Ultrasonic transducer

Abstract

The present application provides a technology in which the relative positional relationship of the oscillators is easily stabilized. An ultrasonic transducer (1) includes a plurality of oscillators (11) and a connecting portion (30) that connects the oscillators (11) to each other. The oscillator (11) has a piezoelectric element (21) and a vibrating plate (20) that is joined to the piezoelectric element (21). The connecting portion (30) connects the vibrating plates (20) to each other. The width (W2) of the connecting portion (30) is smaller than the width (W1) of the vibrating plate (20). According to this structure, the relative positional relationship of the oscillators (11) is easily stabilized.

Description

Technical Field

[0001] This invention relates to an ultrasonic transducer. Background Technology

[0002] Patent Document 1 discloses a parametric loudspeaker. This parametric loudspeaker includes a substrate and a plurality of ultrasonic sound generators (vibrators). The plurality of ultrasonic sound generators (vibrators) are independently disposed on the substrate.

[0003] Prior art documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-175935 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] As in Patent Document 1, in a structure in which multiple oscillators are independently arranged on a substrate, the relative positional relationship between the oscillators is difficult to stabilize.

[0008] The purpose of this invention is to provide a technique for stabilizing the relative positional relationship between oscillators.

[0009] Solution for solving the problem

[0010] The ultrasonic transducer of the present invention includes: a plurality of vibrators; and a connecting portion that connects the vibrators to each other. Each vibrator has a piezoelectric element and a vibrating plate coupled to the piezoelectric element. The connecting portion connects the vibrating plates to each other. The width of the connecting portion is smaller than the width of the vibrating plate.

[0011] According to this structure, since the oscillators are connected to each other using connecting parts, the relative positional relationship between the oscillators is easily stabilized. Furthermore, the oscillators are connected to each other via vibrating plates that constitute the oscillators, and the width of the connecting part that links the vibrating plates is smaller than the width of the vibrating plates. Therefore, it is possible to suppress the transmission of vibration between the vibrating plates via the connecting parts.

[0012] Alternatively, the aforementioned vibrating plate may have a notch cut from the outer periphery of the vibrating plate toward the inner side, and the aforementioned connecting portion is partially connected to the inner surface of the notch, and a recess opening toward the outer periphery of the vibrating plate is formed between the inner surface of the notch and the connecting portion.

[0013] When the vibrating plate vibrates, the vibration increases from the nodes towards the outer periphery in the portion of the vibrating plate that forms annular nodes. Therefore, when the connecting part is connected to the outer periphery of the vibrating plate, the larger vibrations at the outer periphery are transmitted to the connecting part. However, according to the above structure, the connecting part is partially connected to the inner surface of the notch cut inward from the outer periphery of the vibrating plate, and a recess opening towards the outer periphery of the vibrating plate is formed between the inner surface of the notch and the connecting part. Therefore, the direct transmission of larger vibrations at the outer periphery to the connecting part can be avoided. Thus, the transmission of vibration between the vibrating plates via the connecting part can be further suppressed.

[0014] Alternatively, the ultrasonic transducer may include a base and multiple clamping members. Alternatively, the clamping members may be annular, disposed between the vibrator and the base, and engaged with both. Alternatively, the bottom of the recess may be disposed in a plane orthogonal to the thickness direction of the vibrating plate, between an inner circle inscribed in the clamping member and an outer circle inscribed in the clamping member.

[0015] Since the oscillator is joined to the base via the clamping member, vibration is difficult to occur in the portion where the clamping member is joined. In the above structure, the bottom of the recess is positioned in the planar direction between the inner circle inscribed in the clamping member and the outer circle inscribed in the clamping member, which is the portion where the vibrating plate is difficult to vibrate. Therefore, the connecting portion is used to connect the vibrating plate in the portion where vibration is difficult to occur. As a result, the transmission of vibration between the vibrating plates via the connecting portion can be further suppressed.

[0016] Alternatively, the clamping member can be configured such that, in the aforementioned planar direction, the vibration nodes of the vibrating plate are arranged between the inner circle of the clamping member and the outer circle of the clamping member.

[0017] According to this structure, the clamping member is unlikely to obstruct the vibration of the vibrating plate. Moreover, since the connecting part is connected near the node of the vibration of the vibrating plate, it is possible to further suppress the transmission of vibration between the vibrating plates via the connecting part.

[0018] Alternatively, the connecting part may protrude beyond the thickness of the vibrating plate.

[0019] According to this structure, it is possible to suppress the expansion of the ultrasonic transducer into a plane orthogonal to the thickness direction of the vibrating plate, and to extend the connecting part.

[0020] Alternatively, the vibrating plate and the connecting part may be conductive. Alternatively, the ultrasonic transducer may have a wiring section that connects the vibrating plate or the connecting part to the conductive circuit. Alternatively, the number of wiring sections may be one or more but less than the number of vibrating plates.

[0021] According to this structure, fewer wiring sections than the number of diaphragm sections can be used to electrically connect all the diaphragm sections connected by the connecting sections to the conductive circuit.

[0022] The effects of the invention

[0023] According to the present invention, the relative positional relationship between the oscillators is easily stabilized. Attached Figure Description

[0024] Figure 1 This is a schematic cross-sectional view showing the ultrasonic transducer of the first embodiment.

[0025] Figure 2 It is a top view of multiple vibrating plates connected by connecting parts.

[0026] Figure 3 It is an enlarged version of the vibrating plate and connecting parts.

[0027] Figure 4 This is a schematic cross-sectional view showing the ultrasonic transducer of the second embodiment.

[0028] Figure 5 This is a schematic cross-sectional view showing the ultrasonic transducer of the third embodiment.

[0029] Figure 6 This is a top view of the state in which multiple vibrating plates of the fourth embodiment are connected by a connecting part. Detailed Implementation

[0030] <First Embodiment>

[0031] Figure 1 The ultrasonic transducer 1 shown is used, for example, in medical or industrial ultrasonic devices. The ultrasonic transducer 1 generates ultrasonic waves when given a drive signal and converts the ultrasonic waves into electrical signals when received.

[0032] The ultrasonic transducer 1 includes multiple vibrators 11, multiple resonators 12, multiple clamping members 13, a base 14, a wiring section 15, multiple second wiring sections 16, and a housing 17.

[0033] The oscillator 11 has a vibrating plate 20 and a piezoelectric element 21. The vibrating plate 20 and the piezoelectric element 21 are each plate-shaped, arranged in an overlapping position and joined together. In addition, in this specification, "joined" is a concept that includes not only structures joined directly, but also structures joined by means of other components.

[0034] The vibrating plate 20 is conductive, for example, made of metal. The vibrating plate 20 is circular. The width (maximum width) W1 of the vibrating plate 20 is greater than the width (maximum width) of any one of the resonator 12, the clamping member 13, and the piezoelectric element 21. The width (maximum width) W1 of the vibrating plate 20 is the length (maximum length) in a direction orthogonal to the thickness direction of the vibrating plate 20. In this embodiment, the width (maximum width) W1 of the vibrating plate 20 is the diameter of the outer periphery of the vibrating plate 20.

[0035] The vibrating plate 20 vibrates to generate annular (more specifically, circular) nodes 22. Nodes 22 are the portions of the vibrating plate 20 with the smallest displacement in the thickness direction or the portions without vibration during vibration. Nodes 22 are uniquely determined by the shape and material of the vibrator 11 and resonator 12. The outer periphery of the vibrating plate 20 is a free end. That is, the ultrasonic transducer 1 is a so-called open type, which is easier to vibrate compared to a closed type where the outer periphery of the vibrating plate 20 is fixed. Nodes 22 are generated in a plane orthogonal to the thickness direction at positions inside the outer periphery and outside the center of the vibrating plate 20. The vibration of the vibrating plate 20 increases from the nodes 22 toward the outer periphery and from the nodes 22 toward the center.

[0036] A resonator 12 is attached to one side of the vibrating plate 20 in the thickness direction, and a piezoelectric element 21 is attached to the other side of the vibrating plate 20 in the thickness direction.

[0037] The resonator 12 resonates with the vibration of the vibrating plate 20 to generate ultrasonic waves. The resonator 12 is conical. The resonator 12 has a flat portion 12A and a conical portion 12B. The flat portion 12A is flat and plate-shaped (more specifically, circular plate-shaped). The flat portion 12A engages with one side of the vibrating plate 20 in the thickness direction. The conical portion 12B extends in a cylindrical shape from the outer periphery of the flat portion 12A toward the side opposite to the vibrating plate 20. The inner periphery of the conical portion 12B has a conical shape that expands toward the side opposite to the vibrating plate 20.

[0038] The piezoelectric element 21 is rectangular in shape when viewed from the thickness direction of the vibrating plate 20. The piezoelectric element 21 has a plate-shaped piezoelectric body 21A and electrodes 21B and 21C respectively disposed on both sides of the piezoelectric body 21A in the thickness direction. The piezoelectric body 21A is formed of piezoelectric ceramic. One of the electrodes 21B and 21C disposed on both sides of the piezoelectric element 21, electrode 21B, is joined to the vibrating plate 20 and electrically connected to the wiring portion 15 via the vibrating plate 20. The other electrode 21C disposed on both sides of the piezoelectric element 21 is electrically connected to the second wiring portion 16. A base 14 is joined to the side of the piezoelectric element 21 opposite to the vibrating plate 20 (that is, the side of the oscillator 11 opposite to the resonator 12) by means of a clamping member 13.

[0039] The clamping member 13 is disposed between the vibrator 11 (more specifically, the piezoelectric element 21) and the base 14, and engages with the vibrator 11 (more specifically, the piezoelectric element 21) and the base 14. The clamping member 13 is insulating and elastic. The clamping member 13 is formed, for example, from rubber or resin incorporating carbon black, calcium carbonate, etc. The clamping member 13 is annular (more specifically, circular). The axial direction of the clamping member 13 is along the thickness direction of the vibrating plate 20, and more specifically, is the same as the thickness direction of the vibrating plate 20. The clamping member 13 is configured such that, in a plane orthogonal to the thickness direction of the vibrating plate 20, a node 22 of the vibration of the vibrating plate 20 is disposed between the inner circle 13A inscribed in the clamping member 13 and the outer circle 13B inscribed in the clamping member 13 (see reference). Figure 3 ).

[0040] The base 14 is made of synthetic resin and serves as a resin platform. The base 14 is plate-shaped. The thickness direction of the base 14 is along the thickness direction of the vibrating plate 20, and more specifically, it is the same as the thickness direction of the vibrating plate 20. A plurality of oscillators 11 are engaged with one side of the base 14 along the thickness direction. The plurality of oscillators 11 are arranged along a plane orthogonal to the thickness direction.

[0041] The wiring section 15 has a metal terminal 15A. The wiring section 15 is electrically connected to the vibrating plate 20. In addition, the wiring section 15 is electrically connected to one of the positive side conductive path and the negative side conductive path (e.g., ground). That is, the wiring section 15 electrically connects the vibrating plate 20 to the aforementioned conductive path.

[0042] The second wiring section 16 has a metal terminal 16A and a helical spring 16B. A substrate through-hole 14A extending along the thickness direction is formed in the base 14. The second wiring section 16 passes through the substrate through-hole 14A. The terminal 16A is fixed to the base 14 at a position that blocks the opening on the side opposite to the vibrating plate 20 side of the substrate through-hole 14A. The extension and contraction direction of the helical spring 16B is along the thickness direction of the vibrating plate 20, more specifically, the same as the thickness direction. The helical spring 16B is disposed between the piezoelectric element 21 and the terminal 16A, and is disposed in a state where it is compressed by being pushed by the piezoelectric element 21 and the terminal 16A. One end of the helical spring 16B contacts the side of the piezoelectric element 21 opposite to the vibrating plate 20 side (i.e., the electrode 21C of the piezoelectric element 21), and the other end contacts the terminal 16A. The second wiring section 16 is electrically connected to another conductive path in the positive electrode conductive path and the negative electrode conductive path (e.g., ground).

[0043] The housing 17 is a component that protects the oscillator 11 and resonator 12 from contact with foreign objects. The housing 17 is fixed to the base 14. The housing 17 has a peripheral wall portion 17A surrounding the oscillator 11 and the resonator 12. A plurality of openings are formed in the housing 17 on the side opposite to the base 14 to the resonator 12, through which ultrasonic waves are transmitted to the outside and enter the housing 17 from the outside.

[0044] like Figure 1 and Figure 2 As shown, the ultrasonic transducer 1 includes a connecting portion 30. The connecting portion 30 connects the transducers 11 to each other. More specifically, the connecting portion 30 connects the vibrating plates 20 to each other. The connecting portion 30 is conductive, for example, made of metal. The width W2 of the connecting portion 30 is smaller than the width (maximum width) W1 of the vibrating plate 20. The connecting portion 30 and the vibrating plate 20 have the same thickness. Both sides of the connecting portion 30 in the thickness direction are flat and flush with both sides of the vibrating plate 20 in the thickness direction. The connecting portion 30 and the vibrating plate 20 are integrally formed from the same component. The vibrating plate 20 and the connecting portion 30 are formed, for example, by cutting a metal plate. In addition, when the connecting portion 30 does not have a constant width, the width W2 of the connecting portion 30 refers to the width of the widest part.

[0045] like Figure 2 As shown, the vibrating plate 20 has a notch 40 cut out from the outer periphery of the vibrating plate 20 toward the inward side. Multiple notches 40 are provided along the circumference of the vibrating plate 20 (four in this embodiment). A connecting portion 30 is connected to the inner surface of the notch 40.

[0046] like Figure 2 As shown, the vibrating plates 20 are arranged along a plane orthogonal to the thickness direction. An X-direction and a Y-direction intersect (orthogonal in this embodiment) in the plane orthogonal to the thickness direction of the vibrating plates 20. The vibrating plates 20 are arranged along both the X and Y directions. Notches 40 are formed on both sides of the vibrating plates 20 in the X direction and on both sides in the Y direction. The connecting portion 30 has a first connecting portion 31 that connects the vibrating plates 20 arranged along the X direction to each other, and a second connecting portion 32 that connects the vibrating plates 20 arranged along the Y direction to each other. The first connecting portion 31 and the second connecting portion 32 are connected intersectingly. The connecting portion 30 has a curved portion when viewed from the thickness direction of the vibrating plates 20. More specifically, as... Figure 3 As shown, the connecting portion 30 has a straight portion 30A extending in a straight line from the inner surface of the notch portion 40 and a curved portion 30B extending in a curved manner from the end of the straight portion 30A on the side opposite to the notch portion 40.

[0047] like Figure 3As shown, a recess 41 is formed between the inner surface of the notch 40 and the connecting portion 30. The bottom 41A of the recess 41 is disposed in a plane direction orthogonal to the thickness direction of the vibrating plate 20 between the inner circle 13A inscribed in the clamping member 13 and the outer circle 13B inscribed in the clamping member 13. Furthermore, the bottom 41A of the recess 41 is the position closest to the center of the vibrating plate 20 in the recess 41 in the aforementioned plane direction. The center of the vibrating plate 20 is the center of the outer circle inscribed in the vibrating plate 20.

[0048] like Figure 1 As shown, multiple vibrating plates 20 are electrically connected via connecting portions 30. One of the multiple vibrating plates 20 is fitted with a wiring portion 15. The wiring portion 15 is electrically connected to one of the positive-side conductive paths and the negative-side conductive path (e.g., ground). In other words, the multiple vibrating plates 20 are electrically connected to the aforementioned conductive path via a single wiring portion 15.

[0049] The following description relates to the effects of the first embodiment.

[0050] In the ultrasonic transducer 1 of the first embodiment, since the oscillators 11 are connected to each other by the connecting portion 30, the relative positional relationship between the oscillators 11 is easily stabilized. Furthermore, the oscillators 11 are connected to each other by the vibrating plates 20 constituting the oscillators 11, and the width of the connecting portion 30 connecting the vibrating plates 20 is smaller than the width of the vibrating plates 20. Therefore, it is possible to suppress the transmission of vibration between the vibrating plates 20 via the connecting portion 30.

[0051] Furthermore, when the vibrating plate 20 vibrates, the vibration increases as it moves from the corrugation 22 towards the outer periphery in the portion of the vibrating plate 20 where the corrugation 22 is formed. Therefore, when the connecting portion 30 is connected to the outer periphery of the vibrating plate 20, the larger vibrations at the outer periphery are transmitted to the connecting portion 30. However, according to the above structure, the connecting portion 30 is partially connected to the inner surface of the notch 40 cut inward from the outer periphery of the vibrating plate 20, and a recess 41 opening towards the outer periphery of the vibrating plate 20 is formed between the inner surface of the notch 40 and the connecting portion 30. Therefore, the situation where the larger vibrations at the outer periphery are directly transmitted to the connecting portion 30 can be avoided. Thus, the transmission of vibration between the vibrating plates 20 via the connecting portion 30 can be further suppressed.

[0052] Furthermore, since the oscillator 11 is joined to the base 14 via the clamping member 13, vibration is difficult to occur in the portion where the clamping member 13 is joined. In the above structure, the bottom 41A of the recess 41 is disposed in the planar direction between the inner circle 13A inscribed in the clamping member 13 and the outer circle 13B inscribed in the clamping member 13, which is the portion where the vibrating plate 20 is difficult to vibrate. Therefore, the connecting portion 30 connects to the portion of the vibrating plate 20 where vibration is difficult to occur. Thus, the transmission of vibration between the vibrating plates 20 via the connecting portion 30 can be further suppressed.

[0053] Furthermore, the clamping member 13 is configured such that, in a plane orthogonal to the thickness direction of the vibrating plate 20, a node 22 for the vibration of the vibrating plate 20 is disposed between an inner circle 13A circumscribed within the clamping member 13 and an outer circle 13B circumscribed outside the clamping member 13. Therefore, the clamping member 13 can hardly obstruct the vibration of the vibrating plate 20. Moreover, since the connecting portion 30 is connected near the node 22 for the vibration of the vibrating plate 20, the transmission of vibration between the vibrating plates 20 via the connecting portion 30 can be further suppressed.

[0054] Furthermore, both the vibrating plate 20 and the connecting portion 30 are conductive, and the wiring portion 15 connects the vibrating plate 20 to the conductive circuit. Moreover, the number of wiring portions 15 is 1, which is less than the number of vibrating plates 20. Therefore, all the vibrating plates 20 connected by the connecting portion 30 can be electrically connected to the conductive circuit using fewer wiring portions 15 than the number of vibrating plates 20.

[0055] <Second Implementation>

[0056] The connecting portion 230 of the ultrasonic transducer 201 in the second embodiment protrudes beyond the vibrating plate 20 in the thickness direction, which differs from the ultrasonic transducer 1 in the first embodiment, but is the same in other respects. In the following description, the same reference numerals are used to refer to the same structures as in the first embodiment, and detailed descriptions are omitted.

[0057] like Figure 4 As shown, the ultrasonic transducer 201 of the second embodiment has a connecting portion 230. The connecting portion 230 protrudes further away from the base 14 than the vibrating plate 20. With this structure, it is possible to suppress the expansion of the ultrasonic transducer 201 in a plane direction orthogonal to the thickness direction of the vibrating plate 20, and it is possible to extend the connecting portion 230.

[0058] <Third Implementation>

[0059] The connecting portion 330 of the ultrasonic transducer 301 in the third embodiment protrudes in the opposite direction to the connecting portion 230 of the ultrasonic transducer 201 in the second embodiment. In the following description, the same reference numerals are used for structures identical to those in the first embodiment, and detailed descriptions are omitted.

[0060] like Figure 5 As shown, the ultrasonic transducer 301 of the third embodiment has a connecting portion 330. The connecting portion 330 protrudes closer to the base 14 than the vibrating plate 20. With this structure, it is possible to suppress the expansion of the ultrasonic transducer 301 in a plane direction orthogonal to the thickness direction of the vibrating plate 20, and it is possible to extend the connecting portion 330.

[0061] <Fourth Implementation>

[0062] The vibrating plate 20 of the ultrasonic transducer 1 in the first embodiment has a notch 40, but it can also be a structure without the notch 40. Furthermore, the connecting portion 30 of the ultrasonic transducer 1 in the first embodiment has a curved portion when viewed from the thickness direction of the vibrating plate 20, but it can also be a structure without the curved portion. In the fourth embodiment, an example of a structure without the notch 40 and a structure where the connecting portion does not have a curved portion will be described.

[0063] In the fourth embodiment, such as Figure 6 As shown, the vibrating plate 420 does not have a notch 40. Furthermore, the connecting portion 430 is straight when viewed from the thickness direction of the vibrating plate 420. With this structure, since the shapes of the vibrating plate 420 and the connecting portion 430 are simple, the molds used to form the vibrating plate 420 and the connecting portion 430 are easy to manufacture.

[0064] <Other Implementation Methods>

[0065] This invention is not limited to the embodiments described above and in the accompanying drawings. For example, the following embodiments are also included within the scope of protection of this invention. Furthermore, the various features of the above-described embodiments and the embodiments described below can be combined in any way as long as they are not contradictory.

[0066] In the above embodiments, the vibrating plate and the connecting part are conductive structures, but they can also be insulating structures.

[0067] In the above embodiments, the connecting part is a structure formed by the same component as the vibrating plate, but it can also be a structure formed by a component different from the vibrating plate.

[0068] Furthermore, the embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The scope of the invention is not limited to the embodiments disclosed herein, and is intended to include all modifications within the scope defined by the claims or their equivalents.

[0069] Explanation of reference numerals in the attached figures

[0070] 1. Ultrasonic transducer; 11. Vibrator; 12. Resonator; 13. Clamping component; 13A. Inscribed circle; 13B. Outscribed circle; 14. Base; 15. Wiring section; 20. Vibrating plate; 21. Piezoelectric element; 21A. Piezoelectric body; 21B. Electrode; 21C. Electrode; 22. Node; 30. Connecting part; 40. Notch; 41. Recess; 41A. Bottom of the recess; 201. Ultrasonic transducer; 230. Connecting part; 301. Ultrasonic transducer; 330. Connecting part; 420. Vibrating plate; 430. Connecting part; W1. Width of the vibrating plate; W2. Width of the connecting part.

Claims

1. An ultrasonic transducer, wherein, The ultrasonic transducer includes: Multiple oscillators; and The connecting part connects the oscillators to each other. The oscillator has a piezoelectric element and a vibrating plate coupled to the piezoelectric element. The piezoelectric element has a piezoelectric body and electrodes disposed on both sides of the piezoelectric body in the thickness direction. The vibrating plate is engaged with one of the electrodes of the piezoelectric element, and a plurality of the vibrators are arranged along a plane orthogonal to the thickness direction. The connecting portion connects the vibrating plates together, and the connecting portion and the plurality of vibrating plates are integrally formed from the same component. The width of the connecting part is smaller than the width of the vibrating plate.

2. The ultrasonic transducer according to claim 1, wherein, The vibrating plate has a notch cut out from its outer periphery toward the inward side. The connecting portion is partially connected to the inner surface of the notch portion. A recess is formed between the inner surface of the notch and the connecting portion, opening toward the outer periphery of the vibrating plate.

3. The ultrasonic transducer according to claim 2, wherein, The ultrasonic transducer includes: base; and Multiple clamping components, The clamping member is ring-shaped and disposed between the oscillator and the base, engaging with both the oscillator and the base. The bottom of the recess is positioned in a plane orthogonal to the thickness direction of the vibrating plate, between the inscribed circle of the clamping member and the circumscribed circle of the clamping member.

4. The ultrasonic transducer according to claim 3, wherein, The clamping member is configured such that, in the planar direction, the vibration nodes of the vibrating plate are arranged between the inscribed circle and the circumscribed circle.

5. The ultrasonic transducer according to any one of claims 1 to 4, wherein, The connecting part protrudes beyond the vibrating plate in the thickness direction.

6. The ultrasonic transducer according to any one of claims 1 to 4, wherein, The vibrating plate and the connecting part are conductive. The ultrasonic transducer has a wiring section that connects the vibrating plate or the connecting part to the conductive circuit. The number of wiring sections is one or more but less than the number of vibration plates.

Images