Driving circuit, driving method thereof and ultrasonic transducer device

Abstract

The invention discloses a driving circuit, a driving method thereof and an ultrasonic transducer device, and relates to the technical field of transducers. The driving circuit comprises an inductance circuit which is respectively connected with a signal input end and a signal output end, the signal output end is used for being connected with an ultrasonic transducer, the inductance circuit comprises at least one inductor, and the inductor is used for forming a resonance circuit with a capacitor of the ultrasonic transducer. The resonance circuit generates a resonance signal under the action of an excitation signal input by the signal input end, and the resonance signal is used for driving the ultrasonic transducer to generate ultrasonic waves; the detection circuit is used for detecting an electric signal of the ultrasonic transducer; the control circuit is connected with the detection circuit and the inductance circuit and used for generating a control signal according to the electric signal detected by the detection circuit, and the control signal is used for controlling the inductance circuit to adjust the inductance value of the inductance circuit.

Description

Technical Field

[0001] The present disclosure relates to the field of transducer technology, and in particular to a driving circuit and a driving method thereof, and an ultrasonic transducer device. Background Art

[0002] Ultrasound refers to mechanical waves with a frequency greater than 20KHz. Due to its good directivity and penetration, ultrasound is used in technical fields such as ultrasonic imaging and fingerprint recognition. Summary of the invention

[0003] The present disclosure provides a driving circuit, comprising:

[0004] an inductance circuit, connected to the signal input end and the signal output end respectively, the signal output end is used to connect the ultrasonic transducer, the inductance circuit includes at least one inductor, the inductor is used to form a resonant circuit with the capacitor of the ultrasonic transducer, the resonant circuit generates a resonant signal under the action of the excitation signal input from the signal input end, and the resonant signal is used to drive the ultrasonic transducer to generate ultrasonic waves;

[0005] a detection circuit, used for detecting the electrical signal of the ultrasonic transducer; and

[0006] The control circuit is connected to the detection circuit and the inductance circuit respectively, and is used to generate a control signal according to the electrical signal detected by the detection circuit, and the control signal is used to control the inductance circuit to adjust its own inductance value.

[0007] In some embodiments, the at least one inductor comprises a plurality of fixed inductors, and the inductive circuit further comprises:

[0008] A gating circuit, one end of the fixed inductor is connected to the signal input end, and the other end is connected to the gating circuit, the gating circuit is also connected to the control circuit and the signal output end, and the gating circuit is used to conduct the connection between one or more of the fixed inductors and the signal output end according to the control signal sent by the control circuit.

[0009] In some embodiments, the gating circuit comprises:

[0010] A multiplexer, wherein a control end of the multiplexer is connected to the control circuit, different input ends of the multiplexer are connected to different fixed inductors, and an output end of the multiplexer is connected to the signal output end.

[0011] In some embodiments, the gating circuit includes:

[0012] A plurality of switch elements, control electrodes of different switch elements are connected to different output terminals of the control circuit, the first electrodes of the switch elements are connected to the fixed inductors in a one-to-one correspondence, and the second electrodes of the switch elements are connected to the signal output terminal.

[0013] In some embodiments, the switch element includes at least one of the following: a relay and a transistor.

[0014] In some embodiments, the at least one inductor comprises:

[0015] The adjustable inductor is connected between the signal input terminal and the signal output terminal, the control terminal of the adjustable inductor is connected to the control circuit, and the adjustable inductor is used to adjust its own inductance value according to the control signal sent by the control circuit.

[0016] In some embodiments, the electrical signal is a resonant voltage, the resonant voltage is a voltage peak of the resonant signal, and the detection circuit includes:

[0017] The voltage detection circuit is connected to the signal output end and the control circuit respectively, and is used to detect the resonant voltage of the signal output end and send the resonant voltage to the control circuit. The control circuit is used to generate the control signal according to the resonant voltage.

[0018] In some implementations, the voltage detection circuit includes at least one of the following: a voltage peak detection chip and an analog-to-digital converter.

[0019] In some embodiments, the electrical signal is a capacitance value of the ultrasonic transducer, and the detection circuit includes:

[0020] The capacitance detection circuit is connected to the control circuit and the ultrasonic transducer respectively, and is used to detect the capacitance value of the ultrasonic transducer and send the capacitance value to the control circuit. The control circuit is used to generate the control signal according to the capacitance value.

[0021] In some embodiments, the control circuit includes at least one of the following: a central processing unit, a graphics processing unit, a field programmable logic gate array, an application-specific integrated circuit, and a digital signal processing chip.

[0022] The present disclosure provides an ultrasonic transducer device, comprising: an ultrasonic transducer and a driving circuit as described in any embodiment, wherein the ultrasonic transducer is connected to the signal output terminal.

[0023] In some embodiments, the ultrasonic transducer includes at least one of the following: a capacitive ultrasonic transducer and a piezoelectric ultrasonic transducer.

[0024] The present disclosure provides a driving method, which is applied to a driving circuit as described in any embodiment, and the driving method includes:

[0025] Providing an excitation signal to the signal input terminal so that the resonant circuit generates a resonant signal under the action of the excitation signal, and the resonant signal is used to drive the ultrasonic transducer to generate ultrasonic waves;

[0026] Acquiring an electrical signal detected by the detection circuit;

[0027] A control signal is generated according to the electrical signal, and the control signal is used to control the inductance circuit to adjust its own inductance value so as to increase the voltage of the resonant signal.

[0028] In some embodiments, the electrical signal is a resonant voltage, the resonant voltage is a voltage peak of the resonant signal, the detection circuit includes a voltage detection circuit, the voltage detection circuit is respectively connected to the signal output end and the control circuit, and is used to detect the resonant voltage of the signal output end and send the resonant voltage to the control circuit, and the step of obtaining the electrical signal detected by the detection circuit includes:

[0029] Changing the inductance value of the inductance circuit to obtain the resonant voltage corresponding to each inductance value;

[0030] The step of generating a control signal according to the electrical signal comprises:

[0031] Determine a target resonant voltage from the multiple resonant voltages, determine the inductance value corresponding to the target resonant voltage as the target inductance value, the target resonant voltage being the resonant voltage with the largest peak value among the multiple resonant voltages;

[0032] The control signal is generated according to the target inductance value, so that the inductance circuit adjusts its own inductance value to the target inductance value according to the control signal.

[0033] In some implementations, after the step of determining a target resonant voltage from the plurality of resonant voltages and determining the inductance value corresponding to the target resonant voltage as the target inductance value, the method further includes:

[0034] Calculating the amplification factor corresponding to the target inductance value according to the target resonant voltage and the voltage of the excitation signal;

[0035] The voltage of the excitation signal is adjusted according to the amplification factor and the operating voltage of the ultrasonic transducer.

[0036] In some embodiments, the electrical signal is the capacitance value of the ultrasonic transducer, the detection circuit includes a capacitance detection circuit, the capacitance detection circuit is respectively connected to the control circuit and the ultrasonic transducer, and is used to detect the capacitance value of the ultrasonic transducer and send the capacitance value to the control circuit, and the step of obtaining the electrical signal detected by the detection circuit includes:

[0037] Acquiring a capacitance value detected by the capacitance detection circuit;

[0038] The step of generating a control signal according to the electrical signal comprises:

[0039] Calculating a target inductance value according to the capacitance value and the operating frequency of the ultrasonic transducer;

[0040] The control signal is generated according to the target inductance value, so that the inductance circuit adjusts its own inductance value to the target inductance value according to the control signal.

[0041] The above description is only an overview of the technical solution of the present disclosure. In order to more clearly understand the technical means of the present disclosure, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present disclosure more obvious and easy to understand, the specific implementation methods of the present disclosure are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following is a brief introduction to the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be noted that the proportions in the drawings are only for illustration and do not represent the actual proportions.

[0043] Figure 1 A schematic diagram of the structure of a driving circuit and a voltage waveform in the related art are shown;

[0044] Figure 2 A schematic diagram of the structure and voltage waveform of another driving circuit in the related art are shown;

[0045] Figure 3 A schematic structural diagram of a first driving circuit provided by the present disclosure is shown;

[0046] Figure 4 A schematic diagram showing the structure of a second driving circuit provided by the present disclosure is shown;

[0047] Figure 5 A schematic diagram showing the structure of a third driving circuit provided by the present disclosure is shown;

[0048] Figure 6 A schematic structural diagram of a fourth driving circuit provided by the present disclosure is shown. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0050] In the related art, a driving circuit of an ultrasonic transducer is as follows Figure 1 As shown in a in FIG. 1 , the driving circuit includes an excitation source and an ultrasonic transducer, and the internal resistance of the excitation source is R1. The voltage waveforms at V1 and V2 are obtained by simulating the driving circuit, as shown in FIG. Figure 1 As shown in b, the excitation source provides a sinusoidal signal with a voltage V1 of 1V, the voltage V2 on the ultrasonic transducer is a sinusoidal signal of approximately 0.8V, and the divided voltage V2 on the ultrasonic transducer is significantly lower than the voltage V1 provided by the excitation source.

[0051] In the related art, another driving circuit of the ultrasonic transducer is as follows Figure 2 As shown in a in FIG. 1 , the driving circuit includes an excitation source, an ultrasonic transducer and an inductor. The inductor and the capacitor of the ultrasonic transducer form an LC resonant circuit. The driving circuit is simulated to obtain the voltage waveforms at V1 and V2, respectively. Figure 2 As can be seen from b in the figure, the excitation source provides a 1V sinusoidal signal with a voltage V1, which passes through the LC resonant circuit, and finally applies a 2V sinusoidal signal to the ultrasonic transducer with a voltage V2. It can be seen that the excitation method based on LC resonance can provide a larger excitation voltage to the ultrasonic transducer, and the excitation efficiency is higher.

[0052] However, the inductance L in the LC resonant circuit, the capacitance C of the ultrasonic transducer and the excitation frequency f need to satisfy Under the condition of , the maximum excitation voltage can be provided to the ultrasonic transducer. When the inductance is determined, changing the excitation frequency or the capacitance of the ultrasonic transducer will cause the voltage applied to the ultrasonic transducer to be distorted or reduced.

[0053] In order to efficiently drive ultrasonic transducers 32 with different capacitances or different operating frequencies, the present disclosure provides a driving circuit, such as Figures 3 to 6As shown in any one, the driving circuit includes: an inductance circuit 31, the inductance circuit 31 is connected to the signal input terminal IPT and the signal output terminal OPT respectively, the signal output terminal OPT is used to connect the ultrasonic transducer 32, the inductance circuit 31 includes at least one inductor 311, the inductor 311 is used to form a resonant circuit with the capacitance of the ultrasonic transducer 32, the resonant circuit generates a resonant signal under the action of the excitation signal input by the signal input terminal IPT, and the resonant signal is used to drive the ultrasonic transducer 32 to generate ultrasonic waves; a detection circuit 33, used to detect the electrical signal of the ultrasonic transducer 32; and a control circuit 34, respectively connected to the detection circuit 33 and the inductance circuit 31, used to generate a control signal according to the electrical signal detected by the detection circuit 33, and the control signal is used to control the inductance circuit 31 to adjust its own inductance value.

[0054] In a specific implementation, an excitation signal can be first provided to the signal input terminal IPT, so that the resonant circuit generates a resonant signal at the signal output terminal OPT under the action of the excitation signal, and the resonant signal is used to drive the ultrasonic transducer 32 to generate ultrasonic waves; then the control circuit 34 obtains the electrical signal detected by the detection circuit 33, and sends the electrical signal to the control circuit 34, and the control circuit 34 generates a control signal according to the electrical signal, and the control signal is used to control the inductance circuit 31 to adjust its own inductance value to increase the voltage of the resonant signal.

[0055] The driving circuit provided by the present disclosure can adjust the inductance value of the inductance circuit 31 according to the electrical signal in the driving circuit. Through the adaptive adjustment of the inductance value, the ultrasonic transducer 32 with different capacitance or operating frequency can be efficiently driven, which can greatly save costs.

[0056] For example, Figures 3 to 6 As shown in any one of the above, the inductor 311 may be a fixed inductor 312 (eg Figure 3 , Figure 4 as well as Figure 6 ) or an adjustable inductor 314 (as shown Figure 5 shown).

[0057] In some examples, such as Figure 3 or Figure 4 As shown, at least one inductor 311 includes multiple fixed inductors 312, and the inductor circuit 31 also includes: a gating circuit 313, one end of the fixed inductor 312 is connected to the signal input terminal IPT, and the other end is connected to the gating circuit 313, the gating circuit 313 is also connected to the control circuit 34 and the signal output terminal OPT, and the gating circuit 313 is used to conduct the connection between one or more fixed inductors 312 and the signal output terminal OPT according to the control signal sent by the control circuit 34.

[0058] Exemplarily, the inductance values ​​of the plurality of fixed inductors 312 may be different from each other, which is helpful to increase the adjustment range of the inductance value.

[0059] For example, Figure 3 As shown, the selection circuit 313 includes: a multiplexer MUX, a control end of the multiplexer MUX is connected to the control circuit 34, different input ends of the multiplexer MUX are connected to different fixed inductors 312, and an output end of the multiplexer MUX is connected to the signal output end OPT.

[0060] like Figure 3 As shown, the multiplexer MUX includes a plurality of input terminals, and the input terminals of the multiplexer MUX are connected to the fixed inductors 312 in a one-to-one correspondence.

[0061] For example, Figure 4 As shown, the selection circuit 313 includes: multiple switching elements 41, the control electrodes of different switching elements 41 are connected to different output terminals of the control circuit 34, the first electrodes of the switching elements 41 are connected to the fixed inductors 312 in a one-to-one correspondence, and the second electrodes of the switching elements 41 are connected to the signal output terminal OPT.

[0062] like Figure 4 As shown, a fixed inductor 312 and a switch element 41 form a parallel branch, and a plurality of parallel branches are connected in parallel between the signal input terminal IPT and the signal output terminal OPT.

[0063] Exemplarily, the switch element 41 includes at least one of the following: a relay and a transistor. Figure 4 As shown, the switch element 41 includes a transistor, a control electrode of the transistor is connected to the control circuit 34, a first electrode of the transistor is connected to the fixed inductor 312, and a second electrode of the transistor is connected to the signal output terminal OPT.

[0064] In some examples, such as Figure 5 As shown, at least one inductor 311 includes an adjustable inductor 314, which is connected between the signal input terminal IPT and the signal output terminal OPT. The control terminal of the adjustable inductor 314 is connected to the control circuit 34, and the adjustable inductor 314 is used to adjust its own inductance value according to the control signal sent by the control circuit 34.

[0065] In some examples, the electrical signal is a resonance voltage, and the resonance voltage is a voltage peak of the resonance signal.

[0066] For example, Figure 3As shown, the detection circuit 33 includes a voltage detection circuit 331, which is respectively connected to the signal output terminal OPT and the control circuit 34, for detecting the resonant voltage of the signal output terminal OPT and sending the resonant voltage to the control circuit 34, and the control circuit 34 is used to generate a control signal according to the resonant voltage.

[0067] Exemplarily, the voltage detection circuit 331 includes at least one of the following: a voltage peak detection chip and an analog-to-digital converter, wherein the analog-to-digital converter can detect the analog voltage signal of the signal output terminal OPT, and determine the voltage peak value, ie, the resonant voltage, according to the maximum and minimum values ​​of the analog voltage signal.

[0068] During the driving process, the inductance value of the inductance circuit 31 can be first changed to obtain the resonant voltage corresponding to each inductance value. Then, the target resonant voltage is determined from the multiple resonant voltages, and the inductance value corresponding to the target resonant voltage is determined as the target inductance value, and the target resonant voltage is the resonant voltage with the largest peak value among the multiple resonant voltages. Then, according to the target inductance value, a control signal is generated so that the inductance circuit 31 adjusts its own inductance value to the target inductance value according to the control signal.

[0069] In the case where the inductor circuit 31 includes a plurality of fixed inductors 312 and a gating circuit 313, as shown in FIG. Figure 3 or Figure 4 As shown, a square wave signal with a voltage of v0 can be first provided to the signal input terminal IPT, and the frequency of the square wave signal is the operating frequency f of the ultrasonic transducer 32. Then, the control circuit 34 controls the gating circuit 313 to conduct the connection between each fixed inductor 312 and the ultrasonic transducer 32 one by one, so that the fixed inductors 312-1 to 312-n resonate with the ultrasonic transducer 32 one by one, and the resonant voltage of the signal output terminal OPT changes with the change of the inductance value. In the process of conducting one by one, the voltage detection circuit 331 detects the resonant voltage corresponding to each inductance value, and feeds the resonant voltage back to the control circuit 34. The control circuit 34 compares multiple resonant voltages and selects the resonant voltage with the largest peak value as the target resonant voltage. The inductance value corresponding to the target resonant voltage is the target inductance value of the ultrasonic transducer 32 at the operating frequency f. Then, the control circuit 34 generates a control signal according to the target inductance value and sends the control signal to the selection circuit 313. The selection circuit 313 responds to the control signal to connect the fixed inductor 312 whose inductance value is the target inductance value and the ultrasonic transducer 32, thereby providing a larger resonant voltage to the ultrasonic transducer 32.

[0070] In the case where the inductor circuit 31 includes an adjustable inductor 314, as Figure 5As shown, a square wave signal with a voltage of v0 can be first provided to the signal input terminal IPT, and the frequency of the square wave signal is the operating frequency f of the ultrasonic transducer 32. Then, the control circuit 34 adjusts the control signal to change the inductance value of the adjustable inductor 314, and the adjustable inductors 314 corresponding to different inductance values ​​resonate with the ultrasonic transducer 32 respectively, and the resonant voltage of the signal output terminal OPT changes with the change of the inductance value. In the process of the change of the inductance value, the voltage detection circuit 331 detects the resonant voltage corresponding to each inductance value, and feeds the resonant voltage back to the control circuit 34. The control circuit 34 compares multiple resonant voltages and selects the resonant voltage with the largest peak value as the target resonant voltage. The inductance value corresponding to the target resonant voltage is the target inductance value of the ultrasonic transducer 32 at the operating frequency f. The control circuit 34 then generates a control signal based on the target inductance value and sends the control signal to the control end of the adjustable inductor 314. The adjustable inductor 314 adjusts its own inductance value to the target inductance value in response to the control signal, thereby providing a larger resonant voltage to the ultrasonic transducer 32.

[0071] After determining the target resonant voltage, in order to obtain a resonant voltage consistent with the working voltage of the ultrasonic transducer 32, the amplification factor corresponding to the target inductance value can be calculated based on the target resonant voltage and the voltage of the excitation signal; then, the voltage of the excitation signal can be adjusted based on the amplification factor and the working voltage of the ultrasonic transducer 32.

[0072] Assume that the resonant voltage v corresponding to the fixed inductor 312-n is n The peak value is the largest, then the inductance value of the fixed inductor 312-n is the target inductance value, and then the magnification factor corresponding to the target inductance value can be calculated. Assume that the working voltage of the ultrasonic transducer 32 is v t In order to obtain a resonant voltage consistent with the operating voltage, the voltage of the excitation signal can be adjusted to v′0=v t / γ, such an excitation signal is then amplified by γ times by the resonance circuit, and a resonance signal with a voltage equal to the working voltage can be provided to the ultrasonic transducer 32.

[0073] In some examples, the electrical signal is a capacitance value of ultrasound transducer 32 .

[0074] For example, Figure 6 As shown, the detection circuit 33 includes: a capacitance detection circuit 332, which is connected to the control circuit 34 and the ultrasonic transducer 32 respectively, for detecting the capacitance value of the ultrasonic transducer 32 and sending the capacitance value to the control circuit 34, and the control circuit 34 is used to generate a control signal according to the capacitance value.

[0075] Exemplarily, the capacitance detection circuit 332 includes a standard resistor, which forms an RC parallel circuit with the capacitance of the ultrasonic transducer 32. The capacitance value of the ultrasonic transducer 32 can be calculated based on the resistance value of the standard resistor and the charging time or discharging time of the capacitor.

[0076] During the driving process, the capacitance detection circuit 332 can first detect the capacitance value of the ultrasonic transducer 32 and send the capacitance value to the control circuit 34. The control circuit 34 calculates the target inductance value based on the capacitance value and the operating frequency of the ultrasonic transducer 32, and then generates a control signal based on the target inductance value, so that the inductance circuit 31 adjusts its own inductance value to the target inductance value according to the control signal.

[0077] The control circuit 34 can calculate the target inductance value according to the following formula: Wherein, f is the operating frequency of the ultrasonic transducer 32 , and C is the capacitance value of the ultrasonic transducer 32 .

[0078] In the case where the inductor circuit 31 includes a plurality of fixed inductors 312 and a gating circuit 313, as shown in FIG. Figure 3 or Figure 4 As shown, the control circuit 34 generates a control signal according to the calculated target inductance value and sends the control signal to the selection circuit 313. The selection circuit 313 responds to the control signal to connect the fixed inductor 312 whose inductance value is the target inductance value and the ultrasonic transducer 32, thereby providing a larger resonant voltage to the ultrasonic transducer 32.

[0079] In the case where the inductor circuit 31 includes an adjustable inductor 314, as Figure 5 As shown, the control circuit 34 generates a control signal according to the calculated target inductance value and sends the control signal to the control end of the adjustable inductor 314. The adjustable inductor 314 adjusts its own inductance value to the target inductance value in response to the control signal, thereby providing a larger resonant voltage to the ultrasonic transducer 32.

[0080] In some examples, the control circuit 34 includes at least one of the following: a central processing unit (CPU), a graphics processing unit (GPU), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), and a digital signal processing (DSP) chip, etc.

[0081] The present disclosure provides an ultrasonic transducer device, such as Figures 3 to 6 As shown in any one of the embodiments, the ultrasonic transducer device includes: an ultrasonic transducer 32 and a driving circuit 35 as provided in any one of the embodiments, and the ultrasonic transducer 32 is connected to a signal output terminal OPT of the driving circuit 35 .

[0082] Those skilled in the art can understand that the ultrasonic transducer device provided by the present disclosure has the advantages of the driving circuit provided by any of the above embodiments.

[0083] The ultrasonic transducer device provided by the present disclosure can be applied to a fingerprint recognition device, or can be applied to a display device with a fingerprint recognition function requirement, such as a display panel, a display device, a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a car display device, a smart watch, a fitness wristband, a personal digital assistant, and any other product or component with a display function.

[0084] Exemplarily, the ultrasonic transducer 32 may include a capacitive ultrasonic transducer, such as a capacitive micro-machine ultrasonic transducer (CMUT).

[0085] Exemplarily, the ultrasonic transducer 32 may include a piezoelectric ultrasonic transducer, such as a piezoelectric micro-machine ultrasonic transducer (PMUT).

[0086] Exemplarily, the piezoelectric material in the piezoelectric ultrasonic transducer 32 may include, but is not limited to, one or more piezoelectric materials such as piezoelectric ceramics and polyvinylidene fluoride (PVDF). When the piezoelectric material produces mechanical deformation under pressure, a potential difference will be generated between its two end surfaces, that is, it has a piezoelectric effect.

[0087] Exemplarily, the ultrasonic transducer device includes a plurality of ultrasonic transducers 32 arranged in an array.

[0088] For example, Figures 3 to 6 As shown in any one of the figures, the ultrasonic transducer device may further include an excitation source 30 connected to the signal input terminal IPT for providing an excitation signal to the driving circuit.

[0089] The present disclosure provides a driving method, which is applied to a driving circuit provided in any embodiment, and the driving method includes:

[0090] Step S01: providing an excitation signal to the signal input terminal IPT so that the resonant circuit generates a resonant signal under the action of the excitation signal, and the resonant signal is used to drive the ultrasonic transducer 32 to generate ultrasonic waves.

[0091] Step S02: Acquire the electrical signal detected by the detection circuit 33.

[0092] Step S03: Generate a control signal according to the electrical signal, where the control signal is used to control the inductor circuit 31 to adjust its own inductance value to increase the voltage of the resonant signal.

[0093] The driving method provided by the present disclosure can adjust the inductance value of the inductance circuit 31 according to the electrical signal in the driving circuit. Through the adaptive adjustment of the inductance value, the ultrasonic transducer 32 with different capacitance or working frequency can be efficiently driven, which can greatly save costs.

[0094] In some examples, the electrical signal is a resonant voltage, and the resonant voltage is the voltage peak of the resonant signal. The detection circuit 33 includes a voltage detection circuit 331, which is respectively connected to the signal output terminal OPT and the control circuit 34, and is used to detect the resonant voltage of the signal output terminal OPT and send the resonant voltage to the control circuit 34.

[0095] Exemplarily, step S02 may specifically include:

[0096] Step S11: transform the inductance value of the inductance circuit 31 to obtain the resonant voltage corresponding to each inductance value.

[0097] Exemplarily, step S03 may specifically include:

[0098] Step S12: determining a target resonant voltage from the multiple resonant voltages, and determining an inductance value corresponding to the target resonant voltage as a target inductance value, wherein the target resonant voltage is a resonant voltage with the largest peak value among the multiple resonant voltages.

[0099] Step S13: Generate a control signal according to the target inductance value, so that the inductance circuit 31 adjusts its own inductance value to the target inductance value according to the control signal.

[0100] In the case where the inductor circuit 31 includes a plurality of fixed inductors 312 and a gating circuit 313, as shown in FIG. Figure 3 or Figure 4As shown, a square wave signal with a voltage of v0 can be first provided to the signal input terminal IPT, and the frequency of the square wave signal is the operating frequency f of the ultrasonic transducer 32. Then, the control circuit 34 controls the gating circuit 313 to conduct the connection between each fixed inductor 312 and the ultrasonic transducer 32 one by one, so that the fixed inductors 312-1 to 312-n resonate with the ultrasonic transducer 32 one by one, and the resonant voltage of the signal output terminal OPT changes with the change of the inductance value. In the process of conducting one by one, the voltage detection circuit 331 detects the resonant voltage corresponding to each inductance value, and feeds the resonant voltage back to the control circuit 34. The control circuit 34 compares multiple resonant voltages and selects the resonant voltage with the largest peak value as the target resonant voltage. The inductance value corresponding to the target resonant voltage is the target inductance value of the ultrasonic transducer 32 at the operating frequency f. Then, the control circuit 34 generates a control signal according to the target inductance value and sends the control signal to the selection circuit 313. The selection circuit 313 responds to the control signal to connect the fixed inductor 312 whose inductance value is the target inductance value and the ultrasonic transducer 32, thereby providing a larger resonant voltage to the ultrasonic transducer 32.

[0101] In the case where the inductor circuit 31 includes an adjustable inductor 314, as Figure 5 As shown, a square wave signal with a voltage of v0 can be first provided to the signal input terminal IPT, and the frequency of the square wave signal is the operating frequency f of the ultrasonic transducer 32. Then, the control circuit 34 adjusts the control signal to change the inductance value of the adjustable inductor 314, and the adjustable inductors 314 corresponding to different inductance values ​​resonate with the ultrasonic transducer 32 respectively, and the resonant voltage of the signal output terminal OPT changes with the change of the inductance value. In the process of the change of the inductance value, the voltage detection circuit 331 detects the resonant voltage corresponding to each inductance value, and feeds the resonant voltage back to the control circuit 34. The control circuit 34 compares multiple resonant voltages and selects the resonant voltage with the largest peak value as the target resonant voltage. The inductance value corresponding to the target resonant voltage is the target inductance value of the ultrasonic transducer 32 at the operating frequency f. The control circuit 34 then generates a control signal based on the target inductance value and sends the control signal to the control end of the adjustable inductor 314. The adjustable inductor 314 adjusts its own inductance value to the target inductance value in response to the control signal, thereby providing a larger resonant voltage to the ultrasonic transducer 32.

[0102] Exemplarily, after step S12, the following steps may also be included:

[0103] Step S14: Calculate the amplification factor corresponding to the target inductance value according to the target resonant voltage and the voltage of the excitation signal.

[0104] Step S15: adjusting the voltage of the excitation signal according to the amplification factor and the working voltage of the ultrasonic transducer 32 .

[0105] Assume that the resonant voltage v corresponding to the fixed inductor 312-n is n The peak value is the largest, then the inductance value of the fixed inductor 312-n is the target inductance value, and then the magnification factor corresponding to the target inductance value can be calculated. Assume that the working voltage of the ultrasonic transducer 32 is v t In order to obtain a resonant voltage consistent with the operating voltage, the voltage of the excitation signal can be adjusted to v′0=v t / γ, such an excitation signal is then amplified by γ times by the resonance circuit, and a resonance signal with a voltage equal to the working voltage can be provided to the ultrasonic transducer 32.

[0106] In some examples, the electrical signal is the capacitance value of the ultrasonic transducer 32 , and the detection circuit 33 includes a capacitance detection circuit 332 , which is respectively connected to the control circuit 34 and the ultrasonic transducer 32 , and is used to detect the capacitance value of the ultrasonic transducer 32 and send the capacitance value to the control circuit 34 .

[0107] Exemplarily, step S02 may specifically include:

[0108] Step S21: Obtain the capacitance value detected by the capacitance detection circuit 332.

[0109] Exemplarily, step S03 may specifically include:

[0110] Step S22: Calculate the target inductance value according to the capacitance value and the operating frequency of the ultrasonic transducer 32 .

[0111] Step S23: Generate a control signal according to the target inductance value, so that the inductance circuit 31 adjusts its own inductance value to the target inductance value according to the control signal.

[0112] The control circuit 34 can calculate the target inductance value according to the following formula: Wherein, f is the operating frequency of the ultrasonic transducer 32 , and C is the capacitance value of the ultrasonic transducer 32 .

[0113] In the case where the inductor circuit 31 includes a plurality of fixed inductors 312 and a gating circuit 313, as shown in FIG. Figure 3 or Figure 4 As shown, the control circuit 34 generates a control signal according to the calculated target inductance value and sends the control signal to the selection circuit 313. The selection circuit 313 responds to the control signal to connect the fixed inductor 312 whose inductance value is the target inductance value and the ultrasonic transducer 32, thereby providing a larger resonant voltage to the ultrasonic transducer 32.

[0114] When the inductance circuit 31 includes an adjustable inductor 314, the control circuit 34 generates a control signal based on the calculated target inductance value and sends the control signal to the control end of the adjustable inductor 314. The adjustable inductor 314 adjusts its own inductance value to the target inductance value in response to the control signal, thereby providing a larger resonant voltage to the ultrasonic transducer 32.

[0115] In the present disclosure, “plurality” means two or more, and “at least one” means one or more, unless otherwise clearly and specifically defined.

[0116] In the present disclosure, the orientation or positional relationship indicated by the terms "upper" and "lower" are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0117] In this disclosure, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, product or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, commodity or device comprising the element.

[0118] References in this disclosure to "one embodiment", "some embodiments", "exemplary embodiments", "one or more embodiments", "example", "an example", "some examples", etc. are intended to indicate that a particular feature, structure, material, or characteristic associated with the embodiment or example is included in at least one embodiment or example of the present disclosure. Schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials, or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0119] In the present disclosure, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0120] In this specification, "electrically connected" and "coupled" include the situation where the components are connected together through an element having some electrical function. There is no particular limitation on the "element having some electrical function" as long as it can transmit and receive electrical signals between the connected components. Examples of "element having some electrical function" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other elements having various functions.

[0121] In this specification, the term "same-layer arrangement" refers to a structure formed by patterning two (or more) structures through the same patterning process, and their materials may be the same or different. For example, the materials of the precursors forming the multiple structures arranged in the same layer are the same, and the materials finally formed may be the same or different.

[0122] The polygon in this specification is not a strict polygon, and can be an approximate triangle, rectangle, trapezoid, pentagon or hexagon, etc. There can be some small deformations caused by tolerances, and there can be chamfers, rounded corners, arc edges and deformations.

[0123] “At least one of A, B, and C” has the same meaning as “at least one of A, B, or C” and both include the following combinations of A, B, and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B, and C.

[0124] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0125] The use of "for" or "configured to" in this disclosure is meant to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0126] As used in this disclosure, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0127] As used in the present disclosure, "parallel", "perpendicular", "equal", and "flush" include the situations described and situations similar to the situations described, and the range of the similar situations is within the acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 10° or 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 10° or 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one. "Flush" includes absolute flushness and approximate flushness, wherein the acceptable deviation range of approximate flushness can be, for example, that the distance between the two flushes is less than or equal to 5% of the size of either one.

[0128] It will be understood that when a layer or an element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present between the layer or element and the other layer or substrate.

[0129] The present disclosure describes exemplary embodiments with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown in the present disclosure, but include shape deviations due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of the regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A driving circuit, include: an inductance circuit, connected to the signal input end and the signal output end respectively, the signal output end is used to connect the ultrasonic transducer, the inductance circuit includes at least one inductor, the inductor is used to form a resonant circuit with the capacitor of the ultrasonic transducer, the resonant circuit generates a resonant signal under the action of the excitation signal input from the signal input end, and the resonant signal is used to drive the ultrasonic transducer to generate ultrasonic waves; A detection circuit, used for detecting the electrical signal of the ultrasonic transducer; as well as The control circuit is connected to the detection circuit and the inductance circuit respectively, and is used to generate a control signal according to the electrical signal detected by the detection circuit, and the control signal is used to control the inductance circuit to adjust its own inductance value.

2. The driving circuit according to claim 1, in, The at least one inductor comprises a plurality of fixed inductors, the inductor circuit further comprising: A gating circuit, one end of the fixed inductor is connected to the signal input end, and the other end is connected to the gating circuit, the gating circuit is also connected to the control circuit and the signal output end, and the gating circuit is used to conduct the connection between one or more of the fixed inductors and the signal output end according to the control signal sent by the control circuit.

3. The driving circuit according to claim 2, in, The gating circuit comprises: A multiplexer, wherein a control end of the multiplexer is connected to the control circuit, different input ends of the multiplexer are connected to different fixed inductors, and an output end of the multiplexer is connected to the signal output end.

4. The driving circuit according to claim 2, in, The gating circuit comprises: A plurality of switch elements, control electrodes of different switch elements are connected to different output terminals of the control circuit, the first electrodes of the switch elements are connected to the fixed inductors in a one-to-one correspondence, and the second electrodes of the switch elements are connected to the signal output terminal.

5. The driving circuit according to claim 4, in, The switch element includes at least one of the following: a relay and a transistor.

6. The driving circuit according to claim 1, in, The at least one inductor comprises: The adjustable inductor is connected between the signal input terminal and the signal output terminal, the control terminal of the adjustable inductor is connected to the control circuit, and the adjustable inductor is used to adjust its own inductance value according to the control signal sent by the control circuit.

7. The driving circuit according to claim 1, in, The electrical signal is a resonance voltage, the resonance voltage is a voltage peak of the resonance signal, and the detection circuit includes: The voltage detection circuit is connected to the signal output end and the control circuit respectively, and is used to detect the resonant voltage of the signal output end and send the resonant voltage to the control circuit. The control circuit is used to generate the control signal according to the resonant voltage.

8. The driving circuit according to claim 7, in, The voltage detection circuit includes at least one of the following: a voltage peak detection chip and an analog-to-digital converter.

9. The driving circuit according to claim 1, in, The electrical signal is the capacitance value of the ultrasonic transducer, and the detection circuit includes: The capacitance detection circuit is connected to the control circuit and the ultrasonic transducer respectively, and is used to detect the capacitance value of the ultrasonic transducer and send the capacitance value to the control circuit. The control circuit is used to generate the control signal according to the capacitance value.

10. The driving circuit according to any one of claims 1 to 9, in, The control circuit includes at least one of the following: a central processing unit, a graphics processing unit, a field programmable logic gate array, a dedicated integrated circuit and a digital signal processing chip.

11. An ultrasonic transducer device, include: An ultrasonic transducer and a driving circuit as claimed in any one of claims 1 to 10, wherein the ultrasonic transducer is connected to the signal output terminal.

12. The ultrasonic transducer device according to claim 11, in, The ultrasonic transducer includes at least one of the following: a capacitive ultrasonic transducer and a piezoelectric ultrasonic transducer.

13. A driving method, applied to the driving circuit according to any one of claims 1 to 10, wherein the driving method include: Providing an excitation signal to the signal input terminal so that the resonant circuit generates a resonant signal under the action of the excitation signal, and the resonant signal is used to drive the ultrasonic transducer to generate ultrasonic waves; Acquiring an electrical signal detected by the detection circuit; A control signal is generated according to the electrical signal, and the control signal is used to control the inductance circuit to adjust its own inductance value so as to increase the voltage of the resonant signal.

14. The driving method according to claim 13, in, The electrical signal is a resonance voltage, and the resonance voltage is a voltage peak value of the resonance signal. The detection circuit includes a voltage detection circuit, and the voltage detection circuit is respectively connected to the signal output end and the control circuit, and is used to detect the resonance voltage of the signal output end and send the resonance voltage to the control circuit. The step of obtaining the electrical signal detected by the detection circuit includes: Changing the inductance value of the inductance circuit to obtain the resonant voltage corresponding to each inductance value; The step of generating a control signal according to the electrical signal comprises: Determine a target resonant voltage from the multiple resonant voltages, determine the inductance value corresponding to the target resonant voltage as the target inductance value, the target resonant voltage being the resonant voltage with the largest peak value among the multiple resonant voltages; The control signal is generated according to the target inductance value, so that the inductance circuit adjusts its own inductance value to the target inductance value according to the control signal.

15. The driving method according to claim 14, in, After the step of determining a target resonant voltage from the plurality of resonant voltages and determining the inductance value corresponding to the target resonant voltage as the target inductance value, the method further includes: Calculating the amplification factor corresponding to the target inductance value according to the target resonant voltage and the voltage of the excitation signal; The voltage of the excitation signal is adjusted according to the amplification factor and the operating voltage of the ultrasonic transducer.

16. The driving method according to claim 13, in, The electrical signal is the capacitance value of the ultrasonic transducer, the detection circuit includes a capacitance detection circuit, the capacitance detection circuit is respectively connected to the control circuit and the ultrasonic transducer, and is used to detect the capacitance value of the ultrasonic transducer and send the capacitance value to the control circuit, and the step of obtaining the electrical signal detected by the detection circuit includes: Obtaining a capacitance value detected by the capacitance detection circuit; The step of generating a control signal according to the electrical signal comprises: Calculating a target inductance value according to the capacitance value and the operating frequency of the ultrasonic transducer; The control signal is generated according to the target inductance value, so that the inductance circuit adjusts its own inductance value to the target inductance value according to the control signal.

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