Smart interactive tablet

Abstract

The present application relates to the technical field of piezoelectric sensor testing, and relates to a smart interactive tablet, comprising a testing circuit module electrically connected to a piezoelectric sensor. The testing circuit module comprises a signal control circuit, a first access end, a second access end, an operational circuit, a first reference voltage end, and a processor; the processor comprises an excitation signal output end; the excitation signal output end is used for transmitting at least two types of pulse-width signals in a first preset time period and a second preset time period; the signal control circuit receives the pulse-width signals; the operational circuit is separately electrically connected to the signal control circuit, the first reference voltage end, and the processor, and is used for outputting a first conditioned voltage signal and a second conditioned voltage signal to the processor; the processor obtains, on the basis of the first conditioned voltage signal and the second conditioned voltage signal, signal data for testing, then performs cross-correlation computation with preset standard signal data to obtain a cross-correlation result, and determines the state of the piezoelectric sensor on the basis of the cross-correlation result, to achieve state detection of the piezoelectric sensor.

Description

Smart Interactive Flat Panel Technical Field

[0001] This application relates to the field of smart flat panel technology, and in particular to a smart interactive flat panel. Background Technology

[0002] In some large-sized human-computer interaction electronic devices (e.g., large-sized smart interactive flat panels), piezoelectric sensors are generally used to detect the user's touch gestures on the touch screen to perform different interactive functions. Piezoelectric sensors have become one of the essential components of human-computer interaction electronic devices.

[0003] Piezoelectric sensors are typically mounted beneath the inner glass surface of touchscreens in human-computer interaction (HCI) electronic devices. During touchscreen assembly, poor electrical connections in the piezoelectric sensors can occur. If an HCI device with a potentially faulty piezoelectric sensor is used, it can lead to inaccurate touchscreen recognition rates, reduced product quality, and a negative impact on user experience. Currently, these connection problems can generally only be detected after the entire HCI device is assembled. When such a problem is discovered, the device must be disassembled to remove the piezoelectric sensor, which is located beneath the innermost glass surface of the touchscreen. This disassembly process is cumbersome, impacts production efficiency, and carries the risk of damaging other components of the touchscreen, resulting in wasted components and increased manufacturing costs.

[0004] Summary of the Invention

[0005] Therefore, it is necessary to provide a smart interactive flat panel that can detect the quality of the piezoelectric sensor before assembling it into the touch screen.

[0006] In a first aspect, this application provides a smart interactive flat panel, comprising:

[0007] At least two piezoelectric sensors are disposed on the inner surface of the cover plate of the smart interactive flat panel;

[0008] A detection circuit module is electrically connected to at least one of the piezoelectric sensors; wherein the detection circuit module includes: a piezoelectric sensor channel circuit, a calculation circuit, a first reference voltage terminal, and a processor, the processor including an excitation signal output terminal;

[0009] The piezoelectric sensor channel circuit includes a signal control circuit, a first access terminal, and a second access terminal; the first access terminal and the second access terminal are used to electrically connect to the piezoelectric sensor.

[0010] The signal control circuit is electrically connected to the excitation signal output terminal of the processor; the first access terminal is electrically connected to the signal control circuit; and the second access terminal is electrically connected to the first reference voltage terminal.

[0011] The arithmetic circuit is electrically connected to the signal control circuit, the first reference voltage terminal, and the processor, respectively.

[0012] The smart interactive flat panel detects the piezoelectric sensor in the following ways:

[0013] The processor is configured to send an excitation signal with a first pulse width to one of the signal control circuits within a first preset time period; and receive a first conditioning voltage signal sent by the arithmetic circuit; wherein the first conditioning voltage signal is obtained based on the excitation signal with the first pulse width sent to one of the signal control circuits within the first preset time period;

[0014] The processor is configured to send a second pulse width excitation signal to the same signal control circuit within a second preset time period; and receive a second conditioning voltage signal sent by the arithmetic circuit; wherein the second conditioning voltage signal is obtained based on sending the second pulse width excitation signal to the same signal control circuit within the second preset time period;

[0015] Based on at least the first conditioning voltage signal and the second conditioning voltage signal, acquire the signal data to be measured;

[0016] The cross-correlation calculation is performed on the signal data to be tested and the preset standard signal data to obtain the corresponding cross-correlation result, and the state of the piezoelectric sensor is determined based on the cross-correlation result.

[0017] In one embodiment, the processor is configured to determine that the piezoelectric sensor is in the normal state if at least two states obtained for the same piezoelectric sensor within a third preset time period include a normal state;

[0018] The duration of the third preset time period is greater than the sum of the durations of the first preset time period and the second preset time period.

[0019] In one embodiment, the processor is configured to perform state determination on the same piezoelectric sensor within a third preset time period. When the state is determined to be normal, the processor stops the output of the excitation signal from the excitation signal output terminal and determines that the piezoelectric sensor is in the normal state.

[0020] The duration of the third preset time period is greater than the sum of the durations of the first preset time period and the second preset time period.

[0021] In one embodiment, the processor is further configured to block the signals transmitted by the piezoelectric sensors in the abnormal state when the number of piezoelectric sensors in the abnormal state is less than a set value.

[0022] In one embodiment, the excitation signal output terminal of the processor includes a GPIO port, which is electrically connected to the signal control circuit and is used to generate a short square wave pulse signal to the signal control circuit.

[0023] In one embodiment, the signal control circuit includes a transistor and a third resistor. The base of the transistor is electrically connected to the GPIO port, the collector of the transistor is electrically connected to a second reference voltage terminal through the third resistor, and the emitter of the transistor is a first access terminal.

[0024] In one embodiment, the signal control circuit includes a MOS transistor and a fourth resistor. The gate of the MOS transistor is electrically connected to the GPIO port, the drain of the MOS transistor is electrically connected to a second reference voltage terminal through the fourth resistor, and the source of the MOS transistor is a first access terminal.

[0025] In one embodiment, the operational circuit is an operational amplifier circuit, which includes a first current limiting circuit and a signal conditioning circuit, wherein: the first current limiting circuit is electrically connected to the output terminal of the signal control circuit; the signal conditioning circuit is electrically connected to the first current limiting circuit, the first reference voltage terminal and the processor respectively, and is used to output a conditioning voltage signal to the processor.

[0026] In one embodiment, the first current limiting circuit includes a first resistor electrically connected to the output of the signal control circuit.

[0027] In one embodiment, the signal conditioning circuit includes an operational amplifier and a feedback circuit; the positive input terminal of the operational amplifier is electrically connected to a first reference voltage terminal, and the negative input terminal of the operational amplifier is electrically connected to a first current limiting circuit; the output terminal of the operational amplifier is electrically connected to the negative input terminal of the operational amplifier through the feedback circuit, and the output terminal of the operational amplifier is used to output a conditioning voltage signal.

[0028] In one embodiment, the feedback circuit includes a second resistor and a second capacitor, the second resistor and the second capacitor being connected in parallel, and the two terminals of the parallel connection of the second resistor and the second capacitor being electrically connected to the negative input terminal and the output terminal of the operational amplifier, respectively.

[0029] In one embodiment, the piezoelectric sensor channel circuit further includes a second current limiting circuit; wherein the input terminal of the second current limiting circuit is electrically connected to the output terminal of the signal control circuit, and the output terminal of the second current limiting circuit is electrically connected to the input terminal of the first current limiting circuit and the first access terminal, respectively.

[0030] Secondly, this application also provides a smart interactive flat panel, comprising:

[0031] At least two piezoelectric sensors are disposed on the inner surface of the cover plate of the smart interactive flat panel;

[0032] The detection circuit module is electrically connected to at least one of the piezoelectric sensors;

[0033] The detection circuit module includes: a piezoelectric sensor channel circuit, a calculation circuit, a first reference voltage terminal, and a processor;

[0034] The processor includes several pairs of first excitation signal output terminals and second excitation signal output terminals;

[0035] The piezoelectric sensor channel circuit includes a signal control circuit, a first access terminal, and a second access terminal; the first access terminal and the second access terminal are used to electrically connect to the piezoelectric sensor; the signal control circuit is electrically connected to the first excitation signal output terminal and the second excitation signal output terminal of the processor; the first access terminal and the second access terminal are respectively electrically connected to a pair of the first excitation signal output terminals and the second excitation signal output terminals of the processor based on the signal control circuit;

[0036] The computing circuit is electrically connected to each piezoelectric sensor channel circuit, the first reference voltage terminal and the processor, respectively, and is used to output a conditioning voltage signal to the processor;

[0037] The smart interactive flat panel detects the piezoelectric sensor in the following ways:

[0038] The processor is configured to send an excitation signal with a first pulse width to one of the signal control circuits in the piezoelectric sensor channel circuit through the first excitation signal output terminal within a first sub-preset time period; and receive a first conditioning voltage signal sent by the arithmetic circuit; wherein the first conditioning voltage signal is obtained based on the excitation signal with the first pulse width sent to one of the signal control circuits in the piezoelectric sensor channel circuit within the first sub-preset time period;

[0039] The processor is configured to send a second pulse width excitation signal to the same signal control circuit via the first excitation signal output terminal during a second sub-preset time period; and receive a second conditioning voltage signal sent by the arithmetic circuit; wherein the second conditioning voltage signal is obtained based on the second pulse width excitation signal sent to the same signal control circuit via the first excitation signal output terminal during the second sub-preset time period;

[0040] The processor is configured to, within a third sub-preset time period, send an excitation signal of a first pulse width to another signal control circuit in the piezoelectric sensor channel circuit via a second excitation signal output terminal paired with the first excitation signal output terminal; and receive a third conditioning voltage signal sent by the arithmetic circuit; wherein the third conditioning voltage signal is obtained based on the excitation signal of the first pulse width sent to another signal control circuit in the piezoelectric sensor channel circuit via a second excitation signal output terminal paired with the first excitation signal output terminal within the third sub-preset time period;

[0041] The processor is configured to send a second pulse width excitation signal to the other signal control circuit through the second excitation signal output terminal within a fourth sub-preset time period; and receive a fourth conditioning voltage signal sent by the arithmetic circuit; wherein the fourth conditioning voltage signal is obtained based on the second pulse width excitation signal sent to the other signal control circuit through the second excitation signal output terminal within the fourth sub-preset time period;

[0042] Based on at least the first conditioned voltage signal, the second conditioned voltage signal, the third conditioned voltage signal, and the fourth conditioned voltage signal, acquire the signal data to be measured;

[0043] The cross-correlation calculation is performed on the signal data to be tested and the preset standard signal data to obtain the corresponding cross-correlation result, and the state of the piezoelectric sensor is determined based on the cross-correlation result.

[0044] In one embodiment, the first preset time period includes the first sub-preset time period and the second sub-preset time period, and the second preset time period includes the third sub-preset time period and the fourth sub-preset time period;

[0045] The processor is configured to determine that the piezoelectric sensor is in the normal state if at least two states, including the normal state, are obtained for the same piezoelectric sensor within a third preset time period.

[0046] The duration of the third preset time period is greater than the sum of the durations of the first preset time period and the second preset time period.

[0047] In one embodiment, the first preset time period includes the first sub-preset time period and the second sub-preset time period, and the second preset time period includes the third sub-preset time period and the fourth sub-preset time period;

[0048] The processor is used to perform state judgment on the same piezoelectric sensor within a third preset time period. When the state is judged to be normal, the processor stops the output of the excitation signal from the excitation signal output terminal and determines that the piezoelectric sensor is in the normal state.

[0049] The duration of the third preset time period is greater than the sum of the durations of the first preset time period and the second preset time period.

[0050] In one embodiment, the processor is further configured to block the signals transmitted by the piezoelectric sensors in the abnormal state when the number of piezoelectric sensors in the abnormal state is less than a set value.

[0051] The smart interactive flat panel provided in this application includes at least two piezoelectric sensors disposed on the inner surface of the cover plate of the smart interactive flat panel; a detection circuit module electrically connected to at least one piezoelectric sensor; wherein, the detection circuit module includes: a piezoelectric sensor channel circuit, a processing circuit, a first reference voltage terminal, and a processor, the processor including an excitation signal output terminal; the piezoelectric sensor channel circuit includes a signal control circuit, a first access terminal, and a second access terminal; the first access terminal and the second access terminal are used for electrically connecting the piezoelectric sensor; the signal control circuit is electrically connected to the excitation signal output terminal of the processor; the first access terminal is electrically connected to the signal control circuit; the second access terminal is electrically connected to the first reference voltage terminal; the processing circuit is electrically connected to the signal control circuit, the first reference voltage terminal, and the processor respectively; the smart interactive flat panel detects the piezoelectric sensor in the following manner: the processor is used to detect the piezoelectric sensor in a first reference voltage terminal... Within a given time period, a first pulse width excitation signal is sent to a signal control circuit; and a first conditioning voltage signal is received from an arithmetic circuit; wherein the first conditioning voltage signal is obtained based on the first pulse width excitation signal sent to the signal control circuit within a first preset time period; the processor is used to send a second pulse width excitation signal to the same signal control circuit within a second preset time period; and receive a second conditioning voltage signal sent from the arithmetic circuit; wherein the second conditioning voltage signal is obtained based on the second pulse width excitation signal sent to the same signal control circuit within a second preset time period; based on at least the first and second conditioning voltage signals, test signal data is acquired; the test signal data and preset standard signal data are cross-correlated to obtain the corresponding cross-correlation result, and the state of the piezoelectric sensor is determined based on the cross-correlation result. By connecting the piezoelectric sensor to the first and second access terminals of the piezoelectric sensor channel circuit, after the piezoelectric sensor is connected to the detection circuit, the processor can transmit an excitation signal with a first pulse width within a first preset time period and an excitation signal with a second pulse width within a second preset time period. This drives the signal control circuit to conduct according to the corresponding pulse width excitation signal within the first and second preset time periods, respectively. This enables the signal control circuit in the conducting state to transmit an electrical signal with the corresponding pulse width to detect the piezoelectric sensor in real time. The processor can also receive the first and second conditioning voltage signals sent by the arithmetic circuit within the first and second preset time periods, respectively. Based on at least the first and second conditioning voltage signals, the corresponding test signal data is obtained. Then, the test signal data and the preset standard signal data corresponding to the intact state of the piezoelectric sensor of the same specification are cross-correlated to obtain the corresponding cross-correlation result. Based on the cross-correlation result, the state of the piezoelectric sensor is determined, that is, whether the detected piezoelectric sensor is in a normal or abnormal state.Based on the circuit structure design of the smart interactive flat panel provided in this application, it is possible to directly detect whether the piezoelectric sensor has poor electrical connection during the production process, which helps to intercept the problem of poor piezoelectric sensor electrical connection in the early stages of the process, avoiding the troublesome disassembly later, and thus improving the production efficiency of related touch electronic devices. Alternatively, it is also possible to detect whether the piezoelectric sensor has poor electrical connection after the smart interactive flat panel is assembled. If poor piezoelectric sensor electrical connection is detected at the user end after the smart interactive flat panel is assembled, these poorly connected piezoelectric sensors can be shielded in time, ensuring that the touch recognition rate of the smart interactive flat panel is within a controllable range. This solves the problem in related technologies where, when a poor piezoelectric sensor electrical connection is detected after the smart interactive flat panel is assembled, it is necessary to disassemble the piezoelectric sensor installed under the inner surface glass of the touch screen, which is cumbersome and affects production efficiency. Furthermore, it also helps to avoid the possibility of damaging other components of the electronic device's touch screen during disassembly, avoiding waste of touch screen assembly components, and thus helping to reduce the production cost of related touch electronic devices. Furthermore, this application is based on transmitting at least two pulse width excitation signals to the signal control circuit within a first preset time period and a second preset time period, so as to control the signal control circuit to turn on based on the at least two pulse width excitation signals, thereby enabling the piezoelectric sensor to receive the electrical signal corresponding to the pulse width signal, so as to realize the detection of the piezoelectric sensor under the electrical signal of at least two pulse widths. Compared with the detection of the electrical signal of a single pulse width, the detection accuracy of the piezoelectric sensor can be further improved. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 shows a schematic diagram of a time period including a pulse width signal;

[0054] Figure 2 shows a schematic diagram of the piezoelectric sensor.

[0055] Figure 3 shows a schematic diagram of the equivalent circuit of a piezoelectric sensor in current source mode.

[0056] Figure 4 shows a schematic diagram of the equivalent circuit of a piezoelectric sensor in voltage source mode.

[0057] Figure 5 shows a schematic diagram of the first circuit structure of the smart interactive flat panel provided in the embodiment of this application;

[0058] Figure 6 shows a schematic diagram of a second circuit structure of the smart interactive flat panel provided in an embodiment of this application;

[0059] Figure 7 shows a schematic diagram of a third circuit structure of the smart interactive flat panel provided in an embodiment of this application.

[0060] Figure 8 shows a schematic diagram of the fourth circuit structure of the smart interactive flat panel provided in the embodiments of this application;

[0061] Figure 9 shows a schematic diagram of the fifth circuit structure of the smart interactive flat panel provided in the embodiments of this application;

[0062] Figure 10 shows a schematic diagram of the sixth circuit structure of the smart interactive flat panel provided in the embodiments of this application.

[0063] Figure 11 is a schematic diagram of a piezoelectric sensor detection circuit providing an embodiment of this application outputting multiple continuous preset excitation signals;

[0064] Figure 12 is a schematic diagram of the electrical signal corresponding to the reference piezoelectric sensor received by the processor of the piezoelectric sensor detection circuit provided in the embodiment of this application.

[0065] Figure 13 is a schematic diagram of the electrical signal corresponding to the piezoelectric sensor under test received by the processor of the piezoelectric sensor detection circuit provided in the embodiment of this application.

[0066] Figure 14 is a schematic diagram of the electrical signal corresponding to another piezoelectric sensor under test received by the processor of the piezoelectric sensor detection circuit provided in the embodiment of this application.

[0067] Figure 15 is a schematic diagram of the reference signal data corresponding to Figure 12 provided in an embodiment of this application;

[0068] Figure 16 is a schematic diagram of the signal data to be tested corresponding to Figure 13 provided in an embodiment of this application;

[0069] Figure 17 is a schematic diagram of the signal data to be tested corresponding to Figure 14 provided in an embodiment of this application. Detailed Implementation

[0070] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0071] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0072] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0073] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0074] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0075] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0076] In some large-sized smart interactive flat panels, piezoelectric sensors are generally used to detect the user's touch gestures on the touch screen to perform different interactive functions. Piezoelectric sensors have become one of the essential components of smart interactive flat panels.

[0077] Based on the principle of piezoelectric sensors detecting vibrations, the elastic waves generated by a stylus writing on a smart interactive tablet touchscreen can be measured. Differences in the frequencies received by the piezoelectric sensor determine the writing material, such as a finger, pen tip, or pen tip. The current writing is then assigned an ID to execute different interactive functions. For example, a finger can circle and swipe, the pen tip can be lifted to write, and the pen tip can erase.

[0078] Piezoelectric sensors are typically mounted affixed to the inner surface of the touchscreen of a smart interactive flat panel. During the research and development process, the applicant discovered that due to the internal size limitations of the smart interactive flat panel touchscreen, the size and thickness of the piezoelectric sensor needed to be controlled within a small range. This led to various problems with the installation, electrical connection, and structure of the piezoelectric sensor itself. For example, during installation, transportation, and use of the smart interactive flat panel, various vibrations could cause poor electrical connections, breakage, or short circuits in the piezoelectric sensor. Poor electrical connections of the piezoelectric sensor may occur during touchscreen assembly. If a smart interactive flat panel is equipped with a piezoelectric sensor that may have a poor electrical connection, it can cause touchscreen misalignment, reduce product quality, and affect user experience.

[0079] In related technologies, the problem of poor electrical connection of the piezoelectric sensor can generally only be detected after the entire smart interactive flat panel is assembled. When this problem is detected, the device must be disassembled to remove the piezoelectric sensor, which is installed under the inner surface glass of the touch screen. This requires removing the entire frame, back panel, rear shell, and mid-frame of the device, and then disassembling the inner surface glass of the touch screen to remove the piezoelectric sensor underneath. The entire disassembly process is cumbersome, labor-intensive, and affects production efficiency. In addition, since large-size smart interactive flat panels usually require multiple piezoelectric sensors, the detection process provided by related technologies requires checking and testing each one individually, which is labor-intensive and time-consuming. Besides this method, another way to test the quality of piezoelectric sensors is by having an operator manually tap the pressure-sensing surface of the sensor. The sensor then records the electrical signal output after the tap, and the amplitude of the recorded signal is checked. If the amplitude reaches a preset threshold, the piezoelectric sensor is considered to have passed the test and is considered a good product. However, tapping the pressure-sensing surface requires multiple taps, resulting in extremely low detection efficiency. Furthermore, different operators may tap the sensor differently, and the force of each tap cannot be accurately controlled, leading to unstable and inaccurate test results. Additionally, if the piezoelectric sensor or its circuitry has only a minor fault, a larger tap force applied by the operator might cause the corresponding processor to receive a response signal reaching the preset threshold. Such a response signal would obviously result in an inaccurate test result, leading to false detections.

[0080] To address this, some related technologies propose adding a detection circuit module for the piezoelectric sensor. This module allows for convenient detection of the piezoelectric sensor at any time, either during or after assembly. However, in these technologies, the detection circuit module outputs a single excitation signal with a single pulse width to a signal control circuit. This causes the signal control circuit to conduct and output a single electrical signal with the same pulse width to detect the piezoelectric sensor. The applicant's research revealed that during the testing of a piezoelectric sensor, transmitting only one or a small number of detection signals results in low accuracy. Similarly, transmitting detection signals of the same pulse width also leads to low accuracy. For example, if a signal control circuit is configured to transmit one or more detection signals of a specific pulse width to the piezoelectric sensor, the corresponding processor might determine the sensor as defective based on the received conditioning signal. However, during the applicant's actual development, it was found that using a different pulse width detection signal could lead the processor to determine the sensor as good. This is likely because external vibrations during the detection process can interfere with the final result, potentially misclassifying a defective sensor as good or vice versa. Based on this, the applicant believes that when testing the quality of piezoelectric sensors, if only a single pulse width electrical signal is used as the trigger detection signal for the piezoelectric sensor, or if only a small number of electrical signals are provided as the trigger detection signal for the piezoelectric sensor, it is easily affected by external factors, which will lead to insufficient accuracy of the relevant test results.

[0081] It is evident that the quality inspection of piezoelectric sensors in related technologies either affects the production efficiency of related electronic products and increases the manufacturing cost of related electronic equipment, or the test results contain too many subjective human factors, or the test signals are too rigid and singular. All of these will lead to unstable and inaccurate test results of piezoelectric sensors.

[0082] To address the aforementioned technical problems discovered during the research and development process, this application provides an intelligent interactive flat panel, which includes a piezoelectric sensor and a detection circuit module. The piezoelectric sensor is disposed on the inner surface of the cover plate of the intelligent interactive flat panel (e.g., the side of the cover plate away from the light-emitting surface). A single intelligent interactive flat panel may include multiple piezoelectric sensors arranged in parallel. The detection circuit module is electrically connected to the piezoelectric sensor, and each detection circuit module is electrically connected to at least one piezoelectric sensor. Optionally, the detection circuit module and the piezoelectric sensor can be electrically connected in a one-to-one correspondence, or one detection circuit module can be electrically connected to multiple piezoelectric sensors.

[0083] The detection circuit module includes: a piezoelectric sensor channel circuit, a calculation circuit, a first reference voltage terminal, and a processor. The processor includes an excitation signal output terminal, which is controlled based on the processor. The excitation signal output terminal can be integrated into the processor; of course, the excitation signal output terminal and the processor can also be set separately. In the case of separate setting, the excitation signal output terminal needs to be electrically connected to the processor. Here, there is no limitation on whether the excitation signal output terminal is integrated into the processor. The piezoelectric sensor channel circuit includes a signal control circuit, a first access terminal, and a second access terminal. The first and second access terminals are electrically connected to the piezoelectric sensor. The signal control circuit is electrically connected to the excitation signal output terminal and receives the signal emitted by the excitation signal output terminal. The excitation signal output terminal outputs a preset excitation signal, which can be set based on detection requirements. For example, within a detection time period, the excitation signal output terminal can sequentially emit at least two preset excitation signals with different pulse widths. The signal control circuit is turned on when it receives the preset excitation signal, so that the electrical signal at the voltage terminal electrically connected to the signal control circuit can be output to the piezoelectric sensor in this state, thereby providing a detection signal indicating whether the piezoelectric sensor is in a normal state. The first access terminal is electrically connected to the signal control circuit and outputs an electrical signal adjusted based on the preset excitation signal to the piezoelectric sensor to drive it. The second access terminal is electrically connected to a first reference voltage terminal. The arithmetic circuit is electrically connected to the signal control circuit, the first reference voltage terminal, and the processor, respectively, and outputs a conditioned voltage signal to the processor.

[0084] Based on the internal circuit structure of the intelligent interactive flat panel provided in this application, a detection method for a piezoelectric sensor by the intelligent interactive flat panel is provided, specifically: A processor is used to send an excitation signal with a first pulse width to a signal control circuit within a first preset time period; and receive a first conditioning voltage signal sent by a computational circuit; wherein the first conditioning voltage signal is obtained based on the excitation signal with the first pulse width sent to the signal control circuit within the first preset time period; the processor is used to send an excitation signal with a second pulse width to the same signal control circuit within a second preset time period; and receive a second conditioning voltage signal sent by the computational circuit; wherein the second conditioning voltage signal is obtained based on the excitation signal with a second pulse width sent to the same signal control circuit within the second preset time period; a test signal data is obtained based on at least the first and second conditioning voltage signals; cross-correlation calculation is performed on the test signal data and preset standard signal data to obtain the corresponding cross-correlation result; and the state of the piezoelectric sensor is determined based on the cross-correlation result. As can be seen, based on the circuit structure design of the smart interactive flat panel provided in this application, it is possible to directly detect whether the piezoelectric sensor has a poor electrical connection during the production process, intercepting the situation of poor electrical connection of the piezoelectric sensor in the early stage of the process, avoiding the trouble of subsequent disassembly, thereby improving the production efficiency of related touch electronic devices.

[0085] If, after the smart interactive flat panel is assembled, a poor electrical connection of the piezoelectric sensor is detected at the user end, and the number of poorly connected piezoelectric sensors is lower than a set value, it indicates that the number of damaged piezoelectric sensors in the smart interactive flat panel is relatively small. In this case, these poorly connected piezoelectric sensors can be disabled, and only piezoelectric sensors in normal condition can be used. This ensures that the touch recognition rate of the smart interactive flat panel is within a controllable range. This approach, while guaranteeing user performance, also mitigates the possibility of damaging other components of the electronic device's touchscreen during after-sales disassembly, avoiding waste of touchscreen assembly components and thus helping to reduce the production cost of related touch electronic devices.

[0086] It should also be noted that this application is based on transmitting two different pulse width excitation signals to the signal control circuit within a first preset time period and a second preset time period, respectively, to control the signal control circuit to conduct and output an electrical signal of the corresponding pulse width to the piezoelectric sensor being detected. This achieves the detection of the piezoelectric sensor under at least two pulse width electrical signals. Compared with the detection of a single pulse width electrical signal, the probability of the at least two pulse width electrical signals being simultaneously affected by the external environment is smaller, thus further improving the detection accuracy of the piezoelectric sensor. It should be noted that if the preset excitation signal during detection includes two pulse width excitation signals, one detection cycle includes the sum of the first preset time period and the second preset time period as described above. Within this detection cycle, the two pulse width excitation signals are transmitted. For example, one pulse width signal can be continuously transmitted first, followed by the other pulse width signal continuously transmitted. That is, the first preset time period and the second preset time period can be seamlessly connected. Of course, a certain time interval can also be set between the first preset time period and the second preset time period as needed. This application does not make specific limitations on this. If the preset excitation signal during detection includes three pulse widths, one detection cycle consists of performing one round of detection using each of the three pulse widths to determine the state of the piezoelectric sensor. The same logic applies to other excitation signal scenarios.

[0087] It should also be noted that this application is based on sequentially transmitting excitation signals of at least two pulse widths to the signal control circuit within a detection cycle (including a first preset time period and a second preset time period), rather than simply transmitting signals of at least two frequencies sequentially. For ease of understanding, please refer to Figures 1a and 1b: a single-pulse-width signal may itself be a multi-frequency signal. That is, signals with different pulse widths are necessarily signals of different frequencies, but signals of different frequencies are not necessarily signals with different pulse widths. This application achieves the detection of the piezoelectric sensor by sequentially transmitting excitation signals of at least two pulse widths within a detection cycle. Providing multiple pulse width signals helps improve the accuracy of the piezoelectric sensor's detection results.

[0088] It should also be noted that the state of a piezoelectric sensor includes a normal state and an abnormal state. Based on the detection circuit module provided in this application, the piezoelectric sensor is finally found to be in a normal state. This not only indicates that the piezoelectric sensor itself is in a normal state and is a good component, but also indicates that other parts of the circuit in which the piezoelectric sensor performs the sensing function are in a normal state during normal use. Similarly, if the piezoelectric sensor is in an abnormal state, it may not only indicate that the piezoelectric sensor itself is in an abnormal state, but also that other parts of the circuit in which the piezoelectric sensor performs the sensing function are in an abnormal state during normal use, or both the piezoelectric sensor itself and other parts of the circuit in which the piezoelectric sensor performs the sensing function are in an abnormal state during normal use.

[0089] Furthermore, based on the intelligent interactive flat panel and its detection method for piezoelectric sensors provided in this application, when an abnormal state is detected in the piezoelectric sensor, corresponding repairs can be performed as quickly as possible. This helps reduce the cost of fault identification and repair, improves work efficiency, and enhances user experience. Additionally, the intelligent interactive flat panel of this application can employ multiple sets of piezoelectric sensors and detection circuit modules connected in parallel. When the processor determines the detection results, it can also pinpoint the specific piezoelectric sensor that has malfunctioned, significantly improving the efficiency of detection and repair.

[0090] To facilitate understanding of the above-mentioned inventive concept of this application, the above-mentioned inventive concept of this application will be described in more detail below with reference to the accompanying drawings and specific embodiments.

[0091] Figure 2 shows a schematic diagram of the piezoelectric sensor. In Figure 2, the piezoelectric sensor includes a central piezoelectric ceramic material, an upper electrode positioned above the piezoelectric ceramic material, and a lower electrode positioned below the piezoelectric ceramic material. The upper electrode, lower electrode, and central ceramic insulating material form a capacitor. When the piezoelectric sensor is connected to a back-end analog signal processing circuit (such as the detection circuit module of this patent), the piezoelectric sensor can use its equivalent capacitance Cp as part of the circuit.

[0092] When physical pressure is applied to the piezoelectric ceramic material that makes up the piezoelectric sensor, the electric dipole moment in the piezoelectric ceramic material will shorten due to compression. At this time, in order to resist this change, the piezoelectric ceramic material will generate equal amounts of positive and negative charges on opposite surfaces to maintain its original state.

[0093] Figure 3 shows the equivalent circuit diagram of a piezoelectric sensor in current source mode. Referring to Figure 3, in current source mode, it can be represented by the following formula:

[0094] Ip = dQ / dt

[0095] In the above formula, Ip represents the differential of the amount of charge generated by the piezoelectric sensor per unit time, Q represents the charge generated by the piezoelectric sensor during the pressing process, Cp represents the equivalent capacitance of the piezoelectric sensor, and Rp represents the leakage resistance of the piezoelectric sensor (although the resistance of piezoelectric ceramic is very large, it is not infinite and cannot be regarded as an ideal capacitor).

[0096] For ease of calculation, the equivalent circuit of the piezoelectric sensor in current source mode shown in Figure 3 can also be replaced by the equivalent circuit of the piezoelectric sensor in voltage source mode shown in Figure 4. In Figure 4, the equivalent capacitance Cp of the piezoelectric sensor is connected in parallel with the leakage resistance Rp of the piezoelectric sensor. The values ​​of the equivalent capacitance Cp and the leakage resistance Rp of the piezoelectric sensor can be obtained by testing with a digital bridge. The leakage resistance Rp of the piezoelectric sensor is extremely large and can be ignored in the circuit where the equivalent capacitance Cp and the leakage resistance Rp of the piezoelectric sensor are connected in parallel. When physical pressure is applied to the piezoelectric ceramic material that makes up the piezoelectric sensor, the electric dipole moment in the piezoelectric ceramic material will shorten due to compression. At this time, the piezoelectric ceramic material will generate equal amounts of positive and negative charges on opposite surfaces to resist this change. At this time, the generated equal amounts of positive and negative charges can be sampled and converted into corresponding voltage signals by the connected back-end analog signal processing circuit for subsequent processing.

[0097] Figure 5 shows a circuit structure diagram of a smart interactive flat panel provided in an embodiment of this application. Referring to Figure 5, based on the problems existing in related technologies, this application provides a smart interactive flat panel, including:

[0098] At least two piezoelectric sensors 10 are disposed on the inner surface of the cover plate of the smart interactive flat panel; wherein, a smart interactive flat panel may include multiple piezoelectric sensors arranged in parallel;

[0099] The detection circuit module 100 is electrically connected to the piezoelectric sensor 10, and one detection circuit module 100 is electrically connected to at least one piezoelectric sensor 10. Alternatively, the detection circuit module 100 and the piezoelectric sensor 10 can be electrically connected in a one-to-one correspondence, or one detection circuit module 100 can be electrically connected to multiple piezoelectric sensors 10.

[0100] The detection circuit module 100 includes: a piezoelectric sensor channel circuit, an arithmetic circuit 11, a first reference voltage terminal VDD, and a processor 12. The processor 12 includes an excitation signal output terminal 121.

[0101] The piezoelectric sensor channel circuit includes a signal control circuit 13, a first access terminal IN1, and a second access terminal IN2; the first access terminal IN1 and the second access terminal IN2 are used to electrically connect to the piezoelectric sensor 10.

[0102] The excitation signal output terminal 121 is used to transmit excitation signals with at least two pulse widths within one detection cycle. The signal control circuit 13 is electrically connected to the excitation signal output terminal 121 and is used to receive the signals transmitted by the excitation signal output terminal 121. Specifically, the excitation signal output terminal 121 can output a preset excitation signal. Within one detection cycle, the excitation signal output terminal 121 can specifically transmit at least two preset excitation signals with different pulse widths. When the signal control circuit 13 receives the preset excitation signal, it is turned on, so that the electrical signal at the voltage terminal electrically connected to the signal control circuit 13 can be output to the piezoelectric sensor 10 in this state, thereby enabling the detection of the piezoelectric sensor 10. Simultaneously, the signal control circuit 13 can also prevent the signal from the piezoelectric sensor 10 from flowing back into the excitation signal output terminal 121. The first access terminal IN1 is electrically connected to the signal control circuit 13. That is, the output terminal of the signal control circuit 13 is the first access terminal IN1. The first access terminal IN1 is used to output an electrical signal controlled by a preset excitation signal to the piezoelectric sensor 10 to drive the piezoelectric sensor 10. The second access terminal IN2 is electrically connected to the first reference voltage terminal VDD.

[0103] The arithmetic circuit 11 is electrically connected to the signal control circuit 13, the first reference voltage terminal VDD and the processor 12 respectively, and is used to output a conditioning voltage signal to the processor 12.

[0104] Based on the circuit structure of the intelligent interactive flat panel provided in this application, this application also provides a method for the intelligent interactive flat panel to detect piezoelectric sensors, including:

[0105] The processor 12 is configured to send a first pulse width excitation signal to a signal control circuit 13 within a first preset time period; and receive a first conditioning voltage signal sent by the arithmetic circuit 11; wherein the first conditioning voltage signal is obtained based on the excitation signal with the first pulse width sent to the signal control circuit 13 within the first preset time period.

[0106] The processor 12 is used to send a second pulse width excitation signal to the same signal control circuit 13 within a second preset time period; and to receive a second conditioning voltage signal sent by the arithmetic circuit 11; wherein the second conditioning voltage signal is obtained based on the second pulse width excitation signal sent to the same signal control circuit 13 within the second preset time period;

[0107] Based on at least a first conditioning voltage signal and a second conditioning voltage signal, the signals are processed to obtain the corresponding test signal data; the test signal data and the preset standard signal data are cross-correlated to obtain the corresponding cross-correlation result, and the state of the piezoelectric sensor is determined based on the cross-correlation result.

[0108] This application provides a method for determining the state of a piezoelectric sensor based on cross-correlation results. The method involves comparing the cross-correlation results with a preset threshold. When the cross-correlation result is higher than or equal to the preset threshold, the piezoelectric sensor 10 is determined to be in a normal state. When the cross-correlation result is lower than the preset threshold, the piezoelectric sensor 10 is determined to be in an abnormal state.

[0109] In this embodiment, an intelligent interactive flat panel is provided. A piezoelectric sensor 10 is connected to the first access terminal IN1 and the second access terminal IN2 of the piezoelectric sensor channel circuit in the interactive intelligent flat panel. After the piezoelectric sensor 10 is connected to the detection circuit, the processor 12 emits an excitation signal of a first pulse width within a first preset time period and an excitation signal of a second pulse width within a second preset time period. This drives the signal control circuit 13 to conduct according to the corresponding pulse width excitation within the first and second preset time periods and output an electrical signal of the corresponding pulse width, thereby enabling the signal control circuit 13 in the conducting state to transmit an electrical signal of the corresponding pulse width. The piezoelectric sensor 10 is monitored in real time, and the processor 12 receives the first and second conditioning voltage signals respectively sent by the arithmetic circuit 11 within a first and second preset time periods. Based on at least the first and second conditioning voltage signals, the processor obtains the corresponding test signal data. Then, the test signal data and the preset standard signal data corresponding to the intact state of the piezoelectric sensor 10 of the same specification are cross-correlated to obtain the corresponding cross-correlation result. Based on the comparison between the cross-correlation result and a preset threshold, the state of the piezoelectric sensor 10 is determined, i.e., whether the piezoelectric sensor 10 is in a normal or abnormal state. Based on the circuit structure design of the intelligent interactive flat panel provided in this application, it is possible to directly detect whether the piezoelectric sensor 10 has a poor electrical connection during the production process, which helps to intercept the situation of poor electrical connection of the piezoelectric sensor 10 in the early stages of the process, avoiding the trouble of subsequent disassembly, thereby improving the production efficiency of related touch electronic devices. It is also possible to detect whether the piezoelectric sensor has poor electrical connection after the smart interactive flat panel is assembled, based on the requirements. If a poor electrical connection of the piezoelectric sensor 10 is detected at the user end after the smart interactive flat panel is assembled, these poorly connected piezoelectric sensors 10 can be shielded in time to ensure that the touch recognition rate of the smart interactive flat panel is within a controllable range. This can solve the problem of cumbersome disassembly of the piezoelectric sensor 10 installed under the inner surface glass of the touch screen when a poor electrical connection of the piezoelectric sensor 10 is detected after the smart interactive flat panel is assembled. In addition, it is also beneficial to avoid the possibility of damaging other components of the electronic device touch screen during the disassembly process, avoiding waste of touch screen assembly components, and thus helping to reduce the production cost of related touch electronic devices.

[0110] This application is based on transmitting at least two pulse width excitation signals to the signal control circuit 13 within a first preset time period and a second preset time period, so as to control the signal control circuit 13 to turn on based on the at least two pulse width excitation signals, so that the piezoelectric sensor 10 can receive the electrical signal corresponding to the pulse width signal. That is, the pulse width of the electrical signal received by the piezoelectric sensor 10 is the same as the pulse width of the pulse signal emitted by the excitation signal output terminal 121, thereby realizing the detection of the piezoelectric sensor 10 under electrical signals with at least two pulse widths. Compared with the detection of electrical signals with a single pulse width, it is less affected by the external environment (such as external vibration). Even if the piezoelectric sensor is affected by external vibration when detecting under an electrical signal with a certain pulse width, the piezoelectric sensor is not affected by external vibration when detecting under electrical signals with other pulse widths, which is beneficial to improving the detection accuracy of the piezoelectric sensor 10.

[0111] In one embodiment, when multiple piezoelectric sensors 10 are provided in the smart interactive flat panel, the multiple piezoelectric sensors 10 can be connected in parallel, and the number of piezoelectric sensors 10 connected in parallel can be 4-6, or more can be provided as needed.

[0112] In one embodiment, when the smart interactive flat panel is provided with multiple detection circuit modules 100, the piezoelectric sensors 10 arranged in parallel can share the same excitation signal output terminal 121 of the processor 12, or each detection circuit module 100 can be provided with a separate excitation signal output terminal 121 of the processor 12. This application does not make specific limitations on this.

[0113] The detection circuit module 100 provided in this application for the piezoelectric sensor 10 can be configured to first electrically connect to a reference piezoelectric sensor, i.e., a good piezoelectric sensor 10 in good condition, and store the reference signal data corresponding to the reference piezoelectric sensor acquired during the detection process in the processor 12 of the detection circuit module 100 as preset standard signal data. Then, the detection circuit module 100 storing the reference signal data can be used to detect the piezoelectric sensor 10 under test associated with the reference piezoelectric sensor. After the processor 12 receives the signal data under test corresponding to the piezoelectric sensor 10 under test, it only needs to perform cross-correlation calculation between the signal data under test and the preset standard signal data stored in advance to obtain the cross-correlation result between the preset standard signal data and the signal data under test, and output the detection result of the relevant piezoelectric sensor 10 under test based on the comparison between the cross-correlation result and the preset threshold. In this context, the piezoelectric sensor 10 under test associated with the reference piezoelectric sensor can be understood as a piezoelectric sensor 10 of the same specification. If both piezoelectric sensors 10 are of good quality, then when detection is performed based on the same preset excitation signal, the corresponding conditioning voltage signal received by the processor 12 of the corresponding detection circuit module 100 should also be the same or approximately the same. Therefore, the preset standard signal data and the signal data under test acquired by the processor 12 subsequently should also be the same or approximately the same. Using this method, for piezoelectric sensors 10 of the same specification, it is not necessary to collect the conditioning voltage signal corresponding to the reference piezoelectric sensor for each test to obtain the reference signal data, which helps to simplify the detection efficiency of piezoelectric sensors 10 of the same specification.

[0114] Furthermore, for piezoelectric sensors 10 of the same specification, the preset standard signal data corresponding to the reference signal data can be stored in the processor 12 of the detection circuit module 100 in advance. The detection product containing the detection circuit module 100, when it is necessary to detect the yield of the associated piezoelectric sensor 10 under test, each time the detection product (smart interactive flat panel) is powered on, or when the processor 12 receives a test command, it tests the piezoelectric sensor 10 under test that is electrically connected to the detection product. That is, it sends a preset excitation signal associated with one detection cycle of the reference piezoelectric sensor to the piezoelectric sensor 10 under test. Then, the test result (the signal data under test) received by the processor 12 is cross-correlated with the stored preset standard signal data to obtain the corresponding cross-correlation result. Then, based on the comparison between the cross-correlation result and the preset threshold, the state of the piezoelectric sensor 10 under test is determined, that is, the normal state or the abnormal state. If the piezoelectric sensor 10 under test is found to be not a good product (defective product), it can be shielded or the user can be reminded or the information can be sent to the manufacturer.

[0115] Furthermore, this application allows for the optional configuration of the output terminal of the signal control circuit 13 being electrically connected to one signal terminal of the piezoelectric sensor 10, and the input terminal of the arithmetic circuit 11 being electrically connected to each signal terminal of the piezoelectric sensor 10. Specifically, when the piezoelectric sensor 10 has two signal terminals, configuring the output terminal of the signal control circuit 13 to be electrically connected only to one signal terminal of the piezoelectric sensor 10, rather than both, avoids situations where the two signal terminals of the piezoelectric sensor 10 receive the same electrical signal, causing the electrical signals to cancel each other out and preventing the processor 12, which is electrically connected to the piezoelectric sensor 10, from receiving the relevant conditioning voltage signal. This helps ensure the detection effect of the detection circuit module 100 on the piezoelectric sensor 10. However, this application does not limit which signal terminal of the piezoelectric sensor 10 the signal control circuit 13 is electrically connected to; it can choose to electrically connect to any signal terminal of the piezoelectric sensor 10.

[0116] Furthermore, compared to the method in related technologies where the piezoelectric sensor 10 is tested by manually striking its pressure sensing surface, the detection method provided in this application, which inputs relevant electrical signals to the piezoelectric sensor 10 under test based on the excitation signal output terminal 121 and the signal control circuit 13, has higher detection efficiency. Moreover, the uniformity of the preset excitation signal is controllable, which can avoid the problem of deviation in detection results caused by human subjective factors. Compared with the manual striking method in related technologies, it can provide more accurate and stable detection results.

[0117] Furthermore, during the product inspection of the piezoelectric sensor 10, this application can send signals with multiple pulse widths to the signal control circuit 13 based on the excitation signal output terminal 121, so that the piezoelectric sensor 10 under test can receive multiple detection signals with corresponding multiple pulse widths based on the signal control circuit 13. Compared with using only a single frequency electrical signal as the trigger detection signal of the piezoelectric sensor 10, or using only a single pulse width electrical signal as the trigger detection signal of the piezoelectric sensor 10, it is less affected by external vibrations, which is conducive to further improving the accuracy of related detection.

[0118] Please continue to refer to Figure 5. In an exemplary embodiment, the processor 12 is used to determine that the piezoelectric sensor 10 is in a normal state if at least two states, including a normal state, are obtained for the same piezoelectric sensor 10 within a third preset time period.

[0119] The duration of the third preset time period is greater than the sum of the durations of the first preset time period and the second preset time period.

[0120] Specifically, at least two pulse widths are sequentially emitted during a first preset time period and a second preset time period to control the opening and closing of the signal control circuit 13, so that the piezoelectric sensor 10 can receive a detection signal when the signal control circuit 13 is in the open state, thereby realizing the detection of the piezoelectric sensor. This is one detection cycle for the piezoelectric sensor 10.

[0121] In order to improve the accuracy of the detection results, the piezoelectric sensor 10 can be tested multiple times during the process of detecting whether the piezoelectric sensor 10 is in a normal state. That is, two or more detection cycles can be performed on the piezoelectric sensor 10 being tested.

[0122] Based on this, this application provides an optional implementation method in which the piezoelectric sensor 10 to be tested is detected within a third preset time period. The duration of the third preset time period is longer than the sum of the durations of the first preset time period and the second preset time period. For example, the piezoelectric sensor 10 to be tested can be detected for two or more detection cycles within the third preset time period. Correspondingly, the processor 12 will also obtain two or more detection results for the same piezoelectric sensor 10 within the third preset time period. During the detection of the piezoelectric sensor 10, external interference signals or vibrations may cause deviations in the detection results. For example, a piezoelectric sensor 10 that was originally in a normal state may become abnormal due to the presence of external interference signals during the detection process. However, considering that external interference signals or vibrations are sporadic and that the pulse width of the interference electrical signal formed by external interference signals or vibrations is unlikely to always be the same as the pulse width of the pulse signal emitted by the excitation signal output terminal 121, external interference signals or vibrations will, as far as possible, cause the detection results of the piezoelectric sensor 10 in a normal state to become abnormal, or cause the detection results of the piezoelectric sensor 10 in an abnormal state to become normal. Furthermore, external interference signals or vibrations will only cause the detection results of the piezoelectric sensor 10 to be abnormal, but will not cause a good piezoelectric sensor 10 to actually become a defective product, or a defective piezoelectric sensor 10 to actually become a good product. However, if the piezoelectric sensor 10 itself is damaged, then using the solution of this application embodiment for detection will only result in an abnormal detection result. Therefore, if at least one state in the detection results of the same piezoelectric sensor 10 within the third preset time period is a normal state, the processor 12 can determine that the piezoelectric sensor 10 is in a normal state. For example, if two detection cycles are performed on the same piezoelectric sensor 10 within the third preset time period, two detection results will be obtained. As long as one of these two detection results indicates that the piezoelectric sensor 10 is in a normal state, it can be determined that the piezoelectric sensor 10 is in a normal state. This method has higher detection accuracy.

[0123] Please refer to Figure 5. Based on this, this application provides an optional implementation in which the processor 12 is used to perform state judgment on the same piezoelectric sensor 10 within a third preset time period. When the judged state is normal, the processor stops the output signal from the excitation signal output terminal 121 and determines that the piezoelectric sensor 10 is in a normal state.

[0124] The duration of the third preset time period is greater than the sum of the durations of the first preset time period and the second preset time period.

[0125] Specifically, to save energy and shorten the detection cycle of the piezoelectric sensor 10 as much as possible, the processor 12 can choose to determine the state of the same piezoelectric sensor 10 during the third preset time period, i.e., during the detection process. If the detection result indicates that the piezoelectric sensor 10 is in a normal state, then the piezoelectric sensor 10 can be determined to be in a normal state. At the same time, the action of the excitation signal output terminal 121 to output a signal to the signal control circuit 13 can be stopped. That is, the detection process for the piezoelectric sensor 10 has been completed. For example, if the detection of the same piezoelectric sensor 10 is performed during the third preset time period, and the detection result obtained in the first two detection cycles indicates that the piezoelectric sensor 10 is in an abnormal state, but the detection result obtained in the third detection cycle indicates that the piezoelectric sensor 10 is in a normal state, then the piezoelectric sensor 10 can be determined to be in a normal state, and the action of the excitation signal output terminal 121 to output a signal to the signal control circuit 13 can be stopped.

[0126] It should also be added that, during the state judgment process for the same piezoelectric sensor 10 within the third preset time period, if the obtained state detection result is an abnormal state and no normal state is found, and the third preset time period has not yet ended, then the detection of the piezoelectric sensor 10 continues. If, at the end of the third preset time period, all detection results of the piezoelectric sensor 10 indicate that the piezoelectric sensor 10 is in an abnormal state, then the piezoelectric sensor 10 is determined to be in an abnormal state.

[0127] Please continue to refer to Figure 5. In an exemplary embodiment, the processor 12 is also configured to shield the signals transmitted by the piezoelectric sensors 10 that are in abnormal states when the number of piezoelectric sensors 10 in abnormal states is less than a set value.

[0128] Specifically, when all piezoelectric sensors 10 in the entire smart interactive panel are detected to obtain corresponding detection results, if the detection results indicate that the number of piezoelectric sensors 10 in the smart interactive panel is relatively small, specifically less than a set value, the processor 12 can shield the signals transmitted by the piezoelectric sensors 10 in the abnormal state and only use the piezoelectric sensors 10 in the normal state to achieve the required sensing function, thereby ensuring that the sensing recognition rate of the smart interactive panel is within a controllable range as much as possible.

[0129] If the detection results indicate that the number of piezoelectric sensors 10 in an abnormal state in the smart interactive panel is higher than a preset value, the processor 12 can inform the relevant user based on the smart interactive panel that there are too many piezoelectric sensors 10 in an abnormal state in the smart interactive panel, and that they need to be repaired or replaced.

[0130] In one embodiment, when the processor 12 blocks the signal transmitted by the piezoelectric sensor 10 in an abnormal state, the set value of the piezoelectric sensor 10 in an abnormal state depends on the number of piezoelectric sensors 10.

[0131] If, after the smart interactive flat panel is assembled, a poor electrical connection of the piezoelectric sensor 10 is detected at the user end, and the number of poorly connected piezoelectric sensors 10 is lower than a set value, it indicates that the number of damaged piezoelectric sensors 10 in the smart interactive flat panel is relatively small. In this case, the processor 12 can be used to disable these poorly connected piezoelectric sensors 10, using only those in normal condition. This ensures that the touch recognition rate of the smart interactive flat panel remains within a controllable range. This solves the problem in related technologies where, when a poor electrical connection of the piezoelectric sensor 10 is detected after the smart interactive flat panel is assembled, it is necessary to remove the piezoelectric sensor 10 installed under the inner surface glass of the touch screen, which is cumbersome and affects production efficiency. Furthermore, it helps avoid the possibility of damaging other components of the electronic device's touch screen during disassembly, preventing waste of touch screen assembly components and thus reducing the production cost of related touch electronic devices.

[0132] In an exemplary embodiment, acquiring test signal data based on at least a first conditioned voltage signal and a second conditioned voltage signal includes: calling an analog-to-digital conversion module (not shown) in processor 12 to process the analog signal type conditioned voltage signal (at least the first conditioned voltage signal and the second conditioned voltage signal) into test signal data of digital signal type.

[0133] Specifically, the processor 12 may be provided with an analog-to-digital conversion module, which may be an analog-to-digital conversion circuit capable of converting analog electrical signals into digital electrical signals. Regarding the step of the processor 12 acquiring the signal data under test based on at least a first conditioning voltage signal and a second conditioning voltage signal, this application provides an alternative implementation method in which the analog-to-digital conversion module in the processor 12 is invoked to process the conditioning voltage signal of analog signal type into the signal data under test of digital signal type.

[0134] That is, after receiving the analog signal type of the disconnected voltage signal transmitted through the signal conditioning circuit, the processor 12 calls the analog-to-digital conversion module to process the analog signal type of electrical signal into the test signal type of digital signal data, so that the processor 12 can subsequently calculate the cross-correlation results between the test signal data and the preset standard signal data.

[0135] The above-mentioned cross-correlation calculation of the signal data to be tested and the preset standard signal data to obtain the corresponding cross-correlation result includes: acquiring the DC component of the signal data to be tested based on the processor 12, and using the DC component to be tested to acquire the target data to be tested corresponding to the signal data to be tested; and acquiring the reference DC component of the preset standard signal data based on the processor 12, and using the reference DC component to acquire the target reference data corresponding to the preset standard signal data.

[0136] Wherein, the reference DC component represents the first mean of all first sub-data in the reference signal data, and the DC component to be tested represents the second mean of all second sub-data in the signal data to be tested; each third sub-data in the target reference data is the difference between the corresponding first sub-data and the first mean, and each fourth sub-data in the target test data is the difference between the corresponding second sub-data and the second mean.

[0137] The processor 12 acquires the baseline autocorrelation value of the target baseline data and the test autocorrelation value of the target test data; wherein, the baseline autocorrelation value is obtained by summing the squares of each third sub-data in the target baseline data, and the test autocorrelation value is obtained by summing the squares of each fourth sub-data in the target test data.

[0138] The corresponding cross-correlation values ​​are obtained based on the baseline autocorrelation value and the autocorrelation value to be measured; the corresponding cross-correlation values ​​are obtained by multiplying the corresponding data within the autocorrelation value to be measured and the baseline autocorrelation value and then summing them.

[0139] The cross-correlation result is obtained based on the cross-correlation value, the baseline autocorrelation value, and the autocorrelation value to be measured.

[0140] Specifically, when the processor 12 stores associated reference signal data and test signal data, or when the processor 12 stores reference signal data and test signal data corresponding to the piezoelectric sensor 10 of the same specification, the following steps can be further performed: Based on the processor 12, a reference DC component corresponding to the reference signal data is obtained, and the reference DC component is used to obtain the target reference data corresponding to the reference signal data; simultaneously, based on the processor 12, the test DC component corresponding to the test signal data is obtained, and the test DC component is used to obtain the target test data corresponding to the test signal data. It should be explained that the reference DC component is obtained by averaging (first mean) all (first) sub-data in the reference signal data, and the test DC component is obtained by averaging (second mean) all (second) sub-data in the test signal data; the obtained target reference data includes multiple third sub-data corresponding to the first sub-data, each third sub-data being obtained by the difference between the corresponding first sub-data and the first mean; the obtained target test data includes fourth sub-data corresponding to the second sub-data, each fourth sub-data being obtained by the difference between the corresponding second sub-data and the second mean.

[0141] Then, based on the processor 12, each third sub-data in the target reference data is squared and summed to obtain the reference autocorrelation value corresponding to the target reference data. Similarly, based on the processor 12, each fourth sub-data in the target test data is squared and summed to obtain the test autocorrelation value corresponding to the target test data. Then, the data within the obtained reference autocorrelation value and the test autocorrelation value are multiplied and summed to obtain the cross-correlation value between the reference piezoelectric sensor and the test piezoelectric sensor 10. Finally, based on the cross-correlation value, the reference autocorrelation value, and the test autocorrelation value, the associated cross-correlation result between the reference piezoelectric sensor and the test piezoelectric sensor 10 is calculated.

[0142] Referring to Figure 5 and Figures 6-7, the excitation signal output terminal 121 of the processor 12 may include at least one GPIO (General Purpose Input Output) port. The GPIO port is electrically connected to the signal control circuit 13 of the piezoelectric sensor channel circuit and is used to generate a short square wave pulse signal to the signal control circuit 13.

[0143] It should be noted that in Figures 6 and 7, the signal control circuit 13 is identified as Q1.

[0144] In one embodiment, when the detection circuit module 100 includes a multi-channel piezoelectric sensor circuit, the GPIO port is electrically connected to the signal control circuit 13 of each piezoelectric sensor channel circuit to generate a short square wave pulse signal to the signal control circuit 13 of each piezoelectric sensor channel circuit.

[0145] The excitation signal output terminal 121 generates a short square wave pulse signal to the signal control circuit 13, which turns on the signal control circuit 13, thereby enabling real-time detection of the piezoelectric sensor 10 connected to the piezoelectric sensor channel circuit.

[0146] Referring to Figures 5 and 6, in an exemplary embodiment, the signal control circuit 13 includes a transistor Q1 and a third resistor R3. The base of transistor Q1 is electrically connected to the GPIO port, and the collector of transistor Q1 is electrically connected to the second reference voltage terminal VCC through the third resistor R3. The emitter of transistor Q1 is the first access terminal IN1. The reference voltage of the second reference voltage terminal VCC is greater than the reference voltage of the first reference voltage terminal VDD. For example, the reference voltage of the second reference voltage terminal VCC is twice the reference voltage of the first reference voltage terminal VDD.

[0147] Referring to Figures 5 and 7, in another exemplary embodiment, the signal control circuit 13 includes a MOSFET Q1 and a fourth resistor R3. The gate of the MOSFET Q1 is electrically connected to the GPIO port, and the drain of the MOSFET Q1 is electrically connected to the second reference voltage terminal VCC through the fourth resistor R3. The source of the MOSFET Q1 is the first access terminal IN1. The reference voltage of the second reference voltage terminal VCC is greater than the reference voltage of the first reference voltage terminal VDD. For example, the reference voltage of the second reference voltage terminal VCC is twice the reference voltage of the first reference voltage terminal VDD.

[0148] Specifically, it can be understood that the MOSFET can be either a P-type MOSFET or an N-type MOSFET. In Figure 7, a P-type MOSFET is used as an example for illustration, but it is not limited to P-type MOSFETs. Using an N-type MOSFET can achieve the same effect, which will not be explained in detail here.

[0149] Referring to Figures 5-7, in an exemplary embodiment, the operational circuit 11 is an operational amplifier circuit, which includes a first current limiting circuit 111 and a signal conditioning circuit 112. The first current limiting circuit 111 is electrically connected to the output terminal of the signal control circuit 13. The signal conditioning circuit 112 is electrically connected to the first current limiting circuit 111, the first reference voltage terminal VDD, and the processor 12, respectively, and is used to output a conditioning voltage signal to the processor 12.

[0150] Specifically, the first current limiting circuit 111 limits the current of the excitation signal output terminal 121 transmitted through the signal control circuit 13, so as to avoid impact damage to the components in the signal conditioning circuit 112.

[0151] Please continue to refer to Figures 5-7. In an exemplary embodiment, the first current limiting circuit 111 includes a first resistor R1, which is electrically connected to the output terminal of the signal control circuit 13.

[0152] Specifically, the first resistor R1 limits the current of the excitation signal output terminal 121 transmitted through the signal control circuit 13 to avoid impact damage to the components in the signal conditioning circuit 112.

[0153] When the detection circuit module 100 includes a multi-channel piezoelectric sensor circuit, the first resistor R1 is electrically connected to the output terminal of the signal control circuit 13 of each piezoelectric sensor channel circuit.

[0154] As shown in Figures 6 and 7, the signal conditioning circuit 112 includes a first signal input terminal 6, a second signal input terminal 5, and an output terminal 7. The first signal input terminal 6 is electrically connected to the first current limiting circuit 111, and the second signal input terminal 5 is electrically connected to the first reference voltage terminal VDD. The output terminal 7 of the signal conditioning circuit 112 is used to output a conditioning voltage signal, which is used by the processor 12 to determine the state of the piezoelectric sensor 10.

[0155] Please refer to Figures 5-7. In an exemplary embodiment, the signal conditioning circuit 112 includes an operational amplifier and a feedback circuit. The positive input terminal of the operational amplifier is electrically connected to the first reference voltage terminal VDD, and the negative input terminal of the operational amplifier is electrically connected to the first current limiting circuit 111. The output terminal of the operational amplifier is electrically connected to the negative input terminal of the operational amplifier through the feedback circuit, and the output terminal of the operational amplifier is used to output a conditioning voltage signal.

[0156] Specifically, the positive input terminal of the operational amplifier serves as the second signal input terminal 5 of the signal conditioning circuit 112, the negative input terminal of the operational amplifier serves as the first signal input terminal 6 of the signal conditioning circuit 112, and the conditioning voltage signal output from the output terminal of the operational amplifier is used by the processor 12 to determine the state of the piezoelectric sensor 10.

[0157] Please refer to Figures 5-7. In an exemplary embodiment, the feedback circuit includes a second resistor R2 and a second capacitor C2. The second resistor R2 and the second capacitor C2 are connected in parallel. The two terminals of the parallel connection between the second resistor R2 and the second capacitor C2 are electrically connected to the negative input terminal and the output terminal of the operational amplifier, respectively.

[0158] In one embodiment, the processor 12 is electrically connected to the signal conditioning circuit 112 and is used to determine the state of the piezoelectric sensor 10 based on the conditioning voltage signal (e.g., the first conditioning voltage signal and the second conditioning voltage signal) output by the signal conditioning circuit 112. Specifically, the processor 12 processes the conditioning voltage signal to obtain the corresponding test signal data, performs cross-correlation calculation on the test signal data and the preset standard signal data to obtain the corresponding cross-correlation result, and determines that the piezoelectric sensor 10 is in a normal state when the cross-correlation result is higher than or equal to a preset threshold, and determines that the piezoelectric sensor 10 is in an abnormal state when the cross-correlation result is lower than the preset threshold.

[0159] Specifically, the processor 12 is electrically connected to the output terminal 7 of the operational amplifier in the signal conditioning circuit 112, and is used to determine the state of the piezoelectric sensor 10 based on the conditioning voltage signal output by the operational amplifier.

[0160] The processor 12 has data processing and signal processing capabilities and can be an integrated circuit chip. For example, the processor 12 can be a general-purpose processor 12, a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or other programmable logic devices. The general-purpose processor 12 can be a microprocessor, an MCU (Microcontroller Unit), or any conventional processor 12.

[0161] Please refer to Figures 5-7. In an exemplary embodiment, the piezoelectric sensor channel circuit further includes a second current limiting circuit 14. The input terminal of the second current limiting circuit 14 is electrically connected to the output terminal of the signal control circuit 13, and the output terminal of the second current limiting circuit 14 is electrically connected to the input terminal of the first current limiting circuit 111 and the first access terminal IN1, respectively.

[0162] Specifically, as another optional example, when the signal emitted by the excitation signal output terminal 121 is a high-frequency signal, the piezoelectric sensor channel circuit also includes a second current limiting circuit 14. The second current limiting circuit 14 is, for example, the current limiting resistor R4 in Figure 6 or Figure 7. At this time, the current limiting resistor R4 can allow high-frequency signals and block the low-frequency signals of the piezoelectric sensor 10; the sensor signal cannot flow into the excitation signal output terminal 121, and the high-frequency signal of the excitation signal output terminal 121 can flow into the back-end circuit; the first end of the current limiting resistor R4 is electrically connected to the GPIO port, specifically, it is electrically connected to the output terminal of the signal control circuit 13, and the second end of the current limiting resistor R4 is the first access terminal IN1, that is, specifically, the second end is electrically connected to the input terminal of the first current limiting circuit 111 and the first access terminal IN1 respectively.

[0163] Generally, the piezoelectric sensor 10 has several states, including normal, open circuit, short circuit, and broken. The processor 12 can pre-store the voltage signal data corresponding to the normal, open circuit, short circuit, and broken states of the piezoelectric sensor 10. When the processor 12 receives the conditioned voltage signal output by the operational amplifier, it can compare the conditioned voltage signal output by the operational amplifier with the pre-stored voltage signal data to determine the specific state of the piezoelectric sensor 10.

[0164] Referring to Figures 5-7 and Figure 8, based on the same inventive concept, this application also provides a smart interactive flat panel, including:

[0165] At least two piezoelectric sensors 10 are disposed on the inner surface of the cover plate of the smart interactive flat panel;

[0166] The detection circuit module is electrically connected to at least one piezoelectric sensor 10;

[0167] The detection circuit module includes: a piezoelectric sensor channel circuit, an arithmetic circuit 11, a first reference voltage terminal VDD, and a processor 12;

[0168] The processor 12 includes several pairs of first excitation signal output terminals 122 and second excitation signal output terminals 123;

[0169] The piezoelectric sensor channel circuit includes a signal control circuit 13, a first access terminal IN1, and a second access terminal IN2. The first access terminal IN1 and the second access terminal IN2 are used to electrically connect to the piezoelectric sensor 10. The signal control circuit 13 is electrically connected to the first excitation signal output terminal 122 and the second excitation signal output terminal 123, and is used to receive the pulse width signal emitted by the excitation signal output terminals (the first excitation signal output terminal 122 and the second excitation signal output terminal 123). The first access terminal IN1 and the second access terminal IN2 are respectively electrically connected to a pair of first excitation signal output terminals 122 and second excitation signal output terminals 123 of the processor based on the signal control circuit 13.

[0170] The arithmetic circuit 11 is electrically connected to each piezoelectric sensor channel circuit, the first reference voltage terminal VDD, and the processor 12, respectively, and is used to output a conditioning voltage signal to the processor 12.

[0171] The intelligent interactive flat panel uses the following methods to detect the piezoelectric sensor 10:

[0172] The processor 12 is configured to send an excitation signal with a first pulse width to a signal control circuit 13 in the channel circuit of the piezoelectric sensor 10 through the first excitation signal output terminal 122 during a first sub-preset time period; and receive a first conditioning voltage signal sent by the arithmetic circuit 11; wherein the first conditioning voltage signal is obtained based on the excitation signal with the first pulse width sent to the signal control circuit in the channel circuit of the piezoelectric sensor 10 during the first sub-preset time period.

[0173] The processor 12 is used to send a second pulse width excitation signal to the same signal control circuit 13 through the first excitation signal output terminal 122 during the second sub-preset time period; and to receive a second conditioning voltage signal sent by the arithmetic circuit 11; wherein the second conditioning voltage signal is obtained based on the second pulse width excitation signal sent to the same signal control circuit 13 through the first excitation signal output terminal 122 during the second sub-preset time period.

[0174] The processor 12 is configured to send an excitation signal with a first pulse width to another signal control circuit 13 in the channel circuit of the piezoelectric sensor 10 via a second excitation signal output terminal 123 paired with the first excitation signal output terminal 122 within a third sub-preset time period; and receive a third conditioning voltage signal sent by the arithmetic circuit 11; wherein the third conditioning voltage signal is obtained based on the excitation signal with a first pulse width sent to another signal control circuit 13 in the channel circuit of the piezoelectric sensor 10 via a second excitation signal output terminal 123 paired with the first excitation signal output terminal 122 within the third sub-preset time period;

[0175] The processor 12 is used to send a second pulse width excitation signal to another signal control circuit 13 via the second excitation signal output terminal 123 within a fourth sub-preset time period; and to receive a fourth conditioning voltage signal sent by the arithmetic circuit 11; wherein the fourth conditioning voltage signal is obtained based on the second pulse width excitation signal sent to another signal control circuit 13 via the second excitation signal output terminal 123 within the fourth sub-preset time period;

[0176] Data of the signal under test is acquired based on at least a first conditioning voltage signal, a second conditioning voltage signal, a third conditioning voltage signal, and a fourth conditioning voltage signal;

[0177] The cross-correlation calculation is performed between the signal data to be measured and the preset standard signal data to obtain the corresponding cross-correlation result, and the state of the piezoelectric sensor 10 is determined based on the cross-correlation result.

[0178] It should be noted that in the embodiment shown in Figure 8, the first excitation signal output terminal 122 and the second excitation signal output terminal 123 included in the processor 12 are drawn outside the processor 12 only for the clarity of the circuit structure diagram. The first excitation signal output terminal 122 and the second excitation signal output terminal 123 can be selected to be integrated into the processor 12, that is, the first excitation signal output terminal 122 and the second excitation signal output terminal 123 are two signal output ports included in the processor 12, or they can be selected to be set as a circuit structure independent of the processor 12. This application does not make specific limitations on this.

[0179] It should also be noted that, in the embodiment shown in Figure 8, a detection cycle may include, for example, a first sub-preset time period, a second sub-preset time period, a third sub-preset time period, and a fourth sub-preset time period. During the first and second sub-preset time periods, multiple preset excitation signals of preset pulse widths are sent to the electrically connected signal control circuit 13 via the first excitation signal output terminal 122. The signal control circuit 13 is turned on upon receiving the preset excitation signals, enabling the electrical signal at the voltage terminal electrically connected to the signal control circuit 13 to be output to the piezoelectric sensor 10 in this state, thereby enabling detection of the piezoelectric sensor 10. That is, the piezoelectric sensor 10 can receive the corresponding multiple pulse width electrical detection signals based on the signal control circuit 13. Then, after the processor 12 receives the first test data obtained based on this signal, during the third and fourth sub-preset time periods, the second excitation signal is sent to the piezoelectric sensor 10. The signal output terminal 123 sends multiple preset excitation signals of preset pulse widths to the electrically connected signal control circuit 13. The signal control circuit 13 is turned on when it receives the preset excitation signals, so that the electrical signal of the voltage terminal electrically connected to the signal control circuit 13 can be output to the piezoelectric sensor 10 in this state, thereby realizing the detection of the piezoelectric sensor 10. That is, the piezoelectric sensor 10 can receive the corresponding multiple pulse width electrical detection signals based on the signal control circuit 13. Then, after the processor 12 receives the second test data obtained based on the signal, the processor 12 performs cross-correlation calculation on the two sets of data (the first test data and the second test data) with the preset standard signal data to obtain the corresponding cross-correlation result. When the cross-correlation result is higher than or equal to the preset threshold, the piezoelectric sensor 10 is judged to be in a normal state; when the cross-correlation result is lower than the preset threshold, the piezoelectric sensor 10 is judged to be in an abnormal state.

[0180] The process of cross-correlation calculation between these two sets of data (first test data and second test data) and preset standard signal data can also be separate. For example, the first test data and the preset standard signal data can be cross-correlation calculated before the pulse width signal is transmitted to the piezoelectric sensor 10 through the second excitation signal output terminal 123; and then, after the processor 12 receives the second test data related to the conditioning voltage signal (third conditioning voltage signal and fourth conditioning voltage signal) based on the pulse width signal output by the second excitation signal output terminal 123, the second test data and the preset standard signal data can be cross-correlation calculated.

[0181] Referring to Figures 5-7 and Figure 8, in an exemplary embodiment, the first preset time period includes a first sub-preset time period and a second sub-preset time period, and the second preset time period includes a third sub-preset time period and a fourth sub-preset time period. The processor 12 is used to determine that the piezoelectric sensor 10 is in a normal state if at least two states, including a normal state, are obtained for the same piezoelectric sensor 10 within the third preset time period. The duration of the third preset time period is greater than the sum of the durations of the first and second preset time periods. The related technical effects are described above in relation to Figures 5-7 and will not be repeated here.

[0182] In an exemplary embodiment, the first preset time period includes a first sub-preset time period and a second sub-preset time period, and the second preset time period includes a third sub-preset time period and a fourth sub-preset time period. The processor 12 is used to perform state judgment on the same piezoelectric sensor 10 within the third preset time period. When the judged state is normal, the processor stops outputting the excitation signal at the excitation signal output terminal and determines that the piezoelectric sensor 10 is in a normal state. The duration of the third preset time period is greater than the sum of the durations of the first and second preset time periods. For related technical effects, please refer to the above description of Figures 5-7, which will not be repeated here.

[0183] In an exemplary embodiment, the processor 12 is further configured to block the signals transmitted by the piezoelectric sensors 10 that are in abnormal states when the number of piezoelectric sensors 10 in abnormal states is less than a set value. For related technical effects, please refer to the descriptions of Figures 5-7 above; they will not be repeated here.

[0184] Please refer to Figure 9 in conjunction with Figures 5-8. In Figure 9, Q2 corresponds to the transistor in Figure 6; R10 and R11 correspond to the third resistor R3 in Figure 6; R8 and R9 correspond to the current-limiting resistor R4 in Figure 6; R1 and R4 correspond to the first resistor R1 in Figure 6; C2 and C3 correspond to the second capacitor C2 in Figure 6; and R2 and R3 correspond to the second resistor R2 in Figure 6. The related technical effects are described above in relation to Figures 5-6 and will not be repeated here.

[0185] Please refer to Figure 10 in conjunction with Figures 5-8. In Figure 10, Q2 corresponds to the MOSFET in Figure 7, R10 and R11 correspond to the fourth resistor R3 in Figure 7, R8 and R9 correspond to the current-limiting resistor R4 in Figure 7, R1 and R4 correspond to the first resistor R1 in Figure 7, C2 and C3 correspond to the second capacitor C2 in Figure 7, and R2 and R3 correspond to the second resistor R2 in Figure 7. The related technical effects are described above in relation to Figures 5 and 7, and will not be repeated here.

[0186] An optional embodiment of the piezoelectric sensor detection method provided in this application is also provided. Referring to Figures 5 and 6, the specific embodiment is as follows:

[0187] In step S1, the pulse generation circuit (excitation signal output terminal) controls the opening and closing of the signal control circuit, thereby enabling the voltage terminal (VCC) electrically connected to the signal control circuit to output multiple consecutive excitation signals with preset pulse widths for a preset duration to the piezoelectric sensor; specifically, there may be excitation signals with more than or equal to two preset pulse widths.

[0188] In step S2, the signal transmitted by the piezoelectric sensor to the signal conditioning circuit based on the excitation signal is received. The voltage signal (response signal) after passing through the signal conditioning circuit is converted into a digital signal by the analog-to-digital converter module. The processor continuously acquires and saves this digital signal.

[0189] Furthermore, a good product (reference piezoelectric sensor) can be selected in advance, and the above steps S1 and S2 can be performed. Then, the saved digital signal is stored in the processor as standard signal data (reference signal data).

[0190] The product under test (the piezoelectric sensor under test) performs steps S1 and S2, and then the saved digital signal is used as the signal data under test;

[0191] Execute step S3 to perform cross-correlation calculation on the test signal data and the standard signal data to obtain the correlation result (cross-correlation result) between the test signal data and the standard signal data;

[0192] Execute step S4 to compare the correlation result with the preset threshold (preset result). If the correlation result is greater than or equal to the preset threshold, the product under test (the piezoelectric sensor under test) is determined to be good; otherwise, it is determined to be bad.

[0193] Furthermore, before performing step S3, the standard signal data and the signal data to be tested can be preprocessed to improve the discriminative power of the cross-correlation results; the preprocessing methods include:

[0194] First, the mean of the signal data sequence is calculated, and this mean can be considered as the DC component.

[0195] Then, the mean is subtracted from all the data in the data sequence to obtain a new data sequence, which is the preprocessed signal data.

[0196] Both the standard signal data and the signal data under test need to undergo the above preprocessing.

[0197] The detection method for piezoelectric sensors provided in this application can eliminate the subjective factors of testers, making the test results more objective and accurate. Furthermore, the method provided in this application can be fully automated when evaluating whether a piezoelectric sensor is good or not, resulting in higher detection efficiency.

[0198] Figure 11 is a schematic diagram of a piezoelectric sensor detection circuit providing an embodiment of this application outputting multiple continuous preset excitation signals. Figure 12 is a schematic diagram of an electrical signal corresponding to a reference piezoelectric sensor received by the processor of the piezoelectric sensor detection circuit providing an embodiment of this application. Figure 13 is a schematic diagram of an electrical signal corresponding to a piezoelectric sensor under test received by the processor of the piezoelectric sensor detection circuit providing an embodiment of this application. Figure 14 is a schematic diagram of an electrical signal corresponding to another piezoelectric sensor under test received by the processor of the piezoelectric sensor detection circuit providing an embodiment of this application. Figure 15 is a schematic diagram of reference signal data corresponding to Figure 12 provided in an embodiment of this application. Figure 16 is a schematic diagram of signal data under test corresponding to Figure 13 provided in an embodiment of this application. Figure 17 is a schematic diagram of signal data under test corresponding to Figure 14 provided in an embodiment of this application. Please refer to Figures 11-17 in conjunction with Figures 5-10. Figure 11 shows that the piezoelectric sensor detection circuit 100 outputs a continuous excitation signal of 10ms to the piezoelectric sensor 10, and outputs excitation signals of 1kHz, 4kHz and 10kHz in sequence. Then, the piezoelectric sensor detection circuit 100 acquires the conditioning voltage signal shown in Figures 12-14, which specifically includes the standard signal (conditioning voltage signal corresponding to the reference piezoelectric sensor), the product under test 1 signal (conditioning voltage signal corresponding to the first piezoelectric sensor under test) and the product under test 2 signal (conditioning voltage signal corresponding to the second piezoelectric sensor under test). Then, the electrical signals shown in Figures 12-14 are preprocessed to obtain the preprocessed standard signal (reference signal data), the preprocessed product under test 1 signal (test signal data corresponding to the first piezoelectric sensor under test), and the preprocessed product under test 2 signal (test signal data corresponding to the second piezoelectric sensor under test) shown in Figures 15-17.

[0199] Then, the correlation between the signal to be measured and the standard signal can be calculated. For example, the correlation between the signal of the product to be measured 1 and the standard signal is calculated as: 0.997107312, and the correlation between the signal of the product to be measured 2 and the standard signal is: 0.696909468. Then, the test results are judged. The preset threshold of the correlation is 0.99. The corresponding test result of the product to be measured 1 is: good (qualified product), and the test result of the product to be measured 2 is: bad (defective product).

[0200] This application also provides a specific embodiment for preprocessing the reference signal data and the signal data to be measured stored in the processor and calculating the cross-correlation result corresponding to the signal data to be measured, as shown in Table 1 below. The OK data therein refers to the first signal data to be measured, and the NG data refers to the second signal data to be measured. The process of preprocessing the data may include template data processing, sampled data processing, and cross-correlation result calculation, where:

[0201] Template data processing includes:

[0202] Sampling the template data to obtain the result as <F column>;

[0203] Preprocessing the template data: a. Calculating the mean value of the template data to obtain the result: 2326; b. Subtracting the mean value from the <F column> of the template data to obtain the ;

[0204] Performing autocorrelation calculation on the preprocessed template data : a. Squaring each element in the array; b. Summing the results of step a; obtaining the template autocorrelation value;

[0205] Sampled data processing (taking the OK data in column D as an example) includes:

[0206] Sampling the data of the first sample to be measured to obtain the result as <D column>;

[0207] Preprocessing the data of the first sample to be measured: a. Calculating the mean value of the data of the first sample to be measured to obtain the result: 2309; b. Subtracting the mean value from the <G column> of the data of the first sample to be measured to obtain the <G column> data;

[0208] Performing autocorrelation calculation on the preprocessed <G column> data of the first sample to be measured: a. Squaring each element in the array; b. Summing the results of step a; obtaining the autocorrelation value of the first sample to be measured;

[0209] Performing cross-correlation calculation on the preprocessed <G column> data of the first sample to be measured and the preprocessed of the template data: a. Multiplying the data in the array in pairs; b. Summing the results of step a; obtaining the cross-correlation value between the first sample to be measured and the template;

[0210] The cross-correlation result is calculated as: OK and template cross-correlation value / SQRT(OK autocorrelation value * template autocorrelation value), yielding the result for sample 1. Here, SQRT() calculates the square root.

[0211] Table 1

[0212] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0213] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0214] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A smart interactive flat panel, characterized in that, include: At least two piezoelectric sensors are disposed on the inner surface of the cover plate of the smart interactive flat panel; A detection circuit module is electrically connected to at least one of the piezoelectric sensors; wherein the detection circuit module includes: a piezoelectric sensor channel circuit, a calculation circuit, a first reference voltage terminal, and a processor, the processor including an excitation signal output terminal; The piezoelectric sensor channel circuit includes a signal control circuit, a first access terminal, and a second access terminal; the first access terminal and the second access terminal are used to electrically connect to the piezoelectric sensor. The signal control circuit is electrically connected to the excitation signal output terminal of the processor; the first access terminal is electrically connected to the signal control circuit; and the second access terminal is electrically connected to the first reference voltage terminal. The arithmetic circuit is electrically connected to the signal control circuit, the first reference voltage terminal, and the processor, respectively. The smart interactive flat panel detects the piezoelectric sensor in the following ways: The processor is configured to send an excitation signal with a first pulse width to one of the signal control circuits within a first preset time period; and receive a first conditioning voltage signal sent by the arithmetic circuit; wherein the first conditioning voltage signal is obtained based on the excitation signal with the first pulse width sent to one of the signal control circuits within the first preset time period; The processor is configured to send a second pulse width excitation signal to the same signal control circuit within a second preset time period; and receive a second conditioning voltage signal sent by the arithmetic circuit; wherein the second conditioning voltage signal is obtained based on sending the second pulse width excitation signal to the same signal control circuit within the second preset time period; Based on at least the first conditioning voltage signal and the second conditioning voltage signal, acquire the signal data to be measured; The cross-correlation calculation is performed on the signal data to be tested and the preset standard signal data to obtain the corresponding cross-correlation result, and the state of the piezoelectric sensor is determined based on the cross-correlation result.

2. The intelligent interactive flat panel according to claim 1, characterized in that, The processor is configured to determine that the piezoelectric sensor is in the normal state if at least two states, including the normal state, are obtained for the same piezoelectric sensor within a third preset time period. The duration of the third preset time period is greater than the sum of the durations of the first preset time period and the second preset time period.

3. The intelligent interactive flat panel according to claim 1, characterized in that, The processor is used to perform state judgment on the same piezoelectric sensor within a third preset time period. When the state is judged to be normal, the processor stops the output of the excitation signal from the excitation signal output terminal and determines that the piezoelectric sensor is in the normal state. The duration of the third preset time period is greater than the sum of the durations of the first preset time period and the second preset time period.

4. The intelligent interactive flat panel according to any one of claims 1-3, characterized in that, The processor is also configured to block the signals transmitted by the piezoelectric sensors in the abnormal state when the number of piezoelectric sensors in the abnormal state is less than a set value.

5. The intelligent interactive flat panel according to claim 1, characterized in that, The processor's excitation signal output terminal includes a GPIO port, which is electrically connected to the signal control circuit and is used to generate a short square wave pulse signal for the signal control circuit.

6. The intelligent interactive flat panel according to claim 5, characterized in that, The signal control circuit includes a transistor and a third resistor. The base of the transistor is electrically connected to the GPIO port, the collector of the transistor is electrically connected to the second reference voltage terminal through the third resistor, and the emitter of the transistor is the first access terminal.

7. The intelligent interactive flat panel according to claim 5, characterized in that, The signal control circuit includes a MOS transistor and a fourth resistor. The gate of the MOS transistor is electrically connected to the GPIO port, the drain of the MOS transistor is electrically connected to the second reference voltage terminal through the fourth resistor, and the source of the MOS transistor is the first access terminal.

8. The intelligent interactive flat panel according to claim 1, characterized in that, The operational amplifier circuit is an operational amplifier circuit, which includes a first current limiting circuit and a signal conditioning circuit. The first current limiting circuit is electrically connected to the output terminal of the signal control circuit. The signal conditioning circuit is electrically connected to the first current limiting circuit, the first reference voltage terminal, and the processor, respectively, and is used to output a conditioning voltage signal to the processor.

9. The intelligent interactive flat panel according to claim 8, characterized in that, The first current limiting circuit includes a first resistor, which is electrically connected to the output terminal of the signal control circuit.

10. The intelligent interactive flat panel according to claim 8, characterized in that, The signal conditioning circuit includes an operational amplifier and a feedback circuit; the positive input terminal of the operational amplifier is electrically connected to a first reference voltage terminal, and the negative input terminal of the operational amplifier is electrically connected to a first current limiting circuit; the output terminal of the operational amplifier is electrically connected to the negative input terminal of the operational amplifier through the feedback circuit, and the output terminal of the operational amplifier is used to output a conditioning voltage signal.

11. The intelligent interactive flat panel according to claim 10, characterized in that, The feedback circuit includes a second resistor and a second capacitor. The second resistor and the second capacitor are connected in parallel. The two terminals of the parallel connection between the second resistor and the second capacitor are electrically connected to the negative input terminal and the output terminal of the operational amplifier, respectively.

12. The intelligent interactive flat panel according to claim 8, characterized in that, The piezoelectric sensor channel circuit further includes a second current limiting circuit; wherein, the input terminal of the second current limiting circuit is electrically connected to the output terminal of the signal control circuit, and the output terminal of the second current limiting circuit is electrically connected to the input terminal of the first current limiting circuit and the first access terminal, respectively.

13. A smart interactive flat panel, characterized in that, include: At least two piezoelectric sensors are disposed on the inner surface of the cover plate of the smart interactive flat panel; The detection circuit module is electrically connected to at least one of the piezoelectric sensors; The detection circuit module includes: a piezoelectric sensor channel circuit, a calculation circuit, a first reference voltage terminal, and a processor; The processor includes several pairs of first excitation signal output terminals and second excitation signal output terminals; The piezoelectric sensor channel circuit includes a signal control circuit, a first access terminal, and a second access terminal; the first access terminal and the second access terminal are used to electrically connect to the piezoelectric sensor; the signal control circuit is electrically connected to the first excitation signal output terminal and the second excitation signal output terminal of the processor; the first access terminal and the second access terminal are respectively electrically connected to a pair of the first excitation signal output terminals and the second excitation signal output terminals of the processor based on the signal control circuit; The computing circuit is electrically connected to each piezoelectric sensor channel circuit, the first reference voltage terminal and the processor, respectively, and is used to output a conditioning voltage signal to the processor; The smart interactive flat panel detects the piezoelectric sensor in the following ways: The processor is configured to send an excitation signal with a first pulse width to one of the signal control circuits in the piezoelectric sensor channel circuit through the first excitation signal output terminal within a first sub-preset time period; and receive a first conditioning voltage signal sent by the arithmetic circuit; wherein the first conditioning voltage signal is obtained based on the excitation signal with the first pulse width sent to one of the signal control circuits in the piezoelectric sensor channel circuit within the first sub-preset time period; The processor is configured to send a second pulse width excitation signal to the same signal control circuit via the first excitation signal output terminal during a second sub-preset time period; and receive a second conditioning voltage signal sent by the arithmetic circuit; wherein the second conditioning voltage signal is obtained based on the second pulse width excitation signal sent to the same signal control circuit via the first excitation signal output terminal during the second sub-preset time period; The processor is configured to, within a third sub-preset time period, send an excitation signal of a first pulse width to another signal control circuit in the piezoelectric sensor channel circuit via a second excitation signal output terminal paired with the first excitation signal output terminal; and receive a third conditioning voltage signal sent by the arithmetic circuit; wherein the third conditioning voltage signal is obtained based on the excitation signal of the first pulse width sent to another signal control circuit in the piezoelectric sensor channel circuit via a second excitation signal output terminal paired with the first excitation signal output terminal within the third sub-preset time period; The processor is configured to send a second pulse width excitation signal to the other signal control circuit through the second excitation signal output terminal within a fourth sub-preset time period; and receive a fourth conditioning voltage signal sent by the arithmetic circuit; wherein the fourth conditioning voltage signal is obtained based on the second pulse width excitation signal sent to the other signal control circuit through the second excitation signal output terminal within the fourth sub-preset time period; Based on at least the first conditioned voltage signal, the second conditioned voltage signal, the third conditioned voltage signal, and the fourth conditioned voltage signal, acquire the signal data to be measured; The cross-correlation calculation is performed on the signal data to be tested and the preset standard signal data to obtain the corresponding cross-correlation result, and the state of the piezoelectric sensor is determined based on the cross-correlation result.

14. The intelligent interactive flat panel according to claim 13, characterized in that, The first preset time period includes the first sub-preset time period and the second sub-preset time period, and the second preset time period includes the first... The three preset time periods and the fourth preset time period; The processor is configured to determine that the piezoelectric sensor is in the normal state if at least two states, including the normal state, are obtained for the same piezoelectric sensor within a third preset time period. The duration of the third preset time period is greater than the sum of the durations of the first preset time period and the second preset time period.

15. The intelligent interactive flat panel according to claim 13, characterized in that, The first preset time period consists of the first sub-preset time period and the second sub-preset time period, and the second preset time period consists of the third sub-preset time period and the fourth sub-preset time period; The processor is used to perform state judgment on the same piezoelectric sensor within a third preset time period. When the state is judged to be normal, the processor stops the output of the excitation signal from the excitation signal output terminal and determines that the piezoelectric sensor is in the normal state. The duration of the third preset time period is greater than the sum of the durations of the first preset time period and the second preset time period.

16. The intelligent interactive flat panel according to any one of claims 13-15, characterized in that, The processor is also configured to block the signals transmitted by the piezoelectric sensors in the abnormal state when the number of piezoelectric sensors in the abnormal state is less than a set value.

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