A pressure measurement and vibration feedback system and method of operation of the system

Abstract

The application discloses a pressure measurement and vibration feedback system and a running method of the system, the system comprises a touch surface, a cover plate, a PCB plate in sequence, the cover plate and the PCB plate are fixed through bonding glue after being overlapped, the PCB plate, the side of the PCB plate away from the cover plate is distributed with a plurality of integrated sensors and a buffer pad layer for preventing excessive pressure, the plurality of integrated sensors are distributed in the avoiding gap area of the buffer pad layer and the thickness of the buffer pad layer is less than the integrated sensor, an integrated sensor circuit is arranged on the integrated sensor; the side of the PCB plate away from the cover plate is also provided with a plurality of connectors which are symmetrically distributed, the plurality of integrated sensors and the plurality of connectors are electrically connected one by one, and the plurality of connectors are electrically connected to a sensing circuit on the PCB plate. The application uses a plurality of integrated sensors, a touch plate, a pressure measurement chip, a boost circuit and the like to realize accurate measurement of finger pressure of a user on the touch plate and a wide vibration feedback system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tactile feedback, in particular to a pressure measurement and vibration feedback system and a running method of the system. BACKGROUND

[0002] Tactile feedback is a current popular technology, and the measurement of pressure and vibration feedback is a core part of this technology.

[0003] The pressure touchpad uses pressure detection to replace physical button detection to realize confirmation and menu calling operations, and solves the problem that the traditional touchpad can only be pressed locally near the physical button. The pressure touchpad can adjust the response force and vibration feedback intensity of the user's pressing action according to the user's usage habit, and provide the user with more convenient and comfortable operation experience. The quality of the user experience depends largely on the design of the touchpad structure.

[0004] Therefore, it is necessary to improve the pressure touch technology. SUMMARY

[0005] In view of the deficiencies in the prior art, the technical problem to be solved by the present application is to provide a pressure measurement and vibration feedback system and a running method of the system. The purpose of designing the pressure measurement and vibration feedback system and the system is to accurately measure the finger pressure and provide wide vibration feedback.

[0006] To solve the above technical problems, the present application realizes the following scheme: a pressure measurement and vibration feedback system of the present application, from the touch surface downward, is a cover plate, a PCB board, the cover plate and the PCB board are fixed by bonding glue after being overlapped, characterized in that the PCB board, the side away from the cover plate is distributed with a plurality of integrated sensors and a buffer pad layer for preventing excessive pressure, the buffer pad layer has a avoiding gap;

[0007] The plurality of integrated sensors are distributed in the avoiding gap area of the buffer pad layer and the thickness of the buffer pad layer is less than that of the integrated sensor, and an integrated sensor circuit is arranged on the plurality of integrated sensors;

[0008] The PCB board, the side away from the cover plate is also provided with a plurality of connectors distributed symmetrically, the plurality of integrated sensors and the plurality of connectors are electrically connected one by one, and the plurality of connectors are electrically connected to the sensing circuit on the PCB board;

[0009] The sensing circuit comprises:

[0010] The touchpad chip is connected to the output end of the host through the first communication interface;

[0011] The pressure detection and boost control chip is connected to the output end of the touch panel chip through a second communication interface, and the pressure detection and boost control chip is a slave device of the touch panel chip, receives configuration information sent by the host through the touch panel chip, and can upgrade firmware;

[0012] The IO expansion chip is connected to the output end of the pressure detection and boost control chip through a third communication interface, and is connected to the output end of the touch panel chip through the second communication interface.

[0013] A drive circuit is electrically connected to the pressure detection and boost control chip, and the pressure detection and boost control chip controls the operation of the drive circuit, and the integrated sensor circuit generates a plurality of pressure data, which forms differential data output to the pressure detection and boost control chip.

[0014] The integrated sensor circuit includes a plurality of Wheatstone bridge circuits, and one integrated sensor is provided with one Wheatstone bridge circuit.

[0015] The integrated sensor can realize pressure detection and vibration feedback, the drive circuit is connected to the output end of the IO expansion chip, and the integrated sensor circuit is connected to the output end of the drive circuit to receive a vibration signal.

[0016] Further, the first communication interface, the second communication interface and the third communication interface are I2C communication interfaces.

[0017] Further, the drive circuit includes six circuit modules, which are boost switch and protection circuit, flyback switch circuit, feedback circuit, discharge circuit, switch circuit and PWM switching circuit.

[0018] The boost switch and protection circuit, the feedback circuit and the PWM switching circuit are connected to the pressure detection and boost control chip.

[0019] The flyback switch circuit and the PWM switching circuit are connected.

[0020] The switch circuit is connected to the IO expansion chip and the integrated sensor circuit, respectively.

[0021] The output end of the boost switch and protection circuit is connected to the flyback switch circuit, and the output end of the flyback switch circuit is connected to the feedback circuit and the discharge circuit, respectively.

[0022] Further, the boost switch and protection circuit comprises a load switch chip U10, a capacitor C10, a capacitor C11, a capacitor C12 and a resistor R10, one end of the capacitor C11 is grounded, the other end of the capacitor C11 is connected to the VIN pin of the load switch chip U10, the VIN pin of the load switch chip U10 is also connected to a 5V voltage, one end of the capacitor C10 is connected to the DCDC_EN pin of the pressure detection and boost control chip, the other end of the capacitor C10 is connected to the EN pin of the load switch chip U10 and the resistor R10, the other end of the resistor R10 is grounded, the GND pin of the load switch chip U10 is grounded, and the VOUT pin of the load switch chip U10 is connected to the capacitor C12 and a 5V_A voltage, the other end of the capacitor C12 is grounded, and the VOUT pin of the load switch chip U10 is connected to the flyback switch circuit.

[0023] Further, the capacitor C10 and the resistor R10 constitute a differential circuit, according to the time constant τ=RC, the values of the capacitor C10 and the resistor R10 are adjusted, the conduction time of the EN end of the load switch chip U10 at the high level of the DCDC_EN pin can be controlled, and it is ensured that the EN end of U10 can only be turned on for a few milliseconds when DCDC_EN is always high, thereby protecting the subsequent boost circuit from overheating damage.

[0024] Further, the flyback switch circuit comprises a transformer L10, a resistor R11, a capacitor C13, a capacitor C14, a capacitor C15, a diode D10, a diode D11 and an N-MOS tube Q10.

[0025] One end of the primary coil of the transformer L10 is connected to the output end of the boost switch and protection circuit, one end of the capacitor C13 and one end of the resistor R11, the other end of the primary coil of the transformer L10 is connected to the anode of the diode D10 and the source of the N-MOS tube Q10, the cathode of the diode D10 is connected to the other end of the capacitor C13 and the other end of the resistor R11, and the drain of the N-MOS tube Q10 is grounded, and the gate of the N-MOS tube Q10 is connected to the PWM1 end of the PWM switch circuit.

[0026] The same end of the secondary coil corresponding to the primary coil of the transformer L10 connected to the output end of the boost switch and protection circuit is grounded, the other end of the secondary coil is connected to the anode of the diode D11, the cathode of the diode D11 is connected to the capacitor C14, the capacitor C15 and the HV circuit of the integrated sensor circuit, the other end of the capacitor C14 and the capacitor C15 is grounded, and the cathode of the diode D11 is connected to the feedback circuit.

[0027] Further, the feedback circuit comprises a resistor R12 and a resistor R13 connected in series, a circuit node between the resistor R12 and the resistor R13 is connected to an HV_FB pin of the pressure detection and boost control chip, one end of the resistor R12 is connected to an output end of the flyback switching circuit, and the other end of the resistor R13 is grounded.

[0028] Further, the discharge circuit comprises a resistor R14, an NPN transistor Q11, and a resistor R15, one end of the resistor R14 is connected to a base of the NPN transistor Q11, the other end of the resistor R14 is connected to a PWM2 pin of the PWM switching circuit, an emitter of the NPN transistor Q11 is grounded, a collector of the NPN transistor Q11 is connected to the resistor R15, and the other end of the resistor R15 is connected to an output end of the flyback switching circuit.

[0029] Further, the switching circuit comprises a plurality of switching circuit units, and the plurality of switching circuit units are connected to the plurality of integrated sensor units in pairs.

[0030] Further, in the circuit of one switching circuit unit, an NPN transistor Q2n is connected, an emitter of the NPN transistor Q2n is grounded, a collector of the NPN transistor Q2n is connected to a PZTn pin of the integrated sensor circuit, and a base of the NPN transistor Q2n is connected to an OUTn pin of the IO expansion chip through a resistor RZn.

[0031] Further, in the circuit of the PWM switching circuit, an analog switch chip U13 is connected, a selection pin S of the analog switch chip U13 is connected to PWM_SW, a common pin A of the analog switch chip U13 is connected to PWM0, a B0 pin of the analog switch chip U13 is connected to PWM1, and a B1 pin of the analog switch chip U13 is connected to PWM2; PWM0 and PWM_SW are connected to the pressure detection and boost control chip, PWM1 of the analog switch chip U13 is connected to the flyback switching circuit, and PWM2 of the analog switch chip U13 is connected to the discharge circuit.

[0032] Further, the pressure detection and boost control chip configures PWM_SW to be a low level to make PWM0 and PWM1 of the analog switch chip U13 conductive when boosting.

[0033] Further, the pressure detection and boost control chip configures PWM_SW to be a high level to make PWM0 and PWM2 conductive when discharging.

[0034] Further, through the PWM switching circuit 105, only one pressure detection and boost control chip 12 is enabled to output and control the modulation wave of the boost process and the discharge process through time division multiplexing.

[0035] The operation method of the pressure measurement and vibration feedback system comprises the following steps:

[0036] Step one, sensor calibration: when powered on, the pressure detection and boost control chip automatically calibrates and clears the pressure value, and the touch panel chip transmits the required vibration level FORCE_LEVEL, the pressure value FORCE_SEN of the finger pressing, and the pressure value FORCE_SEN_REL of the hand releasing through the second communication interface. The pressure FORCE_SEN_REL of the hand releasing is less than the pressure FORCE_SEN of the pressing;

[0037] When there is no finger touch on the cover plate, the pressure detection and boost control chip detects the pressure slowly through the multi-channel differential voltage of multiple Wheatstone bridge circuits, and dynamically calibrates the baseline value of each integrated sensor;

[0038] When the finger touches the cover plate, the touch panel chip identifies the finger coordinates and the number of fingers through capacitance scanning and calculation, reports the coordinate information of each finger to the host computer, and transmits the information SIG_TOUCH_ON of the finger touch to the pressure detection and boost control chip through the second communication interface;

[0039] Step two, after receiving the information SIG_TOUCH_ON of the finger existing, the pressure detection and boost control chip increases the pressure detection speed, and continuously compares the pressure values of each integrated sensor and the pressures of all integrated sensors. When the set pressure value FORCE_SEN is reached, it is identified as a "key" pressing, and the Button signal line is pulled low;

[0040] At the same time, the pressure detection and boost control chip outputs high level DCDC_ON to make the load switch of the load switch chip U10 conduct, and the input voltage of the flyback switching circuit is 5V;

[0041] Step three, the pressure detection and boost control chip confirms the area where the finger is located by searching for the first three integrated sensors with the maximum pressure, and sends one or more signals PZT_CNTLN of the piezoelectric ceramic conduction to the IO expansion chip through the third communication interface;

[0042] Step 4: The pressure detection and boost control chip finds the corresponding vibration voltage value HV_VOL1 by setting the vibration level FORCE_LEVEL, and controls PWM_SW to be low, so that the PWM0 signal of the pressure detection and boost control chip is turned on to PWM1.

[0043] The pressure detection and boost control chip outputs a series of PWM1 waveform signals by looking up the boost table, so that the voltage of HV reaches the set HV_VOL1;

[0044] The pressure detection and boost control chip detects the HV voltage in real time through HW_FB. When it reaches HV_VOL1, it configures PWM_SW to a high level to turn on PWM0 and PWM2; and sets DCDC_ON to a low level to stop the 5V_A power input of the flyback switching circuit.

[0045] The pressure detection and boost control chip then looks up the discharge table and outputs a specific discharge waveform from PWM2 to make the drop voltage of HV form the required waveform;

[0046] The pressure detection and boost control chip confirms the completion of discharge via HV_FB. When PWM0 outputs low, the discharge is complete, and the vibration process of the finger pressing down is finished.

[0047] Step 5: The touchpad chip receives the signal from the Button pull-down and recognizes it as a "button" being pressed. It then adds a "button" pressed flag to the data reported to the host.

[0048] After the host computer recognizes the "key" pressed icon, it outputs the left or right key in the computer.

[0049] Furthermore, when the pressure of the finger remains greater than the set pressure value FORCE_SEN, the pressure detection and boost control chip will keep the output Button at a low level, the touchpad chip will also report that the "button" is pressed continuously, and the host will also keep the left or right button pressed continuously.

[0050] Furthermore, the pressure detection and boost control chip is changed from HV_VOL1 to HV_VOL2 according to the highest output voltage, so as to provide a vibration effect when releasing the hand, to distinguish it from the vibration when pressing the hand.

[0051] When a finger leaves the touchpad surface, the touchpad chip reports to the host that the finger has left, and notifies the pressure detection and boost control chip's signal pin SIG_TOUCH_OFF via the second communication interface;

[0052] After receiving the SIG_TOUCH_OFF signal, the pressure detection and boost control chip reduces the pressure scan speed and simultaneously clears the pressure baseline value to zero.

[0053] Further, when the pressure of the finger is less than the pressure FORCE_SEN_REL at which the hand is released, the pressure detection and boost control chip will set the Button to high level, and the touchpad chip recognizes that the "button" has been released, and adds a "button" release flag to the data reported to the host computer.

[0054] Further, in step three, the pressure detection and boost control chip has a built-in calibrated vibration table, which has the position index and pressure value of the first three maximum pressures as input, and outputs a plurality of piezoelectric ceramic conduction signals PZT_CNTLN.

[0055] Further, the operation method further includes a firmware upgrade method, wherein the firmware upgrade method is that the touchpad chip sends information to the IO expansion chip 13 through the second communication interface and the third communication interface, so that the IO expansion chip outputs a RESET signal to the pressure detection and boost control chip, the RESET signal is used for abnormal recovery of the touchpad chip to the pressure detection and boost control chip, and in combination with sending data from the touchpad chip to the pressure detection and boost control chip through the second communication interface, firmware upgrade of the pressure detection and boost control chip is realized.

[0056] Compared with the prior art, the application has the following advantages:

[0057] 1. The application uses a plurality of integrated pressure and vibration modules, touchpads, pressure measurement chips and boost circuits to realize accurate measurement of finger pressure on the touchpad and a wide vibration feedback system. The pressure measurement uses a chip that integrates multiple pressure measurement channels. The specific high-voltage waveform required by the piezoelectric ceramic is realized by a flyback boost circuit composed of the PWM0 port of the pressure measurement chip, an external NMOS tube and a transformer. The pressure chip is controlled by the I2C bus of the touch master chip. This system can achieve accurate pressure measurement of more than 100Hz for multiple pressure channels, and can realize 100V to 300V piezoelectric ceramic single / multi-channel modulation waveform output, which can realize wide vibration feedback. And the total module of this system including glass is only 2.0mm thick, which is super-thin.

[0058] 2. The application uses the principle of a Wheatstone bridge to test pressure, which realizes the accuracy of pressure measurement when the pressure changes slowly and remains unchanged. In actual product experience, it can be found that multiple "button" operations or slow force "button" operations cannot accurately identify the force of each press, and the force of the "button" pressed continuously becomes heavier. Using the piezoelectric effect of piezoelectric ceramic deformation as the design of pressure detection, the force of each press can be accurately identified with the same force.

[0059] 3. The integrated sensor of the present application cleverly bonds the deformation on the copper sheet at the back of the piezoelectric ceramic, accurately identifies the pressure, and makes the product light and thin.

[0060] 4. The present application uses a flyback boost circuit, which can directly increase from 5V to 100V to 300V or above. The driving voltage is higher, and the vibration is stronger and wider. At the same time, the primary drive NMOS requires lower voltage, and the gate driving voltage can be directly driven by 3.3V, without the need for diode / capacitor multiple voltage multiplication.

[0061] 5. In the present application, all the raw data of the pressure are calculated and compared by the pressure detection and boost control chip, and are not transmitted to the touchpad chip and the host for processing, thereby reducing the communication time of the touchpad chip, the running time of the touchpad chip and the pressure detection and boost control chip, and reducing the overall power consumption.

[0062] 6. In the boost switch and protection circuit, only two RC elements, resistor R10 and capacitor C10, are used, and the maximum conduction time of load switch chip U10 is limited to a few milliseconds, which can realize the protection of the flyback switch circuit from overheating and burning out due to long-time conduction.

[0063] 7. In the present application, the finger touch signal and the hand release signal are informed by the touchpad chip to the pressure detection and boost control chip, which dynamically adjusts the scanning speed of the pressure chip in real time, so that the power consumption after the hand release is about 1 / 10 or lower than that with the finger touch, and also ensures faster response speed of the pressure detection with the finger touch. On the other hand, from the SIG_TOUCH_OFF signal of the finger release, the pressure detection and boost control chip can ensure the identification of the finger release, and clear the baseline values of each pressure in time, so as to ensure the long-time operation of the system and prevent the zero drift problem of the pressure detection.

[0064] 8. The touchpad chip can control the pressure chip and the IO expansion chip through I2C2 / I2C3, so as to achieve the functions of fault recovery and firmware upgrade of the pressure chip.

[0065] 9. The internal resources of the pressure chip are fully utilized, and the boost control, discharge control and feedback input of the flyback boost circuit are integrated, which greatly reduces the design elements. BRIEF DESCRIPTION OF DRAWINGS

[0066] Figure 1 It is an exploded view of the touchpad with six integrated sensors of the present application.

[0067] Figure 2 It is an assembly drawing of Figure 1 .

[0068] Figure 3 It is an assembly drawing of the touchpad with eight integrated sensors of the present application.

[0069] Figure 4 The general circuit diagram of the pressure measurement and vibration feedback system of the present application.

[0070] Figure 5 The circuit diagram of each functional module of the pressure measurement and vibration feedback system of the present application.

[0071] Figure 6 The integrated sensor circuit diagram of the present application.

[0072] Figure 7 The Ton and Toff relationship diagram of the PWM1 signal of the pressure measurement and vibration feedback system of the present application.

[0073] Figure 8 The common Boost circuit diagram in the prior art.

[0074] Figure 9 The connection structure diagram of each circuit module in the driving circuit of the present application.

[0075] Figure 10 The switch circuit diagram of the present application.

[0076] Figure 11 The PWM switching circuit diagram of the present application.

[0077] Figure 12 The pressure measurement and vibration feedback system with 4 groups of integrated sensors of the present application.

[0078] Figure 13 The pressure measurement and vibration feedback system with 5 groups of integrated sensors of the present application.

[0079] In the drawings, the labels are: cover plate 1, bonding glue 2, PCB board 3, integrated sensor 4, connector 5, reverse-mounted locking nut 6, buffer pad layer 7, sensing circuit 8, main machine 10, touchpad chip 11, pressure detection and boost control chip 12, IO expansion chip 13, driving circuit 14, integrated sensor circuit 15, capacitance scanning and finger recognition 16, boost switch and protection circuit 100, flyback switch circuit 101, feedback circuit 102, discharge circuit 103, switch circuit 104, PWM switching circuit 105. DETAILED DESCRIPTION

[0080] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, so that the advantages and characteristics of the present application can be more easily understood by those skilled in the art, and the protection scope of the present application can be more clearly and definitely defined. Obviously, the described embodiments of the present application are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0081] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0082] Embodiment 1: The specific structure of the present application is as follows:

[0083] As shown in Figures 1-11 , a pressure measurement and vibration feedback system of the present application, from the touch surface down, is a cover plate 1, a PCB board 3 in turn, the cover plate 1 and the PCB board 3 are fixed by bonding glue 2 after being overlapped, the PCB board 3, the side away from the cover plate 1 is distributed with a plurality of integrated sensors 4 and a buffer pad layer 7 to prevent excessive pressure, the buffer pad layer 7 has an avoidance gap, the bonding glue 2 is double-sided adhesive;

[0084] The plurality of integrated sensors 4 are distributed in the avoidance gap area of the buffer pad layer 7 and the thickness of the buffer pad layer 7 is less than the integrated sensor 4;

[0085] The integrated sensor 4 adopts a sensor module with a patent number 2022113279120, or a sensor module with a patent number 2022229043397, or a sensor module with a patent number 202223407896.4.

[0086] The PCB board 3, the side away from the cover plate 1, is also provided with a plurality of connectors 5 distributed symmetrically, the plurality of integrated sensors 4 and the plurality of connectors 5 are electrically connected one by one, and the plurality of connectors 5 are electrically connected to a sensing circuit on the PCB board 3;

[0087] The sensing circuit comprises:

[0088] A touch panel chip 11 is connected to the output end of a host 10 through a first communication interface;

[0089] A pressure detection and boost control chip 12 is connected to the output end of the touch panel chip 11 through a second communication interface, the pressure detection and boost control chip 12 is a slave device of the touch panel chip 11, receives configuration information sent by the host 10 through the touch panel chip 11 and can upgrade firmware.

[0090] An IO expansion chip 13 is connected to the output end of the pressure detection and boost control chip 12 through a third communication interface, and is connected to the output end of the touchpad chip 11 through a second communication interface. The IO expansion chip 13 is also electrically connected to an integrated sensor circuit 15.

[0091] A drive circuit 14 is electrically connected to the pressure detection and boost control chip 12, which serves as the master of the IO expansion chip 13 and controls the operation of the drive circuit 14. The integrated sensor circuit 15 generates multiple channels of pressure data, which form differential data output to the pressure detection and boost control chip 12.

[0092] The integrated sensor circuit 15 includes multiple sets of Wheatstone bridge circuits, and one set of Wheatstone bridge circuits is arranged in one integrated sensor 4.

[0093] The integrated sensor 4 can realize pressure detection and vibration feedback. The drive circuit 14 is connected to the output end of the IO expansion chip 13. The integrated sensor circuit 15 is connected to the output end of the drive circuit 14 to receive vibration signals.

[0094] A preferred technical solution of the embodiment: the first communication interface, the second communication interface, and the third communication interface are all I2C communication interfaces.

[0095] A preferred technical solution of the embodiment: the drive circuit 14 includes six circuit modules, which are a boost switch and protection circuit 100, a flyback switch circuit 101, a feedback circuit 102, a discharge circuit 103, a switch circuit 104, and a PWM switching circuit 105.

[0096] The boost switch and protection circuit 100, the feedback circuit 102, and the PWM switching circuit 105 are all connected to the pressure detection and boost control chip 12.

[0097] The flyback switch circuit 101 is connected to the PWM switching circuit 105.

[0098] The switch circuit 104 is connected to the IO expansion chip 13 and the integrated sensor circuit 15, respectively.

[0099] The output end of the boost switch and protection circuit 100 is connected to the flyback switch circuit 101. The output end of the flyback switch circuit 101 is connected to the feedback circuit 102 and the discharge circuit 103, respectively.

[0100] Embodiment 2:

[0101] As Figure 9 A preferred technical solution of the embodiment: the boost switch and protection circuit 100 includes a load switch chip U10, a capacitor C10, a capacitor C11, a capacitor C12, and a resistor R10. One end of the capacitor C11 is grounded, and the other end is connected to the VIN pin of the load switch chip U10. The VIN pin of the load switch chip U10 is also connected to a 5V voltage. One end of the capacitor C10 is connected to the DCDC_EN pin of the pressure detection and boost control chip 12, and the other end is connected to the EN pin of the load switch chip U10 and the resistor R10. The other end of the resistor R10 is grounded. The GND pin of the load switch chip U10 is grounded, and the VOUT pin is connected to the capacitor C12 and the 5V_A voltage. The other end of the capacitor C12 is grounded. The VOUT pin of the load switch chip U10 is connected to the flyback switching circuit 101.

[0102] A preferred technical solution of the embodiment: the capacitor C10 and the resistor R10 form a differential circuit. According to the time constant τ=RC, the values of the capacitor C10 and the resistor R10 are adjusted to control the conduction time of the EN end of the load switch chip U10 at the high level of the DCDC_EN pin. It is ensured that when DCDC_EN is always high, the EN end of U10 can only be turned on for a few milliseconds, protecting the subsequent boost circuit from overheating and damage.

[0103] Embodiment 3:

[0104] As Figure 9 A preferred technical solution of the embodiment: the flyback switching circuit 101 includes a transformer L10, a resistor R11, a capacitor C13, a capacitor C14, a capacitor C15, a diode D10, a diode D11, and an N-MOS tube Q10.

[0105] One end of the primary coil of the transformer L10 is connected to the output end of the boost switch and protection circuit 100, one end of the capacitor C13, and one end of the resistor R11. The other end of the primary coil of the transformer L10 is connected to the anode of the diode D10 and the source of the N-MOS tube Q10. The cathode of the diode D10 is connected to the other end of the capacitor C13 and the other end of the resistor R11. The drain of the N-MOS tube Q10 is grounded, and its gate is connected to the PWM1 end of the PWM switching circuit 105.

[0106] The primary coil of the transformer L10 connected to the output of the voltage boosting switch and protection circuit 100 is connected to the ground at the same end, and the other end is connected to the positive electrode of the diode D11. The negative electrode of the diode D11 is connected to the HV circuit of the integrated sensor circuit 15, and the other end of the capacitor C14 and the capacitor C15 is connected to the ground, respectively. The negative electrode of the diode D11 is connected to the feedback circuit 102.

[0107] The flyback switch circuit 101 inputs a specific waveform PWM1 signal sequence from the gate of the N-MOS tube Q10, couples through the primary coil of the transformer L10, and amplifies through the secondary coil of the transformer L10, so that the voltage of the HV circuit can be output as required up to 300V.

[0108] The ratio of the primary and secondary turns of the transformer L10 is 5:1 to 20:1, and higher turns are beneficial to output higher voltage.

[0109] The resistance R11, the capacitor C13 and the diode D10 form a spike absorption circuit, which reduces the switching spike voltage and protects the NMOS N-MOS tube Q10 from being broken down by high voltage.

[0110] The diode D11 is a rectifier diode of the secondary coil of the transformer L10, which is filtered by the capacitor C14 and the capacitor C15 to obtain a smooth HV waveform.

[0111] Under ideal conditions, the output voltage Uo of the flyback switch power supply is calculated as follows:

[0112] Uo = N2 / N1 *Ui*Ton / Toff

[0113] Where Uo is the output voltage, corresponding to HV in the present application. Ui is the input voltage, corresponding to 5V in the present application. N2 / N1 is the ratio of the secondary / primary turns of the transformer L10. Ton is the high level time of PWM1, and Toff is the low level time of PWM1.

[0114] Therefore, in the case where N2 / N1 and Ui are determined values, by dynamically adjusting the ratio of Ton / Toff, the specific waveform sequence of HV can be dynamically output.

[0115] In order to achieve better piezoelectric ceramic vibration effect, the driving voltage of the piezoelectric ceramic at both ends should at least reach about 200V. In the present application, the advantages of using a flyback switch circuit are:

[0116] 1), Flyback switching circuit by adjusting the secondary / primary turns ratio, can directly output up to 300V or more voltage, more easily achieve higher voltage than the Boost circuit directly. Therefore, no need to pass through the diode and capacitor voltage, the circuit is more simple, more power saving. In the same kind of patent, compared to the design of application No. 201910581397: after boost circuit and multi-stage diode / capacitor voltage doubling circuit, more simple.

[0117] 2), because the switch tube in the primary, the secondary and the primary have a higher ratio, the required NMOS switch tube N-MOS tube Q10 withstand voltage only needs about 100V. Therefore, the switch tube N-MOS tube Q10 withstand voltage is lower than the direct Boost switch tube, more power saving, easy to select and purchase.

[0118] 3), compared with direct Boost circuit, because the N-MOS tube Q10 withstand voltage is lower, the corresponding required on switch gate voltage is also lower, can directly use the 3.3V level of pressure detection and boost control chip 12 to drive directly, without increasing a large number of drive circuit to improve the drive level.

[0119] Embodiment 4:

[0120] A preferred technical solution of the embodiment: the feedback circuit 102 includes a series of resistors R12 and R13, the circuit node between the resistor R12 and the resistor R13 is connected to the HV_FB pin of the pressure detection and boost control chip 12, the resistor R12 is connected to the output end of the flyback switching circuit 101 at the non-connected end of the resistor R13, and the other end of the resistor R13 is grounded.

[0121] The feedback circuit 102 outputs the HV_FB signal through the voltage division of the resistor R12 and the resistor R13, and directly inputs the HV_FB signal to the pressure detection and boost control chip 12. In this way, the pressure detection and boost control chip 12 can know the voltage of HV in real time through ADC operation, and can realize the output of specific voltage and waveform of HW by adjusting the duty cycle of PWM1.

[0122] Because the voltage of HV is very high, up to 300V, in order to reduce power consumption and affect the circuit, the voltage dividing resistor R12 is at least greater than or equal to 1M ohm. Because the pressure detection and boost control chip 12 is built-in PGA (programmable gain amplifier), the input impedance is more than 100M ohm, so the voltage dividing signal HV_FB can be directly input to the pressure detection and boost control chip 12, without the need to increase the voltage following operational amplifier circuit, the circuit is more simple.

[0123] Embodiment 5:

[0124] A preferred technical solution of the embodiment: the discharge circuit 103 comprises a resistor R14, an NPN transistor Q11 and a resistor R15, one end of the resistor R14 is connected with the base of the NPN transistor Q11, the other end of the resistor R14 is connected with the PWM2 end of the PWM switching circuit 105, the emitter of the NPN transistor Q11 is grounded, the collector of the NPN transistor Q11 is connected with the resistor R15, the other end of the resistor R15 is connected with the output end of the flyback switching circuit 101.

[0125] The discharge circuit 103 needs to discharge after the waveform of the HW reaches the highest point to form a specific output waveform, such as a sine waveform. Therefore, PWM2 needs to discharge through the high-voltage-resistant transistor Q11 through the resistor R15. In order to make the falling voltage waveform of the HV meet the requirements, the signal of PWM2 also needs to be modulated by a specific PWM waveform. In addition, the power of the resistor R15 is large, and a large volume resistor or multiple resistors in series / parallel connection needs to be used.

[0126] Embodiment 6:

[0127] A preferred technical solution of the embodiment: the switching circuit 104 comprises a plurality of switching circuit units, and the plurality of switching circuit units are connected with the plurality of integrated sensor units in pairs.

[0128] A preferred technical solution of the embodiment: in the circuit of one switching circuit unit, an NPN transistor Q2n is connected, the emitter of the NPN transistor Q2n is grounded, the collector of the NPN transistor Q2n is connected with the PZTn pin of the integrated sensor circuit 15, and the base of the NPN transistor Q2n is connected with the OUTn pin of the IO expansion chip 13 through the resistor RZn.

[0129] The switching circuit 104 is used to form a loop to ground for the HV electrode of the integrated sensor circuit 15. The switch of the circuit needs to be turned on, and the switch of the circuit needs to be turned on. According to the position of the finger, in order to achieve better vibration effect, it may be necessary to open multiple switches at the same time to vibrate.

[0130] Embodiment 7:

[0131] A preferred technical solution of the embodiment: the circuit of the PWM switching circuit 105 is connected with an analog switch chip U13, the selection pin S of the analog switch chip U13 is connected with PWM_SW, the common pin A of the analog switch chip U13 is connected with PWM0, the B0 pin of the analog switch chip U13 is connected with PWM1, and the B1 pin of the analog switch chip U13 is connected with PWM2; the PWM0 end and the PWM_SW end are connected to the pressure detection and boost control chip 12, wherein the PWM1 pin of the analog switch chip U13 is connected to the flyback switching circuit 101, and the PWM2 pin of the analog switch chip U13 is connected to the discharge circuit 103.

[0132] The PWM switching circuit 105 needs to time-multiplex one PWM in the pressure detection and boost control chip 12 through the PWM_SW signal due to the limited resources of the pressure detection and boost control chip 12, which has only one PWM port, and switch to PWM1 during boosting and switch to PWM2 during discharging.

[0133] Embodiment 8:

[0134] A preferred technical solution of the embodiment: the pressure detection and boost control chip 12 configures the PWM_SW pin as low during boosting to make PWM0 and PWM1 on the analog switch chip U13 conductive.

[0135] A preferred technical solution of the embodiment: the pressure detection and boost control chip 12 configures the PWM_SW pin as high during discharging to make PWM0 and PWM2 conductive.

[0136] A preferred technical solution of the embodiment: the pressure detection and boost control chip 12 with only one PWM0 realizes the output and control of the modulation wave in the boosting process and the discharging process through time-multiplexing by the PWM switching circuit 105.

[0137] Embodiment 9:

[0138] Factory calibration:

[0139] Since the integrated sensor 4 obtains the pressure value by the deformation of the printed pressure resistance, there are slight differences in each pressure resistance, slight deviations in the positions of the bonded piezoelectric ceramics, and slight deviations in the positions of the rubber sheets, and the pressure and voltage coefficients a and b of all the integrated sensors are different.

[0140] F = aV+b;

[0141] Therefore, a and b need to be calculated for all the integrated sensors before leaving the factory.

[0142] By placing 100g and 200g weights on each integrated sensor, a and b can be calculated and saved to the Flash of the pressure detection and boost control chip 12. The calculated pressure of each integrated sensor is used when calculating the pressure.

[0143] Embodiment 10:

[0144] The operation method of the pressure measurement and vibration feedback system of the present application includes the pressure measurement and vibration feedback system described in Embodiment 1.

[0145] The operation method includes the following steps:

[0146] Step 1, sensor calibration: when powered on, the pressure detection and boost control chip 12 automatically calibrates and clears the pressure value, and the touchpad chip 11 transmits the required vibration level FORCE_LEVEL, the pressure value FORCE_SEN of the finger press, and the pressure value FORCE_SEN_REL of the hand release through the second communication interface. The pressure FORCE_SEN_REL of the hand release is less than the pressure FORCE_SEN of the press;

[0147] When there is no finger touch on the cover plate 1, the pressure detection and boost control chip 12 performs slow pressure detection through the multi-path differential voltage of multiple sets of Wheatstone bridge circuits, and dynamically calibrates the baseline value of each integrated sensor 4;

[0148] When there is a finger touch on the cover plate 1, the touchpad chip 11 identifies the finger coordinates and the number of fingers through capacitance scanning and calculation, reports the coordinate information of each finger to the host 10, and transmits the information SIG_TOUCH_ON of the finger touch to the pressure detection and boost control chip 12 through the second communication interface;

[0149] Step 2, after receiving the information SIG_TOUCH_ON of the finger touch, the pressure detection and boost control chip 12 increases the pressure detection speed, and continuously compares the pressure values of each integrated sensor 4 and the pressures of all integrated sensors 4. When the set pressure value FORCE_SEN is reached, it is identified as a "key" press, and the Button signal line is pulled low;

[0150] At the same time, the pressure detection and boost control chip 12 outputs high level DCDC_ON to make the load switch of the load switch chip U10 conductive, and the input voltage 5V of the flyback switching circuit 101 is obtained;

[0151] Step three, the pressure detection and boost control chip 12 confirms the area where the finger is located by looking up the first three integrated sensors 4 that have the maximum pressure, and sends one or more signals PZT_CNTLN to the IO expansion chip 13 through the third communication interface to turn on the piezoelectric ceramic;

[0152] Step four, the pressure detection and boost control chip 12 finds the corresponding vibration voltage value HV_VOL1 by setting the vibration level FORCE_LEVEL, controls PWM_SW to be low, and makes the PWM0 signal of the pressure detection and boost control chip 12 turn on PWM1;

[0153] The pressure detection and boost control chip 12 looks up the boost table and outputs a series of PWM1 waveform signals to make the voltage of HV reach the set HV_VOL1;

[0154] The pressure detection and boost control chip 12 detects the HV voltage in real time through HW_FB, and when HV_VOL1 has been reached, PWM0 and PWM2 are turned on by configuring PWM_SW to be high, and DCDC_ON is set to be low to stop the 5V_A power input of the flyback switching circuit 101;

[0155] The pressure detection and boost control chip 12 looks up the discharge table and outputs specific discharge waveforms from PWM2 to form the required waveform of the HV drop voltage;

[0156] The pressure detection and boost control chip 12 confirms the completion of discharge through HV_FB, PWM0 is output to be low, the discharge is completed, and the vibration process of the finger pressure is completed;

[0157] Step five, the touchpad chip 11 receives the signal of Button pull-down, recognizes that the “key” is pressed, and adds the flag of “key” press in the data reported to the host 10;

[0158] The host 10 outputs the left key or the right key in the computer after recognizing the flag of “key” press.

[0159] Example 11:

[0160] When the pressure of the finger remains greater than the set pressure value FORCE_SEN, the pressure detection and boost control chip 12 will always keep the output Button low, the touchpad chip 11 also reports that the “key” is always pressed, and the host 10 also keeps the left key or the right key always pressed.

[0161] Example 12:

[0162] The pressure detection and boost control chip 12 changes its output voltage from HV_VOL1 to HV_VOL2 to provide a vibration effect when the hand is released, so as to distinguish it from the vibration when the hand is pressed.

[0163] When a finger leaves the touchpad surface, the touchpad chip 11 reports to the host 10 that the finger has left, and notifies the pressure detection and boost control chip 12 of the signal pin SIG_TOUCH_OFF through the second communication interface;

[0164] After receiving the SIG_TOUCH_OFF signal, the pressure detection and boost control chip 12 reduces the pressure scan speed and simultaneously clears the pressure baseline value to zero.

[0165] Example 13:

[0166] When the pressure of the finger is less than the release pressure FORCE_SEN_REL, the pressure detection and boost control chip 12 will set the Button to a high level, and the touchpad chip 11 will recognize that the "button" has been released and add a "button released" flag to the data reported to the host 10.

[0167] Example 14:

[0168] In step three of Example 10, the pressure detection and boost control chip 12 has a built-in calibrated vibration table. The input of the vibration table is the position index and pressure value of the first three maximum pressures, and the output is the corresponding multiple piezoelectric ceramic conduction signals PZT_CNTLN.

[0169] Example 15:

[0170] A preferred embodiment of this technical solution: the operation method further includes a firmware upgrade method, wherein the touchpad chip 11 sends information to the IO expansion chip 13 through the second communication interface and the third communication interface, enabling the IO expansion chip 13 to output a RESET signal to the pressure detection and boost control chip 12. The RESET signal is used by the touchpad chip 11 to recover from the abnormality of the pressure detection and boost control chip 12. Combined with the touchpad chip 11 sending data to the pressure detection and boost control chip 12 through the second communication interface, the firmware upgrade of the pressure detection and boost control chip 12 is realized.

[0171] Example 16:

[0172] like Figure 12 As shown, Figure 12 The pressure measurement and vibration feedback system of the present invention has 4 integrated sensors. The PCB board 3 is provided with 4 integrated sensors 4, which are located at the four corners of the PCB board 3.

[0173] Example 17:

[0174] Figure 13 The application has a pressure measurement and vibration feedback system with five groups of integrated sensors. Five groups of integrated sensors 4 are arranged on the PCB 3, four groups of integrated sensors 4 are arranged at the four corners of the PCB 3, and the fifth integrated sensor 4 is arranged at the center of the PCB 3.

[0175] In summary, the application uses multiple modules, touch panels, pressure measurement chips, and boost circuits to achieve accurate measurement of finger pressure on the touch panel and a wide vibration feedback system. The pressure measurement uses a chip that integrates multiple pressure measurement channels. The specific waveform high voltage waveform required by the piezoelectric ceramic is achieved by the PWM0 port of the pressure measurement chip and the external NMOS tube and transformer composed of a flyback boost circuit. The pressure chip is controlled by the I2C bus of the touch master chip. This system can achieve accurate pressure measurement of multiple channels over 100Hz, and can achieve 100V to 300V piezoelectric ceramic single / multiple modulation waveform output, which can achieve a wide vibration feedback. And the total module of this system including glass is only 2.0mm thick, which has the advantage of ultra-thin.

[0176] The application uses a principle similar to the Wheatstone bridge of an electronic scale to test pressure, achieving the accuracy of pressure measurement when the pressure changes slowly and remains unchanged. In actual product experience, it can be found that multiple "key" operations or slow force "key" operations cannot accurately identify the force of each press, and the force of the "key" pressed continuously becomes heavier. Using the piezoelectric effect of piezoelectric ceramic deformation as the design of pressure detection, the application can accurately identify the press of the "key" with the same force each time.

[0177] The integrated sensor of the application cleverly bonds the deformation on the copper sheet on the back of the piezoelectric ceramic, accurately identifies the pressure, and makes the product light and thin.

[0178] The application uses a flyback boost circuit, which can directly increase from 5V to 100 to 300V or above. The driving voltage is higher, and the vibration is stronger and wider. At the same time, the NMOS of the primary drive requires a lower voltage, and the gate drive voltage can be directly driven by 3.3V, without the need for multiple voltage doubling of diodes / capacitors.

[0179] In the application, all raw data of pressure are calculated and compared internally by the pressure detection and boost control chip, without being transmitted to the touch panel chip and the host for processing, reducing the communication time of the touch panel chip and the running time of the touch panel chip and the pressure detection and boost control chip, and reducing the overall power consumption.

[0180] In the boost switch and protection circuit, only two RC components, resistor R10 and capacitor C10, are used, the maximum on-time of the load switch chip U10 is limited to several milliseconds, and the protection of the overheat and burnout of the flyback switch circuit in long-time conduction can be realized.

[0181] In the application, the finger touch signal and the hand release signal are informed by the touch panel chip to the pressure detection and boost control chip, on one hand, the scanning speed of the pressure chip is dynamically and real-timely adjusted, the power consumption after the hand release is about 1 / 10 or lower of the power consumption with the finger, and meanwhile, the pressure detection has a faster response speed when the finger touches. On the other hand, from the signal of the finger release SIG_TOUCH_OFF, the pressure detection and boost control chip can ensure the recognition of the finger release, clear the baseline values of each pressure in time, ensure the long-time operation of the system, and the pressure detection will not have the problem of zero drift.

[0182] The touch panel chip can control the pressure chip and the IO expansion chip through I2C2 / I2C3, the functions of the timely recovery of the pressure chip failure and the firmware upgrade can be achieved.

[0183] The internal resources of the pressure chip are fully utilized, the boost control, the discharge control and the feedback input of the flyback boost circuit are integrated, and the design components are greatly reduced.

[0184] The above only describes the preferred embodiments of the application, and does not limit the patent scope of the application, any equivalent structure or equivalent flow transformation by using the content of the specification and the drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. A pressure measuring and vibration feedback system, comprising a touch surface downward, in turn, a cover plate (1), a PCB plate (3), the cover plate (1) and the PCB plate (3) are fixed by bonding glue (2) after superposition, characterized in that, The PCB board (3) is provided with a plurality of integrated sensors (4) and a buffer pad layer (7) for preventing excessive pressure on the side of the PCB board (3) facing away from the cover plate (1), and the buffer pad layer (7) has an avoiding gap; The plurality of integrated sensors (4) are arranged in the avoiding gap area of the buffer pad layer (7) and the thickness of the buffer pad layer (7) is smaller than that of the integrated sensors (4), and the integrated sensor circuit (15) is arranged on the plurality of integrated sensors (4); The PCB board (3) is further provided with a plurality of connectors (5) symmetrically arranged on the side of the PCB board (3) facing away from the cover plate (1), the plurality of integrated sensors (4) and the plurality of connectors (5) are electrically connected one by one, and the plurality of connectors (5) are electrically connected to the sensing circuit on the PCB board (3); The sensing circuit comprises: a touch panel chip (11) connected to the output end of a host (10) through a first communication interface; a pressure detection and boost control chip (12) connected to the output end of the touch panel chip (11) through a second communication interface, the pressure detection and boost control chip (12) serving as a slave device of the touch panel chip (11) receives configuration information sent by the host (10) through the touch panel chip (11) and can upgrade firmware; an IO expansion chip (13) connected to the output end of the pressure detection and boost control chip (12) through a third communication interface and connected to the output end of the touch panel chip (11) through a second communication interface, the IO expansion chip (13) is further electrically connected to an integrated sensor circuit (15); a drive circuit (14) electrically connected to the pressure detection and boost control chip (12), the pressure detection and boost control chip (12) serving as a master device of the IO expansion chip (13) and controlling the operation of the drive circuit (14), the integrated sensor circuit (15) generating a plurality of pressure data, the plurality of pressure data forming differential data and output to the pressure detection and boost control chip (12); The integrated sensor circuit (15) comprises a plurality of Wheatstone bridge circuits, and one integrated sensor (4) is provided with one Wheatstone bridge circuit. The integrated sensor (4) can realize pressure detection and vibration feedback, the drive circuit (14) is connected to the output end of the IO expansion chip (13), and the integrated sensor circuit (15) is connected to the output end of the drive circuit (14) to receive a vibration signal.

2. A pressure measurement and vibration feedback system according to claim 1, wherein, The first communication interface, the second communication interface and the third communication interface are all I2C communication interfaces.

3. The pressure measurement and vibration feedback system of claim 1, wherein, The drive circuit (14) comprises six circuit modules, which are a boost switch and protection circuit (100), a flyback switch circuit (101), a feedback circuit (102), a discharge circuit (103), a switch circuit (104) and a PWM switching circuit (105), wherein: The boost switch and protection circuit (100), the feedback circuit (102) and the PWM switching circuit (105) are connected to the pressure detection and boost control chip (12); The flyback switch circuit (101) and the PWM switching circuit (105) are connected; The switch circuit (104) is connected to the IO expansion chip (13) and the integrated sensor circuit (15) respectively. The output end of the boost switch and protection circuit (100) is connected to the flyback switch circuit (101), and the output end of the flyback switch circuit (101) is connected to the feedback circuit (102) and the discharge circuit (103) respectively.

4. A pressure measurement and vibration feedback system according to claim 3, wherein, The boost switch and protection circuit (100) comprises a load switch chip U10, a capacitor C10, a capacitor C11, a capacitor C12 and a resistor R10. One end of the capacitor C11 is grounded, and the other end is connected to the VIN pin of the load switch chip U10. The VIN pin of the load switch chip U10 is also connected to a 5V voltage. One end of the capacitor C10 is connected to the DCDC_EN pin of the pressure detection and boost control chip (12), and the other end is connected to the EN pin of the load switch chip U10 and the resistor R10. The other end of the resistor R10 is grounded. The GND pin of the load switch chip U10 is grounded, and the VOUT pin is connected to the capacitor C12 and a 5V_A voltage. The other end of the capacitor C12 is grounded. The VOUT pin of the load switch chip U10 is connected to the flyback switch circuit (101).

5. A pressure measurement and vibration feedback system according to claim 4, wherein, The capacitor C10 and the resistor R10 constitute a differential circuit. According to the time constant τ=RC, the values of the capacitor C10 and the resistor R10 are adjusted to control the conduction time of the EN end of the load switch chip U10 at the high level of the DCDC_EN pin. It is ensured that the EN end of U10 can only be turned on for a few milliseconds when DCDC_EN is always high, protecting the subsequent boost circuit from overheating and damage.

6. A pressure measurement and vibration feedback system according to claim 3, wherein, The flyback switch circuit (101) comprises a transformer L10, a resistor R11, a capacitor C13, a capacitor C14, a capacitor C15, a diode D10, a diode D11 and an N-MOS tube Q10. One end of the primary coil of the transformer L10 is connected to the output end of the boost switch and protection circuit (100), one end of the capacitor C13 and one end of the resistor R11. The other end of the primary coil of the transformer L10 is connected to the anode of the diode D10 and the source of the N-MOS tube Q10. The cathode of the diode D10 is connected to the other end of the capacitor C13 and the other end of the resistor R11 respectively. The drain of the N-MOS tube Q10 is grounded, and the gate is connected to the PWM1 end of the PWM switching circuit (105). The transformer L10 primary coil connected to the output of the boost switch and protection circuit (100) corresponds to the secondary coil ground connection, the other end of which is connected to the positive electrode of the diode D11, the negative electrode of which is connected to the HV circuit of the integrated sensor circuit (15), respectively, the other end of the capacitor C14 and the capacitor C15 is grounded, and the negative electrode of the diode D11 is connected to the feedback circuit (102).

7. The pressure measurement and vibration feedback system of claim 3, wherein, The feedback circuit (102) includes resistors R12 and R13 in series, and the circuit node between the resistors R12 and R13 is connected to the HV_FB pin of the pressure detection and boost control chip (12), and the non-connected end of the resistor R12 and the resistor R13 is connected to the output of the flyback switch circuit (101), and the other end of the resistor R13 is grounded.

8. The pressure measurement and vibration feedback system of claim 3, wherein, The discharge circuit (103) includes resistors R14, NPN transistor Q11 and resistor R15, one end of the resistor R14 is connected to the base of the NPN transistor Q11, the other end of the resistor R14 and the PWM2 end of the PWM switching circuit (105) are connected, the emitter of the NPN transistor Q11 is grounded, and the collector is connected to the resistor R15, and the other end of the resistor R15 is connected to the output of the flyback switch circuit (101).

9. The pressure measurement and vibration feedback system of claim 3, wherein, The switch circuit (104) includes a plurality of switch circuit units, and a plurality of integrated sensor pairs are connected.

10. A pressure measurement and vibration feedback system according to claim 9, wherein, In the circuit of one switch circuit unit, an NPN transistor Q2n is connected, the emitter of the NPN transistor Q2n is grounded, the collector is connected to the PZTn pin of the integrated sensor circuit (15), and the base is connected to the OUTn pin of the IO expansion chip (13) after being connected in series with the resistor RZn.

11. The pressure measurement and vibration feedback system of claim 3, wherein, The PWM switching circuit (105) is connected with an analog switch chip U13, the selection pin S of the analog switch chip U13 is connected with PWM_SW, the common pin A of the analog switch chip U13 is connected with PWM0, the B0 pin of the analog switch chip U13 is connected with PWM1, and the B1 pin of the analog switch chip U13 is connected with PWM2; PWM0 end and PWM_SW end are connected to the pressure detection and boost control chip (12), wherein the PWM1 pin of the analog switch chip U13 is connected to the flyback switch circuit (101), and the PWM2 pin of the analog switch chip U13 is connected to the discharge circuit (103).

12. A pressure measurement and vibration feedback system according to claim 11, wherein, The pressure detection and boost control chip (12) configures the PWM_SW pin to be low during boost, so that PWM0 and PWM1 on the analog switch chip U13 are turned on.

13. The pressure measurement and vibration feedback system of claim 11, wherein, The pressure detection and boost control chip (12) configures the PWM_SW pin to be high during discharge, so that PWM0 and PWM2 are turned on.

14. The pressure measurement and vibration feedback system of claim 11, wherein, The PWM switching circuit 105 is used to make only one pressure detection and boost control chip 12 to realize the output and control of the modulation wave of the boost process and the discharge process through time division multiplexing.

15. A method of operating a pressure measurement and vibration feedback system, characterized by, A pressure measurement and haptic feedback system as claimed in any one of claims 1 to 14.

16. The method of operating of claim 15, wherein, The operating method comprises the following steps: Step one, sensor calibration: when powered on, the pressure detection and boost control chip (12) automatically calibrates and clears the pressure value, and the touchpad chip (11) transmits the required vibration level FORCE_LEVEL, the pressure value FORCE_SEN of the finger press, and the pressure value FORCE_SEN_REL of the hand release through the second communication interface. The pressure FORCE_SEN_REL of the hand release is less than the pressure FORCE_SEN of the press; When there is no finger touch on the cover plate (1), the pressure detection and boost control chip (12) performs slow pressure detection through the multi-path differential voltage of multiple Wheatstone bridge circuits and dynamically calibrates the baseline value of each integrated sensor (4); When the finger touches the cover plate (1), the touchpad chip (11) identifies the finger coordinates and the number of fingers through capacitance scanning and calculation, reports the coordinate information of each finger to the host (10), and transmits the information SIG_TOUCH_ON of the finger touch to the pressure detection and boost control chip (12) through the second communication interface; Step two, after receiving the information SIG_TOUCH_ON of the finger touch, the pressure detection and boost control chip (12) increases the pressure detection speed, and continuously compares the pressure values of each integrated sensor (4) and the pressures of all integrated sensors (4). When the set pressure value FORCE_SEN is reached, it is identified as a "key" press, and the Button signal line is pulled low; At the same time, the pressure detection and boost control chip (12) outputs high level DCDC_ON to make the load switch of the load switch chip U10 conductive, and the flyback switching circuit (101) obtains an input voltage of 5V; Step three, the pressure detection and boost control chip (12) confirms the area where the finger is located by searching for the first three integrated sensors (4) with the largest pressure, and sends one or more signals PZT_CNTLN of the piezoelectric ceramic conduction to the IO expansion chip (13) through the third communication interface. Step four, the pressure detection and boost control chip (12) finds the corresponding vibration voltage value HV_VOL1 through the set vibration level FORCE_LEVEL, controls PWM_SW to be low level, and makes the PWM0 signal of the pressure detection and boost control chip (12) conductive to PWM1. The pressure detection and boost control chip (12) finds the corresponding vibration voltage value HV_VOL1 through the set vibration level FORCE_LEVEL, controls PWM_SW to be low level, and makes the PWM0 signal of the pressure detection and boost control chip (12) conductive to PWM1. The pressure detection and boost control chip (12) detects the HV voltage in real time through HW_FB, and when HV_VOL1 is reached, PWM_SW is configured as high level, PWM0 and PWM2 are turned on, and DCDC_ON is set as low level, so that the 5V_A power input of the flyback switching circuit (101) is stopped; The pressure detection and boost control chip (12) further outputs a specific discharge waveform from PWM2 to form a required waveform of the HV drop voltage by looking up a discharge table; The pressure detection and boost control chip (12) confirms the completion of the discharge through HV_FB, PWM0 is output as low, the discharge is completed, and the vibration process of the finger pressing is completed; In step five, the touchpad chip (11) receives the signal of Button pull-down, recognizes that the "key" is pressed, and adds the flag of the "key" pressing in the data reported to the host (10); After the host (10) recognizes the flag of the "key" pressing, the left key or the right key is output in the computer.

17. The method of operating of claim 16, wherein, When the pressure of the finger is always greater than the set pressure value FORCE_SEN, the pressure detection and boost control chip (12) will always output Button as low level, the touchpad chip (11) also reports that the "key" is always pressed, and the host (10) also keeps the left key or the right key always pressed.

18. The method of operating of claim 17, wherein, The highest voltage output by the pressure detection and boost control chip (12) is changed from HV_VOL1 to HV_VOL2 as the vibration effect of releasing the hand, so as to be distinguished from the vibration of pressing; When the finger leaves the surface of the touchpad, the touchpad chip (11) reports to the host (10) that the finger has left, and notifies the signal pin SIG_TOUCH_OFF of the pressure detection and boost control chip (12) through the second communication interface; After receiving the signal SIG_TOUCH_OFF, the pressure detection and boost control chip (12) reduces the pressure scanning speed and clears the value of the pressure baseline at the same time.

19. The method of operating of claim 16, wherein, When the pressure of the finger is less than the pressure FORCE_SEN_REL of releasing the hand, the pressure detection and boost control chip (12) sets Button as high level, the touchpad chip (11) recognizes that the "key" has been released, and adds the flag of the "key" releasing in the data reported to the host (10).

20. The method of operating of claim 16, wherein, In step three, the pressure detection and boost control chip (12) has a built-in vibration table which is calibrated, the input of the vibration table is the position index and the pressure value of the first three maximum pressures, and the output is a plurality of PZT_CNTLN signals corresponding to the turn-on of the piezoelectric ceramic.

21. The method of operating of claim 16, wherein, The operation method further comprises a firmware upgrade method, wherein the touch panel chip (11) sends information to the IO expansion chip (13) through the second communication interface and the third communication interface, so that the IO expansion chip (13) outputs a RESET signal to the pressure detection and boost control chip (12), the RESET signal is used for abnormal recovery of the touch panel chip (11) to the pressure detection and boost control chip (12), and in combination with sending data from the touch panel chip (11) to the pressure detection and boost control chip (12) through the second communication interface, firmware upgrade of the pressure detection and boost control chip (12) is realized.

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