Method, device, equipment and medium for improving touch precision of surface acoustic wave touch screen

Abstract

This invention relates to the field of surface acoustic wave (SAW) touchscreen technology, specifically to a method, apparatus, device, and medium for improving the touch accuracy of SAW touchscreens. The method for improving the touch accuracy of SAW touchscreens, as described in this invention, involves two aspects: firstly, setting multiple temperature sensors on a glass substrate and compensating for the attenuation of sound waves due to temperature, thereby increasing the sound wave signal reception accuracy of the receiving transducer; secondly, by setting corresponding auxiliary receiving transducers at the four corners of the glass substrate, the invention corrects the control sensitivity of the screen edge area, thus compensating for the significant sound wave energy loss at the edge area of ​​a large screen, which leads to a reduced touch signal-to-noise ratio and makes it difficult to accurately detect light touch operations.

Description

Technical Field

[0001] This invention relates to the field of surface acoustic wave (SAW) touchscreen technology, and more specifically, to a method, apparatus, device, and medium for improving the touch accuracy of SAW touchscreens. Background Technology

[0002] Surface acoustic wave (SAW) touchscreens are widely used in public terminals, medical devices, and industrial control due to their advantages such as high light transmittance, scratch resistance, and long lifespan. However, some significant drawbacks still exist in practical applications. For example, the energy of high-frequency sound waves attenuates exponentially with distance when propagating on a glass surface (attenuation coefficient approximately 0.02 dB / mm). In the edge area of ​​a 15-inch screen, sound wave energy loss can reach 30%, causing the touch signal-to-noise ratio (SNR) to drop below 10 dB, making it difficult to accurately detect light touch operations.

[0003] While existing technologies have attempted to alleviate the aforementioned problems by increasing the density of the reflective array or optimizing the algorithm, the hardware modification costs are high and the algorithm complexity increases dramatically. Therefore, there is an urgent need for an innovative solution that can systematically improve touch accuracy through multimodal signal collaborative processing and adaptive compensation mechanisms without changing the core architecture of the surface acoustic wave (SAW) touchscreen. Summary of the Invention

[0004] The purpose of this invention is to provide a method for improving the touch accuracy of surface acoustic wave touch screens, so as to improve the above-mentioned technical problems.

[0005] To achieve the above objectives, the embodiments of this application provide the following technical solutions:

[0006] On one hand, this application provides a method for improving the touch accuracy of a surface acoustic wave (SAW) touchscreen. The SAW touchscreen includes a glass substrate, transmitting and receiving transducers disposed at the X-axis and Y-axis edges of the glass substrate, a reflective array distributed along the four sides of the glass substrate, and a controller. Four temperature sensors are uniformly distributed on the back of the glass substrate, and auxiliary receiving transducers are provided at the four corners of the glass substrate. The method includes: responding to a user's touch operation, acquiring the monitored temperature values ​​corresponding to the four temperature sensors and a first distance between the current touch point and the transmitting transducer; based on multiple monitored temperature values... The compensation gain is calculated based on the corresponding average temperature and the first distance, and then the amplitude of the first acoustic signal from the receiving transducer is amplified. The amplified acoustic signal is marked as the second acoustic signal, and the main touch coordinates are calculated based on the second acoustic signal. The area of ​​the preset edge compensation region is dynamically corrected based on the current average temperature, and the touch point is located in the corrected edge compensation region. The third acoustic signals received by multiple auxiliary receiving transducers are acquired, and the auxiliary touch coordinates are calculated based on the multiple third acoustic signals. The actual touch coordinates are calculated based on the main touch coordinates and the auxiliary touch coordinates through a weighted fusion algorithm.

[0007] Optionally, the step of calculating the compensation gain based on the average temperature corresponding to multiple monitored temperature values ​​and the first distance, and then performing amplitude amplification processing on the first acoustic signal of the receiving transducer, includes:

[0008] Constructing a sound wave energy attenuation model:

[0009] E(d,T)=E0·e -α(T)·d Where E0 is the initial energy, d is the first distance, α(T) = 0.015 + 0.0002T is the temperature-dependent attenuation coefficient, and T is the average temperature;

[0010] The compensation gain G(d,T)=1 / E(d,T) is calculated based on the acoustic energy attenuation model, and then the amplitude of the first acoustic signal from the receiving transducer is amplified.

[0011] Optionally, the step of acquiring the third acoustic wave signals received by multiple auxiliary receiving transducers and calculating the auxiliary touch coordinates based on the multiple third acoustic wave signals includes:

[0012] When the touch point is located in the preset edge area, the arrival time difference of the sound wave is detected by multiple auxiliary receiving transducers, and the distance from the touch point to each auxiliary transducer is calculated by combining the sound wave propagation speed:

[0013] Using the auxiliary receiving transducer as the center and the distance from the touch point to the auxiliary transducer as the radius, a corresponding arc is constructed, resulting in four arc segments. The auxiliary touch coordinates are then obtained by fitting the data using the least squares method.

[0014] Optionally, the actual touch coordinates are calculated using a weighted fusion algorithm based on the primary touch coordinates and the secondary touch coordinates, including:

[0015] The main touch coordinates are obtained, which are calculated by the receiving transducer based on the time difference method of high-frequency acoustic signals.

[0016] Calculate the Euclidean distance deviation between the primary touch coordinates and the secondary touch coordinates, and fuse the final coordinates according to the signal-to-noise ratio weight if the Euclidean distance deviation is less than a preset threshold:

[0017] x = w·x m +(1-w)·x a ,y=w·y m +(1-w)·y a ;where x m The x-coordinate in the primary touch coordinate system, t m The ordinate in the main touch coordinate system, x a To assist in the horizontal coordinate of the touch coordinate system, y a The vertical coordinate in the auxiliary touch coordinate system is w, which is the weight determined by the signal-to-noise ratio (SNR) of the primary received signal. m and auxiliary signal-to-noise ratio (SNR) a Decide:

[0018]

[0019] If the Euclidean distance deviation is less than a preset threshold, the auxiliary receiving transducer or the signal received by the receiving transducer is determined to be an abnormal signal, and the controller re-transmits the sound wave for a second scan verification.

[0020] Optionally, the transmitting transducer disposed at the edges of the glass substrate along the X and Y axes integrates a dual-frequency piezoelectric ceramic unit for generating low-frequency and high-frequency sound waves respectively.

[0021] Among them, low-frequency sound waves are emitted by the transmitting transducers on the left side of the X-axis and the upper side of the Y-axis, and form a reference grid covering the entire screen through the reflection array, which is used to detect environmental interference areas;

[0022] High-frequency sound waves are emitted by transducers on the right side of the X-axis and the bottom side of the Y-axis, and form a high-density positioning grid through a reflective array for calculating the coordinates of the touch point.

[0023] After the receiving transducer collects the mixed acoustic wave signal, it transmits it to the signal separation module of the controller, where a bandpass filter extracts the high-frequency acoustic wave component and the low-frequency acoustic wave component.

[0024] Optionally, the reflective array is composed of piezoelectric thin film stripes etched on the edge of the glass substrate, each stripe being 50 μm wide and 200 μm apart.

[0025] The controller dynamically adjusts the bias voltage applied to the piezoelectric film stripes based on data from multiple temperature sensors and the sound wave propagation time difference, causing the sound wave reflection angle to deflect by 0.1°-0.5°, thus compensating for the sound wave path offset caused by temperature deformation.

[0026] Secondly, this embodiment provides an apparatus for improving the touch accuracy of a surface acoustic wave touchscreen, the apparatus comprising:

[0027] The first acquisition module is used to respond to the user's touch operation and acquire the monitored temperature values ​​corresponding to the four temperature sensors and the first distance between the current touch point and the transmitting transducer.

[0028] The first calculation module is used to calculate the compensation gain based on the average temperature corresponding to multiple monitored temperature values ​​and the first distance, and then perform amplitude amplification processing on the first acoustic signal of the receiving transducer, mark the amplified acoustic signal as the second acoustic signal, and calculate the main touch coordinates based on the second acoustic signal.

[0029] The second acquisition module is used to acquire the third acoustic wave signals received by multiple auxiliary receiving transducers, and calculate the auxiliary touch coordinates based on the multiple third acoustic wave signals.

[0030] The second calculation module is used to calculate the actual touch coordinates based on the main touch coordinates and the auxiliary touch coordinates using a weighted fusion algorithm.

[0031] Thirdly, embodiments of this application provide a device for improving the touch accuracy of a surface acoustic wave touchscreen, the device including a memory and a processor.

[0032] The memory is used to store computer programs; the processor is used to execute the computer programs to implement the steps of the method for improving the touch accuracy of surface acoustic wave touch screens described above.

[0033] Fourthly, embodiments of this application provide a medium on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the method for improving the touch accuracy of a surface acoustic wave touchscreen described above.

[0034] The beneficial effects of this invention are as follows:

[0035] The method for improving the touch accuracy of a surface acoustic wave (SAW) touchscreen as described in this invention, on the one hand, increases the acoustic signal reception accuracy of the receiving transducer by setting multiple temperature sensors on the glass substrate and compensating for the acoustic wave amplitude based on the attenuation of the acoustic waves due to temperature. On the other hand, this invention also corrects the control sensitivity of the screen edge area by setting corresponding auxiliary receiving transducers at the four corners of the glass substrate, thereby compensating for the defect that the acoustic wave energy loss in the edge area of ​​a large screen can be relatively large, resulting in a reduced touch signal-to-noise ratio and making it difficult to accurately detect light touch operations.

[0036] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic flowchart of a method for improving the touch accuracy of a surface acoustic wave touchscreen according to an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of a device structure for improving the touch accuracy of a surface acoustic wave touchscreen, as described in an embodiment of the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of 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, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0041] It should be noted that similar reference numerals or letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0042] Example 1:

[0043] like Figure 1 As shown, this embodiment provides a method for improving the touch accuracy of a surface acoustic wave (SAW) touchscreen. The SAW touchscreen includes a glass substrate, transmitting and receiving transducers (for receiving direct reflected signals of high-frequency / low-frequency sound waves) disposed at the X-axis and Y-axis edges of the glass substrate, a reflective array distributed along the four sides of the glass substrate, and a controller. Four temperature sensors are uniformly distributed on the back of the glass substrate, and auxiliary receiving transducers are provided at the four corners of the glass substrate. The method includes:

[0044] Step S100: In response to the user's touch operation, obtain the monitored temperature values ​​corresponding to the four temperature sensors and the first distance between the current touch point and the transmitting transducer;

[0045] Step S200: Calculate the compensation gain based on the average temperature and first distance corresponding to multiple monitored temperature values, and then perform amplitude amplification processing on the first acoustic signal of the receiving transducer. Mark the amplified acoustic signal as the second acoustic signal, and calculate the main touch coordinates based on the second acoustic signal.

[0046] The specific implementation method for amplifying the amplitude of the first acoustic signal from the receiving transducer is as follows:

[0047] Constructing a sound wave energy attenuation model:

[0048] E(d,T)=E0·e -α(T)·d Where E0 is the initial energy, d is the first distance, α(T) = 0.015 + 0.0002T is the temperature-dependent attenuation coefficient, and T is the average temperature;

[0049] The compensation gain G(d,T)=1 / E(d,T) is calculated based on the acoustic energy attenuation model, and then the amplitude of the first acoustic signal from the receiving transducer is amplified.

[0050] Step S300: Dynamically correct the area of ​​the preset edge compensation region based on the current average temperature, and after the touch point is located in the corrected edge compensation region, acquire the third acoustic wave signals received by multiple auxiliary receiving transducers, and calculate the auxiliary touch coordinates based on the multiple third acoustic wave signals.

[0051] The specific implementation method of step S300 is as follows:

[0052] Step S310: When the touch point is located in the preset edge area, the arrival time difference of the sound wave is detected by multiple auxiliary receiving transducers. Combined with the sound wave propagation speed, the distance from the touch point to each auxiliary transducer is calculated. Each auxiliary receiving transducer synchronously acquires the sound wave signal at a sampling rate of 1MHz using a 12-bit ADC (analog-to-digital converter).

[0053] Step S320: Construct a corresponding arc with the auxiliary receiving transducer as the center and the distance from the touch point to the auxiliary transducer as the radius, thereby obtaining four arc segments, and obtain the auxiliary touch coordinates based on the least squares method.

[0054] Step S400: Based on the main touch coordinates and auxiliary touch coordinates, the actual touch coordinates are calculated using a weighted fusion algorithm;

[0055] The specific implementation method for calculating the actual touch coordinates through the weighted fusion algorithm in step S400 is as follows:

[0056] Step S410: Obtain the main touch coordinates, which are calculated by the receiving transducer based on the time difference method of high-frequency acoustic signals;

[0057] Step S420: Calculate the Euclidean distance deviation between the main touch coordinates and the auxiliary touch coordinates, and if the Euclidean distance deviation is less than a preset threshold, fuse the final coordinates according to the signal-to-noise ratio weight.

[0058] x = w·x m +(1-w)·x a ,y=w·y m +(1-w)·y a ;where x m The x-coordinate in the main touch coordinate system, y m The ordinate in the main touch coordinate system, x a To assist in the horizontal coordinate of the touch coordinate system, y a The vertical coordinate in the auxiliary touch coordinate system is w, which is the weight determined by the signal-to-noise ratio (SNR) of the primary received signal. m and auxiliary signal-to-noise ratio (SNR) a Decide:

[0059]

[0060] Step S430: If the Euclidean distance deviation is less than a preset threshold, the signal received by the auxiliary receiving transducer or the receiving transducer is determined to be an abnormal signal, and the controller re-transmits the sound wave for a second scan verification.

[0061] The method for improving the touch accuracy of a surface acoustic wave (SAW) touchscreen described in this embodiment, on the one hand, increases the acoustic signal reception accuracy of the receiving transducer by setting multiple temperature sensors on the glass substrate and compensating for the acoustic wave amplitude based on the attenuation of the acoustic waves due to temperature. On the other hand, the present invention sets corresponding auxiliary receiving transducers at the four corners of the glass substrate to correct the control sensitivity of the screen edge area, thereby compensating for the defect that the acoustic wave energy loss in the edge area of ​​a large screen can be relatively large, resulting in a reduced touch signal-to-noise ratio and making it difficult to accurately detect light touch operations.

[0062] Example 2:

[0063] Surface acoustic wave (SAW) touchscreens rely on the stability of the surface acoustic wave propagation path. However, water stains, oil, or condensation droplets can absorb or scatter sound wave energy, causing abnormal attenuation of the signal amplitude at the receiver and misinterpreting it as a touch signal. For example, residual water film at the edge of the screen in a humid environment may cause a coordinate drift error of 2-3 mm in the edge area.

[0064] To address the aforementioned shortcomings, this embodiment, based on the method for improving the touch accuracy of a surface acoustic wave touchscreen described in Embodiment 1, further integrates a dual-frequency piezoelectric ceramic unit in the transmitting transducer located at the X-axis and Y-axis edges of the glass substrate, for generating low-frequency acoustic waves (5MHz) and high-frequency acoustic waves (10MHz) respectively.

[0065] Among them, low-frequency sound waves are emitted by the transmitting transducers on the left side of the X-axis and the upper side of the Y-axis, and form a reference grid covering the entire screen through the reflection array, which is used to detect environmental interference areas;

[0066] High-frequency sound waves are emitted by transducers on the right side of the X-axis and the bottom side of the Y-axis, and form a high-density positioning grid through a reflective array for calculating the coordinates of the touch point.

[0067] After the receiving transducer collects the mixed acoustic wave signal, it transmits it to the signal separation module of the controller, where a bandpass filter extracts the high-frequency acoustic wave component and the low-frequency acoustic wave component.

[0068] Dual-frequency signal separation separates environmental noise from the actual touch signal, and combined with wavelet denoising algorithm, reduces the false touch rate by more than 60% in humid environments.

[0069] Secondly, traditional reflective arrays use fixed etching stripes, and their reflection angle and density cannot be dynamically adjusted with ambient temperature or mechanical deformation. Temperature changes (±15℃) can lead to differences in the coefficient of thermal expansion of the glass substrate (approximately 9×10⁻⁶). -6 / ℃), which changes the length of the sound wave propagation path and thus affects the positioning accuracy. Therefore, in this embodiment, the reflective array is composed of piezoelectric thin film stripes etched on the edge of the glass substrate, with each stripe being 50μm wide and 200μm apart.

[0070] The controller dynamically adjusts the bias voltage applied to the piezoelectric film stripes based on data from multiple temperature sensors and the sound wave propagation time difference, causing the sound wave reflection angle to deflect by 0.1°-0.5°, thus compensating for the sound wave path offset caused by temperature deformation.

[0071] Secondly, in step S300, the dynamic correction of the area of ​​the preset edge compensation region based on the current average temperature includes:

[0072] Step S330: Construct a temperature-edge compensation region correlation model based on the thermal expansion coefficient of the glass substrate: W(T)=W0·[1+β·(T-T0)]; where β is the thermal expansion coefficient of the glass substrate, and T is the current average temperature; define the reference temperature T0=25℃, and preset the edge compensation region width W0=20mm; W(T) is the compensation temperature width;

[0073] Step S340: The controller reads the average temperature every 5-7 seconds and calculates the updated W(T) based on the correlation model. If the absolute value of W(T) is greater than 0.5-1mm, the current edge compensation area is redefined as the range within W(T) from the screen boundary.

[0074] Step S350: When the touch point is located within the dynamic edge region W(T), a temperature-related additional gain is superimposed according to the following formula:

[0075] G dynamic (d,T)=G(d,T)×[1+0.05·|T-T0|];

[0076] Among them, G dynamic (d,T) is the dynamic compensation gain, dimensionless, representing the final signal amplification factor after superimposed temperature effects, used for amplitude compensation of touch points in the edge region; |T-T0| is the absolute value of the temperature difference, with a coefficient of 0.05 calibrated experimentally; for touch points that exceed the original preset area (W0=20mm) but are within the range of W(T), the enhanced verification mechanism of the auxiliary receiving transducer is enabled, forcing the weight w≤0.2;

[0077] When T < -10℃ or T > 50℃, the compensation area is locked at W0 = 20mm, and the system is triggered to reduce the frequency to avoid distortion of the acoustic path caused by excessive thermal expansion and contraction.

[0078] The area of ​​the preset edge compensation region is dynamically corrected based on the current average temperature. On the one hand, at T = 40℃, the compensation region automatically expands to W(40) = 20 × [1 + 9e -6[×(40-25)]≈20.27mm, which solves the edge sensitivity shift caused by high temperature expansion; secondly, it offsets the acoustic wave scattering loss caused by temperature gradient by adding gain through temperature difference (such as a 25% increase in gain when T=35℃); thirdly, it freezes the compensation logic at extreme temperatures to prevent coordinate oscillation caused by overcorrection.

[0079] Example 3:

[0080] This embodiment provides a device for improving the touch accuracy of a surface acoustic wave touchscreen, the device comprising:

[0081] The first acquisition module is used to respond to the user's touch operation and acquire the monitored temperature values ​​corresponding to the four temperature sensors and the first distance between the current touch point and the transmitting transducer.

[0082] The first calculation module is used to calculate the compensation gain based on the average temperature corresponding to multiple monitored temperature values ​​and the first distance, and then perform amplitude amplification processing on the first acoustic signal of the receiving transducer, mark the amplified acoustic signal as the second acoustic signal, and calculate the main touch coordinates based on the second acoustic signal.

[0083] The second acquisition module is used to acquire the third acoustic wave signals received by multiple auxiliary receiving transducers, and calculate the auxiliary touch coordinates based on the multiple third acoustic wave signals.

[0084] The second calculation module is used to calculate the actual touch coordinates based on the main touch coordinates and the auxiliary touch coordinates using a weighted fusion algorithm.

[0085] It should be noted that the specific manner in which each module performs its operation in the apparatus described in the above embodiments has been described in detail in the embodiments of the method, and will not be elaborated here.

[0086] Example 4:

[0087] Corresponding to the above method embodiments, this disclosure also provides a device for improving the touch accuracy of a surface acoustic wave (SAW) touchscreen. The device for improving the touch accuracy of a SAW touchscreen described below and the method for improving the touch accuracy of a SAW touchscreen described above can be referred to in correspondence.

[0088] Figure 2 This is a block diagram illustrating a device 800 for improving the touch accuracy of a surface acoustic wave touchscreen according to an exemplary embodiment. Figure 2 As shown, the electronic device 800 may include a processor 801 and a memory 802. The electronic device 800 may also include one or more of a multimedia component 803, an I / O interface 804, and a communication component 805.

[0089] The processor 801 controls the overall operation of the electronic device 800 to complete all or part of the steps in the method for improving the touch accuracy of a surface acoustic wave touchscreen. The memory 802 stores various types of data to support the operation of the electronic device 800. This data may include, for example, instructions for any application or method operating on the electronic device 800, and application-related data such as contact data, sent and received messages, pictures, audio, video, etc. The memory 802 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. Multimedia component 803 may include a screen and an audio component. The screen may be, for example, a touchscreen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signals may be further stored in memory 802 or transmitted via communication component 805. The audio component also includes at least one speaker for outputting audio signals. I / O interface 804 provides an interface between processor 801 and other interface modules, such as a keyboard, mouse, buttons, etc. These buttons may be virtual or physical buttons. Communication component 805 is used for wired or wireless communication between the electronic device 800 and other devices. Wireless communication may include Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, or 4G, or a combination of these. Therefore, the corresponding communication component 805 may include a Wi-Fi module, a Bluetooth module, or an NFC module.

[0090] In an exemplary embodiment, the electronic device 800 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the above-described method for improving the touch accuracy of a surface acoustic wave touchscreen.

[0091] In another exemplary embodiment, a computer-readable storage medium including program instructions is also provided, which, when executed by a processor, implement the steps of the method for improving the touch accuracy of a surface acoustic wave touchscreen described above. For example, the computer-readable storage medium may be the memory 802 including the program instructions described above, which may be executed by the processor 801 of the electronic device 800 to complete the method for improving the touch accuracy of a surface acoustic wave touchscreen described above.

[0092] Example 5:

[0093] Corresponding to the above method embodiments, this disclosure also provides a readable storage medium. The readable storage medium described below can be referred to in conjunction with the method for improving the touch accuracy of a surface acoustic wave touch screen described above.

[0094] A readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the method for improving the touch accuracy of a surface acoustic wave touchscreen as described in the above method embodiments.

[0095] Specifically, the readable storage medium can be a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, or any other readable storage medium capable of storing program code.

[0096] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for improving the touch accuracy of a surface acoustic wave (SAW) touchscreen, the SAW touchscreen comprising a glass substrate, transmitting transducers and receiving transducers disposed at the edges of the glass substrate along the X and Y axes, a reflective array distributed along the four sides of the glass substrate, and a controller, characterized in that, Four temperature sensors are evenly distributed on the back side of the glass substrate, and auxiliary receiving transducers are provided at the four corners of the glass substrate. The method includes: In response to the user's touch operation, the system obtains the monitored temperature values ​​corresponding to the four temperature sensors and the first distance between the current touch point and the transmitting transducer. The compensation gain is calculated based on the average temperature corresponding to multiple monitored temperature values ​​and the first distance. Then, the amplitude of the first acoustic signal of the receiving transducer is amplified. The amplified acoustic signal is marked as the second acoustic signal, and the main touch coordinates are calculated based on the second acoustic signal. The area of ​​the preset edge compensation region is dynamically corrected based on the current average temperature. After the touch point is located in the corrected edge compensation region, the third acoustic wave signals received by multiple auxiliary receiving transducers are acquired, and the auxiliary touch coordinates are calculated based on the multiple third acoustic wave signals. The actual touch coordinates are calculated using a weighted fusion algorithm based on the primary touch coordinates and the auxiliary touch coordinates. Secondly, the area of ​​the preset edge compensation region, which is dynamically corrected based on the current average temperature, includes: A temperature-edge compensation region correlation model is constructed based on the thermal expansion coefficient of the glass substrate: ;in, is the coefficient of thermal expansion of the glass substrate. Define the current average temperature; define the reference temperature. Preset edge compensation area width To compensate for temperature range; The controller reads the average temperature every 5-7 seconds and calculates the updated temperature based on the correlation model. ,like If the absolute value is greater than 0.5-1mm, then the current edge compensation area is redefined as the distance from the screen boundary. Within the range; When the touch point is located in the dynamic edge area During this time, the temperature-related additional gain is superimposed according to the following formula: ； in, Dynamic compensation gain, dimensionless, represents the final signal amplification factor after superimposed temperature effects, used for amplitude compensation of touch points in the edge region; G(d,T) is the compensation gain. The absolute value of the temperature difference is given, with a coefficient of 0.05 determined experimentally.

2. The method for improving the touch accuracy of a surface acoustic wave touchscreen according to claim 1, characterized in that, The calculation of compensation gain based on the average temperature corresponding to multiple monitored temperature values ​​and the first distance, and then the amplitude amplification processing of the first acoustic signal of the receiving transducer, includes: Constructing a sound wave energy attenuation model: ;in, As initial energy, The first distance, This is the temperature-dependent attenuation coefficient. Average temperature; Calculation of compensation gain based on sound wave energy attenuation model ， Then, the amplitude of the first acoustic signal from the receiving transducer is amplified.

3. The method for improving the touch accuracy of a surface acoustic wave touchscreen according to claim 1, characterized in that, The step of acquiring the third acoustic wave signals received by multiple auxiliary receiving transducers and calculating the auxiliary touch coordinates based on the multiple third acoustic wave signals includes: When the touch point is located in the preset edge area, the arrival time difference of the sound wave is detected by multiple auxiliary receiving transducers, and the distance from the touch point to each auxiliary transducer is calculated by combining the sound wave propagation speed: Using the auxiliary receiving transducer as the center and the distance from the touch point to the auxiliary transducer as the radius, a corresponding arc is constructed, resulting in four arc segments. The auxiliary touch coordinates are then obtained by fitting the data using the least squares method.

4. The method for improving the touch accuracy of a surface acoustic wave touchscreen according to claim 3, characterized in that, Based on the primary touch coordinates and secondary touch coordinates, the actual touch coordinates are calculated using a weighted fusion algorithm, including: The main touch coordinates are obtained, which are calculated by the receiving transducer based on the time difference method of high-frequency acoustic signals. Calculate the Euclidean distance deviation between the primary touch coordinates and the secondary touch coordinates, and fuse the final coordinates according to the signal-to-noise ratio weight if the Euclidean distance deviation is less than a preset threshold: ;in, The x-coordinate in the main touch coordinate system. The vertical coordinate in the main touch coordinate system To assist in the horizontal coordinate of the touch coordinate system, To assist the vertical coordinate in the touch coordinate system, The weights are determined by the signal-to-noise ratio of the main received signal. and auxiliary signal-to-noise ratio Decide: ； If the Euclidean distance deviation is less than a preset threshold, the auxiliary receiving transducer or the signal received by the receiving transducer is determined to be an abnormal signal, and the controller re-transmits the sound wave for a second scan verification.

5. The method for improving the touch accuracy of a surface acoustic wave touchscreen according to claim 1, characterized in that, The transmitting transducer, which is located at the edge of the X-axis and Y-axis of the glass substrate, integrates a dual-frequency piezoelectric ceramic unit to generate low-frequency sound waves and high-frequency sound waves respectively. Among them, low-frequency sound waves are emitted by the transmitting transducers on the left side of the X-axis and the upper side of the Y-axis, and form a reference grid covering the entire screen through the reflection array, which is used to detect environmental interference areas; High-frequency sound waves are emitted by transducers on the right side of the X-axis and the bottom side of the Y-axis, and form a high-density positioning grid through a reflective array for calculating the coordinates of the touch point. After the receiving transducer collects the mixed acoustic wave signal, it transmits it to the signal separation module of the controller, where a bandpass filter extracts the high-frequency acoustic wave component and the low-frequency acoustic wave component.

6. The method for improving the touch accuracy of a surface acoustic wave touchscreen according to claim 1, characterized in that, The reflective array is composed of piezoelectric thin film stripes etched on the edge of the glass substrate, with each stripe being 50 μm wide and 200 μm apart; The controller dynamically adjusts the bias voltage applied to the piezoelectric film stripes based on data from multiple temperature sensors and the sound wave propagation time difference, causing the sound wave reflection angle to deflect by 0.1°-0.5°, thus compensating for the sound wave path offset caused by temperature deformation.

7. A device for improving the touch accuracy of a surface acoustic wave touchscreen, characterized in that, The device includes: The first acquisition module is used to respond to the user's touch operation and acquire the monitored temperature values ​​corresponding to the four temperature sensors and the first distance between the current touch point and the transmitting transducer. The first calculation module is used to calculate the compensation gain based on the average temperature corresponding to multiple monitored temperature values ​​and the first distance, and then perform amplitude amplification processing on the first acoustic signal of the receiving transducer, mark the amplified acoustic signal as the second acoustic signal, and calculate the main touch coordinates based on the second acoustic signal. The second acquisition module is used to dynamically correct the area of ​​the preset edge compensation region based on the current average temperature, and after the touch point is located in the corrected edge compensation region, acquire the third acoustic wave signals received by multiple auxiliary receiving transducers, and calculate the auxiliary touch coordinates based on the multiple third acoustic wave signals. The second calculation module is used to calculate the actual touch coordinates based on the main touch coordinates and the auxiliary touch coordinates using a weighted fusion algorithm. Wherein, the area of ​​the preset edge compensation region, which is dynamically corrected based on the current average temperature, includes: A temperature-edge compensation region correlation model is constructed based on the thermal expansion coefficient of the glass substrate: ;in, is the coefficient of thermal expansion of the glass substrate. Define the current average temperature; define the reference temperature. =25℃, preset edge compensation area width To compensate for temperature range; The controller reads the average temperature every 5-7 seconds and calculates the updated temperature based on the correlation model. ,like If the absolute value is greater than 0.5-1mm, then the current edge compensation area is redefined as the distance from the screen boundary. Within the range; When the touch point is located in the dynamic edge area During this time, the temperature-related additional gain is superimposed according to the following formula: ； in, Dynamic compensation gain, dimensionless, represents the final signal amplification factor after superimposed temperature effects, used for amplitude compensation of touch points in the edge region; G(d,T) is the compensation gain; The absolute value of the temperature difference is given, with a coefficient of 0.05 determined experimentally.

8. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor, configured to implement the steps of the method according to any one of claims 1-6 when executing a program stored in memory.

9. A medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the method described in any one of claims 1-6.

Images