JP2007142555A - Ultrasonic probe and ultrasonic diagnostic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic probe in which the design of weighting applied to a transmission strength and reception sensitivity of an ultrasonic wave can be simplified, the beam widths in a slice direction can be uniformized and the side lobes in a slice sound field can be reduced. <P>SOLUTION: An ultrasonic resonator unit 100 includes a dielectric layer unit 130, located in between a piezoelectric element unit 110 and a signal electrode unit 140. The dielectric layer unit 130 comprises a plurality of dielectric layers 131 arranged along the slice direction, and each dielectric layer 131 applies the weighting in the slice direction to the strength of an electric field exerted to a plurality of piezoelectric elements 111 juxtaposed in the slice direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultrasonic probe and an ultrasonic diagnostic apparatus that weights transmission intensity and reception sensitivity of transmitted / received ultrasonic waves, realizes a uniform beam width in the slice direction, and reduces side lobes in a slice sound field. .

  An ultrasonic probe is an apparatus for irradiating ultrasonic waves toward an object and receiving reflected waves from interfaces having different acoustic impedances inside the object for the purpose of imaging the inside of the object. As an ultrasonic imaging apparatus employing such an ultrasonic probe, a medical diagnostic apparatus for inspecting the inside of a human body is known.

  Incidentally, there is an ultrasonic probe called a one-dimensional array ultrasonic probe. This one-dimensional ultrasonic probe includes an ultrasonic transducer unit that transmits and receives ultrasonic waves. The ultrasonic transducer unit is formed on a rectangular parallelepiped piezoelectric element unit made of piezoelectric ceramic that is polarized in the axial direction of the ultrasonic probe, and on two end faces of the piezoelectric element unit that are substantially orthogonal to the axial direction. A signal electrode and a ground electrode.

  The piezoelectric element unit is composed of a plurality of piezoelectric elements arranged in parallel in the array direction at a predetermined interval, and a gap between the piezoelectric elements is not provided to improve the mechanical strength of the piezoelectric element unit. Filled with conductive resin.

  By the way, in the above-described one-dimensional ultrasonic probe, when the same rectangular voltage is applied to each piezoelectric element, the beam width in the slice direction becomes non-uniform, and the side lobe in the slice sound field increases. There are things to do.

  Therefore, in recent years, in order to solve the problems of the beam width and side lobe, several techniques for weighting the intensity of ultrasonic waves to be transmitted and received in the slice direction have been developed.

  For example, there is a technique in which a plurality of grooves are formed in each piezoelectric element at predetermined intervals in the slicing direction, and the driving voltage applied to the part of the piezoelectric element sandwiched between the grooves is weighted (for example, , See Patent Document 3).

  In addition, there is a technique in which a plurality of grooves are formed in each piezoelectric element while changing the interval with respect to the slice direction, and the existence ratio of the piezoelectric elements is weighted (see, for example, Patent Document 2).

Furthermore, there is a technique in which a so-called composite material is used as an ultrasonic vibrator and weights are applied to driving voltages applied to a plurality of piezoelectric elements constituting the composite material (see, for example, Patent Document 3).
JP 05-23331 A Japanese Patent Laid-Open No. 2003-9288A Japanese Patent Laid-Open No. 05-38335

  However, [Patent Document 1] to [Patent Document 3] have the following problems.

  That is, the technique described in [Patent Document 1] complicates the configuration of the device and the circuit, and increases the price of the ultrasonic probe and the ultrasonic diagnostic apparatus.

  Since the technique described in [Patent Document 2] causes a difference in shape between a plurality of piezoelectric elements arranged in parallel in the slice direction, a plurality of vibration modes corresponding to the shape of each piezoelectric element are mixed and desired. Design to obtain weighting becomes difficult.

  Since the technique described in [Patent Document 3] is premised on the use of a composite material, smooth weighting cannot be realized due to a mismatch between the electrode shape and the element shape. In addition, since an electrode is required for each channel, selection of the array pitch is limited.

  The present invention simplifies the design of weighting for ultrasonic transmission intensity and reception sensitivity, and makes it possible to realize a uniform beam width in the slice direction and a reduction in side lobes in the slice sound field. The purpose is to provide.

  In order to solve the above problems and achieve the object, the ultrasonic probe and the ultrasonic diagnostic apparatus of the present invention are configured as follows.

(1) In an ultrasonic probe including an ultrasonic transducer unit that transmits / receives ultrasonic waves to / from a subject, the ultrasonic transducer units are arranged in parallel in a first direction and a second direction orthogonal to each other. A plurality of piezoelectric elements, each of the piezoelectric elements transmitting and receiving ultrasonic waves in a third direction orthogonal to the first direction and the second direction; and A plurality of first electrodes and second electrodes respectively arranged opposite to two end faces substantially orthogonal to the third direction, each of the first electrode and the second electrode being in the second direction A first electrode unit and a second electrode unit for applying an electric field to a plurality of piezoelectric elements arranged side by side, between the piezoelectric element unit and the first electrode unit, or between the piezoelectric element unit and the second electrode unit. Electrode unit And each of the dielectric layers has an electric field strength applied to a plurality of piezoelectric elements juxtaposed in the second direction. And a dielectric layer unit for weighting the direction.

(2) In an ultrasonic probe including an ultrasonic transducer unit that transmits / receives ultrasonic waves to / from a subject, the ultrasonic transducer unit includes a plurality of ultrasonic transducer units arranged in parallel in a first direction. Each of the ultrasonic transducer sections is composed of a plurality of piezoelectric elements arranged in parallel in a second direction orthogonal to the first direction, and each piezoelectric element is in the first direction. And a piezoelectric part that transmits and receives ultrasonic waves in a third direction orthogonal to the second direction, and two end faces that are substantially orthogonal to the third direction of the piezoelectric part, respectively, are arranged opposite to each other to constitute the piezoelectric part A first electrode and a second electrode for applying an electric field to a plurality of piezoelectric elements, and between the piezoelectric portion and the first electrode, or between the piezoelectric portion and the second electrode, The strength of the electric field applied to the plurality of piezoelectric elements constituting the piezoelectric part And a dielectric layer for weighting relative to the second direction.

(3) In the ultrasonic probe described in (1) or (2), the dielectric layer is composed of a dielectric disposed along the second direction, and an area where the dielectric exists. The ratio increases as approaching the two end faces that are substantially orthogonal to the second direction of the piezoelectric element unit.

(4) In the ultrasonic probe described in (3), the dielectric is made of resin.

(5) In the ultrasonic probe described in (1) or (2), the dielectric layer is composed of a dielectric disposed along the second direction, and the thickness of the dielectric is The thickness of the piezoelectric element unit increases as it approaches the two end faces substantially orthogonal to the second direction.

(6) In the ultrasonic probe described in (1) or (2), the dielectric layer is composed of a dielectric disposed along the second direction, and a relative dielectric constant of the dielectric. Becomes smaller as approaching the two end faces substantially orthogonal to the second direction of the piezoelectric element unit.

(7) In the ultrasonic diagnostic apparatus, an ultrasonic probe including an ultrasonic transducer unit that transmits / receives ultrasonic waves to / from a subject, an electric signal is applied to the ultrasonic transducer unit, and the ultrasonic A transmission / reception unit that generates a reception signal corresponding to the reflected wave based on the reflected wave received by the sound wave transducer unit, and an image that generates an image related to the subject based on the reception signal generated by the transmission / reception unit The ultrasonic transducer unit includes a plurality of piezoelectric elements arranged in parallel in a first direction and a second direction orthogonal to each other, and each piezoelectric element is in the first direction and A piezoelectric element unit that transmits and receives ultrasonic waves with respect to a third direction orthogonal to the second direction, and two opposite end faces that are substantially orthogonal to the third direction of the piezoelectric element unit are disposed opposite to each other. A plurality of first electrodes and second electrodes, and each of the first electrodes and the second electrodes applies an electric field to the plurality of piezoelectric elements arranged in parallel in the second direction. A plurality of dielectric layers disposed between the electrode unit and the second electrode unit, and between the piezoelectric element unit and the first electrode unit, or between the piezoelectric element unit and the second electrode unit And each dielectric layer includes a dielectric layer unit that weights the electric field strength applied to the plurality of piezoelectric elements arranged in parallel in the second direction with respect to the second direction. Yes.

(8) In the ultrasonic diagnostic apparatus, an ultrasonic probe including an ultrasonic transducer unit that transmits / receives ultrasonic waves to / from a subject, an electric signal is applied to the ultrasonic transducer unit, and the ultrasonic A transmission / reception unit that generates a reception signal corresponding to the reflected wave based on the reflected wave received by the sound wave transducer unit, and an image that generates an image related to the subject based on the reception signal generated by the transmission / reception unit And the ultrasonic transducer unit includes a plurality of ultrasonic transducer units arranged in parallel in the first direction, and each of the ultrasonic transducer units includes the first direction. A plurality of piezoelectric elements arranged in parallel in a second direction orthogonal to each other, and each piezoelectric element transmits and receives ultrasonic waves in the first direction and a third direction orthogonal to the second direction. A piezoelectric portion; A first electrode and a second electrode, which are respectively arranged opposite to two end faces substantially orthogonal to the third direction of the electric part and apply an electric field to a plurality of piezoelectric elements constituting the piezoelectric part; the piezoelectric part; Weighting with respect to the second direction to the strength of the electric field applied to the plurality of piezoelectric elements that are arranged between the first electrode or between the piezoelectric part and the second electrode and that constitute the piezoelectric part A dielectric layer.

  According to the present invention, weighting design for ultrasonic transmission intensity and reception sensitivity is simplified, and it is possible to realize uniform beam width in the slice direction and reduction of side lobes in the slice sound field.

Hereinafter, the first to third embodiments will be described with reference to the drawings.
(First embodiment)
[Configuration of ultrasonic diagnostic equipment]
FIG. 1 is a schematic view of an ultrasonic diagnostic apparatus according to the first embodiment of the present invention.

  As shown in FIG. 1, the ultrasonic diagnostic apparatus according to the present embodiment images an inside of a subject using ultrasonic waves, and includes an apparatus main body 10 and an ultrasonic probe 20. Yes.

  The apparatus main body 10 is provided with a caster 11 so that a bedside diagnosis can be performed, and a drive signal is applied to the ultrasonic probe 20 and received based on an echo signal acquired by the ultrasonic probe 20. A transmission / reception circuit (transmission / reception unit) 12 that generates a signal and an image generation unit (image generation unit) 13 that generates an ultrasound image of the subject based on the reception signal generated by the transmission / reception circuit 12 are provided. Yes. In addition, a monitor 14 that displays an ultrasonic image generated by the image generation unit 13 is disposed on the upper part of the apparatus main body 10. The apparatus main body 10 and the ultrasonic probe 20 are connected by a cable 15, and data communication is performed by the cable 15.

  FIG. 2 is a perspective view of the ultrasonic probe 20 according to the embodiment. In FIG. 2, the probe case is omitted.

  As shown in FIG. 2, the ultrasonic probe 20 according to the present embodiment is a so-called one-dimensional array type ultrasonic probe, and includes an ultrasonic transducer unit 100 that transmits and receives ultrasonic waves to and from a subject, An acoustic matching unit 200 that is disposed in front of the acoustic transducer unit 100 and matches the acoustic impedance of the ultrasound transducer unit 100 and the subject, and an ultrasound matching unit 200 that is disposed in front of the acoustic matching unit 200 and is transmitted and received. An acoustic lens 300 that converges the beam width in the slice direction, a flexible substrate 400 that is disposed opposite to the side surface of the ultrasonic transducer unit 100 and connects the ultrasonic transducer unit 100 and the cable 15, and the ultrasonic transducer unit 100 Backing that is disposed on the back surface of the ultrasonic transducer unit 100 and absorbs ultrasonic waves transmitted from the ultrasonic transducer unit 100 to the back surface It is and a 500.

  Hereinafter, these constituent requirements will be described in detail.

[Ultrasonic transducer unit 100]
FIG. 3 is a perspective view of the ultrasonic transducer unit 100 according to the embodiment.

  As shown in FIG. 3, the ultrasonic transducer unit 100 according to this embodiment includes a piezoelectric element unit 110, a ground electrode unit 120, a dielectric layer unit 130, and a signal electrode unit 140.

  The piezoelectric element unit 110 is composed of a plurality of piezoelectric elements 111 arranged in parallel in a first direction and a second direction orthogonal to each other, and the piezoelectric element unit 110 is disposed in a gap between the piezoelectric element 111 and the piezoelectric element 111. In order to improve the mechanical strength of 110, a non-conductive resin 112 such as epoxy is filled.

  These piezoelectric elements 111 are formed of piezoelectric ceramics in a thin rod shape, and are polarized with respect to a first direction and a third direction orthogonal to the second direction by prior processing. In addition, although the raw material of piezoelectric ceramic is not specifically limited, 1-3 composite is used in this embodiment. Hereinafter, the first direction is the array direction, the second direction is the slice direction, and the third direction is the axial direction.

  The ground electrode unit 120 is disposed on the front surface of the piezoelectric element unit 110, and includes a plurality of ground electrodes 121 arranged in parallel in the array direction. Each ground electrode 121 is disposed so as to cover a plurality of piezoelectric elements 111 arranged in parallel in the slice direction, and a common ground voltage is applied to these piezoelectric elements 111. The material of the ground electrode 121 is not particularly limited, but a metal such as copper having good conductivity is used in this embodiment.

  The dielectric layer unit 130 is disposed on the back surface of the piezoelectric element unit 110, and includes a plurality of dielectric layers 131 having a low relative dielectric constant arranged in parallel in the array direction. Each dielectric layer 131 is composed of a plurality of dielectrics 1311 arranged in parallel in the slice direction, and is disposed so as to partially cover the plurality of piezoelectric elements 111 arranged in parallel in the slice direction. The material of the dielectric layer 131 is not particularly limited, but in this embodiment, a resin such as epoxy (relative permittivity: 2 to 50) is used as a material having a low relative permittivity. The thickness of the dielectric layer 131 is set to about 2 μm.

  The area ratio in which the dielectric 1311 exists is determined so as to increase as it approaches the two end surfaces 110a substantially orthogonal to the slice direction of the piezoelectric element unit 110 according to a weighting function such as a Hamming function. Hereinafter, an end surface substantially orthogonal to the slice direction is referred to as a slice end surface 110a. In this embodiment, the Hamming function is used as the weighting function, but the present invention is not limited to this. For example, a harmonic function may be used.

  The signal electrode unit 140 is disposed on the back surface of the piezoelectric element unit 110 and includes a plurality of signal electrodes 141 arranged in parallel in the array direction. The material of the signal electrode 141 is not particularly limited, but copper is used as a highly conductive metal in the present embodiment. Each signal electrode 141 includes signal electrode pieces 1411 arranged in parallel in the slice direction, and applies a signal voltage to a plurality of piezoelectric elements 111 arranged in parallel in the slice direction. Each signal electrode piece 1411 is disposed in a gap between the dielectric 1311 and the dielectric 1311, and the thickness thereof is equivalent to that of the dielectric 1311. That is, the signal electrode unit 140 and the dielectric layer unit 130 are disposed at the same position with respect to the axial direction of the ultrasonic probe 20.

  A plurality of signal wirings (described later) 421 included in the flexible substrate 400 are bonded to the back surfaces of the dielectric layer unit 130 and the signal electrode unit 140 along the slice direction. Each signal wiring 421 electrically connects a plurality of dielectrics 1311 and signal electrode pieces 1411 arranged in parallel in the slice direction.

  As described above, a portion where the dielectric 1311 exists and a portion where the dielectric 1311 does not exist are formed between the piezoelectric element unit 110 and the signal wiring 421. The area ratio in which the dielectric 1311 exists is determined so as to become smaller as the slice end surface 110a of the piezoelectric element unit 110 is approached.

  Thereby, the intensity of the electric field applied to the piezoelectric element 111 decreases as the slice end face 110a of the piezoelectric element unit 110 approaches, and approaches the center portion with respect to the slice direction as the distance from the slice end face 110a of the piezoelectric element unit 110 increases. As it grows.

  In the present embodiment, the signal wiring 421 is regarded as a part of the signal electrode 141. Thereby, it can be understood that the dielectric layer unit 130 is disposed between the piezoelectric element unit 110 and the signal electrode unit 140.

[Acoustic matching unit 200]
As shown in FIG. 2, the acoustic matching unit 200 according to the present embodiment is composed of a plurality of acoustic matching bodies 210 arranged in parallel in the array direction, and in the gap between the acoustic matching body 210 and the acoustic matching body 210. Is filled with a non-conductive resin 220 such as epoxy.

  Each acoustic matching body 210 is disposed so as to cover the plurality of piezoelectric elements 111 arranged in parallel in the slice direction, and the acoustic impedance changes stepwise from the ultrasonic transducer unit 100 toward the subject. In addition, the first acoustic matching body 211 and the second acoustic matching body 212 are made of different materials.

[Acoustic lens 300]
As shown in FIG. 2, the acoustic lens 300 covers all the acoustic matching bodies 210 constituting the acoustic matching unit 200. The material of the acoustic lens 300 is not particularly limited, but in the present embodiment, a silicone rubber having an acoustic impedance close to the subject, that is, the living body is used.

[Flexible substrate 400]
The flexible substrate 400 has a two-layer structure. A ground wiring 411 is disposed inside the first layer 410, and a plurality of electrically independent signal wirings 421 are disposed in the second layer 420. Has been. The ground wiring 411 is electrically connected to all the ground electrodes 121 arranged in parallel in the array direction. As described above, each signal wiring 421 is electrically connected to the plurality of dielectrics 1311 and signal electrode pieces 1411 arranged in parallel in the slice direction. The material of the ground wiring 411 and the signal wiring 421 is not particularly limited, but copper is used as a metal having good conductivity in this embodiment.

[Backing material 500]
The backing material 500 is formed in a rectangular block shape, and a groove 510 is formed on the front surface thereof at a position corresponding to the gap between the piezoelectric element 111 and the piezoelectric element 111. These grooves 510 are formed in the manufacturing process of the ultrasonic probe 20, and the inside thereof is filled with a non-conductive resin 520 such as epoxy.

[Manufacturing process of ultrasonic probe 20]
FIG. 4 is an explanatory diagram of the manufacturing process of the ultrasonic probe 20 according to the embodiment.
First, as shown in FIG. 4A, a 1-3 composite piezoelectric block 110A is prepared. The 1-3 composite type piezoelectric body block 110A is composed of a plurality of piezoelectric elements 111 arranged in parallel in the array direction and the slice direction, and a gap between the piezoelectric element 111 and the piezoelectric element 111 is made of epoxy or the like. A non-conductive resin 112 is filled. Note that the piezoelectric element 111 of the piezoelectric body block 110A is previously polarized in the axial direction perpendicular to the array direction and the slice direction.

  Next, as shown in FIG. 4B, the first electrode 120A and the second electrode 140A are respectively applied to the first side surface and the second side surface substantially orthogonal to the axial direction of the piezoelectric body block 110A. Is formed. Note that the material of the first electrode 120A and the second electrode 140A is made of a metal such as copper having good conductivity.

  Next, as shown in FIG. 4C, an etching process is performed on the second electrode 140A, and a predetermined portion of the second electrode 140A is removed. Note that the predetermined portion to be etched is determined so as to increase in width as it approaches the two end faces substantially orthogonal to the slice direction, according to a weighting function such as a Hamming function. Thereby, the convex part M in which the second electrode 140A exists and the concave part N in which the second electrode 140A does not exist are formed on the first side surface of the piezoelectric body block 110A.

  Next, as shown in FIG. 4D, a non-conductive adhesive such as epoxy is thinly applied to the first electrode 120A, and the acoustic matching material block 200A is joined thereto. The acoustic matching material block 200A includes two types of first acoustic matching material plates 211A and second acoustic matching material plates 212A that are different in material.

  Next, as shown in FIG. 4E, a non-conductive adhesive such as epoxy is thinly applied to the second electrode 140A, and the second layer 420A of the flexible substrate material 400A is bonded thereon. Note that the tip of the second layer 420A of the flexible substrate material 400A is stripped in advance, and the wiring portion 421A is exposed. Thereby, the second electrode 140A and the wiring portion 421A of the second layer 420A of the flexible substrate material 400A are electrically connected by the pressure applied for bonding. Then, the non-conductive adhesive applied to the second electrode 140A is filled in the recess N formed on the second side surface of the piezoelectric block 110A by the bonding pressure applied for bonding. As a result, a non-conductive adhesive layer 130A is formed between the piezoelectric block 110A and the second electrode 140A. Note that the non-conductive adhesive that joins the second electrode 140A and the second layer 420A of the flexible substrate material 400A is applied very thinly, so that the second electrode 140A and the second layer 420A of the flexible substrate material 400A are formed. The conduction of the wiring portion 421A is not hindered.

  At the same time, a non-conductive adhesive such as epoxy is applied to the side surface substantially orthogonal to the slice direction of the piezoelectric block 110A, and the first layer 410A of the flexible substrate material 400A is bonded thereon. Note that the front end portion of the first layer 410A of the flexible substrate material 400A is stripped in advance, and the wiring portion 411A is exposed. Accordingly, the first electrode 120A and the wiring portion 411A of the flexible substrate material 400A are electrically connected by the bonding pressure applied for bonding.

  Next, as shown in FIG. 4F, a non-conductive adhesive is applied to the second layer 420A of the flexible substrate material 400A, and the backing material block 500A is joined thereto. Through the above steps, a unit U composed of the piezoelectric body block 110A, the acoustic matching material block 200A, the flexible substrate material 400A, and the backing material block 500A is completed.

  Next, as shown in FIG. 4G, the completed unit U is diced from the first electrode 120A side of the piezoelectric body block 110A. This dicing is for arraying the units U, and is performed until the grooves 510 are formed in the backing material block 500A. Then, a non-conductive resin 112 such as epoxy is filled in the groove formed in the unit U by dicing.

  Accordingly, the piezoelectric block 110A is provided in the piezoelectric element unit 110, the first electrode 120A is provided in the ground electrode unit 120, the nonconductive adhesive layer 130A is provided in the dielectric layer unit 130, and the second electrode 140A is provided in the second electrode 140A. In the signal electrode unit 140, a non-conductive adhesive filled in a recess is in the dielectric layer unit 130, an acoustic matching material block 200A is in the acoustic matching unit 200, a flexible substrate material 400A is in the flexible substrate 400, The backing material block 500 </ b> A becomes the backing material 500. Thus, the ultrasonic transducer unit 100, the acoustic matching unit 200, and the backing material 500 are completed.

  Next, as shown in FIG. 4 (h), a non-conductive adhesive such as epoxy is applied to the acoustic matching unit 200, and the acoustic lens 300 is joined thereto. Finally, the ultrasonic transducer unit 100, the acoustic matching unit 200, the backing material 500, the acoustic lens 300, and the flexible substrate 400 are accommodated in a probe case (not shown), and the flexible substrate 400 and the cable 150 are electrically connected. Connected. Thus, the ultrasonic probe 20 is completed.

  In the manufacturing process of the ultrasonic probe 20 in the present embodiment, the second electrode 140A is formed on the second side surface of the piezoelectric body block 110A, and the second electrode 140A is etched to perform the piezoelectric body. After the recess N is formed on the second side surface of the block 110, the second electrode 140A and the wiring portion 421A of the second layer 420A of the flexible substrate material 400A are joined.

  However, the present invention is not limited to this. For example, the second electrode 140A is formed on the wiring portion 421A of the second layer 420A of the flexible substrate material 400A, and the second electrode 140A is etched. After forming the recess, the piezoelectric block 110A and the wiring portion 421A of the second layer 420A of the flexible substrate material 400A may be joined.

[Operation according to this embodiment]
The ultrasonic transducer unit 100 according to this embodiment includes a dielectric layer 131 having a low relative dielectric constant between the piezoelectric element unit 110 and the signal wiring 421. The dielectric layer 131 is composed of a plurality of dielectrics 1311 arranged at intervals in the slice direction, and the area ratio of the dielectrics 1311 is present on the slice end surface 110a of the piezoelectric element unit 110. It is determined to become smaller as it approaches.

  Therefore, when a signal voltage is applied to the signal electrode 141, the electric field applied to the piezoelectric element 111 is weighted so that the strength decreases as the slice end surface 110 a of the piezoelectric element unit 110 is approached. As a result, the beam width in the slice direction of the transmitted and received ultrasonic waves is made uniform, and the side lobes in the slice sound field are reduced. Moreover, the apparatus and circuit are not complicated.

[simulation result]
Next, a simulation result performed by the inventor will be described.

  FIG. 5 is a characteristic diagram of the sound field related to the slice direction when the ultrasonic probe 20 according to the embodiment is used, and FIG. 11 is a characteristic diagram of the sound field related to the slice direction when the conventional ultrasonic probe 20 is used. .

  In this figure, the horizontal axis represents the distance from the acoustic lens 300 with respect to the axial direction of the ultrasonic probe 20, the vertical axis represents the distance from the center of the ultrasonic probe 20 with respect to the slice direction, and each curve represents the isosonic pressure line. ing. In addition, the sound pressure indicated by each equal sound pressure line becomes lower as the distance from the axis of the ultrasonic probe 20 increases.

  5 and 11, it can be seen that when the ultrasonic probe 20 according to the present embodiment is used, the isosonic pressure line approaches the axis of the ultrasonic probe 20.

  In particular, in the vicinity of the ultrasonic probe 20, it can be seen that the isosonic pressure lines are much closer to the axis of the ultrasonic probe 20 than the conventional ultrasonic probe. This indicates that the beam width in the slice direction is reduced in the vicinity of the ultrasonic probe 20 and the ultrasonic resolution is improved.

  Furthermore, it can be seen that, compared to the conventional ultrasonic probe 20, the isosonic pressure line having a low sound pressure is considerably close to the axis of the ultrasonic probe 20. This indicates that the side lobes in the ultrasonic slice sound field are reduced.

  FIG. 6 is a characteristic diagram of transmission sound pressure with respect to the slice direction when the ultrasonic probe 20 according to the embodiment is used. In this figure, the horizontal axis indicates the distance from the axis of the ultrasonic probe 20 in the slice direction, and the vertical axis indicates the sound pressure. A solid line indicates the sound pressure when the ultrasonic probe 20 according to the present embodiment is used, and a dotted line indicates a weight function.

  FIG. 6 shows that when the ultrasonic probe 20 according to the present embodiment is used, the transmission sound pressure characteristic with respect to the slice direction generally corresponds to the weight function. This indicates that a desired transmission sound pressure characteristic in the slice direction can be obtained according to the selection of the weight function.

  As described above, it has also been confirmed by simulation that the beam width in the slice direction of the transmitted and received ultrasonic waves is made uniform and the side lobes in the slice sound field are reduced.

(Second Embodiment)
[Ultrasonic transducer unit 100 ']
FIG. 7 is a perspective view of an ultrasonic transducer unit 100 ′ according to the second embodiment of the present invention.

  As shown in FIG. 7, the ultrasonic transducer unit 100 ′ according to this embodiment includes a piezoelectric element unit 110 ′, a ground electrode unit 120 ′, a dielectric layer unit 130 ′, and a signal electrode unit 140 ′. It is configured.

  The piezoelectric element unit 110 ′ is composed of a plurality of piezoelectric elements 111 ′ arranged in parallel in a first direction and a second direction orthogonal to each other, and in the gap between the piezoelectric elements 111 ′ and the piezoelectric element 111 ′. In order to improve the mechanical strength of the piezoelectric element unit 110 ′, a non-conductive resin 112 ′ such as epoxy is filled.

  These piezoelectric elements 111 ′ are formed in a thin rod shape with piezoelectric ceramics, and are polarized with respect to a first direction and a third direction orthogonal to the second direction by a prior process. In addition, although the raw material of piezoelectric ceramic is not specifically limited, 1-3 composite is used in this embodiment. Hereinafter, the first direction is the array direction, the second direction is the slice direction, and the third direction is the axial direction.

  The ground electrode unit 120 ′ is disposed on the front surface of the piezoelectric element unit 110 ′, and includes a plurality of ground electrodes 121 ′ arranged in parallel in the array direction. Each ground electrode 121 ′ is disposed so as to cover a plurality of piezoelectric elements 111 ′ arranged in parallel in the slice direction, and a common ground voltage is applied to these piezoelectric elements 111 ′. The material of the ground electrode 121 ′ is not particularly limited, but a metal such as copper having good conductivity is used in this embodiment.

  The dielectric layer unit 130 ′ is disposed on the back surface of the piezoelectric element unit 110 ′, and includes a plurality of dielectric layers 131 ′ arranged in parallel in the array direction and having a low relative dielectric constant. Each dielectric layer 131 ′ is arranged so as to cover a plurality of piezoelectric elements 111 ′ arranged in parallel in the slice direction. The thickness of the dielectric layer 131 ′ is determined so as to increase as it approaches the slice end surface 110a ′ of the piezoelectric element unit 110 ′ according to a weight function such as a Hamming function. The material of the dielectric layer 131 ′ is not particularly limited, but in the present embodiment, a resin such as an epoxy having a low relative dielectric constant (relative dielectric constant: 2 to 50) is used. In this embodiment, the Hamming function is used as the weighting function, but the present invention is not limited to this. For example, a harmonic function may be used.

  The signal electrode unit 140 ′ is disposed on the back surface of the dielectric layer unit 130 ′ and includes a plurality of signal electrodes 141 ′ arranged in parallel in the array direction. The material of the signal electrode 141 ′ is not particularly limited, but a metal such as copper having good conductivity is used in this embodiment. Each signal electrode 141 ′ is arranged along the slice direction so as to cover the dielectric layer 131 ′, and a plurality of piezoelectric elements 111 ′ arranged in parallel in the slice direction with the dielectric layer 131 ′ interposed therebetween. Is applied with a signal voltage.

  As described above, the dielectric layer 131 ′ having a low relative dielectric constant is disposed between the piezoelectric element unit 110 ′ and the signal electrode 141 ′. Moreover, the thickness of the dielectric layer 131 ′ is determined so as to increase as it approaches the slice end surface 110a ′ of the piezoelectric element unit 110 ′.

  Accordingly, the intensity of the electric field applied to the piezoelectric element 111 ′ decreases as the slice end surface 110a ′ of the piezoelectric element unit 110 ′ approaches, and as the distance from the slice end surface 110a ′ of the piezoelectric element unit 110 ′ increases, that is, in the slice direction. On the other hand, it becomes larger as it approaches the center.

[Manufacturing process of ultrasonic probe 20]
FIG. 8 is an explanatory diagram of the manufacturing process of the ultrasonic probe 20 according to the embodiment.
First, as shown in FIG. 8A, a rectangular parallelepiped piezoelectric block 110A ′ is prepared. The piezoelectric body block 110A ′ is previously polarized in the axial direction.

  Next, as shown in FIG. 8B, the second side surface substantially orthogonal to the axial center direction of the piezoelectric body block 110A ′ is wrapped to form a predetermined curved surface. The shape of the curved surface is determined according to a weighting function such as a Hamming function so that the thickness of the piezoelectric body block 110A ′ with respect to the axial direction decreases as approaching two side surfaces that are substantially orthogonal to the slice direction.

  Next, as shown in FIG. 8C, the piezoelectric body block 110 </ b> A ′ is diced along the array direction substantially orthogonal to the axial direction. This dicing is for weighting and is performed from the curved surface side of the piezoelectric body block 110A ′ to the middle part of the piezoelectric body block 110A ′. Thereby, a plurality of grooves are formed in the piezoelectric body block 110A ′ along the array direction.

  Next, as shown in FIG. 8D, the dielectric plate 130A ′ is joined to the curved surface of the piezoelectric block 110A ′ by a non-conductive adhesive such as epoxy. The dielectric plate 130A ′ is formed so as to correspond to the curved surface of the piezoelectric body block 110A ′ according to a weight function such as a Hamming function. The groove formed in the piezoelectric body block 110A ′ is filled with a nonconductive resin used for joining the piezoelectric body block 110A ′ and the dielectric plate 130A ′.

  Next, as shown in FIG. 8E, the piezoelectric body block 110A ′ is lapped. This lapping is performed until the groove portion is reached from the first side surface of the piezoelectric body block 110A ′. Since the groove portion of the piezoelectric body block 110A is filled with a non-conductive adhesive, even if the piezoelectric body block 110A ′ is wrapped, the piezoelectric body block 110A ′ is not divided into a plurality of parts.

  Next, as shown in FIG. 8F, the first electrode 120A ′ and the second electrode 140A ′ are formed on the first side surface of the piezoelectric body block 110A ′ and the dielectric plate 130A ′, respectively. Is done. Note that the first electrode 120A ′ and the second electrode 140A ′ are made of a metal such as copper having good conductivity.

  Next, as shown in FIG. 8G, a non-conductive adhesive such as epoxy is thinly applied to the first electrode 120A ′, and the acoustic matching material block 200A ′ is bonded thereon. This acoustic matching material block 200A ′ is composed of two types of first acoustic matching material plates 211A ′ and second acoustic matching material plates 212A ′ of different materials.

  Next, as shown in FIG. 8 (h), a non-conductive adhesive such as epoxy is thinly applied to the second electrode 140A ′, and the second layer 420A ′ of the flexible substrate material 400A ′ is bonded thereon. The Note that the outer end portion of the second layer 420A ′ of the flexible substrate material 400A ′ is stripped in advance, and the wiring portion 421A ′ is exposed. Accordingly, the second electrode 140A ′ and the wiring portion 421A ′ of the second layer 420A ′ of the flexible substrate material 400A are electrically connected by the bonding pressure applied for bonding. Note that the non-conductive adhesive that joins the second electrode 140A ′ and the flexible substrate material 400A ′ is applied very thinly, so that the wiring between the second electrode 140A ′ and the second layer 420A ′ of the flexible substrate material 400 is used. The conduction of the portion 421A ′ is not hindered.

  At the same time, a non-conductive adhesive such as epoxy is applied to the side surface substantially orthogonal to the slice direction of the piezoelectric block 110A ′, and the first layer 410A ′ of the flexible substrate material 400A is bonded thereon. Note that the outer portion of the predetermined portion of the first layer 410A ′ of the flexible substrate material 400A ′ is stripped in advance, and the wiring portion 411A ′ is exposed. Accordingly, the first electrode 120A ′ and the wiring portion 411A ′ of the first layer 410A ′ of the flexible substrate material 400A ′ are electrically connected by the bonding pressure applied for bonding.

  Next, as shown in FIG. 8 (I), a non-conductive adhesive is applied to the second layer 420A ′ of the flexible substrate material 400A ′, and the backing material block 500A ′ is joined thereto. Through the above steps, a unit U ′ composed of the piezoelectric body block 110A ′, the acoustic matching material block 200A ′, the flexible substrate material 400A ′, and the backing material block 500A ′ is completed.

  Next, as shown in FIG. 8J, the completed unit U ′ is diced from the first electrode 120A ′ side of the piezoelectric body block 110A ′. This dicing is for arraying the units U ′, and is performed until the groove 510A ′ is formed in the backing material block 500A ′. Then, the groove formed in the unit U ′ by dicing is filled with a nonconductive resin such as epoxy.

  Accordingly, the piezoelectric block 110A ′ is the piezoelectric element unit 110 ′, the first electrode 120A ′ is the ground electrode unit 120 ′, the dielectric plate 130A ′ is the dielectric layer unit 130 ′, and the second The electrode 140A ′ is the signal electrode unit 140 ′, the acoustic matching material block 200A is the acoustic matching unit 200 ′, the flexible substrate material 400A ′ is the flexible substrate 400 ′, and the backing material block 500A ′ is the backing material 500 ′. become. Thus, the ultrasonic transducer unit 100 ′, the acoustic matching unit 200 ′, and the backing material 500 ′ are completed.

  Next, as shown in FIG. 8 (k), a non-conductive adhesive such as epoxy is applied to the acoustic matching unit 200 ′, and the acoustic lens 300 ′ is joined thereto. Finally, the ultrasonic transducer unit 100 ′, the acoustic matching unit 200 ′, the backing material 500 ′, the acoustic lens 300 ′, and the flexible substrate 400 ′ are accommodated in a probe case (not shown), and the flexible substrate 400 ′. The cable 150 is electrically connected. Thus, the ultrasonic probe 20 ′ is completed.

[Operation according to this embodiment]
In the ultrasonic transducer unit 100 ′ according to the present embodiment, a dielectric layer 131 ′ that increases in thickness as it approaches the slice end surface 110a ′ of the piezoelectric element unit 110 ′ between the piezoelectric element unit 110 ′ and the signal electrode 141 ′. It is arranged.

  Therefore, when a signal voltage is applied to the signal electrode 141 ′, the electric field applied to the piezoelectric element 111 ′ is weighted so that the strength decreases as the slice end surface 110 a ′ of the piezoelectric element unit 110 ′ is approached. As a result, as in the first embodiment, the beam width in the slice direction of the transmitted and received ultrasonic waves is made uniform, and the side lobes in the slice sound field are reduced. Moreover, the apparatus and circuit are not complicated.

  The dielectric layer 131 ′ in this embodiment is configured to bite toward the front surface of the piezoelectric element unit 110 ′ as it approaches the slice end surface 110 a ′ of the piezoelectric element unit 110 ′. Is not limited to this. That is, the dielectric layer 131 ′ may be configured to rise in a direction away from the back surface of the piezoelectric body block 110 </ b> A ′ as it approaches the slice end surface 110 a ′ of the piezoelectric element unit 110 ′. With such a configuration, it is not necessary to polish the back surface of the piezoelectric body block 110A ′, so that the manufacturing process of the ultrasonic probe 20 ′ is simplified.

(Third embodiment)
[Ultrasonic transducer unit 100 ″]
FIG. 9 is a perspective view of an ultrasonic transducer unit 100 ″ according to the third embodiment of the present invention.

  As shown in FIG. 9, the ultrasonic transducer unit 100 ″ according to this embodiment includes a piezoelectric element unit 110 ″, a ground electrode unit 120 ″, a dielectric layer unit 130 ″, and a signal electrode unit. 140 ″.

  The piezoelectric element unit 110 ″ is composed of a plurality of piezoelectric elements 111 ″ arranged in parallel in a first direction and a second direction orthogonal to each other. The piezoelectric element 111 ″ and the piezoelectric element 111 ″ In order to improve the mechanical strength of the piezoelectric element unit 110 ″, the gap is filled with a non-conductive resin 112 ″ such as epoxy.

  These piezoelectric elements 111 ″ are made of piezoelectric ceramic and are polarized with respect to a first direction and a third direction orthogonal to the second direction by a prior process. In addition, although the raw material of piezoelectric ceramic is not specifically limited, 1-3 composite is used in this embodiment. Hereinafter, the first direction is the array direction, the second direction is the slice direction, and the third direction is the axial direction.

  The ground electrode unit 120 ″ is disposed on the front surface of the piezoelectric element unit 110 ″ and includes a plurality of ground electrodes 121 ″ arranged in parallel in the array direction. Each ground electrode 121 ″ is arranged so as to cover a plurality of piezoelectric elements 111 ″ arranged in parallel in the slice direction, and a common ground voltage is applied to these piezoelectric elements 111 ″. Yes. The material of the ground electrode 121 ″ is not particularly limited, but a metal such as copper having good conductivity is used in this embodiment.

  The dielectric layer unit 130 ″ is disposed on the back surface of the piezoelectric element unit 110 ″, and includes a plurality of dielectric layers 131 ″ arranged in parallel in the array direction. Each dielectric layer 131 ″ is arranged so as to cover a plurality of piezoelectric elements 111 ″ arranged in parallel in the slice direction, and the first to fourth dielectrics 1311 ″ having different relative dielectric constants from each other. ˜1314 ″.

  The first to fourth dielectrics 1311 ″ to 1314 ″ are arranged so that the relative dielectric constant decreases as the slice end surface 110a ″ of the piezoelectric element unit 110 ″ approaches according to a weighting function such as a Hamming function. Has been.

  As a result, the relative dielectric constant of each dielectric layer 131 ″ gradually decreases as it approaches the slice end surface 110a ″ of the piezoelectric element unit 110 ″. In this embodiment, the Hamming function is used as the weighting function, but the present invention is not limited to this. For example, a harmonic function may be used.

  The material of the first to fourth dielectrics 1311 ″ to 1314 ″ is not particularly limited, but in the present embodiment, ceramics having a high relative dielectric constant (relative dielectric constant: 500 to 1000) or the like is used. A material such as a material or an epoxy having a low relative permittivity (relative permittivity: 2 to 50) is used. The thickness of the dielectric layer 131 ″ is set to about 2 μm.

  The signal electrode unit 140 ″ is disposed on the back surface of the dielectric layer unit 130 ″ and includes a plurality of signal electrodes 141 ″ arranged in parallel in the array direction. The material of the signal electrode 141 ″ is not particularly limited, but a metal such as copper having good conductivity is used in this embodiment. Each signal electrode 141 ″ is arranged along the slice direction so as to cover the dielectric layer 131 ″, and a plurality of piezoelectric electrodes arranged in parallel in the slice direction with the dielectric layer 131 ″ interposed therebetween. A signal voltage is applied to the element 111 ″.

  As described above, the dielectric layer 131 ″ composed of the first to fourth dielectrics 1311 ″ to 1314 ″ is arranged between the piezoelectric element unit 110 ″ and the signal electrode 141 ″. It is installed. Moreover, the first to fourth dielectrics 1311 ″ to 1314 ″ are arranged so that the relative dielectric constant decreases as they approach the slice end surface 110a ″ of the piezoelectric element unit 110 ″.

  Accordingly, the intensity of the electric field applied to the piezoelectric element 111 ″ decreases as the slice end surface 110 a ″ of the piezoelectric element unit 110 ″ approaches, and as the distance from the slice end surface 110 a ″ of the piezoelectric element unit 110 ″ increases. That is, it becomes larger as approaching the center with respect to the slice direction.

[Manufacturing process of ultrasonic probe 20 '']
FIG. 10 is an explanatory diagram of the manufacturing process of the ultrasonic probe 20 ″ according to the embodiment.
First, as shown in FIG. 10A, a 1-3 composite type piezoelectric body block 110A ″ is prepared. The 1-3 composite type piezoelectric body block 110A ″ includes a plurality of piezoelectric elements 111 ″ arranged in parallel in the array direction and the slice direction. The piezoelectric element 111 ″ and the piezoelectric element ″ The gap is filled with a non-conductive resin such as epoxy. In addition, the piezoelectric element 111 ″ of the piezoelectric body block 110A ″ is previously polarized in the axial direction perpendicular to the array direction and the slice direction.

  Next, as illustrated in FIG. 10B, the dielectric plate 130 </ b> A ″ is formed on the second side surface that is substantially orthogonal to the axial direction of the piezoelectric body block 110 </ b> A ″. The dielectric plate 130A ″ includes first to fourth dielectric pieces 1311A ″ to 1314A ″ arranged in parallel in the slice direction. The first to fourth dielectric pieces 1311A ″ to 1314A ″ have different relative dielectric constants, and are two side surfaces that are substantially orthogonal to the slice direction of the piezoelectric block 110A ″ according to a weighting function such as a Hamming function. It is arranged so that the relative dielectric constant decreases as it approaches. As a result, the relative dielectric constant of the dielectric plate 130 </ b> A ″ generally decreases gradually as it approaches two side surfaces that are substantially orthogonal to the slice direction of the piezoelectric block.

  Next, as shown in FIG. 10C, the first electrode 120A ″ and the second electrode 140A ′ are respectively formed on the first side surface of the piezoelectric body block 110A ″ and the dielectric plate 130A ″. 'Is formed. Note that the first electrode 120A ″ and the second electrode 140A ″ are made of a metal such as copper having good conductivity.

  Next, as shown in FIG. 10D, a non-conductive adhesive such as epoxy is thinly applied to the first electrode 120A ″, and the acoustic matching material block 200A ″ is joined thereto. This acoustic matching material block 200A ″ is composed of two types of first acoustic matching material plates 211A ″ and second acoustic matching material plates 212A ″ of different materials.

  Next, as shown in FIG. 10E, a non-conductive adhesive such as epoxy is thinly applied to the second electrode 140A ″, and the second layer 420A ″ of the flexible substrate material 400 ″ is formed thereon. Are joined. In addition, the front-end | tip part of 2nd layer 420A '' of flexible board | substrate raw material 400A '' is peeled beforehand, and the wiring part 421A '' is exposed. Accordingly, the second electrode 140A ″ and the wiring portion 421A ″ of the second layer 420A ″ of the flexible substrate 400A ″ are electrically connected by the bonding pressure applied for bonding. Note that the non-conductive adhesive that joins the second electrode 140A ″ and the flexible substrate 400A ″ is applied very thinly, and therefore the second layer 420A of the second electrode 140A ″ and the flexible substrate 400A ″. The continuity with the wiring portion 421A ″ of ″ is not hindered.

  At the same time, a non-conductive adhesive such as epoxy is applied to the side surface substantially orthogonal to the slicing direction of the piezoelectric block 110A ″, and the first layer 410A ″ of the flexible substrate 400A ″ is joined thereto. Is done. Note that the outer end portion of the first layer 410A ″ of the flexible substrate 400A ″ is stripped in advance, and the wiring portion 411A ″ is exposed. Accordingly, the first electrode 120A ″ and the wiring portion 412A ″ of the flexible substrate 400A ′ are electrically connected by the bonding pressure applied for bonding.

  Next, as shown in FIG. 10F, a non-conductive adhesive is applied to the back surface of the second layer 420A ″ of the flexible substrate 400A ″, and the backing material block 500A ″ is bonded thereon. . Through the above steps, a unit U ″ including the piezoelectric body block 110A ″, the acoustic matching material block 200A ″, the flexible substrate 400A ″, and the backing material block 500A ″ is completed.

  Next, as shown in FIG. 10G, the completed unit U ″ is diced from the first electrode 120A ″ side of the piezoelectric body block 110A ″. This dicing is for arraying the units U ″, and is performed until a groove is formed in the backing material block 500A ″. Then, the groove formed in the unit U ″ by dicing is filled with a nonconductive resin such as epoxy.

  Accordingly, the piezoelectric block 110A ″ is the piezoelectric element unit 110 ″, the first electrode 120A ″ is the ground electrode unit 120 ″, and the dielectric plate 130A ″ is the dielectric layer unit 130 ′. ′, The second electrode 140A ″ is the signal electrode unit 140 ″, the acoustic matching material block 200A ″ is the acoustic matching unit 200 ″, and the flexible substrate material 400A ″ is the flexible substrate 400 ″. Further, the backing material block 500A ″ is the backing material 500 ″. Thus, the ultrasonic transducer unit 100 ″, the acoustic matching unit 200 ″, and the backing material 500 ″ are completed.

  Next, as shown in FIG. 10H, a non-conductive adhesive such as epoxy is applied to the acoustic matching unit 200 ″, and the acoustic lens 300 ″ is joined thereto. Finally, the ultrasonic transducer unit 100 ″, the acoustic matching unit 200 ″, the backing material 500, the acoustic lens 300 ″, and the flexible substrate 400 ″ are accommodated in a probe case (not shown), and the flexible substrate 400 ″ and the cable 150 are electrically connected. Thus, the ultrasonic probe 20 ″ is completed.

(Operation by this embodiment)
The ultrasonic transducer unit 100 ″ in the present embodiment includes first to fourth dielectrics 1311 ″ arranged in parallel in the slice direction between the piezoelectric element unit 110 ″ and the signal electrode 141 ″. A dielectric layer 131 ″ made of 1314 ″ is provided. Moreover, the first to fourth dielectrics 1311 ″ to 1314 ″ have different relative dielectric constants, and the relative dielectric constant decreases as they approach the slice end surface 110a ″ of the piezoelectric element unit 110 ″. It is arranged like this.

  Therefore, when a driving voltage is applied to the signal electrode 141 ″, the strength of the electric field applied to the piezoelectric element 111 ″ decreases as the slice end surface 110a ″ of the piezoelectric element unit 110 ″ approaches. Weighting is done. As a result, as in the first embodiment, the beam width in the slice direction of the transmitted and received ultrasonic waves is made uniform, and the side lobes in the slice sound field are reduced. Moreover, the apparatus and circuit are not complicated.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

1 is a schematic diagram of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention. The perspective view of the ultrasonic probe which concerns on the same embodiment. The perspective view of the ultrasonic transducer | vibrator unit which concerns on the same embodiment. Explanatory drawing of the manufacturing process of the ultrasonic transducer | vibrator unit which concerns on the embodiment. The characteristic figure of the sound field regarding the slice direction obtained by the ultrasonic probe which concerns on the embodiment. The characteristic figure of the transmission sound pressure regarding the slice direction obtained by the ultrasonic probe concerning the embodiment. The perspective view of the ultrasonic transducer | vibrator unit which concerns on the 2nd Embodiment of this invention. Explanatory drawing of the manufacturing process of the ultrasonic transducer | vibrator unit which concerns on the embodiment. The perspective view of the ultrasonic transducer | vibrator unit which concerns on the 3rd Embodiment of this invention. Explanatory drawing of the manufacturing process of the ultrasonic transducer | vibrator unit which concerns on the embodiment. The characteristic figure of the sound field regarding a slice direction when the conventional ultrasonic probe is used.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 12 ... Transmission / reception circuit (transmission / reception means), 13 ... Image generation part (image generation means), 20 ... Ultrasonic probe, 100 ... Ultrasonic transducer unit, 110 ... Piezoelectric element unit, 111 ... Piezoelectric element, 120 ... Ground electrode unit , 121, ground electrode, 130, dielectric layer unit, 131, dielectric layer, 1311, dielectric, 140, signal voltage unit, 141, signal electrode, 1411, signal electrode piece.

Claims (8)

In an ultrasound probe equipped with an ultrasound transducer unit that transmits and receives ultrasound to and from a subject,
The ultrasonic transducer unit is
It is composed of a plurality of piezoelectric elements arranged in parallel in a first direction and a second direction orthogonal to each other, and each piezoelectric element is in a third direction orthogonal to the first direction and the second direction. A piezoelectric element unit for transmitting and receiving ultrasonic waves,
The piezoelectric element unit is composed of a plurality of first electrodes and second electrodes respectively arranged opposite to two end faces substantially orthogonal to the third direction, and the first electrodes and the second electrodes are respectively A first electrode unit and a second electrode unit for applying an electric field to a plurality of piezoelectric elements arranged in parallel in the second direction;
It is composed of a plurality of dielectric layers disposed between the piezoelectric element unit and the first electrode unit, or between the piezoelectric element unit and the second electrode unit. An ultrasonic probe comprising: a dielectric layer unit that weights the electric field strength applied to a plurality of piezoelectric elements arranged in parallel in the second direction with respect to the second direction. In an ultrasound probe equipped with an ultrasound transducer unit that transmits and receives ultrasound to and from a subject,
The ultrasonic transducer unit is
It is composed of a plurality of ultrasonic transducer parts arranged in parallel in the first direction,
Each of the ultrasonic transducer parts is
It is composed of a plurality of piezoelectric elements arranged in parallel in a second direction orthogonal to the first direction, and each piezoelectric element is in a third direction orthogonal to the first direction and the second direction. A piezoelectric part for transmitting and receiving ultrasonic waves;
A first electrode and a second electrode, which are respectively arranged opposite to two end faces substantially orthogonal to the third direction of the piezoelectric portion, and which applies an electric field to a plurality of piezoelectric elements constituting the piezoelectric portion;
The strength of the electric field applied to a plurality of piezoelectric elements disposed between the piezoelectric portion and the first electrode or between the piezoelectric portion and the second electrode is applied to the first and second electrodes. An ultrasonic probe comprising: a dielectric layer that performs weighting with respect to two directions.   The dielectric layer is composed of a dielectric disposed along the second direction, and an area ratio where the dielectric exists is a two-end surface that is substantially orthogonal to the second direction of the piezoelectric element unit. The ultrasonic probe according to claim 1, wherein the ultrasonic probe increases as the distance to the ultrasonic probe increases.   The ultrasonic probe according to claim 3, wherein the dielectric is made of resin.   The dielectric layer is composed of a dielectric disposed along the second direction, and the thickness of the dielectric approaches the two end faces that are substantially orthogonal to the second direction of the piezoelectric element unit. The ultrasonic probe according to claim 1, wherein the ultrasonic probe becomes thicker as the thickness increases.   The dielectric layer is composed of a dielectric disposed along the second direction, and the relative dielectric constant of the dielectric is at two end faces substantially perpendicular to the second direction of the piezoelectric element unit. The ultrasonic probe according to claim 1, wherein the ultrasonic probe becomes smaller as approaching. An ultrasonic probe including an ultrasonic transducer unit that transmits and receives ultrasonic waves to and from a subject;
Transmitting and receiving means for applying an electric signal to the ultrasonic transducer unit and generating a reception signal corresponding to the reflected wave based on the reflected wave received by the ultrasonic transducer unit;
Image generating means for generating an image relating to the subject based on the received signal generated by the transmitting / receiving means,
The ultrasonic transducer unit is
It is composed of a plurality of piezoelectric elements arranged in parallel in a first direction and a second direction orthogonal to each other, and each piezoelectric element is in a third direction orthogonal to the first direction and the second direction. A piezoelectric element unit for transmitting and receiving ultrasonic waves;
The piezoelectric element unit is composed of a plurality of first electrodes and second electrodes respectively arranged opposite to two end faces substantially orthogonal to the third direction, and the first electrodes and the second electrodes are respectively A first electrode unit and a second electrode unit for applying an electric field to a plurality of piezoelectric elements arranged in parallel in the second direction;
A plurality of dielectric layers disposed between the piezoelectric element unit and the first electrode unit or between the piezoelectric element unit and the second electrode unit, each dielectric layer being An ultrasonic diagnostic apparatus comprising: a dielectric layer unit that weights the electric field strength applied to the plurality of piezoelectric elements arranged in parallel in the second direction with respect to the second direction. . An ultrasonic probe including an ultrasonic transducer unit that transmits and receives ultrasonic waves to and from a subject;
Transmitting and receiving means for applying an electrical signal to the ultrasonic transducer unit and generating a received signal corresponding to the reflected wave based on the reflected wave received by the ultrasonic transducer unit;
Image generating means for generating an image relating to the subject based on the received signal generated by the transmitting / receiving means,
The ultrasonic transducer unit is
It is composed of a plurality of ultrasonic transducer parts arranged in parallel in the first direction,
Each of the ultrasonic transducer parts is
It is composed of a plurality of piezoelectric elements arranged in parallel in a second direction orthogonal to the first direction, and each piezoelectric element is in a third direction orthogonal to the first direction and the second direction. A piezoelectric part for transmitting and receiving ultrasonic waves;
A first electrode and a second electrode, which are respectively arranged opposite to two end faces substantially orthogonal to the third direction of the piezoelectric portion, and which applies an electric field to a plurality of piezoelectric elements constituting the piezoelectric portion;
The strength of the electric field applied to a plurality of piezoelectric elements disposed between the piezoelectric portion and the first electrode or between the piezoelectric portion and the second electrode is applied to the first and second electrodes. An ultrasonic diagnostic apparatus comprising: a dielectric layer that performs weighting in two directions.

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