step 8: Through the automatic calibration module, dynamically adjust the sensitivity parameters according to the external touch changes to ensure the accuracy and linearity of the detection output position.
[0036] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.
Claims
1. A touch panel sensitivity testing system, characterized in that: include: Signal excitation source module: generates waveform signals for capacitance test and ITO resistance test; Differential to single-ended conversion module: converts differential signals into single-ended signals to adapt to subsequent processing; Level shifting module: adjusts the signal level to adapt to different signal modes; Voltage measurement path module: voltage measurement is achieved using a differential input amplifier; Current measurement path module: converts current to voltage through a programmable gain impedance amplifier and performs gain adjustment; Level conversion and single-ended to differential conversion module: perform level conversion and format conversion on the signal to meet ADC input requirements; Data processing module: uses high-resolution SAR ADC for digital sampling and subsequent data processing; Automatic calibration module: dynamically adjusts sensitivity parameters according to external touch changes to ensure the accuracy and linearity of the detection output position; The output of the signal excitation source module is connected to the differential to single-ended conversion module, the output of the differential to single-ended conversion module is connected to the level shifting module, the output of the level shifting module is respectively connected to the voltage measurement path module and the current measurement path module, the outputs of the voltage measurement path module and the current measurement path module are both connected to the level conversion and single-ended to differential conversion module, the output of the level conversion and single-ended to differential conversion module is connected to the data processing module, and the output of the data processing module is connected to the automatic calibration module to achieve closed-loop control.
2. A touch panel sensitivity testing system according to claim 1, characterized in that: The signal excitation source module comprises: Digital signal processor: responsible for generating accurate test waveforms, including sine waves and square waves, for testing capacitors and ITO resistors; Direct digital synthesizer: provides stable frequency and phase control to generate high-quality test signals; Power Amplifier: Amplifies the signal generated by DSP or DDS to sufficient power level to drive the test of capacitors and ITO resistors.
3. A touch panel sensitivity testing system according to claim 2, characterized in that: The differential to single-ended conversion module comprises: Differential signal receiver: receives the differential signal from the signal excitation source module; Balanced to unbalanced converter: converts differential signals to single-ended signals for subsequent signal processing; Output buffer: Provides driving capability for the converted single-ended signal to ensure that the signal can be stably transmitted to the next module.
4. A touch panel sensitivity testing system according to claim 3, characterized in that: The level shifting module comprises: Level control unit: adjusts the signal level as needed to match the input requirements of subsequent modules; Voltage follower: provides distortion-free transmission of signals and realizes level adjustment at the same time; Output Level Detector: Monitors the level of the output signal to ensure it is within the expected range.
5. A touch panel sensitivity testing system according to claim 4, characterized in that: The voltage measurement path module comprises: Differential input amplifier: receives and amplifies the differential voltage signal from the device under test; Filter: removes noise and unwanted frequency components from the signal to improve measurement accuracy; Analog-to-digital converter: Converts the amplified analog voltage signal into a digital signal for subsequent processing.
6. A touch panel sensitivity testing system according to claim 5, characterized in that: The current measurement path module comprises: Current-to-voltage converter: converts the current through the device under test into a voltage signal; Programmable gain amplifier: adjust the gain according to the current to adapt to different measurement ranges; Impedance matching unit: ensures impedance matching between the amplifier and the device under test to reduce measurement errors.
7. A touch panel sensitivity testing system according to claim 6, characterized in that: The level conversion and single-ended to differential conversion module includes: Level converter: adjusts the level of a single-ended signal to a level compatible with differential signaling; Format converter: converts single-ended signals into differential signal formats to meet the input requirements of ADC; Signal Synchronizer: Ensures that the converted signal is synchronized with the system clock to avoid timing errors.
8. A touch panel sensitivity testing system according to claim 7, characterized in that: The data processing module comprises: High-resolution SAR ADC: performs high-precision analog-to-digital conversion to obtain precise measurement data; Digital signal processor: processes the data converted by ADC, such as filtering and Fourier transform; Data buffer: Temporarily stores processed data for further analysis or output.
9. A touch panel sensitivity testing system according to claim 8, characterized in that: The automatic calibration module comprises: Sensitivity detection unit: monitors the sensitivity changes of the touch panel and feeds the data back to the calibration algorithm; Calibration algorithm processor: dynamically adjusts sensitivity parameters based on data provided by the sensitivity detection unit; Parameter adjustment unit: According to the instructions of the calibration algorithm processor, adjust the sensitivity parameters of the system to achieve optimal performance.
10. A touch panel sensitivity testing method, using a touch panel sensitivity testing system as claimed in claims 1 to 9, characterized in that: The following steps are involved: Step 1: Use the signal excitation source module to generate waveform signals for capacitance test and ITO resistance test; Step 2: Convert the differential signal to a single-ended signal through a differential to single-ended conversion module to adapt to subsequent processing; Step 3: Adjust the signal level through the level shifting module to adapt to different signal modes; Step 4: Use the voltage measurement path module to achieve voltage measurement using a differential input amplifier; Step 5: Convert the current into voltage through a gain impedance amplifier in the current measurement path module and perform gain adjustment; Step 6: The level conversion and single-ended to differential conversion module converts the signal level and format to meet the ADC input requirements; Step 7: Use the data processing module to perform digital sampling and subsequent data processing; Step 8: Through the automatic calibration module, dynamically adjust the sensitivity parameters according to the external touch changes to ensure the accuracy and linearity of the detection output position.