Ultrasonic driving circuit, ultrasonic transmitting circuit and recording shielding device

Abstract

The utility model relates to an ultrasonic wave drive circuit, an ultrasonic wave emission circuit and a recording shielding device, the ultrasonic wave drive circuit comprises a control signal generation unit, a first oscillation unit and a second oscillation unit; the control signal generation unit is used for generating a first control signal and a second control signal; the first oscillation unit is electrically connected with the control signal generation unit to receive the first control signal and can be electrically connected with the positive end of the ultrasonic probe; the first oscillation unit is used for inputting a positive driving signal to the positive end of the ultrasonic probe according to the first control signal and the second control signal; the second oscillation unit is electrically connected with the control signal generation unit to receive the second control signal and can be electrically connected with the negative end of the ultrasonic probe; the second oscillation unit is used for inputting a negative driving signal to the negative end of the ultrasonic probe according to the first control signal and the second control signal; wherein the positive driving signal and the negative driving signal are differential signals. According to the utility model, double-path driving of the ultrasonic probe is realized, and the driving efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of ultrasonic drive circuits, in particular to an ultrasonic drive circuit, an ultrasonic transmitting circuit and a recording blocker. Background Art

[0002] If the ultrasonic probe is driven in the way of LC parallel resonance, see Figure 1 , since the positive terminal and the negative terminal of the ultrasonic probe need to be connected in parallel with the resonance capacitor C1, the ultrasonic probe can only be driven by a single - path voltage (that is, the ultrasonic probe can only be driven by a single - phase power supply), resulting in low drive efficiency. If you want to increase the drive power, it can only be achieved by increasing the drive voltage, which will lead to the complication of the drive circuit and is not conducive to reducing the volume of the drive circuit and the circuit cost. Summary of the Utility Model

[0003] The technical problem to be solved by the utility model is to provide an ultrasonic drive circuit, an ultrasonic transmitting circuit and a recording blocker for the defect of low drive efficiency of the ultrasonic probe existing in the traditional technology.

[0004] The technical solution adopted by the utility model to solve its technical problem is: to construct an ultrasonic drive circuit, including a control signal generation unit, a first oscillation unit and a second oscillation unit;

[0005] The control signal generation unit is used to generate a first control signal and a second control signal; the first oscillation unit is electrically connected to the control signal generation unit to receive the first control signal and can be electrically connected to the positive terminal of the ultrasonic probe; the first oscillation unit is used to input a positive drive signal to the positive terminal of the ultrasonic probe according to the first control signal and the second control signal;

[0006] The second oscillation unit is electrically connected to the control signal generation unit to receive the second control signal and can be electrically connected to the negative terminal of the ultrasonic probe; the second oscillation unit is used to input a negative drive signal to the negative terminal of the ultrasonic probe according to the first control signal and the second control signal; wherein, the positive drive signal and the negative drive signal are differential signals to each other.

[0007] Preferably, the signal formed by the positive drive signal and the negative drive signal is a sine - wave signal.

[0008] Preferably, the first oscillation unit includes a first LC oscillation unit; the second oscillation unit includes a second LC oscillation unit; the first LC oscillation unit is electrically connected to the positive terminal of the ultrasonic probe, and the second LC oscillation unit is electrically connected to the negative terminal of the ultrasonic probe.

[0009] Preferably, the first oscillation unit further includes a first switch; the second oscillation unit further includes a second switch;

[0010] For the first switch, its first terminal is electrically connected to the first LC oscillation unit, and its second terminal is electrically connected to the control signal generation unit; the first switch is configured to conduct or turn off according to the first control signal;

[0011] For the second switch, its first terminal is electrically connected to the second LC oscillation unit, and its second terminal is electrically connected to the control signal generation unit; the second switch is configured to conduct or turn off according to the second control signal;

[0012] When the first switch is turned off and the second switch is turned on, the first LC oscillation unit forms an LC oscillation circuit with the ultrasonic probe and inputs the positive drive signal to the positive terminal of the ultrasonic probe;

[0013] When the first switch is turned on and the second switch is turned off, the second LC oscillation unit forms an LC oscillation circuit with the ultrasonic probe and inputs the negative drive signal to the negative terminal of the ultrasonic probe.

[0014] Preferably, the first LC oscillation unit includes a first inductor unit and a first capacitor unit;

[0015] For the first inductor unit, its first terminal is electrically connected to the drive voltage, its second terminal is electrically connected to the first terminal of the first switch and is grounded through the first capacitor unit, and the second terminal can also be electrically connected to the positive terminal of the ultrasonic probe;

[0016] The second LC oscillation unit includes a second inductor unit and a second capacitor unit;

[0017] For the second inductor unit, its first terminal is electrically connected to the drive voltage, its second terminal is electrically connected to the first terminal of the second switch and is grounded through the second capacitor unit, and the second terminal can also be electrically connected to the negative terminal of the ultrasonic probe.

[0018] Preferably, the first inductor unit includes a first inductor L1, and the first capacitor unit includes a first capacitor C1;

[0019] The first terminal of the first inductor L1 is electrically connected to the drive voltage, the second terminal of the first inductor L1 is electrically connected to the first terminal of the first switch and can be electrically connected to the positive terminal of the ultrasonic probe, and the second terminal of the first inductor L1 is also grounded through the first capacitor C1;

[0020] The second inductor unit includes a second inductor L2, and the second capacitor unit includes a second capacitor C2;

[0021] The first end of the second inductor L2 is electrically connected to the driving voltage. The second end of the second inductor L2 is electrically connected to the first end of the second switch and can be electrically connected to the negative end of the ultrasonic probe. The second end of the second inductor L2 is also electrically connected to ground through the second capacitor C2.

[0022] Preferably, the first switch includes a first MOS transistor Q1. The gate of the first MOS transistor Q1 is electrically connected to the control signal generating unit to receive the first control signal. The drain of the first MOS transistor Q1 is electrically connected to the first LC oscillation unit. The source of the first MOS transistor Q1 is electrically connected to ground.

[0023] The second switch includes a second MOS transistor Q2. The gate of the second MOS transistor Q2 is electrically connected to the control signal generating unit to receive the second control signal. The drain of the second MOS transistor Q2 is electrically connected to the second LC oscillation unit. The source of the second MOS transistor Q2 is electrically connected to ground.

[0024] Preferably, the control signal generating unit includes a square wave generating unit and a square wave amplifying unit.

[0025] The square wave generating unit is used to generate a first square wave signal and a second square wave signal that are differential signals.

[0026] The square wave amplifying unit is electrically connected to the square wave generating unit, the first oscillation unit, and the second oscillation unit respectively. The square wave amplifying unit is used to amplify the amplitudes of the first square wave signal and the second square wave signal to output the first control signal and the second control signal.

[0027] The present invention also constructs an ultrasonic transmitting circuit, including a plurality of ultrasonic probes and the ultrasonic driving circuit described above.

[0028] The first oscillation unit is electrically connected to the positive ends of the ultrasonic probes. The negative driving signal output end of the second oscillation unit is electrically connected to the negative ends of the ultrasonic probes.

[0029] The present invention also constructs a recording blocker, including the ultrasonic transmitting circuit described above.

[0030] In the technical solution provided by the embodiments of the present invention, through the mutual cooperation of the control signal generating unit, the first oscillation unit, and the second oscillation unit, and by inputting differential driving signals to the ultrasonic probes using the first oscillation unit and the second oscillation unit, dual-channel driving of the ultrasonic probes is achieved. This not only enables the driving voltage of the ultrasonic probes to be doubled, thereby efficiently driving the ultrasonic probes without using a high-voltage power supply, but also significantly improves the driving efficiency of the ultrasonic probes, which plays a positive role in simplifying the circuit structure, reducing the circuit volume, and lowering the driving voltage of the probes. Description of the Drawings

[0031] The present utility model will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0032] Figure 1 is a circuit structure block diagram of an ultrasonic drive circuit in the related art;

[0033] Figure 2 is a circuit block diagram of an ultrasonic drive circuit in some embodiments of the present utility model;

[0034] Figure 3 is a waveform diagram of a first square wave signal and a second square wave signal in some embodiments of the present utility model;

[0035] Figure 4 is a circuit schematic diagram of a square wave amplification unit in some embodiments of the present utility model;

[0036] Figure 5 is a waveform diagram of an ultrasonic drive signal in some embodiments of the present utility model;

[0037] Figure 6 is a circuit schematic diagram of a first oscillation unit and a second oscillation unit in some embodiments of the present utility model;

[0038] Figure 7 is a waveform diagram of a first control signal and a second control signal in some embodiments of the present utility model;

[0039] Figure 8 is a waveform diagram of a positive drive signal and a negative drive signal in some embodiments of the present utility model;

[0040] Figure 9 is a circuit schematic diagram in another embodiment of the present utility model, where the first oscillation unit and the second oscillation unit are respectively connected to a plurality of ultrasonic probes. Detailed Embodiments

[0041] In order to have a clearer understanding of the technical features, objectives, and effects of the present utility model, the detailed embodiments of the present utility model will now be described in detail with reference to the drawings.

[0042] It should be noted that the flowcharts shown in the drawings are only illustrative descriptions and do not necessarily include all the contents and operations / steps, nor do they necessarily need to be executed in the described order. For example, some operations / steps can be decomposed, while some operations / steps can be combined or partially combined. Therefore, the actual execution order may change according to the actual situation.

[0043] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software form, or implemented in one or more hardware modules or integrated circuits, or implemented in different networks and / or processor devices and / or microcontroller devices.

[0044] An embodiment of the present utility model discloses an ultrasonic drive circuit, which can be applied to an ultrasonic transmitting circuit. It can not only realize dual-channel driving of an ultrasonic probe, but also has advantages such as high driving efficiency and simple circuit structure. Please refer to Figure 2 , the ultrasonic drive circuit may include a control signal generation unit 1, a first oscillation unit 2, and a second oscillation unit 3.

[0045] The control signal generation unit 1 is used to generate a first control signal and a second control signal. Among them, the first control signal and the second control signal can be square wave signals, sine wave signals, or other waveform signals.

[0046] In some embodiments, as Figure 2 shown, the control signal generation unit 1 may include a square wave generation unit 11 and a square wave amplification unit 12.

[0047] The square wave generation unit 11 is used to generate a first square wave signal and a second square wave signal that are differential signals. Please refer to Figure 3 , the waveform diagram PWM_P corresponds to the waveform diagram of the first square wave signal, and the waveform diagram PWM_N corresponds to the waveform diagram of the second square wave signal. It can be understood that the first square wave signal and the second square wave signal that are differential signals mean that the first square wave signal and the second square wave signal will not be at a high level or a low level at the same time. In addition, the first square wave signal and the second square wave signal can be provided by an existing square wave generation unit 11, such as provided by a single-chip microcomputer, such as a micro control unit MCU, a field programmable gate array FPGA, etc. Obtaining square wave signals through a single-chip microcomputer has advantages such as low acquisition difficulty, simple modulation, and easy signal synchronization.

[0048] The square-wave amplification unit 12 is electrically connected to the square-wave generation unit 11, the first oscillation unit 2, and the second oscillation unit 3 respectively. The square-wave amplification unit 12 is used to amplify the amplitudes of the first square-wave signal and the second square-wave signal, and output a first control signal and a second control signal that are differential signals. Since the voltage amplitudes of the square-wave signals output by some single-chip microcomputers or waveform generators may be relatively low and not sufficient to directly drive the first oscillation unit 2 and the second oscillation unit 3, if the driving ability is insufficient, phenomena such as voltage drop or inability to drive directly may occur. To avoid affecting the normal operation of the ultrasonic probe, in this embodiment, the square-wave amplification unit 12 amplifies the voltage amplitudes of the first square-wave signal and the second square-wave signal to obtain a first control signal and a second control signal with stronger driving ability and better voltage stability respectively, which helps to improve the stability and reliability of the driving circuit.

[0049] In some embodiments, as Figure 4 shown, the square-wave amplification unit 12 may include a MOSFET driver. In this embodiment, a single chip (i.e., the MOSFET driver) can simultaneously amplify the voltage amplitudes of the first square-wave signal and the second square-wave signal, which helps to reduce the circuit volume. Of course, a non-inverting amplifier circuit or an inverting amplifier circuit built with operational amplifiers, or an amplifier circuit built with transistors can also be used, which will not be elaborated here.

[0050] As Figure 2 shown, the first oscillation unit 2 is electrically connected to the control signal generation unit 1 to receive the first control signal, and the first oscillation unit 2 can be electrically connected to the positive terminal of the ultrasonic probe. "Can be electrically connected" means that if this ultrasonic driving circuit is applied to an ultrasonic probe, the first oscillation unit 2 is electrically connected to the positive terminal of the ultrasonic probe. The first oscillation unit 2 is used to input a positive driving signal to the positive terminal of the ultrasonic probe according to the first control signal and the second control signal. Specifically, under the action of the first control signal and the second control signal, the first oscillation unit 2 can cooperate with the ultrasonic probe to oscillate, and input a positive driving signal with a specific frequency to the positive terminal of the ultrasonic probe to drive the ultrasonic probe to work.

[0051] As Figure 2As shown, the second oscillation unit 3 is electrically connected to the control signal generation unit 1 to receive the second control signal, and the second oscillation unit 3 can be electrically connected to the negative terminal of the ultrasonic probe. "Can be electrically connected" means that when this ultrasonic drive circuit is applied to the ultrasonic probe, the second oscillation unit 3 is electrically connected to the negative terminal of the ultrasonic probe. The second oscillation unit 3 is used to input a negative drive signal to the negative terminal of the ultrasonic probe. Among them, the positive drive signal and the negative drive signal are differential signals to each other. Specifically, under the action of the first control signal and the second control signal, the second oscillation unit 3 can cooperate with the ultrasonic probe to oscillate and input a negative drive signal with a specific frequency to the negative terminal of the ultrasonic probe to drive the ultrasonic probe to work. With the cooperation of the first oscillation unit 2 and the second oscillation unit 3, the ultrasonic probe will be driven by the positive drive signal and the negative drive signal, and the positive drive signal and the negative drive signal are differential signals to each other. Compared with driving the ultrasonic probe with a single signal (i.e., single-channel drive), using differential signals to drive can double the voltage output to the ultrasonic probe.

[0052] It can be understood that with the cooperation of the control signal generation unit 1, the second oscillation unit 3 and the first oscillation unit 2, the second oscillation unit 3 and the first oscillation unit 2 will input drive signals to the positive and negative terminals of the ultrasonic probe, enabling the ultrasonic probe to not only draw power from the positive terminal to work, but also draw power from the negative terminal to work, realizing dual-channel driving of the ultrasonic probe. Theoretically, this can double the driving voltage of the ultrasonic probe, enabling the ultrasonic probe to obtain higher driving ability without increasing the driving voltage, that is, it can efficiently drive the ultrasonic probe without using a high-voltage power supply, improving the driving efficiency of the ultrasonic probe and playing a positive role in simplifying the circuit structure, reducing the circuit volume, and lowering the driving voltage of the probe.

[0053] In some embodiments, such as Figure 5 As described, the signal formed by the positive drive signal and the negative drive signal is a sine wave signal. Therefore, if this ultrasonic drive circuit is used to drive the ultrasonic probe, after the positive drive signal and the negative drive signal are respectively input to the positive and negative terminals of the ultrasonic probe, a sine wave signal will be formed to drive the ultrasonic probe. Since the sine wave signal is the fundamental wave and does not contain other frequency signals, it can utilize all the energy to drive the ultrasonic probe to generate ultrasonic waves as much as possible with small energy loss. Therefore, the driving efficiency of the ultrasonic probe can be improved. If other waveform signals, such as square waves, are used, since the square wave includes the fundamental wave and harmonics, only the fundamental wave can effectively drive the ultrasonic probe, while the harmonics will cause energy loss, resulting in large energy loss.

[0054] In some embodiments, such as Figure 6As shown, the first oscillation unit 2 may include a first LC oscillation unit 22. The first LC oscillation unit 22 is electrically connected to the positive terminal of the ultrasonic probe. Correspondingly, the second oscillation unit 3 may include a second LC oscillation unit 32. The second LC oscillation unit 32 is electrically connected to the negative terminal of the ultrasonic probe.

[0055] In this embodiment, the first LC oscillation unit 22 or the second LC oscillation unit 32 is an oscillation circuit composed of an inductor and a capacitor, avoiding using a transformer to form an oscillation circuit, which helps to reduce the volume of the ultrasonic drive circuit. In addition, the first LC oscillation unit 22 or the second LC oscillation unit 32 includes, but is not limited to, existing inductor three-point oscillation circuits or capacitor three-point oscillation circuits, etc., as long as it can generate a sine wave signal with a stable oscillation frequency.

[0056] In some embodiments, as Figure 6 shown, the first oscillation unit 2 may further include a first switch 21. Correspondingly, the second oscillation unit 3 may further include a second switch 31. The first end of the first switch 21 is electrically connected to the first LC oscillation unit 22, and the second end of the first switch 21 is electrically connected to the control signal generation unit 1. The first switch 21 is used to conduct or cut off according to the first control signal. The first LC oscillation unit 22 forms an LC oscillation circuit with the ultrasonic probe (such as SPK1) when the first switch 21 is cut off and the second switch 31 is conducted, and inputs a positive drive signal to the positive terminal of the ultrasonic probe. The first end of the second switch 31 is electrically connected to the second LC oscillation unit 32, and the second end of the second switch 31 is electrically connected to the control signal generation unit 1. The second switch 31 is used to conduct or cut off according to the second control signal. The second LC oscillation unit 32 forms an LC oscillation circuit with the ultrasonic probe when the first switch 21 is conducted and the second switch 31 is cut off, and inputs a negative drive signal to the negative terminal of the ultrasonic probe.

[0057] Furthermore, by controlling the waveforms of the first square wave signal and the second square wave signal, the waveforms of the first control signal and the second control signal can be made into differential and complementary signals as Figure 7 shown, where the waveform diagram OUT_P corresponds to the waveform diagram of the first control signal, and the waveform diagram OUT_N corresponds to the waveform diagram of the second control signal. Under the action of the first control signal and the second control signal, the first switch 21 and the second switch 31 will conduct alternately, that is, when the first switch 21 is cut off, the second switch 31 is conducted, and when the first switch 21 is conducted, the second switch 31 is cut off, which is equivalent to making the ultrasonic probe alternately form an LC oscillation circuit with the first LC oscillation unit 22 and the second LC oscillation unit 32. In this way, the voltage change between the positive and negative terminals of the ultrasonic probe can be referred to Figure 8The signals shown, where the waveform SPK_N corresponds to a negative drive signal and the waveform SPK_P corresponds to the waveform of a positive drive signal. It should be noted that the positive drive signal and the negative drive signal are superimposed to form a sine wave signal.

[0058] In some embodiments, as Figure 6 shown, the first switch 21 may include a first MOS transistor Q1. The gate of the first MOS transistor Q1 is electrically connected to the control signal generation unit 1 to receive a first control signal. The drain of the first MOS transistor Q1 is electrically connected to the first LC oscillation unit 22, and the source of the first MOS transistor Q1 is electrically connected to ground. Correspondingly, the second switch 31 may include a second MOS transistor Q2. The gate of the second MOS transistor Q2 is electrically connected to the control signal generation unit 1 to receive a second control signal. The drain of the second MOS transistor Q2 is electrically connected to the second LC oscillation unit 32, and the source of the second MOS transistor Q2 is electrically connected to ground.

[0059] In this embodiment, the first and second MOS transistors may be NMOS transistors. On the one hand, by utilizing the fast switching characteristics of MOS transistors, the positive and negative drive signals generated by the oscillation of the ultrasonic probe with the first LC oscillation unit 22 or the second LC oscillation unit 32 can be superimposed to form a sine wave signal that is as close as possible to the theoretical standard sine wave, which helps to reduce the waveform distortion, improve the signal frequency stability and control accuracy. On the other hand, by utilizing the characteristic of low on-resistance of MOS transistors, the power consumption of the circuit can be reduced, thereby improving the driving efficiency of the ultrasonic probe. In addition, the drain of the first MOS transistor Q1 corresponds to the first end of the first switch 21, and the gate of the first MOS transistor Q1 corresponds to the second end of the first switch 21. Of course, the first MOS transistor Q1 can also be replaced by an NPN transistor.

[0060] In some embodiments, as Figure 6 shown, the first LC oscillation unit 22 may include a first inductor unit 221 and a first capacitor unit 222. The first end of the first inductor unit 221 is electrically connected to the drive voltage. The second end of the first inductor unit 221 is electrically connected to the first end of the first switch 21 and is electrically connected to ground through the first capacitor unit 222. The second end of the first inductor unit 221 may also be electrically connected to the positive end of the ultrasonic probe. Correspondingly, the second LC oscillation unit 32 may include a second inductor unit 321 and a second capacitor unit 322. The first end of the second inductor unit 321 is electrically connected to the drive voltage. The second end of the second inductor unit 321 is electrically connected to the first end of the second switch 31 and is electrically connected to ground through the second capacitor unit 322. The second end of the second inductor unit 321 may also be electrically connected to the negative end of the ultrasonic probe.

[0061] Please refer to Figure 6, the ultrasonic probe can be equivalent to a capacitor (SPK1). In this embodiment, when the first switch 21 is turned off and the second switch 31 is turned on, the first capacitor unit 222 and the ultrasonic probe form a parallel capacitor, and this parallel capacitor and the first inductor unit 221 form a series LC oscillation circuit. When the first switch 21 is turned on and the second switch 31 is turned off, the second capacitor unit 322 and the ultrasonic probe form another parallel capacitor, and this parallel capacitor and the second inductor unit 321 form another series LC oscillation circuit. Since series resonance is adopted in this embodiment, the two LC oscillation circuits can respectively input drive signals at the positive and negative ends of the ultrasonic probe, achieving the effect of driving the ultrasonic probe in a differential manner, and doubling the driving voltage of the ultrasonic probe. Moreover, when the first control signal and the second control signal are differential signals, since the input voltages of the two LC oscillation circuits are opposite and they work alternately, a drive signal as shown in Figure 8 will be generated at both positive and negative ends of the ultrasonic probe, and a sine wave signal as shown in Figure 5 will be formed inside the ultrasonic probe. That is, finally, the ultrasonic probe can be driven by the sine wave signal. Since the sine wave signal belongs to the fundamental wave and has no harmonics of other frequencies, all energy can be utilized as much as possible to drive the ultrasonic probe, thereby significantly improving the driving efficiency of the ultrasonic probe.

[0062] In some embodiments, as shown in Figure 6 , the first inductor unit 221 may include a first inductor L1, and the first capacitor unit 222 may include a first capacitor C1. The first end of the first inductor L1 is electrically connected to the drive voltage, the second end of the first inductor L1 is electrically connected to the first end of the first switch 21 and can be electrically connected to the positive end of the ultrasonic probe, and the second end of the first inductor L1 is also electrically connected to the ground through the first capacitor C1. In this embodiment, the first LC oscillation unit 22 composed of the first inductor L1 and the first capacitor C1 has the advantages of simple circuit structure and small circuit volume. Of course, to obtain the most ideal resonance effect, the first inductor unit 221 can be composed of multiple inductors in series, parallel, or series-parallel manners. Similarly, the first capacitor unit 222 can be composed of multiple capacitors in series, parallel, or series-parallel manners.

[0063] In some embodiments, as shown in Figure 6As shown, the second inductor unit 321 may include a second inductor L2, and the second capacitor unit 322 may include a second capacitor C2. The first end of the second inductor L2 is electrically connected to the driving voltage, the second end of the second inductor L2 is electrically connected to the first end of the second switch 31 and may be electrically connected to the negative end of the ultrasonic probe, and the second end of the second inductor L2 is also electrically connected to the ground through the second capacitor C2. In this embodiment, the second LC oscillation unit 32 is formed by the second inductor L2 and the second capacitor C2, which has the advantages of simple circuit structure and small circuit volume. Of course, in order to obtain the most ideal resonance effect, the second inductor unit 321 may be composed of multiple inductors in series, parallel or series-parallel connection. Similarly, the second capacitor unit 322 may be composed of multiple capacitors in series, parallel or series-parallel connection.

[0064] In some embodiments, as Figure 2 shown, the ultrasonic driving circuit further includes a power management unit 4, and the power management unit 4 is used to supply power to the ultrasonic driving circuit.

[0065] Please refer to Figure 2 and Figure 6 , the principle of the ultrasonic driving circuit driving the ultrasonic probe to generate ultrasonic waves is as follows.

[0066] The square wave generating unit 11 generates a first square wave signal PWM_P and a second square wave signal PWM_N that are differential signals (as Figure 3 shown). After the two square wave signals are amplified by the square wave amplifying unit 12, a first control signal OUT_P and a second control signal OUT_N are respectively generated (as Figure 7 shown). When the square wave amplifying unit 12 inputs the first control signal OUT_P and the second control signal OUT_N to the first switch 21 and the second switch 31 respectively, the first switch 21 and the second switch 31 will be alternately turned on.

[0067] 1. When the first switch 21 is turned off and the second switch 31 is turned on, the connection end of the second inductor L2 and the second capacitor C2 (i.e., the second end of the second inductor L2) is grounded through the second switch 31. At this time, the first capacitor unit 222 and the ultrasonic probe (equivalent to a capacitor) form a parallel capacitor, and this parallel capacitor and the first inductor unit 221 form a series LC oscillation circuit, and this LC oscillation circuit will generate a positive driving signal SPK_P as Figure 8 shown at the positive end of the ultrasonic probe. Among them, the capacitive reactance of the ultrasonic probe, the first capacitor unit 222, and the first inductor unit 221 need to be matched according to the frequency of the ultrasonic probe to meet

[0068]

[0069] Among them, f is the frequency of the ultrasonic probe, L is the inductance value of the first inductance unit 221, and C is the capacitance value of the parallel capacitance formed by the first capacitance unit 222 and the ultrasonic probe.

[0070] 2. When the first switch 21 is turned on and the second switch 31 is turned off, the connection end of the first inductor L1 and the first capacitor C1 (i.e., the second section of the first inductor L1) is grounded through the first switch 21. At this time, the second capacitor unit 322 and the ultrasonic probe (equivalent to a capacitor) form a parallel capacitance, and this parallel capacitance and the second inductor unit 321 form another series LC oscillation circuit, and this LC oscillation circuit will generate a negative drive signal SPK_N as shown in Figure 8 at the negative end of the ultrasonic probe. Among them, the capacitive reactance of the ultrasonic probe, the second capacitor unit 322, and the second inductor unit 321 need to be matched according to the frequency of the ultrasonic probe to meet

[0071]

[0072] Among them, f is the frequency of the ultrasonic probe, L is the inductance value of the second inductor unit 321, and C is the capacitance value of the parallel capacitance formed by the second capacitor unit 322 and the ultrasonic probe.

[0073] Under the combined action of the positive drive signal SPK_P and the negative drive signal SPK_N, a sine wave signal as shown in Figure 5 will finally be formed in the ultrasonic probe to drive the ultrasonic probe.

[0074] The embodiment of the present invention also provides an ultrasonic transmitting circuit. Refer to Figure 9 , which includes a plurality of ultrasonic probes and the ultrasonic drive circuit provided in the above embodiment of the present invention. The first oscillation unit 2 is electrically connected to the positive ends of each ultrasonic probe, and the second oscillation unit 3 is electrically connected to the negative ends of each ultrasonic probe. Specifically, the frequencies of all ultrasonic probes are the same.

[0075] Please refer to Figure 9 , because each ultrasonic probe can be equivalent to a capacitor, and each ultrasonic probe is connected in parallel with each other. Therefore, all ultrasonic probes can be equivalent to a plurality of capacitors SPK1,..., SPKN connected in parallel with each other, where N is a natural number greater than 1.

[0076] Thus, if the first switch 21 is turned off and the second switch 31 is turned on, the first capacitor unit 222 and all the ultrasonic probes (equivalent to capacitors) form a parallel capacitance, and this parallel capacitance and the first inductor unit 221 form a series LC oscillation circuit, and this LC oscillation circuit will generate a positive drive signal as shown in Figure 8The positive drive signal SPK_P shown. Among them, the capacitive reactance of all ultrasonic probes, the first capacitor unit 222, and the first inductor unit 221 need to be matched according to the frequency of the ultrasonic probes to meet

[0077]

[0078] Among them, f is the frequency of the ultrasonic probe, L is the inductance value of the first inductor unit 221, and C is the capacitance value of the parallel capacitor formed by the first capacitor unit 222 and all ultrasonic probes.

[0079] When the first switch 21 is turned on and the second switch 31 is turned off, the second capacitor unit 322 and all ultrasonic probes (equivalent to capacitors) form a parallel capacitor, and this parallel capacitor and the second inductor unit 321 form another series LC oscillation circuit, and this LC oscillation circuit will generate at the negative end of each ultrasonic probe as Figure 8 The negative drive signal SPK_N shown. Among them, the capacitive reactance of all ultrasonic probes, the second capacitor unit 322, and the second inductor unit 321 need to be matched according to the frequency of the ultrasonic probes to meet

[0080]

[0081] Among them, f is the frequency of the ultrasonic probe, L is the inductance value of the second inductor unit 321, and C is the capacitance value of the parallel capacitor formed by the second capacitor unit 322 and all ultrasonic probes.

[0082] Under the combined action of the positive drive signal SPK_P and the negative drive signal SPK_N, a sine wave signal as shown in Figure 5 will finally be formed in each ultrasonic probe to drive each ultrasonic probe. The embodiment of the present invention also provides a recording blocker, including the ultrasonic transmitting circuit provided in each of the above embodiments of the present invention. After adopting the above ultrasonic transmitting circuit, the recording blocker can emit ultrasonic waves to prevent illegal recording devices from recording.

[0083] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0084] Those skilled in the art may further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present utility model.

[0085] The steps of the methods or algorithms described in combination with the embodiments disclosed herein can be directly implemented by hardware, software modules executed by a processor, or a combination of the two. The software modules can be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium well-known in the technical field.

[0086] It can be understood that the above embodiments only represent the preferred embodiments of the present utility model, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, the above technical features can be freely combined, and several deformations and improvements can also be made, which all belong to the protection scope of the present utility model. Therefore, all equivalent transformations and modifications made to the scope of the claims of the present utility model shall fall within the scope covered by the claims of the present utility model.

Claims

1. An ultrasonic driving circuit, characterized in that: comprising a control signal generating unit, a first oscillating unit and a second oscillating unit; The control signal generating unit is used to generate a first control signal and a second control signal; the first oscillating unit is electrically connected to the control signal generating unit to receive the first control signal, and can be electrically connected to the positive end of the ultrasonic probe; the first oscillating unit is used to input a positive driving signal to the positive end of the ultrasonic probe according to the first control signal and the second control signal; The second oscillation unit is electrically connected to the control signal generating unit to receive the second control signal, and can be electrically connected to the negative end of the ultrasonic probe; the second oscillation unit is used to input a negative drive signal to the negative end of the ultrasonic probe based on the first control signal and the second control signal; wherein the positive drive signal and the negative drive signal are differential signals.

2. The ultrasonic driving circuit according to claim 1, characterized in that: The signal formed by the positive driving signal and the negative driving signal is a sine wave signal.

3. The ultrasonic driving circuit according to claim 1, characterized in that: The first oscillation unit includes a first LC oscillation unit; the second oscillation unit includes a second LC oscillation unit; the first LC oscillation unit is electrically connected to the positive terminal of the ultrasonic probe, and the second LC oscillation unit is electrically connected to the negative terminal of the ultrasonic probe.

4. The ultrasonic driving circuit according to claim 3, characterized in that: The first oscillation unit further includes a first switch; the second oscillation unit further includes a second switch; The first switch has a first end electrically connected to the first LC oscillation unit and a second end electrically connected to the control signal generating unit; the first switch is used to be turned on or off according to the first control signal; The second switch has a first end electrically connected to the second LC oscillation unit and a second end electrically connected to the control signal generating unit; the second switch is used to be turned on or off according to the second control signal; The first LC oscillation unit forms an LC oscillation circuit with the ultrasonic probe when the first switch is turned off and the second switch is turned on, and inputs the positive driving signal to the positive terminal of the ultrasonic probe; The second LC oscillation unit forms an LC oscillation circuit with the ultrasonic probe when the first switch is turned on and the second switch is turned off, and inputs the negative driving signal to the negative terminal of the ultrasonic probe.

5. The ultrasonic driving circuit according to claim 4, characterized in that: The first LC oscillation unit includes a first inductor unit and a first capacitor unit; The first inductor unit has a first end electrically connected to a driving voltage, a second end electrically connected to a first end of the first switch and electrically connected to the ground via the first capacitor unit, and the second end can also be electrically connected to a positive end of the ultrasonic probe; The second LC oscillation unit includes a second inductance unit and a second capacitance unit; The second inductor unit has a first end electrically connected to the driving voltage, a second end electrically connected to the first end of the second switch and electrically connected to the ground via the second capacitor unit, and the second end can also be electrically connected to the negative end of the ultrasonic probe.

6. The ultrasonic driving circuit according to claim 5, characterized in that: The first inductor unit includes a first inductor L1, and the first capacitor unit includes a first capacitor C1; The first end of the first inductor L1 is electrically connected to the driving voltage, the second end of the first inductor L1 is electrically connected to the first end of the first switch and can be electrically connected to the positive end of the ultrasonic probe, and the second end of the first inductor L1 is also electrically connected to the ground via the first capacitor C1; The second inductor unit includes a second inductor L2, and the second capacitor unit includes a second capacitor C2; The first end of the second inductor L2 is electrically connected to the driving voltage, the second end of the second inductor L2 is electrically connected to the first end of the second switch and can be electrically connected to the negative end of the ultrasonic probe, and the second end of the second inductor L2 is also electrically connected to the ground via the second capacitor C2.

7. The ultrasonic driving circuit according to claim 4, characterized in that: The first switch includes a first MOS transistor Q1; a gate of the first MOS transistor Q1 is electrically connected to the control signal generating unit to receive the first control signal, a drain of the first MOS transistor Q1 is electrically connected to the first LC oscillation unit, and a source of the first MOS transistor Q1 is electrically connected to the ground; The second switch includes a second MOS tube Q2; the gate of the second MOS tube Q2 is electrically connected to the control signal generating unit to receive the second control signal, the drain of the second MOS tube Q2 is electrically connected to the second LC oscillation unit, and the source of the second MOS tube Q2 is electrically connected to the ground.

8. The ultrasonic drive circuit according to any one of claims 1 to 7, characterized in that: The control signal generating unit includes a square wave generating unit and a square wave amplifying unit; The square wave generating unit is used to generate a first square wave signal and a second square wave signal which are differential signals. The square wave amplifying unit is electrically connected to the square wave generating unit, the first oscillating unit, and the second oscillating unit respectively; the square wave amplifying unit is used to amplify the amplitudes of the first square wave signal and the second square wave signal to output the first control signal and the second control signal.

9. An ultrasonic transmitting circuit, characterized in that: comprising a plurality of ultrasonic probes, and an ultrasonic drive circuit as claimed in any one of claims 1 to 8; The first oscillation unit is electrically connected to the positive end of each of the ultrasonic probes, and the second oscillation unit is electrically connected to the negative end of each of the ultrasonic probes.

10. A recording jammer, characterized in that: Comprising the ultrasonic transmitting circuit as claimed in claim 9.

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