CN106903037A - Ultrasonic transducer, ultrasonic array probe and ultrasonic image-forming system - Google Patents

Abstract

The invention provides a kind of ultrasonic transducer, ultrasonic array probe and ultrasonic image-forming system, belong to ultrasonic technique field, the ultrasonic transducer includes：The polarised direction of piezoelectric patches group, piezoelectric patches of the piezoelectric patches group including the superposition of at least two through-thickness and two neighboring piezoelectric patches is opposite.The present invention is superimposed by by the different two panels of polarised direction or multi-disc piezoelectric patches, so that the ultrasonic transducer also has multiple synthesis resonant frequencies in addition to the reference frequency with each piezoelectric patches for constituting its working lining, such that it is able to realize high frequency ultrasound imaging and multiple frequency ultrasonic imaging, the bandwidth and imaging resolution of transducer are improve.

Description

Ultrasound transducer, ultrasound array probe and ultrasound imaging system

technical field

The invention relates to the field of ultrasonic technology, in particular to an ultrasonic transducer, an ultrasonic array probe and an ultrasonic imaging system.

Background technique

The ultrasonic transducer is a device that converts electrical signals into ultrasonic signals and converts ultrasonic echoes into electrical signals through the piezoelectric effect and the inverse piezoelectric effect. It is the core device of the ultrasonic imaging system. For example, the probe used in clinical B-ultrasound detection is composed of an array of ultrasonic transducers.

With the development of clinical technology, especially the increasing popularity of interventional ultrasound technology, the resolution requirements of ultrasound imaging are getting higher and higher. The resolution of the ultrasonic image is mainly determined by the center frequency of the ultrasonic transducer. The higher the frequency, the shorter the wavelength and the higher the resolution. However, the traditional technology requires that high-frequency ultrasonic transducers must use very thin piezoelectric ceramic sheets as their working layer. The general thickness is one-half of the wavelength of the working frequency. The thickness of the layer is generally 35 to 40 microns, which poses a great challenge to the processing and development of the transducer. At the same time, with the emergence of new multi-frequency ultrasound imaging technologies, such as harmonic imaging, dual-frequency imaging technology, etc., there are more requirements for the working range of the center frequency of the transducer. At present, the main multi-frequency ultrasonic transducer technologies mainly include multi-layer distribution and reverse distribution, as follows:

The inverse distributed transducer mainly uses the heat treatment process of piezoelectric ceramics such as lithium niobate or lithium tantalate crystals during sintering, so that the polarization directions of the upper and lower layers of the same ceramic sheet are different, so that harmonic vibration is generated when excited, and then formed Broadband ultrasonic transducer. If the thickness of the upper and lower layers is the same, its resonant frequency is twice its reference frequency. However, this method needs to modify the ceramic material itself, which requires high processing technical conditions and devices, and is not easy to popularize.

The multi-layer transducer uses bonding and superposition of multiple identical or different ceramic sheets, and realizes multi-frequency detection or harmonic imaging by controlling the number of excitation and reception sheets. However, the polarization directions of different layers of ceramic sheets are the same. For example, two ceramic sheets of the same thickness are superimposed according to a multi-layer transducer, and their resonant frequency is twice the reference frequency (the center frequency of a single ceramic sheet). However, this method requires wiring and separate control of each layer of ceramic sheets, and the production and control process is relatively complicated.

Contents of the invention

Therefore, the technical problem to be solved by the present invention is that the existing technology of using low-frequency piezoelectric materials to obtain high-frequency ultrasonic signals or multi-frequency ultrasonic signals either requires high processing of piezoelectric materials, or the manufacturing process and control methods are complex.

For this reason, the embodiment of the present invention provides following technical scheme:

An embodiment of the present invention provides an ultrasonic transducer, including: a piezoelectric sheet group, the piezoelectric sheet group includes at least two piezoelectric sheets stacked along the thickness direction and the poles of two adjacent piezoelectric sheets in the opposite direction.

Optionally, electrodes are further included, and the electrodes are respectively connected to the outer surfaces of the piezoelectric sheets on both sides of the piezoelectric sheet group.

Optionally, it also includes at least one backing layer and/or at least one matching layer, and electrodes, the backing layer is set on one side of the piezoelectric sheet group, the matching layer is set on the piezoelectric sheet group On the other side of the electrode group, one of the electrodes is connected to the outermost conductive backing layer, and the other electrode is connected to the outermost conductive matching layer.

Optionally, glue or epoxy resin or silver glue or double-sided adhesive may be used to bond between two adjacent piezoelectric sheets.

Optionally, the piezoelectric sheet is a rectangular sheet, a square sheet, a circular sheet, an annular sheet, a prismatic sheet, a bowl-shaped concave spherical sheet, a convex spherical sheet, or an arc-shaped sheet.

Optionally, the piezoelectric sheet group includes a first piezoelectric sheet disposed on the outermost layer on one side, and at least two second piezoelectric sheets respectively connected to one side of the first piezoelectric sheet.

Optionally, the first piezoelectric sheet is grounded, and the second piezoelectric sheets disposed on the outermost layer are respectively connected to electrodes.

Optionally, the thicknesses of the piezoelectric sheets in the piezoelectric sheet group are the same or different.

Optionally, the piezoelectric sheet is one or more of piezoelectric ceramics, piezoelectric single crystals, piezoelectric films and composite piezoelectric ceramics.

An embodiment of the present invention also provides an ultrasonic array probe, which is characterized in that it comprises: a multi-element array composed of a plurality of ultrasonic transducers arranged in arrangement.

Optionally, the multi-element arrays are distributed in a linear array, a convex array, a bowl concave array or a matrix.

Optionally, the ultrasonic transducers share one bottom or top piezoelectric sheet, and the corresponding top or bottom piezoelectric sheets are arranged separately, wherein the shared piezoelectric sheet can be used as a common ground terminal, and each separately arranged piezoelectric sheet Electrodes are respectively connected to electrodes.

The embodiment of the present invention also provides an ultrasonic imaging system, which is characterized in that it includes: the ultrasonic transducer, the ultrasonic transmitting circuit, the ultrasonic echo receiving circuit, and an ultrasonic echo receiving circuit for processing and converting the ultrasonic echo into an image A processing circuit, and a transceiving switch for switching and conducting the ultrasonic transmitting circuit and the ultrasonic echo receiving circuit.

The technical solution of the present invention has the following advantages:

1. In the ultrasonic transducer provided by the embodiment of the present invention, by superimposing two or more piezoelectric sheets with different polarization directions, the ultrasonic transducer has the reference frequency of each piezoelectric sheet forming its working layer. In addition, there are multiple synthetic resonant frequencies, and it is different from the traditional multi-layer stacked ultrasonic transducer and the traditional inverse layer transducer: when the thickness of each layer of piezoelectric film is the same, the resonance frequency is no longer 2 Double the frequency but triple the frequency. Therefore, low-frequency piezoelectric materials can be used to obtain high-frequency ultrasonic signals, and at the same time, multi-frequency ultrasonic signals can also be obtained. In addition, if a combination of piezoelectric sheets with different thicknesses is used, more combinations of operating frequencies with different changing laws can be obtained. Therefore, high-frequency ultrasonic imaging and multi-frequency ultrasonic imaging can be realized, and the bandwidth and imaging resolution of the transducer can be improved.

2. In the ultrasonic imaging system provided by the embodiment of the present invention, the piezoelectric working layer of the ultrasonic transducer is composed of at least two piezoelectric sheets stacked along the thickness direction, and the polarization directions of two adjacent piezoelectric sheets 1 are opposite, Therefore, it can transmit and receive ultrasonic signals containing different frequencies (reference frequency, synthesized different resonant frequencies) at one time, so that ultrasonic images of different frequencies can be obtained at one time, including ultrasonic echo images of the reference frequency and ultrasonic echoes of each synthesized resonant frequency. Ultrasound images of different frequencies can also be fused accordingly.

3. Since the ultrasonic imaging system provided by the embodiment of the present invention can work at different center frequencies, the working mode can be switched without changing probes with different frequencies. Among them, the low-frequency reference frequency working mode can obtain ultrasonic imaging detection in a deeper range, and the high-frequency multiplication working mode can obtain superficial high-resolution ultrasonic images. That is to say, ultrasonic imaging with different scales and different resolutions can be realized by using one ultrasonic probe. In addition, harmonic imaging can also be realized by using the frequency doubling rule of the ultrasonic transducer and combining microbubbles, which effectively simplifies the previous method of harmonic imaging that requires low-frequency probe excitation and high-frequency probe reception.

Description of drawings

In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the specific implementation or description of the prior art. Obviously, the accompanying drawings in the following description The drawings show some implementations of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work.

Fig. 1 is a schematic structural view of an ultrasonic transducer in Embodiment 1 of the present invention;

FIG. 2 is a schematic structural view of the second ultrasonic transducer in Embodiment 1 of the present invention;

3 is a schematic structural diagram of an ultrasonic array probe in Embodiment 2 of the present invention;

4 is a schematic structural diagram of an ultrasonic array probe in Embodiment 2 of the present invention;

Fig. 5 is a structural block diagram of an ultrasonic imaging system in Embodiment 3 of the present invention;

Fig. 6 is an echo signal spectrum of an inverted layer distributed ultrasonic transducer provided by an embodiment of the present invention.

Reference signs: 1-piezoelectric sheet, 11-piezoelectric working layer, 2-electrode, 3-matching layer, 4-backing layer, 01-first piezoelectric sheet, 02-second piezoelectric sheet, 21- Ultrasonic probe, 22-transmitting switch, 23-pulse transmitter, 24-echo receiver, 25-IL time gain compensation unit, 26-analog-to-digital conversion unit, 27-IL beamforming unit, 28-IL signal processing unit , 29-IL image processing unit, 30-display screen, 31-user control input unit.

detailed description

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, or in a specific orientation. construction and operation, therefore, should not be construed as limiting the invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it can be mechanically or electrically connected; it can be directly connected, or indirectly connected through an intermediary, or it can be the internal communication of two components, which can be wireless or wired connect. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as there is no conflict with each other.

Example 1

As shown in Figures 1 and 2, this embodiment provides an ultrasonic transducer, including: a piezoelectric sheet group, the piezoelectric sheet group includes at least two piezoelectric sheets 1 stacked along the thickness direction and two adjacent piezoelectric sheets 1 Electrode 1 is polarized in the opposite direction.

In the ultrasonic transducer provided in this embodiment, by superimposing two or more piezoelectric sheets 1 with different polarization directions, the ultrasonic transducer has the reference frequency of each piezoelectric sheet 1 forming its working layer. There are also multiple synthetic resonant frequencies, and the difference from the traditional multi-layer superimposed ultrasonic transducer and the traditional reverse layer transducer is that when the thickness of each layer of piezoelectric sheet 1 is the same, the frequency at which the resonance occurs is no longer 2 Double the frequency but triple the frequency. Fig. 6 shows the echo signal spectrum of an inverted layer ultrasonic transducer based on piezoelectric sheets with the same thickness and a center frequency of 20MHz, which contains two peaks of a reference frequency of 20.8MHz and a synthetic resonance frequency of 67MHz. Therefore, low-frequency piezoelectric materials can be used to obtain high-frequency ultrasonic signals, and at the same time, multi-frequency ultrasonic signals can also be obtained. In addition, if a combination of piezoelectric sheets 1 with different thicknesses is used, more combinations of operating frequencies with different changing rules can be obtained. Therefore, high-frequency ultrasonic imaging and multi-frequency ultrasonic imaging can be realized, and the bandwidth and imaging resolution of the transducer are improved.

As a specific embodiment, the ultrasonic transducer further includes electrodes 2, and the electrodes 2 are respectively connected to the outer surfaces of the piezoelectric sheets 1 on both sides of the piezoelectric sheet group. In this embodiment, two or more piezoelectric sheets 1 with different polarization directions are bonded together along the thickness direction to form a piezoelectric working layer 11, and the electrodes 2 are respectively connected to the upper surface and the lower surface of the piezoelectric working layer 11. (that is, the upper surface of the topmost piezoelectric sheet 1 and the lower surface of the bottommost piezoelectric sheet 1) is enough, and there is no need to connect each layer of piezoelectric sheets 1 like a traditional laminated ultrasonic transducer. As shown in Figures 1 and 2, in order to make an ultrasonic imaging probe, a matching layer 3 and a backing layer 4 need to be arranged on the upper and lower surfaces of the piezoelectric working layer 11 of the ultrasonic transducer, that is, the backing layer 4 is arranged on the piezoelectric working layer 11. One side of the piezoelectric sheet group and the matching layer 3 are arranged on the other side of the piezoelectric sheet group. If the backing layer 4 is a conductive material, such as silver glue and metal, etc., the electrodes 2 on the lower surface of the piezoelectric working layer 11 can also be connected on the lower surface of the backing layer 4; The electrodes 2 on the upper surface of the electrical working layer 11 may also be connected to the upper surface of the matching layer 3 . In addition, the backing layer 4 can be multilayer, so one of the electrodes 2 can be connected with the conductive backing layer 4 of the outermost layer; the matching layer 3 can also be multilayer, so another electrode 2 can be connected with the conductive backing layer 4 of the outermost layer Matching layer 3 connections.

Specifically, the above-mentioned two adjacent piezoelectric sheets 1 can be closely bonded by glue or epoxy resin or silver glue or double-sided adhesive. The above-mentioned piezoelectric sheets 1 that form the piezoelectric sheet group can be the same piezoelectric material, or different piezoelectric materials, and can be made of piezoelectric ceramics, piezoelectric single crystals, piezoelectric films, and composite piezoelectric ceramics. One or more of piezoelectric ceramics such as PZT, piezoelectric single crystals such as PMN-PT, piezoelectric films such as PVDF and composite piezoelectric ceramics such as 1-3 piezoelectric composite/2-2 piezoelectric composite, and can also be Other piezoelectric materials with polarization directions. The thicknesses of the piezoelectric sheets 1 can be the same or different, for example, the bottom piezoelectric sheet 1 is 200 microns, and the top piezoelectric sheet 1 is 100 microns. The center frequency of each piezoelectric sheet 1 can be the same or different, for example, the center frequency of the bottom piezoelectric sheet 1 is 15Mhz, and the top piezoelectric sheet 1 is 20MHz. The size and shape of the working area of each piezoelectric sheet 1 can be the same or different. For example, the piezoelectric sheet 1 at the bottom can be a rectangular sheet of 10×5×0.2mm, and the piezoelectric sheet 1 at the top can be It is a square sheet of 5×5×0.2 mm.

As an optional embodiment, the shape of each piezoelectric sheet 1 above can be a rectangular sheet, a square sheet, a circular sheet, an annular sheet, a prismatic sheet, a bowl-shaped concave spherical sheet, a convex spherical sheet, or an arc-shaped sheet.

Example 2

An embodiment of the present invention provides an ultrasonic array probe, which includes: a multi-element array formed by a plurality of ultrasonic transducers arranged in arrangement.

As shown in FIG. 3 , the ultrasonic transducer includes at least two piezoelectric sheet groups, and one side surfaces of the at least two piezoelectric sheet groups are commonly connected by a conductive member. The ultrasonic transducer may include a plurality of piezoelectric sheet groups, and the plurality of piezoelectric sheet groups may form an array as ultrasonic array elements.

As an optional implementation mode, the ultrasonic transducers of this embodiment share a bottom or top piezoelectric sheet, and the corresponding top or bottom piezoelectric sheets are arranged separately, wherein the shared piezoelectric sheet can be used as a common ground terminal, The separately arranged piezoelectric sheets are respectively connected to the electrodes, so as to realize the control of a single ultrasonic transducer.

As shown in FIG. 3 , after the ultrasonic array is formed, each piezoelectric sheet group can have a common backing layer 4 and a common matching layer 3 . However, in order to control each array element (that is, piezoelectric sheet group) separately, electrodes need to be provided on one side of each piezoelectric sheet group, and these electrodes are not electrically connected to each other. For example, the backing layer 4 or the matching layer 3 may be an insulating material, and the electrodes of each piezoelectric sheet group close to the backing layer 4 or the matching layer 3 are arranged on the outer surface of the piezoelectric sheet group. In order to simplify the structure and reduce wiring, the other side of each piezoelectric sheet group can be connected through a metal wire or a conductive matching layer or a conductive backing layer to achieve common grounding. The multi-element array may be a linear array or a convex array or a bowl concave array or a matrix. The slits between each piezoelectric sheet group can be air, or can be filled with insulating fillers such as epoxy resin or rubber.

In addition, the ultrasonic array element may also be composed of the above-mentioned multiple piezoelectric sheet groups, and then the ultrasonic array element is formed into an ultrasonic array.

As one of the modified implementations, as shown in Figure 4, the piezoelectric sheet group includes a first piezoelectric sheet 01 arranged on the outermost layer on one side, at least two of which are respectively connected to one side of the first piezoelectric sheet 01 The second piezoelectric sheet 02. Specifically, the second piezoelectric sheet 02 may have multiple pieces, some of which are respectively superimposed and connected to one side of the first piezoelectric sheet 01, and the other parts are respectively arranged on the second piezoelectric sheet connected to the first piezoelectric sheet 01. 02 above. Each piezoelectric sheet is stacked along the thickness direction, and the polarization directions of adjacent two remain opposite. The first piezoelectric sheet 01 is used as a common bottom or top piezoelectric sheet, and the second piezoelectric sheet 02 connected on one side is separated in groups, and the gap between each group of second piezoelectric sheets 02 can be Air, or it can be filled with an insulating filler such as epoxy or rubber. The first piezoelectric sheet 01 can be connected to an electrode as a common ground terminal, and the electrodes of each group of second piezoelectric sheets 02 are connected independently, that is, the second piezoelectric sheet 02 arranged on the outermost layer is respectively connected to electrodes, thereby realizing independent control. Each group of second piezoelectric sheets 02 stacked along the thickness direction together with the first piezoelectric sheets 01 can be used as an array element, and the multiple groups of second piezoelectric sheets 02 stacked along the thickness direction together with the first piezoelectric sheets 01 An array of ultrasonic transducers can be formed. In this modified embodiment, the piezoelectric sheets may be of the same piezoelectric material or of different piezoelectric materials, and the thicknesses of the piezoelectric sheets may be the same or different.

Example 3

As shown in Figure 5, this embodiment provides an ultrasonic imaging system, including: any ultrasonic transducer with reversed layer distribution provided in the above-mentioned embodiment 1, an ultrasonic transmitting circuit, an ultrasonic echo receiving circuit, and an ultrasonic echo receiving circuit for A processing circuit for processing the ultrasonic echo and converting it into an image, and a transceiving switch (T/R Switch) for switching and conducting the ultrasonic transmitting circuit and the ultrasonic echo receiving circuit.

Specifically, the above-mentioned ultrasonic transducer forms an ultrasonic probe 21; the transceiving switch 22 is used to control the switching of the ultrasonic transmitting circuit and the ultrasonic echo receiving circuit; the ultrasonic transmitting circuit includes a pulse transmitter 23; the ultrasonic echo receiving circuit includes an echo Receiver 24; processing circuit includes IL (inversion layer, inversion layer) time gain compensation (TGC) unit 25, analog-to-digital (A/D) conversion unit 26, IL beam synthesis unit 27, IL signal processing unit 28 and IL image Processing unit 29.

During work, the transceiver switch 22 first controls the conduction of the ultrasonic transmitting circuit, and the pulse transmitter 23 in the ultrasonic transmitting circuit generates a wide-band narrow pulse sequence to excite the ultrasonic transducer to generate ultrasonic waves; the transmitting and receiving switch 22 controls the conduction of the ultrasonic echo receiving circuit , the ultrasonic echo of the detection target is converted into an electric signal by the ultrasonic transducer and then received by the echo receiver 24; the electric signal output by the echo receiver is time-gain compensated by the IL time gain compensation (TGC) unit 25 and passed through The analog-to-digital (A/D) conversion unit 26 converts the digital signal into a digital signal, and then performs beamforming processing on it by the IL beamforming unit 27, and finally performs filtering, denoising and other processing on it by the IL signal processing unit 28, and then is processed by the IL image Unit 29 converts this into visual image information, which can be displayed by display 30 . In addition, the ultrasonic imaging system also includes a user control input unit 31, which can be used to input basic information of the detection target (such as a patient), and can also be used to select the operating frequency (reference frequency or synthesized resonance frequency) and time gain of the ultrasonic probe. Compensation parameters, depth of focus and modes of image processing/display, etc.

When processing the ultrasonic echo signal, it is different from the traditional single center frequency ultrasonic imaging system:

When calculating the time gain, it is necessary to calculate the corresponding gain according to the reference frequency and different resonance frequencies of the ultrasonic transducer; the time gain compensation curve can be calculated by the parameters of the corresponding pre-stored imaging mode and the following function: TGC(i)=Depth( i)*Att(i,f)*IL(f)*2+Base, where i represents the target detection point, Depth(i) represents the depth of the target detection point, Att(i,f) represents the corresponding work of the target detection point Frequency attenuation coefficient, IL (f) represents the operating frequency (base frequency or a synthetic resonant frequency), and Base represents the initial gain.

When performing beamforming processing, it is necessary to perform corresponding beamforming according to the reference frequency and different resonance frequencies of the ultrasonic transducer;

When performing signal processing, it is necessary to perform corresponding signal processing according to the reference frequency and different resonance frequencies of the ultrasonic transducer, that is, different center frequencies;

When performing image processing, it is necessary to perform corresponding image processing according to the reference frequency and different resonance frequencies of the ultrasonic transducer, that is, different center frequencies, so that the signals of different center frequencies can be imaged separately, and the signals of different center frequencies can also be imaged. Signal imaging was performed for fusion. Furthermore, the display can be used to display ultrasound images of different frequencies and the fused ultrasound image.

In the ultrasonic imaging system provided by this embodiment, the piezoelectric working layer of the ultrasonic transducer is composed of at least two piezoelectric sheets 1 superimposed along the thickness direction, and the polarization directions of two adjacent piezoelectric sheets 1 are opposite, so its It can transmit and receive ultrasonic signals containing different frequencies (reference frequency and synthesized different resonant frequencies) at one time, so that ultrasonic images of different frequencies can be obtained at one time, including ultrasonic echo images of the reference frequency and ultrasonic echo images of each synthesized resonant frequency , Ultrasound images of different frequencies can also be fused accordingly.

Since the ultrasonic imaging system provided by this embodiment can work at different center frequencies, the working mode can be switched without changing probes with different frequencies. Among them, the low-frequency reference frequency working mode can obtain ultrasonic imaging detection in a deeper range, and the high-frequency multiplication working mode can obtain superficial high-resolution ultrasonic images. That is to say, ultrasonic imaging with different scales and different resolutions can be realized by using one ultrasonic probe. In addition, harmonic imaging can also be realized by using the frequency doubling rule of the ultrasonic transducer and combining microbubbles, which effectively simplifies the previous method of harmonic imaging that requires low-frequency probe excitation and high-frequency probe reception. Specifically, when using the ultrasonic imaging system to realize ultrasonic imaging with different scales and different resolutions, it is possible to transmit ultrasonic waves containing different reference frequencies (and to form different resonance frequencies) at one time, and to distinguish different ultrasonic waves by filtering after receiving the ultrasonic echo signals. Frequency signal, and then use the filtered signal to convert the ultrasonic image of the corresponding frequency, not only the imaging speed is fast but also the operation is simple.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (13)

1. a kind of ultrasonic transducer, it is characterised in that including：Piezoelectric patches group, the piezoelectric patches group includes at least two along thickness Direction superposition piezoelectric patches and the two neighboring piezoelectric patches polarised direction it is opposite.

2. ultrasonic transducer according to claim 1, it is characterised in that also including electrode, the electrode is connected to The outer surface of the piezoelectric patches of the piezoelectric patches group both sides.

3. ultrasonic transducer according to claim 1, it is characterised in that also including at least one of which back sheet and/or at least One layer of matching layer, and electrode, the back sheet are located at the piezoelectric patches located at the side of the piezoelectric patches group, the matching layer The opposite side of group, one of them described electrode is connected with outermost conductive back sheet, another described electrode with it is outermost Conductive matching layer connection.

4. ultrasonic transducer according to claim 1, it is characterised in that can be by glue between the two neighboring piezoelectric patches Water or epoxy resin or elargol or two-sided glue sticking.

5. ultrasonic transducer according to claim 1, it is characterised in that the piezoelectric patches is rectangular bar thin slice or square Thin slice or thin rounded flakes or annular wafer or prismatic thin slice or bowl-shape concave spherical surface thin slice or convex spherical thin slice or arcuation thin slice.

6. ultrasonic transducer according to claim 1, it is characterised in that the piezoelectric patches group include one located at side most The second piezoelectric patches that first piezoelectric patches, at least two of outer layer are connected with the first piezoelectric patches side respectively.

7. ultrasonic transducer according to claim 6, it is characterised in that the first piezoelectric patches ground connection, located at outermost layer Second piezoelectric patches difference receiving electrode.

8. ultrasonic transducer according to claim 1, it is characterised in that the thickness phase of each piezoelectric patches in the piezoelectric patches group It is same or different.

9. ultrasonic transducer according to claim 1, it is characterised in that the piezoelectric patches uses piezoelectric ceramics, piezoelectricity list One or more in brilliant, piezoelectric membrane and composite piezoelectric ceramic.

10. a kind of ultrasonic array probe, it is characterised in that including：Ultrasonic transduction any one of multiple claim 1-9 Many array element arrays that device is rearranged.

11. ultrasonic array probes according to claim 10, it is characterised in that many array element arrays with linear array, convex battle array, The recessed battle array of bowl face or matrix distribution.

12. ultrasonic array probes according to claim 10, it is characterised in that the ultrasonic transducer shares a bottom Or the piezoelectric patches at top, corresponding top or bottom piezoelectric patches be provided separately, wherein, shared piezoelectric patches can be used as common End, the individual piezoelectric patches difference connection electrode being respectively provided separately.

A kind of 13. ultrasonic image-forming systems, it is characterised in that including：Ultrasonic transducer any one of claim 1-9, Ultrasound emission circuit, ultrasonic echo receiving circuit and for being processed ultrasonic echo and be converted to the process circuit of image, And for switched conductive ultrasound emission circuit and the transmit-receive switch of ultrasonic echo receiving circuit.