A pressure detection circuit and a pressure detection device

Abstract

The application discloses a pressure detection circuit and a pressure detection device. The pressure detection circuit comprises a signal conversion module, a first processing module and a second processing module. The signal conversion module collects a charge signal and converts the charge signal into an analog voltage signal output to the first processing module. The first processing module outputs corresponding sensing characteristic information to the second processing module based on the analog voltage signal. The sensing characteristic information is at least one of an integral result and a peak digital signal. The second processing module determines a static pressure value based on the sensing characteristic information and a preset corresponding relationship. The preset corresponding relationship is a corresponding relationship between the sensing characteristic information and the static pressure value preset by the second processing module. The integral result and the preset corresponding relationship are used to detect the static pressure, and / or the peak digital signal and the preset corresponding relationship are used to detect the static pressure, so that the detection of the dynamic pressure and the static pressure is integrated, and the user interaction experience is improved.

Description

Technical Field

[0001] This application belongs to the field of electronic technology, specifically relating to a pressure detection circuit and a pressure detection device. Background Technology

[0002] In related technologies, touchpads with pressure detection functions typically employ capacitive or resistive touch technologies to acquire touch sensing signals. However, capacitive touch technology suffers from drawbacks such as slow response and susceptibility to environmental influences, while resistive touch technology suffers from high power consumption. Furthermore, both types of touch structures are difficult to integrate seamlessly, resulting in a large overall stack thickness, which is detrimental to the design of thinner and lighter devices.

[0003] To improve the above problems, some touchpads that support force sensing use strain gauges or piezoelectric sensors to collect signals, but they can only detect dynamic pressing signals and have difficulty detecting static pressure signals, which affects the user's interactive experience. Summary of the Invention

[0004] This application aims to provide a pressure detection circuit and a pressure detection device, which at least solves one of the problems of how to detect static pressure and how to improve the user's interactive experience.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application provide a pressure detection circuit, comprising: The system includes a signal conversion module, a first processing module, and a second processing module; the first processing module is electrically connected to the signal conversion module, and the second processing module is electrically connected to the first processing module. The signal conversion module is used to acquire charge signals and convert the charge signals into analog voltage signals, which are then output to the first processing module. The charge signals are obtained by the piezoelectric sensing unit based on the piezoelectric effect, converting the mechanical deformation caused by pressure. The first processing module is used to output corresponding sensing feature information to the second processing module based on the analog voltage signal; wherein, the sensing feature information is at least one of an integration result and a peak digital signal, the integration result is the result of continuous sampling and integration of the digital signal corresponding to the analog voltage signal, and the peak digital signal is the digital signal corresponding to the peak pressure when the piezoelectric sensing unit is pressed; The second processing module is used to determine the static pressure value based on the sensing feature information and the preset correspondence; wherein the preset correspondence is a correspondence between the sensing feature information and the static pressure value pre-set by the second processing module.

[0006] In one optional embodiment, the first processing module includes an analog-to-digital conversion submodule and a processing submodule. The analog-to-digital conversion submodule is electrically connected to the signal conversion module, the processing submodule is electrically connected to the analog-to-digital conversion submodule, and the second processing module is electrically connected to the processing submodule. The analog-to-digital conversion submodule and the signal conversion module are integrated, and the processing submodule and the second processing module are integrated. The analog-to-digital conversion submodule is used to convert the analog voltage signal into a digital signal and output the digital signal to the processing submodule; The processing submodule is configured to, in response to receiving the digital signal, perform time-domain integration on the continuously sampled digital signal and send the integration result to the second processing module in real time. The second processing module is specifically used to determine the static pressure value based on the current integration result and a first preset correspondence when the processing submodule detects that the pressed state of the piezoelectric sensing unit has terminated; wherein, the first preset correspondence is a correspondence between the integration value and the static pressure value preset by the second processing module.

[0007] In one optional embodiment, the first processing module includes a first voltage holding submodule, an analog-to-digital conversion submodule, and a processing submodule; the analog-to-digital conversion submodule is electrically connected to the signal conversion module, the processing submodule is electrically connected to the analog-to-digital conversion submodule, and the second processing module is electrically connected to the processing submodule; the first voltage holding submodule is electrically connected to the signal conversion module, the second processing module, and the processing submodule; the first voltage holding submodule, the analog-to-digital conversion submodule, and the signal conversion module are integrated, and the processing submodule is integrated with the second processing module; The analog-to-digital conversion submodule is used to convert the analog voltage signal into a digital signal and output the digital signal to the processing submodule; The processing submodule is configured to, in response to receiving the digital signal, send a control signal to the first voltage holding submodule based on the digital signal; wherein the control signal is a signal that controls the start and stop of the voltage acquisition function of the first voltage holding submodule; The first voltage holding submodule is used to store the peak analog signal corresponding to the peak pressure when the piezoelectric sensing unit is pressed in response to the control signal output by the processing submodule, and convert the peak analog signal into a peak digital signal and output it to the second processing module. The second processing module is specifically used to read the peak digital signal corresponding to the peak analog signal, and determine the static pressure value based on the peak digital signal and the second preset correspondence; wherein, the second preset correspondence is a correspondence between the peak digital signal value and the static pressure value preset by the second processing module.

[0008] In one optional implementation, the first processing module includes a second voltage holding submodule and a peak detection submodule; the second voltage holding submodule is electrically connected to the signal conversion module, the second processing module is electrically connected to the second voltage holding submodule, the peak detection submodule is electrically connected to the signal conversion module, and the second processing module is electrically connected to the peak detection submodule; the second voltage holding submodule, the peak detection submodule, and the signal conversion module are integrated into one unit. The second voltage holding submodule is used to store the peak analog signal corresponding to the peak pressure when the piezoelectric sensing unit is pressed in response to the control signal output by the second processing module, and convert the peak analog signal into a peak digital signal and output it to the second processing module. The peak detection submodule is used to detect the occurrence of the peak analog signal corresponding to the peak pressure when the piezoelectric sensing unit is pressed. When the peak analog signal is detected, a pulse signal is output to the second processing module so that the second processing module reads the peak digital signal corresponding to the peak analog signal in response to the pulse signal. The second processing module is specifically used to determine the static pressure value based on the peak digital signal and the third preset correspondence; wherein, the third preset correspondence is a correspondence between the peak digital signal value and the static pressure value preset by the second processing module.

[0009] In one optional implementation, the second processing module includes a lookup table storage submodule; the lookup table storage submodule is electrically connected to the processing submodule. The processing submodule is specifically used to respond to receiving the digital signal, and when the digital signal is detected to be greater than a first preset threshold and the duration of the digital signal being greater than the first preset threshold reaches a first preset duration, to perform time-domain integration processing on the continuously sampled digital signal and send the integration result to the lookup storage submodule in real time. The lookup and storage submodule is used to determine the pressure value corresponding to the piezoelectric sensing unit based on the current integration result and the first preset correspondence, store the current pressure value in its own register, and update the pressure value stored in the register by overwriting the old pressure value when the next new pressure value is obtained. The processing submodule is specifically used to terminate the time-domain integration process and send a termination signal to the lookup storage submodule when it detects that the digital signal is less than the second preset threshold and the duration of the digital signal being less than the second preset threshold reaches the second preset duration. The lookup storage submodule is also used to respond to the termination signal, terminate the update of the pressure value stored in its own register, and determine that the pressure value stored in the register after the termination of the update is a static pressure value.

[0010] In one optional implementation, the first voltage holding submodule includes a first voltage follower, a first switch, a second switch, a first storage capacitor, a second voltage follower, and a first analog-to-digital converter. The non-inverting input terminal of the first voltage follower is electrically connected to the signal conversion module. The output terminal of the first voltage follower is electrically connected to the first terminal of the first switch and its own inverting input terminal. The control terminal of the first switch is electrically connected to the processing submodule. The second terminal of the first switch is electrically connected to the first terminal of the second switch, the first terminal of the first storage capacitor, and the non-inverting input terminal of the second voltage follower. The output terminal of the second voltage follower is electrically connected to the input terminal of the first analog-to-digital converter and its own inverting input terminal. The output terminal of the first analog-to-digital converter is electrically connected to the second processing module. The second terminal of the second switch is electrically connected to the second terminal of the first storage capacitor and ground potential, respectively; the control terminal of the second switch is electrically connected to the processing submodule and the second processing module, respectively.

[0011] In one optional implementation, the second voltage holding submodule includes a voltage follower, a diode, a switch, a second storage capacitor, and a second analog-to-digital converter, and the peak detection submodule includes a delay buffer, a comparator, and a pulse generator; The non-inverting input terminal of the voltage follower is electrically connected to the signal conversion module. The output terminal of the voltage follower is electrically connected to the anode of the diode and its own inverting input terminal. The cathode of the diode is electrically connected to the first terminal of the switch, the first terminal of the second storage capacitor, and the input terminal of the second analog-to-digital converter. The output terminal of the second analog-to-digital converter is electrically connected to the second processing module. The second terminal of the switch is electrically connected to the second terminal of the second storage capacitor and ground potential, respectively; the control terminal of the switch is electrically connected to the second processing module. The input terminal of the delay buffer is electrically connected to the signal conversion module and the non-inverting input terminal of the comparator, respectively. The output terminal of the delay buffer is electrically connected to the inverting input terminal of the comparator. The output terminal of the comparator is electrically connected to the trigger input terminal of the pulse generator. The pulse output terminal of the pulse generator is electrically connected to the second processing module.

[0012] In one optional implementation, the second processing module further includes a reset submodule; the reset submodule is electrically connected to the lookup table storage submodule; The reset submodule is used to output a reset signal to the lookup table storage submodule when it detects that the piezoelectric sensing unit is in a continuous unpressed state, so that the lookup table storage submodule clears the pressure value stored in its own register in response to receiving the reset signal.

[0013] In one optional implementation, the second processing module further includes a vibration driving submodule; the vibration driving submodule is electrically connected to the lookup table storage submodule and the subsequent circuit, respectively. The lookup and storage submodule is also used to send the acquired pressure values ​​to the vibration drive submodule in real time. The vibration drive submodule is used to generate different drive waveforms based on different pressure values, and output each drive waveform to the subsequent circuit in real time.

[0014] Secondly, embodiments of this application provide a pressure detection device, comprising: The piezoelectric sensing unit and the pressure detection circuit described in any of the first aspects above; The piezoelectric sensing unit is electrically connected to the signal conversion module in the pressure detection circuit; The piezoelectric sensing unit is used to convert the mechanical deformation generated by pressing into a corresponding charge signal based on the piezoelectric effect, so that the signal conversion module can collect the charge signal and convert the charge signal into an analog voltage signal.

[0015] In one optional embodiment, the pressure detection device further includes a substrate and a common electrode layer; The common electrode layer is disposed on the substrate, the piezoelectric thin film of the pressure detection device is disposed on the side of the common electrode layer away from the substrate, and the patterned electrode layer of the pressure detection device is disposed on the side of the piezoelectric thin film away from the substrate; The patterned electrode layer includes a driving electrode and N piezoelectric sensing electrode blocks; For each piezoelectric sensing electrode block, the piezoelectric sensing electrode block and the piezoelectric thin film in the target area together form a piezoelectric sensing unit, and the orthographic projection of the target area on the substrate coincides with the orthographic projection of the piezoelectric sensing electrode block on the substrate. The orthographic projection of each of the piezoelectric sensing electrode blocks onto the substrate is located in the peripheral region of the substrate, and the orthographic projection of the driving electrode onto the substrate is located in the central region of the substrate; Where N is an integer not less than 1.

[0016] In one optional embodiment, the substrate, the common electrode layer, the piezoelectric thin film, and the patterned electrode layer are combined to form a piezoelectric sensor; the piezoelectric sensing device further includes a support, a first adhesive layer, a printed circuit board, and a cover plate; The first adhesive layer is disposed on the support member, the piezoelectric sensor is disposed on the first adhesive layer on the side away from the support member, the printed circuit board is disposed on the piezoelectric sensor on the side away from the support member, and the cover plate is disposed on the printed circuit board on the side away from the support member.

[0017] In one optional embodiment, the substrate, the common electrode layer, the piezoelectric thin film, and the patterned electrode layer are combined to form a piezoelectric sensor; the piezoelectric sensing device further includes a support, a first adhesive layer, a second adhesive layer, a printed circuit board, and a cover plate; The first adhesive layer is disposed on the support member, the piezoelectric sensor is disposed on the first adhesive layer on the side away from the support member, the second adhesive layer is disposed on the piezoelectric sensor on the side away from the support member, the printed circuit board is disposed on the second adhesive layer on the side away from the support member, and the cover plate is disposed on the printed circuit board on the side away from the support member.

[0018] Beneficial effects: This application provides a pressure detection circuit and a pressure detection device. The pressure detection circuit includes a signal conversion module, a first processing module, and a second processing module. The first processing module is electrically connected to the signal conversion module, and the second processing module is electrically connected to the first processing module. The signal conversion module is used to collect a charge signal and convert the charge signal into an analog voltage signal, which is then output to the first processing module. The charge signal is a signal obtained by converting the mechanical deformation caused by pressure by a piezoelectric sensing unit based on the piezoelectric effect. The first processing module is used to output corresponding sensing feature information to the second processing module based on the analog voltage signal. The sensing feature information is at least one of an integration result and a peak digital signal. The integration result is the result of continuously sampling and integrating the digital signal corresponding to the analog voltage signal, and the peak digital signal is the digital signal corresponding to the peak pressure of the piezoelectric sensing unit when it is pressed. The second processing module is used to determine a static pressure value based on the sensing feature information and a preset correspondence. The preset correspondence is a correspondence between the sensing feature information and the static pressure value pre-set by the second processing module. By integrating continuously sampled digital signals to obtain an integration result, and determining the static pressure value based on the integration result and a preset correspondence, and / or by acquiring a peak digital signal and determining the static pressure value based on the peak digital signal and a preset correspondence, the static pressure can be detected. This achieves the integration of dynamic and static pressure detection of the piezoelectric sensor, improving the user's interactive experience.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the first structure of the pressure detection circuit proposed in the embodiments of this application; Figure 2 This is a schematic diagram of the second structure of the pressure detection circuit proposed in the embodiments of this application; Figure 3 This is a schematic diagram of the third structure of the pressure detection circuit proposed in the embodiments of this application; Figure 4 This is a schematic diagram of the fourth structure of the pressure detection circuit proposed in the embodiments of this application; Figure 5 This is a schematic diagram of the fifth structure of the pressure detection circuit proposed in the embodiments of this application; Figure 6 This is a schematic diagram of the sixth structure of the pressure detection circuit proposed in the embodiments of this application; Figure 7 This is a schematic diagram of the seventh structure of the pressure detection circuit proposed in the embodiments of this application; Figure 8 This is a schematic diagram of the eighth structure of the pressure detection circuit proposed in the embodiments of this application; Figure 9 This is a schematic diagram of the ninth structure of the pressure detection circuit proposed in the embodiments of this application; Figure 10 This is a schematic diagram of the tenth structure of the pressure detection circuit proposed in the embodiments of this application; Figure 11 This is a schematic diagram of the eleventh structure of the pressure detection circuit proposed in the embodiments of this application; Figure 12 This is a schematic diagram of the drive circuit of the pressure detection device proposed in the embodiments of this application; Figure 13 This is a schematic diagram of the first structure of the pressure detection device proposed in the embodiments of this application; Figure 14 This is a schematic diagram of a second structure of the pressure detection device proposed in the embodiments of this application; Figure 15 This is a top view schematic diagram of the graphic electrode layer of the pressure detection device proposed in the embodiments of this application; Figure 16 This is a schematic diagram of the third structure of the pressure detection device proposed in the embodiments of this application; Figure 17 This is a schematic diagram of the fourth structure of the pressure detection device proposed in the embodiments of this application. Explanation of reference numerals in the attached figures: 1. Pressure detection circuit; 11. Signal conversion module; 12. First processing module; 13. Second processing module; 111. Charge-to-voltage conversion submodule; 112. Signal amplification submodule; 121. Analog-to-digital conversion submodule; 122. Processing submodule; 123. First voltage holding submodule; 124. Second voltage holding submodule; 125. Peak detection submodule; 131. Look-up table storage submodule; 132. Reset submodule; 133. Vibration drive submodule; 2. Pressure detection device; 21. Piezoelectric sensor; 22. Support component; 23. First adhesive layer; 24. Printed circuit board; 25. Cover plate; 26. Second adhesive layer; 27. Drive circuit; 211. Substrate; 212. Common electrode layer; 213. Piezoelectric thin film; 214. Patterned electrode layer. Detailed Implementation

[0021] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0022] First, a brief explanation of the relevant technologies is as follows: Touchpads with pressure detection capabilities typically employ capacitive or resistive touch technologies to acquire touch sensing signals. However, capacitive touch technology suffers from drawbacks such as slow response and susceptibility to environmental influences, while resistive touch technology suffers from high power consumption. Furthermore, both types of touch structures are difficult to integrate seamlessly, resulting in a relatively large overall thickness, which is detrimental to the design of thinner and lighter devices.

[0023] To improve the above problems, some touchpads that support force sensing use strain gauges or piezoelectric sensors to collect signals, but they can only detect dynamic pressing signals and have difficulty detecting static pressure signals, which affects the user's interactive experience.

[0024] To address at least one of the aforementioned problems, embodiments of this application propose a pressure detection circuit. Figure 1 A schematic diagram of a first structure of the pressure detection circuit proposed in this application is shown, as follows: Figure 1 As shown, the pressure detection circuit 1 includes a signal conversion module 11, a first processing module 12, and a second processing module 13; the signal conversion module 11 is electrically connected to the piezoelectric sensing unit of the pressure detection device, the first processing module 12 is electrically connected to the signal conversion module 11, and the second processing module 13 is electrically connected to the first processing module 12.

[0025] The signal conversion module 11 is used to collect charge signals and convert the charge signals into analog voltage signals for output to the first processing module 12; wherein, the charge signal is a signal obtained by the piezoelectric sensing unit based on the piezoelectric effect to convert the mechanical deformation caused by pressing.

[0026] The first processing module 12 is used to output corresponding sensing feature information to the second processing module 13 based on the analog voltage signal; wherein, the sensing feature information is at least one of the integral result and the peak digital signal, the integral result is the result of continuous sampling and integration of the digital signal corresponding to the analog voltage signal, and the peak digital signal is the digital signal corresponding to the peak pressure when the piezoelectric sensing unit is pressed.

[0027] The second processing module 13 is used to determine the static pressure value based on the sensing feature information and the preset correspondence; wherein, the preset correspondence is the correspondence between the sensing feature information and the static pressure value pre-set by the second processing module 13.

[0028] In some alternative implementations, the signal conversion module 11 may include a charge-to-voltage conversion submodule, and the signal conversion module 11 may also include a charge-to-voltage conversion submodule and a signal amplification submodule. This application does not impose specific limitations on this.

[0029] Optionally, such as Figure 2 As shown, the signal conversion module 11 includes a charge-to-voltage conversion submodule 111 and a signal amplification submodule 112. The charge-to-voltage conversion submodule 111 is used to acquire the charge signal, convert the charge signal into a corresponding analog voltage signal, and transmit the analog voltage signal to the signal amplification submodule 112. The signal amplification submodule 112 is used to amplify the analog voltage signal and output it to the first processing module 12.

[0030] In some optional embodiments, the first processing module 12 may include an analog-to-digital conversion submodule 121 and a processing submodule 122. The first processing module 12 may also include a second voltage holding submodule 124 and a peak detection submodule 125. Alternatively, the first processing module 12 may include an analog-to-digital conversion submodule 121, a processing submodule 122, and a first voltage holding submodule 123. The first processing module 12 may also include an analog-to-digital conversion submodule 121, a processing submodule 122, a second voltage holding submodule 124, and a peak detection submodule 125. These embodiments will be described in detail below.

[0031] Correspondingly, the second processing module 13 can determine the static pressure value in any of the following ways: First, the second processing module 13 can determine the static pressure value based on the integration result and a preset correspondence; second, the second processing module 13 can determine the static pressure value based on the peak digital signal and a preset correspondence; third, the second processing module 13 can acquire both the integration result and the peak digital signal. In this case, the static pressure value can be determined based on either the integration result and the preset correspondence or the peak digital signal and the preset correspondence.

[0032] In some optional implementations, the preset correspondence can be a correspondence table, a correspondence curve, or other correspondence representations. This application does not impose specific limitations on this.

[0033] In this embodiment, static pressure is detected by integrating continuously sampled digital signals to obtain an integral result, determining the static pressure value based on the integral result and a preset correspondence, and / or by acquiring a peak digital signal and determining the static pressure value based on the peak digital signal and a preset correspondence. This achieves integrated detection of dynamic and static pressure by the piezoelectric sensor, enhancing the user's interactive experience. Compared to capacitive or resistive touch technologies used in related technologies, the pressure detection circuit 1 proposed in this embodiment has a faster and more stable response speed, lower power consumption, and a thinner overall design.

[0034] In one alternative implementation, such as Figure 3 As shown, the first processing module 12 includes an analog-to-digital conversion submodule 121 and a processing submodule 122. The analog-to-digital conversion submodule 121 is electrically connected to the signal conversion module 11, and the processing submodule 122 is electrically connected to the analog-to-digital conversion submodule 121. The second processing module 13 is electrically connected to the processing submodule 122. The analog-to-digital conversion submodule 121 is integrated with the signal conversion module 11, and the processing submodule 122 is integrated with the second processing module 13.

[0035] The analog-to-digital conversion submodule 121 is used to convert analog voltage signals into digital signals and output the digital signals to the processing submodule 122. The processing submodule 122 is used to perform time-domain integration processing on the continuously sampled digital signals in response to the received digital signals and send the integration result to the second processing module 13 in real time. The second processing module 13 is specifically used to determine the static pressure value based on the current integration result and a first preset correspondence when the processing submodule 122 detects that the pressed state of the piezoelectric sensing unit has terminated. The first preset correspondence is a correspondence between the integration value and the static pressure value preset by the second processing module 13.

[0036] It should be noted that the processing submodule 122 and the second processing module 13 are integrated on a single chip. This chip can be an MCU (Microcontroller Unit), an FPGA (Field Programmable Gate Array), or other types of processor chips. This application does not impose any specific restrictions on this.

[0037] It should be noted that the analog-to-digital conversion submodule 121 and the signal conversion module 11 are integrated on a single circuit board.

[0038] The processing submodule 122 continuously receives discrete sampled data output from the analog-to-digital conversion submodule 121 and can perform digital filtering on the discrete sampled data to filter out voltage fluctuations caused by circuit noise and electromagnetic interference, so as to obtain smooth and stable real-time sampled values. The processing submodule 122 can determine whether integration can be enabled based on the filtered sampled values. When it is determined that integration can be enabled, the historical integration cache results are cleared and initialized. After the integration function is enabled, the filtered real-time sampled values ​​are continuously periodically accumulated to obtain the real-time integration result. Specifically, in each sampling period, the current sampled value is superimposed on the total integration value to obtain the integration result, and the integration result is output to the second processing module 13 in real time.

[0039] The processing submodule 122 can determine the termination of integration based on the filtered sampled value. After the integration function is terminated, the second processing module 13 determines the static pressure value based on the current integration result and the first preset correspondence.

[0040] In some optional implementations, the first preset correspondence can be a correspondence table, a correspondence curve, or other correspondence representations. This application does not impose specific limitations on this.

[0041] In one optional implementation, during factory calibration, multiple levels of known standard constant static pressure are applied to the piezoelectric sensing unit, the total integral of the pressing corresponding to each level of static pressure is collected, a calibration curve of integral value-static pressure is fitted, and the curve is stored in the second processing module 13.

[0042] It should be noted that, based on the embodiment where the signal conversion module 11 includes a charge-to-voltage conversion submodule 111 and a signal amplification submodule 112, the signal transmission process is as follows: the charge-to-voltage conversion submodule 111 converts the charge signal into a corresponding analog voltage signal and transmits it to the signal amplification submodule 112. The signal amplification submodule 112 amplifies the analog voltage signal and outputs it to the analog-to-digital conversion submodule 121. The analog-to-digital conversion submodule 121 converts the amplified analog voltage signal into a digital signal and outputs it to the processing submodule 122.

[0043] In this embodiment, the static pressure value is determined by integrating the continuously sampled digital signal to obtain the integration result, and then determining the static pressure value based on the integration result and the first preset correspondence, thereby realizing the detection of static pressure and integrating the detection of dynamic and static pressure of the piezoelectric sensor, thus improving the user's interactive experience.

[0044] In one alternative implementation, such as Figure 4As shown, the first processing module 12 includes a first voltage holding submodule 123, an analog-to-digital conversion submodule 121, and a processing submodule 122; the analog-to-digital conversion submodule 121 is electrically connected to the signal conversion module 11, the processing submodule 122 is electrically connected to the analog-to-digital conversion submodule 121, and the second processing module 13 is electrically connected to the processing submodule 122; the first voltage holding submodule 123 is electrically connected to the signal conversion module 11, the second processing module 13, and the processing submodule 122 respectively; the first voltage holding submodule 123, the analog-to-digital conversion submodule 121, and the signal conversion module 11 are integrated, and the processing submodule 122 is integrated with the second processing module 13.

[0045] The analog-to-digital conversion submodule 121 is used to convert analog voltage signals into digital signals and output the digital signals to the processing submodule 122.

[0046] The processing submodule 122 is used to send a control signal to the first voltage holding submodule 123 based on the received digital signal in response to the digital signal; wherein the control signal is a signal that controls the start and stop of the voltage acquisition function of the first voltage holding submodule 123.

[0047] The first voltage holding submodule 123 is used to store the peak analog signal corresponding to the peak pressure when the piezoelectric sensing unit is pressed in response to the control signal output by the processing submodule 122, and convert the peak analog signal into a peak digital signal and output it to the second processing module 13.

[0048] The second processing module 13 is specifically used to read the peak digital signal corresponding to the peak analog signal, and determine the static pressure value based on the peak digital signal and the second preset correspondence; wherein, the second preset correspondence is the correspondence between the peak digital signal value and the static pressure value preset by the second processing module 13.

[0049] It should be noted that the processing submodule 122 and the second processing module 13 are integrated on a single chip, which can be an MCU, an FPGA, or other types of processor chip. This application does not impose any specific restrictions on this.

[0050] It should be noted that the first voltage holding submodule 123, the analog-to-digital conversion submodule 121, and the signal conversion module 11 are integrated on a single circuit board.

[0051] In an alternative implementation, the first voltage holding submodule 123 can store the peak analog signal by setting a storage capacitor.

[0052] In some optional implementations, the second preset correspondence can be a correspondence table, a correspondence curve, or other correspondence representations. This application does not impose any specific limitations on this.

[0053] In one optional implementation, during factory calibration, multiple known standard constant static pressures are applied to the piezoelectric sensing unit, digital sampling curves of the pressing process at each level are collected and peak sampling values ​​are extracted. A calibration curve between the peak digital signal value and the static pressure value is established as a second preset correspondence and stored in the second processing module 13.

[0054] It is understood that the embodiments of this application are implemented based on the human-defined peak digital signal corresponding to the static pressure of this press.

[0055] In this embodiment, the static pressure value is determined by acquiring the peak digital signal and the second preset correspondence, thereby realizing the detection of static pressure and integrating the detection of dynamic and static pressure of the piezoelectric sensor, thus improving the user's interactive experience.

[0056] In one alternative implementation, based on Figure 4 In a corresponding embodiment, the processing submodule 122 is further configured to perform time-domain integration processing on the continuously sampled digital signal and send the integration result to the second processing module 13 in real time; the second processing module 13 is further configured to determine the static pressure value based on the current integration result and the first preset correspondence when the processing submodule 122 detects that the pressed state of the piezoelectric sensing unit has terminated; wherein, the first preset correspondence is the correspondence between the integration value and the static pressure value preset by the second processing module 13.

[0057] The specific analysis is the same as above, and will not be repeated here.

[0058] In this embodiment, the second processing module 13 can choose to determine the static pressure value based on either the integration result and a first preset correspondence, or it can choose to determine the static pressure value based on the peak digital signal and a second preset correspondence. It can choose one of the two methods or execute both methods to obtain separately determined static pressure values, and then compare and select the appropriate value. This achieves the detection of static pressure, integrating the detection of dynamic and static pressure by the piezoelectric sensor, thus improving the user's interactive experience.

[0059] In one alternative implementation, such as Figure 5As shown, the first processing module 12 includes a second voltage holding submodule 124 and a peak detection submodule 125; the second voltage holding submodule 124 is electrically connected to the signal conversion module 11, the second processing module 13 is electrically connected to the second voltage holding submodule 124, the peak detection submodule 125 is electrically connected to the signal conversion module 11, and the second processing module 13 is electrically connected to the peak detection submodule 125; the second voltage holding submodule 124, the peak detection submodule 125, and the signal conversion module 11 are integrated into one unit.

[0060] The second voltage holding submodule 124 is used to store the peak analog signal corresponding to the peak pressure when the piezoelectric sensing unit is pressed, in response to the control signal output by the second processing module 13, and convert the peak analog signal into a peak digital signal and output it to the second processing module 13; the peak detection submodule 125 is used to detect the occurrence of the peak analog signal corresponding to the peak pressure when the piezoelectric sensing unit is pressed, and output a pulse signal to the second processing module 13 when the peak analog signal is detected, so that the second processing module 13 reads the peak digital signal corresponding to the peak analog signal in response to the pulse signal; the second processing module 13 is specifically used to determine the static pressure value based on the peak digital signal and a third preset correspondence; wherein, the third preset correspondence is a correspondence between the peak digital signal value and the static pressure value preset by the second processing module 13.

[0061] It should be noted that the second voltage holding submodule 124, the peak detection submodule 125, and the signal conversion module 11 are integrated on a single circuit board.

[0062] In one alternative implementation, the second voltage holding submodule 124 can store the peak analog signal by setting a storage capacitor.

[0063] In one alternative implementation, the peak detection submodule 125 can detect the occurrence of a peak analog signal by setting a delay buffer and a comparator to compare the delayed analog voltage signal with the original analog voltage signal.

[0064] In some optional implementations, the third preset correspondence can be a correspondence table, a correspondence curve, or other correspondence representations. This application does not impose specific limitations on this.

[0065] In one optional implementation, during factory calibration, multiple known standard constant static pressures are applied to the piezoelectric sensing unit, digital sampling curves of the pressing process at each level are collected and peak sampling values ​​are extracted. A calibration curve between the peak digital signal value and the static pressure value is established as a third preset correspondence and stored in the second processing module 13.

[0066] It is understood that the embodiments of this application are implemented based on the human-defined peak digital signal corresponding to the static pressure of this press.

[0067] In this embodiment, the static pressure value is determined by acquiring the peak digital signal and the third preset correspondence, thereby realizing the detection of static pressure and integrating the detection of dynamic and static pressure of the piezoelectric sensor, thus improving the user's interactive experience.

[0068] In one alternative implementation, such as Figure 6 As shown, based on Figure 5 In a corresponding embodiment, the first processing module 12 further includes an analog-to-digital conversion submodule 121 and a processing submodule 122; the analog-to-digital conversion submodule 121 is electrically connected to the signal conversion module 11, the processing submodule 122 is electrically connected to the analog-to-digital conversion submodule 121, and the second processing module 13 is electrically connected to the processing submodule 122; the analog-to-digital conversion submodule 121, the second voltage holding submodule 124, the peak detection submodule 125, and the signal conversion module 11 are integrated, and the processing submodule 122 is integrated with the second processing module 13.

[0069] The analog-to-digital conversion submodule 121 is used to convert analog voltage signals into digital signals and output the digital signals to the processing submodule 122. The processing submodule 122 is used to perform time-domain integration processing on the continuously sampled digital signals in response to the received digital signals and send the integration result to the second processing module 13 in real time. The second processing module 13 is also used to determine the static pressure value based on the current integration result and a first preset correspondence when the processing submodule 122 detects that the pressed state of the piezoelectric sensing unit has terminated. The first preset correspondence is a correspondence between the integration value and the static pressure value preset by the second processing module 13.

[0070] The specific analysis is the same as above, and will not be repeated here.

[0071] It should be noted that the processing submodule 122 and the second processing module 13 are integrated on a single chip, which can be an MCU, an FPGA, or other types of processor chip. This application does not impose any specific restrictions on this.

[0072] It should be noted that the analog-to-digital conversion submodule 121, the second voltage holding submodule 124, the peak detection submodule 125, and the signal conversion module 11 are integrated on a single circuit board.

[0073] In this embodiment, the second processing module 13 can choose to determine the static pressure value based on either the integration result and a first preset correspondence, or it can choose to determine the static pressure value based on the peak digital signal and a third preset correspondence. It can choose one of the two methods or execute both methods to obtain separately determined static pressure values, and then compare and select the appropriate value. This achieves the detection of static pressure, integrating the detection of dynamic and static pressure by the piezoelectric sensor, thus improving the user's interactive experience.

[0074] In one alternative implementation, such as Figure 7 As shown, the second processing module 13 includes a lookup table storage submodule 131; the lookup table storage submodule 131 is electrically connected to the processing submodule 122.

[0075] The processing submodule 122 is specifically used to respond to the received digital signal, and when the digital signal is detected to be greater than a first preset threshold and the duration of the digital signal being greater than the first preset threshold reaches a first preset duration, to perform time-domain integration processing on the continuously sampled digital signal and send the integration result to the lookup table storage submodule 131 in real time.

[0076] The lookup and storage submodule 131 is used to determine the current pressure value of the piezoelectric sensing unit based on the current integration result and the first preset correspondence, store the current pressure value in its own register, and update the pressure value stored in the register by overwriting the old pressure value when the next new pressure value is obtained.

[0077] The processing submodule 122 is specifically used to terminate the time-domain integration processing and send a termination signal to the lookup table storage submodule 131 when it detects that the digital signal is less than the second preset threshold and the duration of the digital signal being less than the second preset threshold reaches the second preset duration.

[0078] The lookup table storage submodule 131 is also used to respond to the received termination signal, terminate the update of the pressure value stored in its own register, and determine that the pressure value stored in the register after the termination of the update is the static pressure value.

[0079] The processing submodule 122 continuously receives discrete sampled data output from the analog-to-digital conversion submodule 121 and performs digital filtering on the discrete sampled data to obtain smooth and stable real-time sampled values. When the sampled value is detected to be greater than a first preset threshold and the duration of the sampled value being greater than the first preset threshold reaches a first preset duration, the integration function is started. At the same time, the historical integration cache results are cleared and initialized. After the integration function is started, the filtered real-time sampled values ​​are continuously periodically accumulated to obtain the real-time integration result. Specifically, in each sampling period, the current sampled value is superimposed on the total integration value to obtain the integration result, and the integration result is output to the lookup table storage submodule 131 in real time.

[0080] The lookup and storage submodule 131 determines the current pressure value corresponding to the piezoelectric sensing unit based on the current integration result and the first preset correspondence, stores the current pressure value in its own register, and updates the pressure value stored in the register by overwriting the old pressure value when the next new pressure value is obtained.

[0081] When the processing submodule 122 detects that the sampled value is less than the second preset threshold and the duration of the sampled value being less than the second preset threshold reaches the second preset duration, it terminates the time-domain integration processing and sends a termination signal to the lookup table storage submodule 131.

[0082] In response to receiving a termination signal, the lookup storage submodule 131 terminates the update of the pressure value stored in its own register and determines that the pressure value stored in the register after the termination of the update is the static pressure value.

[0083] Understandably, when the sampled value is greater than the first preset threshold and the duration reaches the first preset duration, the integration function is activated to filter out brief interferences such as light touches and instantaneous taps, ensuring that the effective continuous pressing state is entered. When the sampled value is less than the second preset threshold and the duration reaches the second preset duration, the integration function is terminated to filter out instantaneous signal drop interference caused by hand tremors during the pressing process, thereby improving the accuracy of determining the termination of the pressing action.

[0084] It is understandable that the first preset threshold, the first preset duration, the second preset threshold, and the second preset duration can be set based on empirical values ​​obtained from multiple tests.

[0085] In this embodiment, by continuously integrating and accumulating the digital signal within the integration start-to-end interval, the signal attenuation problem caused by charge leakage of the piezoelectric sensing unit can be reduced, and the accuracy of static pressure detection in long-press scenarios can be improved.

[0086] In one alternative implementation, such as Figure 8As shown, the charge-to-voltage conversion submodule 111 includes a first operational amplifier, a feedback capacitor, a bleeder resistor, a first resistor, a second resistor, a third resistor, and a first capacitor; the signal amplification submodule 112 includes a second operational amplifier, a fourth resistor, a fifth resistor, and a second capacitor; and the analog-to-digital conversion submodule 121 includes a third analog-to-digital converter.

[0087] The first end of the first resistor is electrically connected to the piezoelectric sensing unit, the second end of the first resistor is electrically connected to the first end of the first capacitor, the second end of the first capacitor is electrically connected to the inverting input terminal of the first operational amplifier, the first end of the bleed resistor, and the first end of the feedback capacitor, respectively, the non-inverting input terminal of the first operational amplifier is electrically connected to the second end of the second resistor and the first end of the third resistor, the first end of the second resistor is electrically connected to the power supply voltage terminal, and the second end of the third resistor is electrically connected to the ground potential.

[0088] The positive terminal of the power supply of the first operational amplifier is electrically connected to the power supply voltage terminal, the negative terminal of the power supply of the first operational amplifier is electrically connected to the ground potential, and the output terminal of the first operational amplifier is electrically connected to the second terminal of the bleed resistor, the second terminal of the feedback capacitor, and the non-inverting input terminal of the second operational amplifier.

[0089] The inverting input terminal of the second operational amplifier is electrically connected to the first terminal of the fourth resistor and the first terminal of the fifth resistor, respectively. The positive terminal of the power supply of the second operational amplifier is electrically connected to the power supply voltage terminal, and the negative terminal of the power supply of the second operational amplifier is electrically connected to the ground potential. The output terminal of the second operational amplifier is electrically connected to the second terminal of the fourth resistor and the input terminal of the third analog-to-digital converter, respectively. The output terminal of the third analog-to-digital converter is electrically connected to the processing submodule 122.

[0090] The second end of the fifth resistor is electrically connected to the first end of the second capacitor, and the second end of the second capacitor is electrically connected to ground potential.

[0091] Specifically, the charge-to-voltage conversion submodule 111 is used to acquire the charge signal generated by the piezoelectric sensing unit when it is pressed, and convert it into a corresponding analog voltage signal. The second and third resistors are used to generate a bias voltage for subsequent processing, while the first resistor and first capacitor act as DC blocking and filtering components. The output voltage of the feedback capacitor is inversely proportional to its capacitance value.

[0092] The signal amplification submodule 112 is used to amplify the analog voltage signal to match the subsequent third analog-to-digital converter. The fifth resistor and the second capacitor form a low-pass filter, and the fifth resistor and the fourth resistor form a forward amplifier circuit with a gain of (R4+R5) / R4, where R4 is the resistance value of the fourth resistor and R5 is the resistance value of the fifth resistor.

[0093] The third analog-to-digital converter is used to convert the amplified analog voltage signal into a digital signal and output it to the processing submodule 122.

[0094] In this embodiment of the application, by setting up a charge-to-voltage conversion submodule 111, a signal amplification submodule 112, and an analog-to-digital conversion submodule 121, the charge signal generated by the piezoelectric sensing unit is converted into a digital signal that can be recognized by the processor.

[0095] In one alternative implementation, such as Figure 9 As shown, the first voltage holding submodule 123 includes a first voltage follower, a first switch, a second switch, a first storage capacitor, a second voltage follower, and a first analog-to-digital converter.

[0096] The non-inverting input of the first voltage follower is electrically connected to the signal conversion module 11. The output of the first voltage follower is electrically connected to the first terminal of the first switch and its own inverting input. The control terminal of the first switch is electrically connected to the processing submodule 122. The second terminal of the first switch is electrically connected to the first terminal of the second switch, the first terminal of the first storage capacitor, and the non-inverting input of the second voltage follower. The output of the second voltage follower is electrically connected to the input of the first analog-to-digital converter and its own inverting input. The output of the first analog-to-digital converter is electrically connected to the second processing module 13. The second terminal of the second switch is electrically connected to the second terminal of the first storage capacitor and ground potential. The control terminal of the second switch is electrically connected to the processing submodule 122 and the second processing module 13.

[0097] The analog-to-digital conversion submodule 121 is electrically connected to the signal conversion module 11, the processing submodule 122 is electrically connected to the analog-to-digital conversion submodule 121, and the second processing module 13 is electrically connected to the processing submodule 122.

[0098] The first voltage follower is an operational amplifier that performs voltage following. It is used to isolate the analog voltage signal output by the signal conversion module 11 and then send it to the first switch. The amplification factor of the first voltage follower is 1, that is, the signal is copied and output as is. The key is to isolate the load and protect the front-end signal from loss.

[0099] The second voltage follower is an operational amplifier that performs voltage following functions. It is used to isolate the analog voltage signal on the first storage capacitor and then send it to the first analog-to-digital converter.

[0100] The first analog-to-digital converter is used to acquire the analog voltage signal on the first storage capacitor and convert it into a corresponding digital signal, which is then output to the second processing module 13.

[0101] The specific working principle is as follows: Initially, the first switch is in the off state, the second switch is in the on state, and the voltage value of the voltage signal on the first storage capacitor is 0. When the processing submodule 122 detects that the digital signal is greater than the set threshold and the duration of the digital signal being greater than the set threshold reaches the set duration (which can filter out short-term interference signals such as instantaneous touch), it sends a control signal to control the first switch to be in the on state and the second switch to be in the off state, starts the voltage acquisition function, and charges the first storage capacitor with the simulated voltage signal. The voltage on the first storage capacitor is input to the first analog-to-digital converter through the second voltage follower. The second processing module 13 can read the real-time voltage on the first storage capacitor through the first analog-to-digital converter.

[0102] After the processing submodule 122 detects the appearance of the peak digital signal, it sends a control signal to control the first switch to be in the off state, terminates the voltage acquisition function, and the voltage on the first storage capacitor no longer changes. At this time, the second processing module 13 can read the peak digital signal at any time through the first analog-to-digital converter, determine the static pressure value based on the peak digital signal and the second preset correspondence, and store the static pressure value in its own register.

[0103] The reset module of the second processing module 13 can be used to continuously monitor the touch signal. When it is detected that the piezoelectric sensing unit is in an idle continuous state without being pressed, a control signal is sent to control the second switch to be in the conducting state, discharge the first storage capacitor, clear the peak analog signal on the first storage capacitor, and clear the static pressure value in the register at the same time.

[0104] The processing submodule 122 is used to detect the occurrence of peak digital signals. In an optional embodiment, the processing submodule 122 can determine the occurrence of a peak digital signal by comparing adjacent digital signals in real time, thereby determining the occurrence of a pressure peak.

[0105] In this embodiment, the peak analog signal is stored by the first storage capacitor and converted into a peak digital signal by the first analog-to-digital converter, so that the second processing module 13 determines the static pressure value based on the peak digital signal and the second preset correspondence, thereby realizing the detection of static pressure and integrating the detection of dynamic and static pressure of the piezoelectric sensor, thus improving the user's interactive experience.

[0106] In one alternative implementation, such as Figure 10 As shown, the second voltage holding submodule 124 includes a voltage follower, a diode, a switch, a second storage capacitor, and a second analog-to-digital converter, while the peak detection submodule 125 includes a delay buffer, a comparator, and a pulse generator.

[0107] The non-inverting input of the voltage follower is electrically connected to the signal conversion module 11. The output of the voltage follower is electrically connected to the anode of the diode and its own inverting input. The cathode of the diode is electrically connected to the first terminal of the switch, the first terminal of the second storage capacitor, and the input of the second analog-to-digital converter. The output of the second analog-to-digital converter is electrically connected to the second processing module 13. The second terminal of the switch is electrically connected to the second terminal of the second storage capacitor and ground potential. The control terminal of the switch is electrically connected to the second processing module 13.

[0108] The input terminal of the delay buffer is electrically connected to the signal conversion module 11 and the non-inverting input terminal of the comparator, respectively. The output terminal of the delay buffer is electrically connected to the inverting input terminal of the comparator. The output terminal of the comparator is electrically connected to the trigger input terminal of the pulse generator. The pulse output terminal of the pulse generator is electrically connected to the second processing module 13.

[0109] The voltage follower is an operational amplifier that performs voltage following. It is used to isolate the analog voltage signal output by the signal conversion module 11 and send it to the diode. The diode is unidirectional and is used to immediately reverse-cut off when the analog voltage signal begins to fall back and is lower than the storage voltage on the second storage capacitor, so as to prevent the charge in the second storage capacitor from flowing back and to prevent the peak analog signal from being discharged. The second storage capacitor is used to store the analog voltage signal. The second analog-to-digital converter is used to acquire the analog voltage signal on the second storage capacitor and convert it into the corresponding digital signal.

[0110] The delay buffer is used to delay the analog voltage signal for a period of time. The comparator is used to compare the original analog voltage signal and the delayed analog voltage signal to determine the occurrence of the peak analog signal. The pulse generator is used to generate a pulse signal when the level of the trigger input is detected to be reversed.

[0111] The specific working principle is as follows: Initially, the switch is in the ON state, and the voltage signal on the second storage capacitor is 0. Assuming the pressure curve starts to rise, the comparator output is positive. When the piezoelectric sensing unit enters the pressed state, the comparator output is positive, the pulse generator has no output, and the second processing module 13 sends a control signal to control the switch to the OFF state, charging the second storage capacitor with an analog voltage signal. When the pressure curve reaches its peak, the comparator output reverses, becoming negative. At this time, the pulse generator outputs a pulse signal. After detecting the pulse signal, the second processing module 13 reads the peak digital signal through the second analog-to-digital converter. Based on the peak digital signal and the third preset correspondence, it determines the static pressure value and stores it in its register. When the piezoelectric sensing unit leaves the pressed state, the pressure curve generates a reverse peak, the comparator output reverses again, and the pulse generator generates a pulse signal again. After detecting this pulse signal, the second processing module 13 clears the static pressure value in the register and simultaneously controls the switch to turn on, clearing the peak analog signal on the second storage capacitor.

[0112] In this embodiment, the peak analog signal is stored in a second storage capacitor and converted into a peak digital signal by a second analog-to-digital converter. This allows the second processing module 13 to determine the static pressure value based on the peak digital signal and a third preset correspondence, thus achieving static pressure detection. This integrates the detection of dynamic and static pressure by the piezoelectric sensor, enhancing the user's interactive experience. In this embodiment, the peak detection submodule 125 detects the appearance of the peak analog signal, causing the second processing module 13 to read the peak digital signal in response to a pulse signal. Compared to... Figure 10 In the corresponding embodiment, the computing resources of the second processing module 13 can be saved and the response speed is faster.

[0113] In one alternative implementation, such as Figure 11 As shown, the second processing module 13 also includes a reset submodule 132; the reset submodule 132 is electrically connected to the lookup table storage submodule 131; the reset submodule 132 is used to output a reset signal to the lookup table storage submodule 131 when it detects that the piezoelectric sensing unit is in a continuous state of not being pressed, so that the lookup table storage submodule 131 clears the pressure value stored in its own register in response to receiving the reset signal.

[0114] It should be noted that when the processing submodule 122 detects that the piezoelectric sensing unit has stopped being pressed, the second processing module 13 determines the static pressure value based on the current integration result and the first preset correspondence. This value is the moment when the pressing action is terminated. When the reset submodule 132 detects that the piezoelectric sensing unit is in a continuous state of not being pressed, it outputs a reset signal to the lookup table storage submodule 131. This value is the result of the complete end of the recognition interaction and the unit being in a continuous state of not being pressed.

[0115] In this embodiment of the application, the register is cleared by setting a reset submodule 132 to reset and wait for the next pressing action.

[0116] In one alternative implementation, such as Figure 11 As shown, the second processing module 13 also includes a vibration drive submodule 133; the vibration drive submodule 133 is electrically connected to the lookup table storage submodule 131 and the subsequent circuit respectively; the lookup table storage submodule 131 is also used to send the acquired pressure values ​​to the vibration drive submodule 133 in real time; the vibration drive submodule 133 is used to generate different drive waveforms based on different pressure values ​​and output each drive waveform to the subsequent circuit in real time.

[0117] In one alternative implementation, the subsequent circuit is: Figure 12 The driving circuit 27 shown is used to amplify the driving waveform. The driving circuit 27 includes a sixth resistor, a seventh resistor, and a third operational amplifier. The non-inverting input terminal of the third operational amplifier is electrically connected to the vibration driving submodule 133. The inverting input terminal of the third operational amplifier is electrically connected to the second terminal of the sixth resistor and the first terminal of the seventh resistor, respectively. The positive terminal of the power supply of the third operational amplifier is electrically connected to the power supply voltage terminal. The negative terminal of the power supply of the third operational amplifier is electrically connected to the ground potential. The output terminal of the third operational amplifier is electrically connected to the second terminal of the seventh resistor and the driving electrode of the piezoelectric sensor, respectively. The first terminal of the sixth resistor is electrically connected to the ground potential.

[0118] The driving waveform is input from the non-inverting input of the third operational amplifier, amplified by the sixth and seventh resistors, and then sent to the output of the third operational amplifier. The amplification factor is (R6+R7) / R6, where R6 is the resistance value of the sixth resistor and R7 is the resistance value of the seventh resistor.

[0119] In this embodiment, by setting a vibration drive submodule 133, different drive waveforms are generated according to different pressure values, and each drive waveform is transmitted to the drive circuit 27 in real time so that the drive circuit 27 drives the corresponding electrode to produce different vibration effects.

[0120] This application also proposes a pressure detection device 2, such as Figure 13As shown, it includes a piezoelectric sensing unit and a pressure detection circuit 1 as described in any of the above embodiments; the piezoelectric sensing unit is electrically connected to the signal conversion module 11 in the pressure detection circuit 1; the piezoelectric sensing unit is used to convert the mechanical deformation generated by pressing into a corresponding charge signal based on the piezoelectric effect, so that the signal conversion module 11 can collect the charge signal and convert the charge signal into an analog voltage signal.

[0121] In one alternative implementation, such as Figure 14 As shown, the pressure detection device 2 also includes a substrate 211 and a common electrode layer 212; the common electrode layer 212 is disposed on the substrate 211, the piezoelectric thin film 213 of the pressure detection device 2 is disposed on the side of the common electrode layer 212 away from the substrate 211, and the patterned electrode layer 214 of the pressure detection device 2 is disposed on the side of the piezoelectric thin film 213 away from the substrate 211.

[0122] The patterned electrode layer 214 includes a driving electrode and N piezoelectric sensing electrode blocks, where N is an integer not less than 1. (See also...) Figure 15 ( Figure 15 (Taking N=4 as an example for illustration) The patterned electrode layer 214 is also provided with a lead area, which is used to electrically connect the driving electrode and the piezoelectric sensing electrode block to the driving circuit 27 of the pressure detection circuit 1 and the pressure detection device 2 by means of wiring. The position of the lead area can be adjusted according to the actual situation of the product. Optionally, the lead area can be located at the edge of the patterned electrode layer 214.

[0123] For each piezoelectric sensing electrode block, the piezoelectric sensing electrode block and the piezoelectric thin film 213 in the target area together form a piezoelectric sensing unit, and the orthographic projection of the target area on the substrate 211 coincides with the orthographic projection of the piezoelectric sensing electrode block on the substrate 211.

[0124] In some alternative embodiments, the orthographic projection of the piezoelectric sensing electrode block on the substrate 211 can be located in the peripheral region of the substrate 211, or the orthographic projection of the piezoelectric sensing electrode block on the substrate 211 can be located in the central region of the substrate 211.

[0125] Optionally, the orthographic projection of each piezoelectric sensing electrode block on the substrate 211 is located in the peripheral region of the substrate 211 to facilitate wire laying, while the orthographic projection of the driving electrode on the substrate 211 is located in the central region of the substrate 211.

[0126] In one alternative implementation, such as Figure 16 As shown, the substrate 211, the common electrode layer 212, the piezoelectric thin film 213, and the patterned electrode layer 214 are combined to form the piezoelectric sensor 21; the piezoelectric sensing device 2 also includes a support member 22, a first adhesive layer 23, a printed circuit board 24, and a cover plate 25.

[0127] The first adhesive layer 23 is disposed on the support member 22, the piezoelectric sensor 21 is disposed on the side of the first adhesive layer 23 away from the support member 22, the printed circuit board 24 is disposed on the side of the piezoelectric sensor 21 away from the support member 22, and the cover plate 25 is disposed on the side of the printed circuit board 24 away from the support member 22.

[0128] The cover plate 25 can be made of Mylar film or glass; the printed circuit board 24 is used to realize the traditional touch function; the piezoelectric sensor 21 is used to realize the piezoelectric sensing and vibration function; the first adhesive layer 23 is used to connect the piezoelectric sensor 21 and the support 22, while ensuring that the vibration is not attenuated; the support 22 can be made of stainless steel.

[0129] In one alternative implementation, such as Figure 17 As shown, the substrate 211, the common electrode layer 212, the piezoelectric thin film 213, and the patterned electrode layer 214 are combined to form the piezoelectric sensor 21; the piezoelectric sensing device 2 also includes a support member 22, a first adhesive layer 23, a second adhesive layer 26, a printed circuit board 24, and a cover plate 25.

[0130] The first adhesive layer 23 is disposed on the support member 22, the piezoelectric sensor 21 is disposed on the side of the first adhesive layer 23 away from the support member 22, the second adhesive layer 26 is disposed on the side of the piezoelectric sensor 21 away from the support member 22, the printed circuit board 24 is disposed on the side of the second adhesive layer 26 away from the support member 22, and the cover plate 25 is disposed on the side of the printed circuit board 24 away from the support member 22.

[0131] By providing a second adhesive layer 26 between the piezoelectric sensor 21 and the printed circuit board 24, the vibration uniformity is improved.

[0132] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0133] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application 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 this application.

[0134] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0135] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," 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 expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0136] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A pressure detection circuit, characterized in that, include: The system includes a signal conversion module, a first processing module, and a second processing module; the first processing module is electrically connected to the signal conversion module, and the second processing module is electrically connected to the first processing module. The signal conversion module is used to acquire charge signals and convert the charge signals into analog voltage signals, which are then output to the first processing module. The charge signals are obtained by the piezoelectric sensing unit based on the piezoelectric effect, converting the mechanical deformation caused by pressure. The first processing module is used to output corresponding sensing feature information to the second processing module based on the analog voltage signal; wherein, the sensing feature information is at least one of an integration result and a peak digital signal, the integration result is the result of continuous sampling and integration of the digital signal corresponding to the analog voltage signal, and the peak digital signal is the digital signal corresponding to the peak pressure when the piezoelectric sensing unit is pressed; The second processing module is used to determine the static pressure value based on the sensing feature information and the preset correspondence; wherein the preset correspondence is a correspondence between the sensing feature information and the static pressure value pre-set by the second processing module.

2. The pressure detection circuit according to claim 1, characterized in that, The first processing module includes an analog-to-digital conversion submodule and a processing submodule. The analog-to-digital conversion submodule is electrically connected to the signal conversion module, and the processing submodule is electrically connected to the analog-to-digital conversion submodule. The second processing module is electrically connected to the processing submodule. The analog-to-digital conversion submodule and the signal conversion module are integrated, and the processing submodule and the second processing module are integrated. The analog-to-digital conversion submodule is used to convert the analog voltage signal into a digital signal and output the digital signal to the processing submodule; The processing submodule is configured to, in response to receiving the digital signal, perform time-domain integration on the continuously sampled digital signal and send the integration result to the second processing module in real time. The second processing module is specifically used to determine the static pressure value based on the current integration result and a first preset correspondence when the processing submodule detects that the pressed state of the piezoelectric sensing unit has terminated; wherein, the first preset correspondence is a correspondence between the integration value and the static pressure value preset by the second processing module.

3. The pressure detection circuit according to claim 1, characterized in that, The first processing module includes a first voltage holding submodule, an analog-to-digital conversion submodule, and a processing submodule; the analog-to-digital conversion submodule is electrically connected to the signal conversion module, the processing submodule is electrically connected to the analog-to-digital conversion submodule, and the second processing module is electrically connected to the processing submodule; the first voltage holding submodule is electrically connected to the signal conversion module, the second processing module, and the processing submodule; the first voltage holding submodule, the analog-to-digital conversion submodule, and the signal conversion module are integrated, and the processing submodule is integrated with the second processing module; The analog-to-digital conversion submodule is used to convert the analog voltage signal into a digital signal and output the digital signal to the processing submodule; The processing submodule is configured to, in response to receiving the digital signal, send a control signal to the first voltage holding submodule based on the digital signal; wherein the control signal is a signal that controls the start and stop of the voltage acquisition function of the first voltage holding submodule; The first voltage holding submodule is used to store the peak analog signal corresponding to the peak pressure when the piezoelectric sensing unit is pressed in response to the control signal output by the processing submodule, and convert the peak analog signal into a peak digital signal and output it to the second processing module. The second processing module is specifically used to read the peak digital signal corresponding to the peak analog signal, and determine the static pressure value based on the peak digital signal and the second preset correspondence; wherein, the second preset correspondence is a correspondence between the peak digital signal value and the static pressure value preset by the second processing module.

4. The pressure detection circuit according to claim 1, characterized in that, The first processing module includes a second voltage holding submodule and a peak detection submodule; the second voltage holding submodule is electrically connected to the signal conversion module, the second processing module is electrically connected to the second voltage holding submodule, the peak detection submodule is electrically connected to the signal conversion module, and the second processing module is electrically connected to the peak detection submodule; the second voltage holding submodule, the peak detection submodule, and the signal conversion module are integrated into one unit. The second voltage holding submodule is used to store the peak analog signal corresponding to the peak pressure when the piezoelectric sensing unit is pressed in response to the control signal output by the second processing module, and convert the peak analog signal into a peak digital signal and output it to the second processing module. The peak detection submodule is used to detect the occurrence of the peak analog signal corresponding to the peak pressure when the piezoelectric sensing unit is pressed. When the peak analog signal is detected, a pulse signal is output to the second processing module so that the second processing module reads the peak digital signal corresponding to the peak analog signal in response to the pulse signal. The second processing module is specifically used to determine the static pressure value based on the peak digital signal and the third preset correspondence; wherein, the third preset correspondence is a correspondence between the peak digital signal value and the static pressure value preset by the second processing module.

5. The pressure detection circuit according to claim 2, characterized in that, The second processing module includes a lookup and storage submodule; the lookup and storage submodule is electrically connected to the processing submodule. The processing submodule is specifically used to respond to receiving the digital signal, and when the digital signal is detected to be greater than a first preset threshold and the duration of the digital signal being greater than the first preset threshold reaches a first preset duration, to perform time-domain integration processing on the continuously sampled digital signal and send the integration result to the lookup storage submodule in real time. The lookup and storage submodule is used to determine the pressure value corresponding to the piezoelectric sensing unit based on the current integration result and the first preset correspondence, store the current pressure value in its own register, and update the pressure value stored in the register by overwriting the old pressure value when the next new pressure value is obtained. The processing submodule is specifically used to terminate the time-domain integration process and send a termination signal to the lookup storage submodule when it detects that the digital signal is less than the second preset threshold and the duration of the digital signal being less than the second preset threshold reaches the second preset duration. The lookup storage submodule is also used to respond to the termination signal, terminate the update of the pressure value stored in its own register, and determine that the pressure value stored in the register after the termination of the update is a static pressure value.

6. The pressure detection circuit according to claim 3, characterized in that, The first voltage holding submodule includes a first voltage follower, a first switch, a second switch, a first storage capacitor, a second voltage follower, and a first analog-to-digital converter; The non-inverting input terminal of the first voltage follower is electrically connected to the signal conversion module. The output terminal of the first voltage follower is electrically connected to the first terminal of the first switch and its own inverting input terminal. The control terminal of the first switch is electrically connected to the processing submodule. The second terminal of the first switch is electrically connected to the first terminal of the second switch, the first terminal of the first storage capacitor, and the non-inverting input terminal of the second voltage follower. The output terminal of the second voltage follower is electrically connected to the input terminal of the first analog-to-digital converter and its own inverting input terminal. The output terminal of the first analog-to-digital converter is electrically connected to the second processing module. The second terminal of the second switch is electrically connected to the second terminal of the first storage capacitor and ground potential, respectively; the control terminal of the second switch is electrically connected to the processing submodule and the second processing module, respectively.

7. The pressure detection circuit according to claim 4, characterized in that, The second voltage holding submodule includes a voltage follower, a diode, a switch, a second storage capacitor, and a second analog-to-digital converter; the peak detection submodule includes a delay buffer, a comparator, and a pulse generator. The non-inverting input terminal of the voltage follower is electrically connected to the signal conversion module. The output terminal of the voltage follower is electrically connected to the anode of the diode and its own inverting input terminal. The cathode of the diode is electrically connected to the first terminal of the switch, the first terminal of the second storage capacitor, and the input terminal of the second analog-to-digital converter. The output terminal of the second analog-to-digital converter is electrically connected to the second processing module. The second terminal of the switch is electrically connected to the second terminal of the second storage capacitor and ground potential, respectively; the control terminal of the switch is electrically connected to the second processing module. The input terminal of the delay buffer is electrically connected to the signal conversion module and the non-inverting input terminal of the comparator, respectively. The output terminal of the delay buffer is electrically connected to the inverting input terminal of the comparator. The output terminal of the comparator is electrically connected to the trigger input terminal of the pulse generator. The pulse output terminal of the pulse generator is electrically connected to the second processing module.

8. The pressure detection circuit according to claim 5, characterized in that, The second processing module further includes a reset submodule; the reset submodule is electrically connected to the lookup table storage submodule; The reset submodule is used to output a reset signal to the lookup table storage submodule when it detects that the piezoelectric sensing unit is in a continuous unpressed state, so that the lookup table storage submodule clears the pressure value stored in its own register in response to receiving the reset signal.

9. The pressure detection circuit according to claim 5, characterized in that, The second processing module further includes a vibration drive submodule; the vibration drive submodule is electrically connected to the lookup table storage submodule and the subsequent circuit. The lookup and storage submodule is also used to send the acquired pressure values ​​to the vibration drive submodule in real time. The vibration drive submodule is used to generate different drive waveforms based on different pressure values, and output each drive waveform to the subsequent circuit in real time.

10. A pressure detection device, characterized in that, include: The piezoelectric sensing unit and the pressure detection circuit according to any one of claims 1-9 above; The piezoelectric sensing unit is electrically connected to the signal conversion module in the pressure detection circuit; The piezoelectric sensing unit is used to convert the mechanical deformation generated by pressing into a corresponding charge signal based on the piezoelectric effect, so that the signal conversion module can collect the charge signal and convert the charge signal into an analog voltage signal.

11. The pressure detection device according to claim 10, characterized in that, The pressure detection device also includes a substrate and a common electrode layer; The common electrode layer is disposed on the substrate, the piezoelectric thin film of the pressure detection device is disposed on the side of the common electrode layer away from the substrate, and the patterned electrode layer of the pressure detection device is disposed on the side of the piezoelectric thin film away from the substrate; The patterned electrode layer includes a driving electrode and N piezoelectric sensing electrode blocks; For each piezoelectric sensing electrode block, the piezoelectric sensing electrode block and the piezoelectric thin film in the target area together form a piezoelectric sensing unit, and the orthographic projection of the target area on the substrate coincides with the orthographic projection of the piezoelectric sensing electrode block on the substrate. The orthographic projection of each of the piezoelectric sensing electrode blocks onto the substrate is located in the peripheral region of the substrate, and the orthographic projection of the driving electrode onto the substrate is located in the central region of the substrate; Where N is an integer not less than 1.

12. The pressure detection device according to claim 11, characterized in that, The substrate, the common electrode layer, the piezoelectric thin film, and the patterned electrode layer are combined to form a piezoelectric sensor; the piezoelectric sensing device also includes a support, a first adhesive layer, a printed circuit board, and a cover plate; The first adhesive layer is disposed on the support member, the piezoelectric sensor is disposed on the first adhesive layer on the side away from the support member, the printed circuit board is disposed on the piezoelectric sensor on the side away from the support member, and the cover plate is disposed on the printed circuit board on the side away from the support member.

13. The pressure detection device according to claim 11, characterized in that, The substrate, the common electrode layer, the piezoelectric thin film, and the patterned electrode layer are combined to form a piezoelectric sensor; the piezoelectric sensing device also includes a support, a first adhesive layer, a second adhesive layer, a printed circuit board, and a cover plate; The first adhesive layer is disposed on the support member, the piezoelectric sensor is disposed on the first adhesive layer on the side away from the support member, the second adhesive layer is disposed on the piezoelectric sensor on the side away from the support member, the printed circuit board is disposed on the second adhesive layer on the side away from the support member, and the cover plate is disposed on the printed circuit board on the side away from the support member.

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