Intelligent interactive tablet

Abstract

The application relates to the field of flat plates and discloses an intelligent interactive flat plate. The intelligent interactive flat plate comprises a plurality of piezoelectric sensors arranged in parallel, and a plurality of detection circuit modules corresponding to the piezoelectric sensors one by one; the detection circuit module comprises a signal transmitting circuit, a piezoelectric sensor channel circuit, an operation circuit, a first reference voltage end and a processor; the piezoelectric sensor channel circuit comprises a signal isolation circuit, a first access end and a second access end; the signal isolation circuit is electrically connected with the output end of the signal transmitting circuit; the second access end is electrically connected with the first reference voltage end; the operation circuit is electrically connected with the signal isolation circuit, the first reference voltage end and the processor respectively, and outputs a regulated voltage signal to the processor, so that the processor judges the state of the piezoelectric sensor according to the regulated voltage signal. Therefore, the poor electrical connection of the piezoelectric sensor is intercepted in the previous process, and the subsequent disassembly is avoided.

Description

[0001] Cross-references to related applications This application claims priority to international patent application filed on March 22, 2023, with application number PCT / CN2024 / 083229, entitled "An Intelligent Interactive Flat Panel", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the field of tablet computers, and more particularly to a smart interactive tablet computer. Background Technology

[0003] 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.

[0004] Piezoelectric sensors are typically mounted affixed to the inner surface of the touchscreen of a smart interactive flat panel. During touchscreen assembly, poor electrical connections in the piezoelectric sensors can occur. If a smart interactive flat panel is equipped with a potentially faulty piezoelectric sensor, it can lead to inaccurate touchscreen recognition rates, reduced product quality, and a negative impact on user experience. Currently, these poor connections can generally only be detected after the entire smart interactive flat panel is assembled. When this is discovered, the device must be disassembled to remove the piezoelectric sensor, which is located beneath the innermost layer of the touchscreen's inner surface glass. This disassembly process is cumbersome and impacts production efficiency. Summary of the Invention

[0005] The present invention aims to provide a smart interactive flat panel that can solve the problem that when a poor electrical connection of the piezoelectric sensor is found after the assembly of the existing smart interactive flat panel, it is necessary to remove the piezoelectric sensor installed under the inner surface glass of the touch screen, which is cumbersome and affects production efficiency.

[0006] To address the aforementioned technical problems, a first aspect of the present invention provides an intelligent interactive flat panel, comprising: Multiple piezoelectric sensors are arranged in parallel and installed under the glass on the inner surface of the smart interactive flat panel touch screen; multiple detection circuit modules correspond one-to-one with the multiple piezoelectric sensors; The detection circuit module includes: a signal transmitting circuit, a piezoelectric sensor channel circuit, a calculation circuit, a first reference voltage terminal, and a processor; The piezoelectric sensor channel circuit includes a signal isolation circuit, a first access terminal, and a second access terminal; the first access terminal and the second access terminal are used to connect to the piezoelectric sensor; the signal isolation circuit is electrically connected to the output terminal of the signal transmitting circuit and is used to receive the signal transmitted by the signal transmitting circuit; the first access terminal is electrically connected to the signal isolation circuit; the second access terminal is electrically connected to a first reference voltage terminal. The arithmetic circuit is electrically connected to the signal isolation circuit, the first reference voltage terminal, and the processor, respectively, and is used to output a conditioning voltage signal to the processor; The processor is used to determine the state of the piezoelectric sensor based on the conditioning voltage signal; specifically: when the conditioning voltage signal is higher than a preset threshold, the piezoelectric sensor is determined to be in a normal state; when the conditioning voltage signal is lower than the preset threshold, the piezoelectric sensor is determined to be in an abnormal state, and when the number of piezoelectric sensors in an abnormal state is lower than a set value, the processor blocks the signals transmitted by the piezoelectric sensors in an abnormal state.

[0007] In one embodiment, the signal transmitting circuit includes at least one GPIO port, which is electrically connected to the signal isolation circuit of the piezoelectric sensor channel circuit, for generating a short square wave pulse signal to the signal isolation circuit.

[0008] In one embodiment, the signal isolation 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.

[0009] In one embodiment, the signal isolation 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.

[0010] In one embodiment, the operational circuit is an operational amplifier circuit, which includes a current limiting circuit and a signal conditioning circuit, wherein: the current limiting circuit is electrically connected to the output terminal of the signal isolation circuit; the signal conditioning circuit is electrically connected to the current limiting circuit, the first reference voltage terminal and the processor, respectively, and is used to output a conditioning voltage signal to the processor.

[0011] In one embodiment, the current limiting circuit includes a first resistor electrically connected to the output of the signal isolation circuit.

[0012] 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 the 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.

[0013] 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.

[0014] In one embodiment, the reference voltage at the second reference voltage terminal is greater than the reference voltage at the first reference voltage terminal.

[0015] Accordingly, a second aspect of the present invention also provides an intelligent interactive flat panel, comprising: a plurality of piezoelectric sensors, wherein the plurality of piezoelectric sensors are installed under the glass on the inner surface of the touch screen of the intelligent interactive flat panel; and a plurality of detection circuit modules corresponding one-to-one with the plurality of piezoelectric sensors; The detection circuit module includes: a signal transmitting circuit, a piezoelectric sensor channel circuit, a calculation circuit, a first reference voltage terminal, and a processor; The signal transmitting circuit includes several pairs of short square wave pulse differential signals, and the output terminals of each pair of short square wave pulse differential signals include a first differential signal output terminal and a second differential signal output terminal. Each piezoelectric sensor channel circuit includes a first access terminal and a second access terminal; the first access terminal and the second access terminal are used to access the piezoelectric sensor; the first access terminal and the second access terminal are electrically connected to the first differential signal output terminal and the second differential signal output terminal of a pair of differential signals of the signal transmitting circuit, respectively; 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 processor is used to determine the state of the piezoelectric sensor based on the conditioning voltage signal; specifically: when the conditioning voltage signal is higher than a preset threshold, the piezoelectric sensor is determined to be in a normal state; when the conditioning voltage signal is lower than the preset threshold, the piezoelectric sensor is determined to be in an abnormal state; when the number of piezoelectric sensors in an abnormal state is lower than a set value, the processor blocks the signals transmitted by the piezoelectric sensors in an abnormal state.

[0016] In one embodiment, the operational circuit is an operational amplifier circuit, which includes a current limiting circuit and a signal conditioning circuit. The current limiting circuit is electrically connected to the output terminal of the signal isolation circuit. The signal conditioning circuit is electrically connected to the current limiting circuit, the first reference voltage terminal, and the processor, respectively, and is used to output a conditioning voltage signal to the processor.

[0017] In one embodiment, the current limiting circuit includes a first resistor electrically connected to the output of the signal isolation circuit.

[0018] 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 the 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.

[0019] 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.

[0020] Compared to existing technologies, this invention provides a smart interactive flat panel, comprising multiple piezoelectric sensors arranged in parallel, the multiple piezoelectric sensors being installed beneath the glass on the inner surface of the touchscreen of the smart interactive flat panel; and multiple detection circuit modules corresponding one-to-one with the multiple piezoelectric sensors; wherein: each detection circuit module includes a signal transmitting circuit, a piezoelectric sensor channel circuit, a processing circuit processor, and a first reference voltage terminal; the piezoelectric sensor channel circuit includes a signal isolation circuit, a first access terminal, and a second access terminal; the first access terminal and the second access terminal are respectively used to connect to the first and second terminals of the piezoelectric sensors; the signal isolation circuit is electrically connected to the output terminal of the signal transmitting circuit to prevent piezoelectric transmission. The sensor signal flows into the signal transmitting circuit; the output terminal of the signal isolation circuit is the first access terminal; the second access terminal is electrically connected to the first reference voltage terminal; the arithmetic circuit is electrically connected to the signal isolation circuit, the first reference voltage terminal, and the processor respectively, and is used to output a conditioning voltage signal to the processor; the processor is used to determine the state of the piezoelectric sensor based on the conditioning voltage signal, specifically: when the conditioning voltage signal is higher than a preset threshold, the piezoelectric sensor is determined to be in a normal state; when the conditioning voltage signal is lower than the preset threshold, the piezoelectric sensor is determined to be in an abnormal state, and when the number of piezoelectric sensors in an abnormal state is lower than a set value, the processor blocks the signals transmitted by the piezoelectric sensors in an abnormal state. Thus, 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 signal transmitting circuit outputs a signal to turn on the signal isolation circuit, thereby realizing real-time detection of the piezoelectric sensor, and causing the signal conditioning circuit to output a conditioning voltage signal to the processor, the processor determines the state of the piezoelectric sensor based on the change in the conditioning voltage signal data and the piezoelectric sensor's good condition data. This allows for direct detection of poor electrical connections in piezoelectric sensors during the production process, intercepting such issues at an earlier stage and avoiding subsequent disassembly complications, thus improving production efficiency. If poor electrical connections are detected at the user end, the processor can disable these faulty sensors, ensuring the recognition rate remains within a controllable range. This solves the problem of existing smart interactive flat panels requiring the removal of piezoelectric sensors installed beneath the inner glass of the touchscreen after assembly when poor connections are detected, a cumbersome process that impacts production efficiency. Attached Figure Description

[0021] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0022] Figure 1 This is a schematic diagram of the structure of a piezoelectric sensor; Figure 2 This is a schematic diagram of the equivalent circuit of a piezoelectric sensor represented in current source mode; Figure 3 This is a schematic diagram of the equivalent circuit of a piezoelectric sensor represented in voltage source mode; Figure 4 This is a structural schematic diagram of an intelligent interactive flat panel provided by the present invention; Figure 5 This is another structural schematic diagram of an intelligent interactive flat panel provided by the present invention; Figure 6 This is a first circuit diagram of a detection circuit module for an intelligent interactive flat panel provided by the present invention; Figure 7 This is a second circuit diagram of a detection circuit module for an intelligent interactive flat panel provided by the present invention; Figure 8 This is a third circuit diagram of a detection circuit module for an intelligent interactive flat panel provided by the present invention; Figure 9 This is a schematic diagram of the detection circuit module of an intelligent interactive flat panel provided by the present invention for detecting that the piezoelectric sensor is in an open circuit state; Figure 10 This is a schematic diagram of the detection circuit module of an intelligent interactive flat panel provided by the present invention for detecting that the piezoelectric sensor is in a short-circuit state; Figure 11 This is a schematic diagram of the detection circuit module of an intelligent interactive flat panel provided by the present invention for detecting that the piezoelectric sensor is in a broken state; Figure 12 This is another structural schematic diagram of an intelligent interactive flat panel provided by the present invention.

[0023] Explanation of key component symbols: Detailed Implementation To facilitate understanding of the present invention, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "inner," "outer," "bottom," etc., used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0025] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] 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.

[0027] 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.

[0028] 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 inventors 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 caused by the piezoelectric sensor can lead to poor electrical connection, sensor breakage, and short circuits. Poor electrical connection 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 will cause misalignment of the touchscreen recognition rate, reduce product quality, and affect the user experience. Currently, this type of piezoelectric sensor electrical connection problem can generally only be detected after the entire smart interactive flat panel is assembled. When this problem is discovered, the device must be disassembled to remove the piezoelectric sensor, which is located beneath the innermost touchscreen glass. This requires removing the entire frame, back panel, rear shell, and mid-frame of the device, and then opening the inner touchscreen glass to access the piezoelectric sensor. The entire disassembly process is cumbersome, labor-intensive, and impacts production efficiency. Furthermore, since large-size smart interactive flat panels typically require multiple piezoelectric sensors, the testing process necessitates checking and testing each one individually, resulting in a large workload and long processing time.

[0029] To address the aforementioned technical problems discovered during the research and development process, this application provides an intelligent interactive flat panel, comprising multiple piezoelectric sensors arranged in parallel, mounted beneath the glass on the inner surface of the touchscreen; and multiple detection circuit modules corresponding one-to-one with each piezoelectric sensor. Each detection circuit module includes a signal transmitting circuit, a piezoelectric sensor channel circuit, a processing circuit, and a processor. The piezoelectric sensor channel circuit includes a signal isolation circuit. By connecting the piezoelectric sensor to a first and second access terminal of the piezoelectric sensor channel circuit, after the piezoelectric sensor is connected to the detection circuit module, the signal transmitting circuit outputs a signal to activate the signal isolation circuit, enabling real-time detection of the piezoelectric sensor. The processing circuit then outputs a conditioning voltage signal to the processor, which determines the state of the piezoelectric sensor based on the change between the conditioning voltage signal data and the piezoelectric sensor's condition data. This allows for direct detection of poor electrical connections in the piezoelectric sensor during production, intercepting such issues in earlier stages and avoiding subsequent disassembly complications, thus improving production efficiency. If the number of piezoelectric sensor electrical connection defects detected at the user end is lower than a set value, the processor can shield the faulty piezoelectric sensors, using only the signals from normally functioning piezoelectric sensors to ensure the signal recognition rate remains within a controllable range. This solves the problem of existing smart interactive flat panels requiring the removal of piezoelectric sensors installed under the inner surface glass of the touchscreen after assembly when faulty connections are detected, which is cumbersome and affects production efficiency. Furthermore, this application embodiment can diagnose four different states of the piezoelectric sensor based on the conditioned voltage signal: normal operation, short circuit, open circuit, and sensor breakage. Subsequent repairs can be performed based on the diagnosed states, significantly reducing the cost of fault identification and repair and improving work efficiency. In addition, the smart interactive flat panel of this application uses parallel piezoelectric sensors and detection circuit modules. When the processor determines the detection results, it can also locate the faulty sensor, greatly improving the efficiency of detection and repair.

[0030] To facilitate understanding of the above-mentioned inventive concept of the present invention, the above-mentioned inventive concept of the present invention will be described in more detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1 The diagram shows the structure of a piezoelectric sensor. Figure 1In this design, 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.

[0032] 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.

[0033] like Figure 2 The diagram shows the equivalent circuit of a piezoelectric sensor in current source mode. In current source mode, it can be represented by the following formula: Ip=dQ / dt 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).

[0034] For ease of calculation, Figure 2 The equivalent circuit of the piezoelectric sensor shown in current source mode can also be used. Figure 3 The piezoelectric sensor shown is replaced by an equivalent circuit represented in voltage source mode. Figure 3 In this circuit, the equivalent capacitance Cp of the piezoelectric sensor is connected in parallel with its leakage resistance Rp. The values ​​of Cp and Rp can be obtained using a digital bridge circuit. The leakage resistance Rp is extremely large and can be ignored in a circuit where Cp and Rp are connected in parallel. When physical pressure is applied to the piezoelectric ceramic material that makes up the piezoelectric sensor, the electric dipole moment within the material shortens due to compression. To resist this change, the piezoelectric ceramic material generates equal amounts of positive and negative charges on opposite surfaces. These charges can be sampled and converted into corresponding voltage signals by a connected analog signal processing circuit for further processing.

[0035] In one embodiment, such as Figure 4As shown, the present invention provides a smart interactive flat panel 100, which includes: a plurality of piezoelectric sensors C1 arranged in parallel, the plurality of piezoelectric sensors C1 being installed below the glass on the inner surface of the touch screen of the smart interactive flat panel; and a plurality of detection circuit modules 1 corresponding one-to-one with the plurality of piezoelectric sensors C1; wherein: The detection circuit module 1 includes a signal transmitting circuit 11, a piezoelectric sensor channel circuit 12, an arithmetic circuit 13, a processor 15, and a first reference voltage terminal VDD, wherein: The piezoelectric sensor channel circuit 12 includes a signal isolation circuit 123, a first access terminal IN1, and a second access terminal IN2. The first access terminal IN1 and the second access terminal IN2 are respectively used to connect to the first and second terminals of the piezoelectric sensor C1. The signal isolation circuit 123 is electrically connected to the output terminal of the signal transmitting circuit 11 to prevent the piezoelectric sensor signal from flowing into the signal transmitting circuit 11. The output terminal of the signal isolation circuit 123 is the first access terminal IN1. The second access terminal IN2 is electrically connected to the first reference voltage terminal VDD. The arithmetic circuit 13 is electrically connected to the signal isolation circuit 123, the first reference voltage terminal VDD, and the processor 15, respectively, and is used to output a conditioning voltage signal to the processor 15. The processor 15 is used to determine the state of the piezoelectric sensor C1 based on the conditioning voltage signal; specifically: when the conditioning voltage signal is higher than a preset threshold, the piezoelectric sensor is determined to be in a normal state; when the conditioning voltage signal is lower than the preset threshold, the piezoelectric sensor is determined to be in an abnormal state, and when the number of piezoelectric sensors in an abnormal state is lower than a set value, the processor blocks the signals transmitted by the piezoelectric sensors in an abnormal state.

[0036] In this embodiment, a smart interactive flat panel is provided, including multiple piezoelectric sensors arranged in parallel, which are installed under the glass on the inner surface of the touch screen of the smart interactive flat panel; and multiple detection circuit modules corresponding one-to-one with the multiple piezoelectric sensors; wherein: the detection circuit module includes a signal transmitting circuit, a piezoelectric sensor channel circuit, a processing circuit processor, and a first reference voltage terminal; the piezoelectric sensor channel circuit includes a signal isolation circuit, a first access terminal, and a second access terminal; the first access terminal and the second access terminal are respectively used to connect to the first and second terminals of the piezoelectric sensor; the signal isolation circuit is electrically connected to the output terminal of the signal transmitting circuit to prevent the piezoelectric sensor signal from flowing out. The signal transmitting circuit is connected to the signal isolation circuit; the output terminal of the signal isolation circuit is the first access terminal; the second access terminal is electrically connected to the first reference voltage terminal; the arithmetic circuit is electrically connected to the signal isolation circuit, the first reference voltage terminal, and the processor respectively, and is used to output a conditioning voltage signal to the processor; the processor is used to determine the state of the piezoelectric sensor based on the conditioning voltage signal, specifically: when the conditioning voltage signal is higher than a preset threshold, the piezoelectric sensor is determined to be in a normal state; when the conditioning voltage signal is lower than the preset threshold, the piezoelectric sensor is determined to be in an abnormal state, and when the number of piezoelectric sensors in an abnormal state is lower than a set value, the processor blocks the signals transmitted by the piezoelectric sensors in an abnormal state. Thus, 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 module, the signal transmitting circuit outputs a signal to turn on the signal isolation circuit, thereby realizing real-time detection of the piezoelectric sensor, and causing the signal conditioning circuit to output a conditioning voltage signal to the processor. The processor determines the state of the piezoelectric sensor based on the change in the conditioning voltage signal data and the piezoelectric sensor's good condition data. This allows for direct detection of poor electrical connections in piezoelectric sensors during the production process, intercepting such issues at an earlier stage and avoiding subsequent disassembly complications, thus improving production efficiency. If poor electrical connections are detected at the user end, the processor can disable these faulty sensors, ensuring the recognition rate remains within a controllable range. This solves the problem of existing smart interactive flat panels requiring the removal of piezoelectric sensors installed beneath the inner glass of the touchscreen after assembly when poor connections are detected, a cumbersome process that impacts production efficiency.

[0037] In one embodiment, 4-6 piezoelectric sensors are arranged in parallel, and more can be arranged as needed.

[0038] In one embodiment, when the processor blocks the signal transmitted by a piezoelectric sensor in an abnormal state, the set value of the piezoelectric sensor in the abnormal state depends on the number of piezoelectric sensors.

[0039] In one embodiment, the piezoelectric sensor detection circuit modules arranged in parallel can share the same signal transmission circuit and processor, or each piezoelectric sensor detection circuit module can have its own separate signal transmission circuit and processor.

[0040] In one embodiment, the signal transmitting circuit 11 is electrically connected to the signal isolation circuit 123 of each piezoelectric sensor channel circuit 12, and is used to generate a short square wave pulse signal to the signal isolation circuit 123.

[0041] In one embodiment, such as Figure 6 As shown, the signal transmitting circuit 11 includes at least one GPIO (General Purpose Input Output) port, which is electrically connected to the signal isolation circuit 123 of the piezoelectric sensor channel circuit 12, and is used to generate a short square wave pulse signal to the signal isolation circuit 123.

[0042] In one embodiment, when the detection circuit module 1 includes a multi-channel piezoelectric sensor circuit, the GPIO port is electrically connected to the signal isolation circuit 123 of each piezoelectric sensor channel circuit 12, and is used to generate a short square wave pulse signal to the signal isolation circuit 123 of each piezoelectric sensor channel circuit.

[0043] The signal transmitting circuit generates a short square wave pulse signal to the signal isolation circuit, which then conducts the signal isolation circuit, thereby enabling real-time detection of the piezoelectric sensor connected to the piezoelectric sensor channel circuit.

[0044] In one embodiment, the piezoelectric sensor channel circuit 12 includes a signal isolation circuit 123, a first access terminal IN1, and a second access terminal IN2. The first access terminal IN1 and the second access terminal IN2 are respectively used to connect to the first and second ends of the piezoelectric sensor. The signal isolation circuit 123 is electrically connected to the output terminal of the signal transmitting circuit 11, and the output terminal of the signal isolation circuit 123 is the first access terminal IN1. The second access terminal IN2 is electrically connected to the first reference voltage terminal VDD. The signal isolation circuit 123 is used to transmit the signal from the signal transmitting circuit to the piezoelectric sensor and the subsequent current limiting circuit 131, and to block the signal from the piezoelectric sensor from flowing into the signal transmitting circuit 11.

[0045] Specifically, such as Figure 6As shown, as an optional example, the signal isolation circuit 123 includes a transistor Q1 and a third resistor R3. The base of the transistor Q1 is electrically connected to the GPIO port, and the collector of the transistor Q1 is electrically connected to the second reference voltage terminal VCC through the third resistor R3. The emitter of the 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.

[0046] like Figure 7 As shown, as another optional example, the signal isolation circuit 123 includes a MOSFET Q2 and a fourth resistor R4. The gate of the MOSFET Q2 is electrically connected to the GPIO port, and the drain of the MOSFET Q2 is electrically connected to the second reference voltage terminal VCC through the fourth resistor R4. The source of the MOSFET Q2 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.

[0047] It is understandable that the MOSFET Q2 can be either a P-type MOSFET or an N-type MOSFET. Figure 7 In this example, the MOSFET Q2 is a P-type MOSFET, but it is not limited to P-type MOSFETs. Using an N-type MOSFET can achieve the same effect, but it will not be explained in detail here.

[0048] like Figure 8 As shown, as another optional example, when the signal transmitted by the signal transmitting circuit is a high-frequency signal, the signal isolation circuit 123 includes a third capacitor C3. At this time, the third capacitor can allow high-frequency signals to pass through and block low-frequency signals from the piezoelectric sensor; the sensor signal cannot flow into the signal transmitting circuit, and the high-frequency signal from the signal transmitting circuit can flow into the back-end circuit; the first end of the third capacitor C3 is electrically connected to the GPIO port, and the second end of the third capacitor C3 is the first access terminal IN1.

[0049] In one embodiment, the arithmetic circuit 13 is electrically connected to the signal isolation circuit 123, the first reference voltage terminal VDD, and the processor 15, respectively, and is used to output a conditioning voltage signal to the processor 15.

[0050] Specifically, such as Figure 5 As shown, the operational amplifier circuit 13 includes a current limiting circuit 131 and a signal conditioning circuit 132, wherein: The current limiting circuit 131 is electrically connected to the output of the signal isolation circuit 123. The current limiting circuit 131 limits the current of the signal transmitted from the signal transmission circuit 11 through the signal isolation circuit 123, preventing damage to the operational amplifier P1 in the signal conditioning circuit 132. Specifically, as... Figures 6 to 11 As shown, the current limiting circuit 131 includes a first resistor R1, which is electrically connected to the output terminal of the signal isolation circuit 123 of the piezoelectric sensor channel circuit 12. The first resistor R1 limits the current of the signal transmitting circuit 11 transmitted through the signal isolation circuit 123 to avoid impacting the operational amplifier P1 in the signal conditioning circuit 132 and damaging the operational amplifier P1.

[0051] In one embodiment, when the detection circuit module 1 includes a multi-channel piezoelectric sensor circuit, the first resistor R1 is electrically connected to the output terminal of the signal isolation circuit of each channel piezoelectric sensor circuit.

[0052] The signal conditioning circuit 132 is electrically connected to the current limiting circuit 131, the first reference voltage terminal VDD, and the processor 15, respectively, and is used to output a conditioning voltage signal to the processor 15.

[0053] Specifically, the signal conditioning circuit 132 includes a first signal input terminal, a second signal input terminal, and an output terminal. The first signal input terminal is electrically connected to the current limiting circuit 131, the second signal input terminal is electrically connected to the first reference voltage terminal VDD, and the output terminal of the signal conditioning circuit is used to output a conditioning voltage signal, which is used by the processor 15 to determine the state of the piezoelectric sensor based on the conditioning voltage signal.

[0054] In one embodiment, such as Figures 6 to 11 As shown, the signal conditioning circuit 132 includes an operational amplifier P1 and a feedback circuit 1321. The positive input terminal of the operational amplifier P1 is electrically connected to the first reference voltage terminal VDD as the second signal input terminal, and the negative input terminal of the operational amplifier P1 is electrically connected to the current limiting circuit 131 as the first signal input terminal. Specifically, the negative input terminal of the operational amplifier P1 is electrically connected to the first resistor R1 as the first signal input terminal. The output terminal OUT of the operational amplifier P1 is electrically connected to the negative input terminal of the operational amplifier P1 through the feedback circuit 1321. The output terminal OUT of the operational amplifier P1 is used to output a conditioning voltage signal, which is used by the processor 15 to determine the state of the piezoelectric sensor based on the conditioning voltage signal.

[0055] In one embodiment, the feedback circuit 1321 includes a second resistor R2 and a second capacitor C2 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 OUT of the operational amplifier P1, respectively.

[0056] In one embodiment, the processor 15 is electrically connected to the signal conditioning circuit 132 and is used to determine the state of the piezoelectric sensor based on the conditioning voltage signal output by the signal conditioning circuit 132. Specifically, when the conditioning voltage signal is higher than a preset threshold, the piezoelectric sensor is determined to be in a normal state; when the conditioning voltage signal is lower than the preset threshold, the piezoelectric sensor is determined to be in an abnormal state; and when the number of piezoelectric sensors in an abnormal state is lower than a set value, the processor blocks the signals transmitted by the piezoelectric sensors in the abnormal state.

[0057] Specifically, the processor 15 is electrically connected to the output terminal OUT of the operational amplifier P1 in the signal conditioning circuit 132, and is used to determine the state of the piezoelectric sensor based on the conditioning voltage signal output by the operational amplifier P1.

[0058] The processor 15 has data processing and signal processing capabilities and can be an integrated circuit chip. For example, the processor can be a general-purpose processor, a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or other programmable logic devices. The general-purpose processor can be a microprocessor, an MCU (Microcontroller Unit), or any conventional processor.

[0059] Generally, piezoelectric sensors have several states, including normal, open circuit, short circuit, and broken. The processor pre-stores the voltage signal data corresponding to each of these states. When the processor 15 receives the conditioned voltage signal output from the operational amplifier P1, it compares the conditioned voltage signal with the pre-stored voltage signal data to determine the state of the piezoelectric sensor.

[0060] like Figure 6 The diagram shown is also a schematic of the detection circuit module when the piezoelectric sensor is in normal operation. Figure 6In this circuit, the piezoelectric sensor is designated C1. When the piezoelectric sensor C1 is connected to the detection circuit module 1, if the piezoelectric sensor C1 is in a normal state, the piezoelectric sensor C1 and the detection circuit module 1 are electrically connected. At this time, when the signal transmitting circuit 11 generates a signal to the base of the transistor Q1, causing the transistor Q1 to conduct, the reference voltage of the second reference voltage terminal VCC, after passing through the third resistor R3 and the transistor Q1, will be applied to the first access terminal IN1 of the piezoelectric sensor channel circuit 12. At this time, the capacitance value of the piezoelectric sensor C1 is equal to the capacitance value of the piezoelectric sensor equivalent capacitance Cp, and the current generated at the first access terminal IN1 will flow to the first resistor R1 and the piezoelectric sensor C1 respectively. After the current flows into the piezoelectric sensor C1, the voltage will rise. When the voltage rises to a certain level, it will cause the transistor Q1 to turn off. At this time, the detection circuit module 1 slowly discharges through the first resistor R1 and the second resistor R2. At this time, because the voltage of the piezoelectric sensor C1 rises after current flows in, the voltage input from the first reference voltage terminal VDD to the positive input terminal of the operational amplifier P1 exceeds the voltage input from the first resistor R1 to the negative input terminal of the operational amplifier P1. The output terminal OUT of the operational amplifier P1 outputs a first high-level conditioning voltage signal and transmits it to the processor 15. Upon receiving the first conditioning voltage signal output by the operational amplifier P1, the processor 15 compares this signal with pre-stored voltage signal data to determine that the piezoelectric sensor C1 is in a normal state, thereby determining the current state of the piezoelectric sensor.

[0061] like Figure 9 The diagram shown illustrates the detection circuit module when the piezoelectric sensor is in an open-circuit state. Figure 9In this circuit, the piezoelectric sensor is designated C1. When the piezoelectric sensor C1 is connected to the detection circuit module 1, if the piezoelectric sensor C1 is in an open-circuit state, then the piezoelectric sensor C1 is not actually connected to the detection circuit module 1. At this time, when the signal transmitting circuit 11 generates a signal to the base of the transistor Q1, causing the transistor Q1 to conduct, the voltage generated by the second reference voltage VCC after passing through the third resistor R3 and the transistor Q1 will be applied to the first access terminal IN1 of the piezoelectric sensor channel circuit 12. At this time, since the piezoelectric sensor C1 is in an open-circuit state, the current generated at the first access terminal IN1 will only flow into the first resistor R1 and cannot flow into the piezoelectric sensor C1. At this time, the voltage input from the first resistor R1 to the negative input terminal of the operational amplifier P1 exceeds the voltage input from the first reference voltage terminal VDD to the positive input terminal of the operational amplifier P1. The output terminal OUT of the operational amplifier P1 outputs a low-level second conditioning voltage signal and transmits it to the processor 15. When the processor 15 receives the second conditioning voltage signal output by the operational amplifier P1, it compares the second conditioning voltage signal with the pre-stored voltage signal data to determine that the piezoelectric sensor C1 is in an open circuit state, thereby determining the current state of the piezoelectric sensor.

[0062] like Figure 10 The diagram shown is a schematic of the detection circuit module when the piezoelectric sensor is in a short-circuit state. Figure 10 In this circuit, the piezoelectric sensor is denoted by C1. When the piezoelectric sensor C1 is connected to the detection circuit module 1, if the piezoelectric sensor C1 is in a short-circuit state, the piezoelectric sensor C1 is bypassed by the detection circuit module 1. At this time, the emitter of the transistor Q1 is directly electrically connected to the first reference terminal VDD. When the signal transmitting circuit 11 generates an impulse signal to the base of the transistor Q1, causing the transistor Q1 to conduct, the voltage generated by the second reference voltage VCC after passing through the third resistor R3 and the transistor Q1 will be applied to the first access terminal IN1 of the piezoelectric sensor channel circuit. At this time, since the piezoelectric sensor C1 is in a short-circuit state, the third resistor R3 acts as a current limiter, and the current generated at the first access terminal IN1 will flow to the first reference voltage terminal VDD and the first resistor R1, so that the voltage of the first reference voltage terminal VDD exceeds the voltage input to the negative input terminal of the operational amplifier P1 by the first resistor R1. The output terminal OUT of the operational amplifier P1 outputs a second high-level third conditioning voltage signal and transmits it to the processor 15. When the processor 15 receives the third conditioning voltage signal output by the operational amplifier P1, it compares the third conditioning voltage signal with the pre-stored voltage signal data to determine that the piezoelectric sensor C1 is in a short-circuit state, thereby determining the current state of the piezoelectric sensor.

[0063] like Figure 11 The diagram shown is a schematic of the detection circuit module when the piezoelectric sensor is in a broken state. Figure 11In this circuit, the piezoelectric sensor is denoted by C1. When the piezoelectric sensor C1 is connected to the detection circuit module 1, if the piezoelectric sensor C1 is in a broken state, the piezoelectric sensor C1 is electrically connected to the detection circuit module 1, but the capacitance value of the piezoelectric sensor C1 will decrease accordingly (for example, the capacitance value of the piezoelectric sensor C1 decreases to half the capacitance value of the equivalent capacitance Cp of the piezoelectric sensor; the capacitance change is related to the breaking ratio). At this time, when the signal transmitting circuit 11 generates a signal to the base of the transistor Q1, causing the transistor Q1 to conduct, the voltage generated by the second reference voltage VCC after passing through the third resistor R3 and the transistor Q1 will be applied to the first access terminal IN1 of the piezoelectric sensor channel circuit. At this time, the current generated at the first access terminal IN1 will flow to the first resistor R1 and the piezoelectric sensor C1 respectively. Since the piezoelectric sensor C1 is in a broken state, the capacitance value of the piezoelectric sensor C1 decreases accordingly, causing the ratio of the current flowing to the first resistor R1 to the current flowing to the piezoelectric sensor C1 to change further. At this time, because the voltage of the piezoelectric sensor C1 rises after current flows in, the voltage input from the first reference voltage terminal VDD to the positive input terminal of the operational amplifier P1 exceeds the voltage input from the first resistor R1 to the negative input terminal of the operational amplifier P1. The output terminal OUT of the operational amplifier P1 outputs a second high-level fourth conditioning voltage signal and transmits it to the processor 15. Upon receiving the fourth conditioning voltage signal output by the operational amplifier P1, the processor 15 compares this signal with pre-stored voltage signal data to determine that the piezoelectric sensor C1 is in a broken state, thereby determining the current state of the piezoelectric sensor.

[0064] Based on the same concept, in one embodiment, such as Figure 12 As shown, this invention also provides a smart interactive flat panel 100, comprising: a plurality of piezoelectric sensors, the plurality of piezoelectric sensors being installed below the glass on the inner surface of the smart interactive flat panel touch screen; and a plurality of detection circuit modules 1 corresponding one-to-one with the plurality of piezoelectric sensors; wherein: The detection circuit module 1 includes: a signal transmitting circuit 11, a piezoelectric sensor channel circuit 12, an arithmetic circuit 13, a first reference voltage terminal VDD, and a processor 15; The signal transmitting circuit 11 includes several pairs of differential signals, each pair of differential signals including a first differential signal output terminal D+ and a second differential signal output terminal D-; Each piezoelectric sensor channel circuit 12 includes 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 connect to the first terminal and the second terminal of the piezoelectric sensor C1; the first access terminal IN1 and the second access terminal IN2 are electrically connected to the first differential signal output terminal D+ and the second differential signal output terminal D- of a pair of differential signals of the signal transmitting circuit 11, respectively, that is, the first access terminal IN1 is electrically connected to the first differential signal output terminal D+ of a pair of differential signals of the signal transmitting circuit 11, and the second access terminal IN2 is electrically connected to the second differential signal output terminal D- of the same pair of differential signals of the signal transmitting circuit 11; The arithmetic circuit 13 is electrically connected to each of the piezoelectric sensor channel circuits 12, the first reference voltage terminal VDD, and the processor 15, respectively, and is used to output a conditioning voltage signal to the processor 15. The processor 15 is used to determine the state of the piezoelectric sensor based on the conditioning voltage signal; specifically: when the conditioning voltage signal is higher than a preset threshold, the piezoelectric sensor is determined to be in a normal state; when the conditioning voltage signal is lower than the preset threshold, the piezoelectric sensor is determined to be in an abnormal state; when the number of piezoelectric sensors in an abnormal state is lower than a set value, the processor blocks the signals transmitted by the piezoelectric sensors in an abnormal state.

[0065] In one embodiment, the signal transmitting circuit 11 is electrically connected to each piezoelectric sensor channel circuit 12 and includes several pairs of short square wave pulse differential signals. Each pair of short square wave pulse differential signals has an output terminal including a first differential signal output terminal D+ and a second differential signal output terminal D-. The signal transmitting circuit 11 is used to generate several pairs of short square wave pulse differential signals, and one pair of short square wave pulse differential signals is sent to one piezoelectric sensor channel circuit 12. This enables real-time detection of the piezoelectric sensor C1 connected to each piezoelectric sensor channel circuit 12.

[0066] In one embodiment, the arithmetic circuit 13 is electrically connected to the signal isolation circuit 123, the first reference voltage terminal VDD, and the processor 15, respectively, and is used to output a conditioning voltage signal to the processor 15.

[0067] Specifically, such as Figure 5 As shown, the operational amplifier circuit 13 includes a current limiting circuit 131 and a signal conditioning circuit 132, wherein: The current limiting circuit 131 is electrically connected to the output of the signal isolation circuit 123. The current limiting circuit 131 limits the current of the signal transmitted from the signal transmission circuit 11 through the signal isolation circuit 123, preventing damage to the operational amplifier P1 in the signal conditioning circuit 132. Specifically, as... Figures 6 to 11As shown, the current limiting circuit 131 includes a first resistor R1, which is electrically connected to the output terminal of the signal isolation circuit 123 of the piezoelectric sensor channel circuit 12. The first resistor R1 limits the current of the signal transmitting circuit 11 transmitted through the signal isolation circuit 123 to avoid impacting the operational amplifier P1 in the signal conditioning circuit 132 and damaging the operational amplifier P1.

[0068] In one embodiment, when the detection circuit module 1 includes a multi-channel piezoelectric sensor circuit, the first resistor R1 is electrically connected to the output terminal of the signal isolation circuit of each channel piezoelectric sensor circuit.

[0069] The signal conditioning circuit 132 is electrically connected to the current limiting circuit 131, the first reference voltage terminal VDD, and the processor 15, respectively, and is used to output a conditioning voltage signal to the processor 15.

[0070] Specifically, the signal conditioning circuit 132 includes a first signal input terminal, a second signal input terminal, and an output terminal. The first signal input terminal is electrically connected to the current limiting circuit 131, the second signal input terminal is electrically connected to the first reference voltage terminal VDD, and the output terminal of the signal conditioning circuit is used to output a conditioning voltage signal, which is used by the processor 15 to determine the state of the piezoelectric sensor based on the conditioning voltage signal.

[0071] In one embodiment, such as Figures 6 to 11 As shown, the signal conditioning circuit 132 includes an operational amplifier P1 and a feedback circuit 1321. The positive input terminal of the operational amplifier P1 is electrically connected to the first reference voltage terminal VDD as the second signal input terminal, and the negative input terminal of the operational amplifier P1 is electrically connected to the current limiting circuit 131 as the first signal input terminal. Specifically, the negative input terminal of the operational amplifier P1 is electrically connected to the first resistor R1 as the first signal input terminal. The output terminal OUT of the operational amplifier P1 is electrically connected to the negative input terminal of the operational amplifier P1 through the feedback circuit 1321. The output terminal OUT of the operational amplifier P1 is used to output a conditioning voltage signal, which is used by the processor 15 to determine the state of the piezoelectric sensor based on the conditioning voltage signal.

[0072] In one embodiment, the feedback circuit 1321 includes a second resistor R2 and a second capacitor C2 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 OUT of the operational amplifier P1, respectively.

[0073] In a further embodiment, the signal transmitting circuit transmits signals with different frequency combinations. After the signals pass through the detection circuit, the processor calculates the cross-correlation between the received conditioning voltage signal and the preset signal. When the calculated value is greater than the preset threshold, the piezoelectric sensor is determined to be in a normal state. When the calculated value is lower than the preset threshold, the piezoelectric sensor is determined to be in an abnormal state. When the number of piezoelectric sensors in an abnormal state is lower than a set value, the processor blocks the signals transmitted by the piezoelectric sensors in an abnormal state.

[0074] In this embodiment, a smart interactive flat panel is provided, comprising: multiple piezoelectric sensors mounted below the glass on the inner surface of the touchscreen of the smart interactive flat panel; and multiple detection circuit modules corresponding one-to-one with the multiple piezoelectric sensors; wherein: the detection circuit module includes: a signal transmitting circuit, a piezoelectric sensor channel circuit, a calculation circuit, a first reference voltage terminal, and a processor; the signal transmitting circuit includes several pairs of differential signals, each pair of differential signals including a first differential signal output terminal and a second differential signal output terminal; each piezoelectric sensor channel circuit includes a first access terminal and a second access terminal; the first access terminal and the second access terminal are used to connect to the first terminal and the second terminal of the piezoelectric sensor; the first access terminal and the second access terminal are respectively connected to the first differential signal output terminal and the second differential signal output terminal of a pair of differential signals of the signal transmitting circuit. The signal output terminals are electrically connected, specifically, the first access terminal is electrically connected to the first differential signal output terminal of a pair of differential signals of the signal transmitting circuit, and the second access terminal is electrically connected to the second differential signal output terminal of the same pair of differential signals of the signal transmitting circuit. The arithmetic 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 processor is used to determine the state of the piezoelectric sensor based on the conditioning voltage signal. Specifically: when the conditioning voltage signal is higher than a preset threshold, the piezoelectric sensor is determined to be in a normal state; when the conditioning voltage signal is lower than the preset threshold, the piezoelectric sensor is determined to be in an abnormal state; when the number of piezoelectric sensors in an abnormal state is lower than a set value, the processor blocks the signals transmitted by the piezoelectric sensors in an abnormal state. Therefore, during the production process, it is possible to directly detect whether the piezoelectric sensor has a poor electrical connection, intercepting the situation at the upstream process, avoiding subsequent disassembly hassles, and improving production efficiency. If a poor electrical connection of the piezoelectric sensor is detected at the user end, the processor can be used to disable these poorly connected piezoelectric sensors, ensuring the recognition rate remains within a controllable range. This solves the problem of existing smart interactive flat panels requiring the removal of the piezoelectric sensor, which is installed under the inner surface glass of the touchscreen, when a poor electrical connection is detected after assembly. This removal is cumbersome and affects production efficiency.

[0075] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above. For the sake of brevity, they are not provided in detail. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A smart interactive flat panel, characterized in that, include: Multiple piezoelectric sensors are arranged in parallel and installed under the glass on the inner surface of the smart interactive flat panel touch screen; Multiple detection circuit modules corresponding one-to-one with the multiple piezoelectric sensors; The detection circuit module includes: a signal transmitting circuit, a piezoelectric sensor channel circuit, a calculation circuit, a first reference voltage terminal, and a processor; The piezoelectric sensor channel circuit includes a signal isolation circuit, a first access terminal, and a second access terminal; the first access terminal and the second access terminal are used to connect to the piezoelectric sensor; the signal isolation circuit is electrically connected to the output terminal of the signal transmitting circuit and is used to receive the signal transmitted by the signal transmitting circuit; the first access terminal is electrically connected to the signal isolation circuit; the second access terminal is electrically connected to a first reference voltage terminal. The arithmetic circuit is electrically connected to the signal isolation circuit, the first reference voltage terminal, and the processor, respectively, and is used to output a conditioning voltage signal to the processor; The processor is used to determine the state of the piezoelectric sensor based on the conditioning voltage signal; specifically: when the conditioning voltage signal is higher than a preset threshold, the piezoelectric sensor is determined to be in a normal state; when the conditioning voltage signal is lower than the preset threshold, the piezoelectric sensor is determined to be in an abnormal state, and when the number of piezoelectric sensors in an abnormal state is lower than a set value, the processor blocks the signals transmitted by the piezoelectric sensors in an abnormal state.

2. The intelligent interactive flat panel according to claim 1, characterized in that, The signal transmitting circuit includes at least one GPIO port, which is electrically connected to the signal isolation circuit of the piezoelectric sensor channel circuit, and is used to generate a short square wave pulse signal to the signal isolation circuit.

3. The intelligent interactive flat panel according to claim 2, characterized in that, The signal isolation 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.

4. The intelligent interactive flat panel according to claim 2, characterized in that, The signal isolation 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.

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

6. The intelligent interactive flat panel according to claim 5, characterized in that, The current limiting circuit includes a first resistor, which is electrically connected to the output terminal of the signal isolation circuit.

7. The intelligent interactive flat panel according to claim 5, 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 the 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.

8. The intelligent interactive flat panel according to claim 7, 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.

9. The intelligent interactive flat panel according to claim 3 or 4, characterized in that, The reference voltage at the second reference voltage terminal is greater than the reference voltage at the first reference voltage terminal.

10. A smart interactive flat panel, characterized in that, include: Multiple piezoelectric sensors are installed under the glass on the inner surface of the smart interactive flat panel touch screen; Multiple detection circuit modules corresponding one-to-one with the multiple piezoelectric sensors; The detection circuit module includes: a signal transmitting circuit, a piezoelectric sensor channel circuit, a calculation circuit, a first reference voltage terminal, and a processor; The signal transmitting circuit includes several pairs of short square wave pulse differential signals, and the output terminals of each pair of short square wave pulse differential signals include a first differential signal output terminal and a second differential signal output terminal. Each piezoelectric sensor channel circuit includes a first access terminal and a second access terminal; the first access terminal and the second access terminal are used to access the piezoelectric sensor; the first access terminal and the second access terminal are electrically connected to the first differential signal output terminal and the second differential signal output terminal of a pair of differential signals of the signal transmitting circuit, respectively; 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 processor is used to determine the state of the piezoelectric sensor based on the conditioning voltage signal; specifically: when the conditioning voltage signal is higher than a preset threshold, the piezoelectric sensor is determined to be in a normal state; when the conditioning voltage signal is lower than the preset threshold, the piezoelectric sensor is determined to be in an abnormal state; when the number of piezoelectric sensors in an abnormal state is lower than a set value, the processor blocks the signals transmitted by the piezoelectric sensors in an abnormal state.

11. The intelligent interactive flat panel according to claim 10, characterized in that, The operational amplifier circuit is an operational amplifier circuit, which includes a current limiting circuit and a signal conditioning circuit. The current limiting circuit is electrically connected to the output terminal of the signal isolation circuit. The signal conditioning circuit is electrically connected to the current limiting circuit, the first reference voltage terminal, and the processor, respectively, and is used to output a conditioning voltage signal to the processor.

12. The intelligent interactive flat panel according to claim 11, characterized in that, The current limiting circuit includes a first resistor, which is electrically connected to the output terminal of the signal isolation circuit.

13. The intelligent interactive flat panel according to claim 11, 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 the 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.

14. The intelligent interactive flat panel according to claim 13, 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.

Images