JPH05285135A - Ultrasonic probe - Google Patents

Abstract

PURPOSE:To provide a matching coil built-in ultrasonic probe which can execute easily a coil mounting work, can use a stable matching oil, and also, can be connected simply to a piezoelectric element electrode. CONSTITUTION:The ultrasonic probe is provided with a coil holding member 15 in which a screw 16 is threaded, and an insulating member 12 in which a screw 13 to be fitted to its screw 16 is threaded, and also, can hold a piezoelectric element 1. In the holding member 15, a coil element wire 17 is wound round to an element wire groove 18, a coil whose shape and electric characteristic are stable is formed and held, and an electrode part 21 for allowing its coil and a piezoelectric element electrode 1a to conduct is provided. The coil wound- round holding member 15 is screwed in and inserted into the insulating member 12 and fixed. In connection with screwing-in, the electrode part 21 is pressed against the piezoelectric element electrode, and its electric connection is also attained. A small-sized ultrasonic prove in a shape formed by embedding a matching coil in a backing material can be assembled stably and easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe used in an ultrasonic diagnostic apparatus and the like, and more particularly to a small ultrasonic probe having a matching coil built therein.

[0002]

2. Description of the Related Art A diagnostic method is widely used, in which ultrasonic waves are applied to the inside of a body and the state of the inside of the body is drawn from the echo signal to detect and diagnose a lesion, which is used in such an ultrasonic diagnostic apparatus. An ultrasonic probe is disclosed in Japanese Patent Laid-Open No. 1-129184. This uses a piezoelectric element as a means for generating ultrasonic waves and has a matching coil for impedance matching in the vicinity of the piezoelectric element.

As shown in FIG. 8 as an example, this ultrasonic probe is a piezoelectric element for applying a pulse signal between surface electrodes.
1 is fixed to the structure consisting of the housing 2 and the insulating member 3, and a prefabricated air-core coil 4 alone with a predetermined diameter is mounted in the space behind the piezoelectric element 1, and one end of the coil 4 and the center of the coaxial cable 5 are mounted. Conductor 6a and bottom surface (back surface) of piezoelectric element 1
The electrode 1a is connected via the wire 7. The other end of the coil 4 and the outer conductor 6b of the coaxial cable 5 are connected to the housing 2 by soldering. Further, the upper surface (front surface) electrode 1b of the piezoelectric element 1 is connected to the housing 2 through the wire rod 8, the air core coil 4 is mounted, and the coil of the wire rod 7 after the wire is wired.
Damping material 9 is filled in the hollow of 4 and hardened,
Finally, coil 4 is embedded and fixed.

[0004]

According to this, it is possible to realize an ultrasonic probe with a built-in matching coil,
Even in the case of an ultrasonic probe in an intracorporeal ultrasonic probe that is endoscopically inserted into the body cavity, a good matching with the transmission line by the coaxial cable is taken without causing an increase in size due to the addition of a coil. Although it is possible to achieve higher frequency and higher resolution of the drive pulse signal, when considering the following aspects,
There is room for improvement.

That is, in the manufacture, the method of housing the coil in the housing for holding the piezoelectric element as described above requires the work of inserting the air-core coil into a small space and wiring. Therefore, there is a possibility that the coil may be deformed during the work to change the characteristics required for matching, and the management for avoiding this is extremely complicated, and as a result, the number of steps tends to be large and it takes time and effort. Further, the work of wiring the electrodes of the piezoelectric element with the coil and the coaxial cable in a narrow space requires a great deal of skill, which also contributes to an increase in manufacturing cost. Especially, in the case of the small-sized ultrasonic probe with the intracorporeal ultrasonic probe as described above, such a tendency becomes more remarkable, and therefore, if these improvements can be further realized, the effect is great.

The present invention, therefore, can meet the above-mentioned needs.
Even a small ultrasonic probe with a built-in matching coil can be easily assembled using a stable coil with a shape that does not deform during mounting of the coil. It is an object of the present invention to provide an ultrasonic probe that can be connected to electrodes very efficiently and easily without requiring special skill.

[0007]

An ultrasonic probe of the present invention is a ultrasonic probe having a piezoelectric element and a matching coil in the vicinity of the piezoelectric element, the coil having a screw portion. A holding member and a piezoelectric element holding member provided with a threaded portion that fits into the threaded portion of the coil holding member, and the coil holding member is provided with an electrode for electrically connecting the holding coil and the electrode of the piezoelectric element. It is provided.

[0008]

According to the present invention, a coil having a stable shape is formed on the coil holding member provided with the screw portion, and the coil holding member is screwed and fixed to the piezoelectric element holding member provided with the screw portion. In addition, the electrode held in contact with the coil held by the coil holding member is pressed against the piezoelectric element electrode,
The coil and the piezoelectric element electrode are electrically connected.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows an embodiment of an ultrasonic probe according to the present invention. The piezoelectric element 1 made of a piezoelectric material of PZT is held in the housing by a piezoelectric element holding member, but in the illustrated example, the housing 2 made of stainless steel or the like is provided with, for example, an annular projection 11 on the inner peripheral surface thereof. Part 11 and insulating member
The piezoelectric element 1 is fixed so as to be sandwiched between 12 steps. Therefore, in this case, the upper surface (front surface) electrode 1b of the piezoelectric element 1
With this fixed assembly, the conductive housing 2 is directly conducted, and no special work is required for electrical connection between the two. On the inner surface of the insulating member 12, there is provided a female screw 13 to which a threaded coil holding member described later is screwed.
Further, on the upper surface electrode 1b of the piezoelectric element 1, if necessary,
As in the case of FIG. 8, the acoustic lens 14 is adhered and thereby the ultrasonic waves are converged.

The coil holding member 15 is screwed and fixed to the insulating member 12. The coil holding member 15 has a male screw 16 around it.
Is provided, and a coil wire groove 18 for holding a coil wire 17 that forms a matching coil is provided at the bottom of the thread groove in parallel with the thread groove.
The coil holding member 15 is formed of a damping material in order to give the piezoelectric element 1 a damping effect. Further, in the coil holding member 15, from the upper end of the wire groove 18 to the upper surface of the coil holding member 15, that is, the piezoelectric element lower surface (back surface) electrode 1a.
A hole 19 is provided to reach the surface facing the side. In this example, the hole 19 is further provided as a first lead wire hole 19 that penetrates through the upper surface to the lower surface of the coil holding member. Further, a second lead wire hole 20 penetrating from the lower end of the wire groove 18 to the lower surface of the coil holding member 15 is provided. The coil wire 17 is wound around the coil holding member 15 along the spiral wire groove 18, and is held in this manner,
Both the coil wire end portions 17a and 17b are drawn out to the lower surface side of the coil holding member 15 through the first lead wire hole 19 and the second lead wire hole 20.

Here, the part where the coil wire 17 is once pulled out to the upper surface of the coil holding member is an electrode portion for electrically connecting with the piezoelectric element lower surface electrode 1a by pressure welding as the coil holding member 15 is screwed. Form 21. In this manner, the present ultrasonic probe has an electrode for electrically connecting the coil and the piezoelectric element electrode to a part of the coil holding member 15. Further, the lower surface of the coil holding member 15 is formed with a driver groove 22 used when the coil holding member 15 is screwed.

Next, the procedure for assembling the ultrasonic probe will be described. This can be performed as follows. In this embodiment, the piezoelectric element 1 is fixed and held so as to be sandwiched between the lower surface of the protrusion 11 of the housing 2 and the stepped portion of the insulating member 12 provided on the inner peripheral surface of the housing.
An assembly of the housing 2 and the insulating member 12 is prepared. On the other hand, the coil wire 17 is wound along the wire groove 18, and one end of the coil wire 17 is exposed on the upper surface of the coil holding member 15 in the middle of the electrode portion.
The coil-wound coil holding member 15 is drawn out to the outside of the lower surface from the first lead wire hole 19 in a state of forming 21 and the other end side is drawn to the outside of the lower surface from the second lead wire hole 20. Is prepared.

In the latter assembly part on the side of the coil-wound coil holding member 15, at this stage, a coil having a stable shape is formed on the coil holding member 15 on which the fixing screw for the former assembly is threaded. It will be. A coil holding member 15 in which a wire groove 18 for holding a coil wire is formed together with a screw groove.
This coil body formed by including the above-mentioned electrode portion 21 by winding the coil wire 17 around the coil has a stable physical shape and is easy to handle. Arrangement of the matching coil in the vicinity of the piezoelectric element and electrical connection thereto in a state where the characteristics are stable can be easily performed as follows.

That is, the coil holding member 17 on which the coil wire 17 is wound is inserted inside the insulating member 12 on the assembly side,
It is screwed in using the thread groove that fits. Therefore, the matching coil can be easily arranged by this screwing. At the time of screwing, a screwdriver can be put into the driver groove 22 to facilitate the work in this example.
The electrode part 21 is screwed in until it comes into contact with the piezoelectric element lower surface electrode 1a, and tightened with a torque that provides a contact pressure necessary for electrical connection. You can then fix it as shown and screw 1
Since 3,16 is provided, in the process of screwing in,
An electrode part that is electrically connected to the coil provided on the coil holding member 15.
21 (in this example, the exposed coil wire itself) is the piezoelectric element 1
The coil and the piezoelectric element are pressed into contact with the lower surface electrode 1a, and the electrical connection between the coil and the piezoelectric element is also included in the work and simultaneously performed. Therefore, of course, the connection via the wire 7 as shown in FIG. 8 is unnecessary, and the work for the purpose of special electrical connection to the piezoelectric element lower surface electrode 1a is not necessary.
The number of steps can be reduced. Although the coil wire 17 is used as it is in the electrode portion 21 here, a dedicated electrode member having a spring property may be attached for reliable conduction.

After the screwing is completed, the center conductor of the coaxial cable 5 is attached to the coil wire end portions 17a and 17b in a state where it is pulled out to the lower surface side of the fixed coil holding member 15.
6a and the outer conductor 6b are connected by soldering or the like. The outer conductor 6b serving as the ground is also connected to the housing 2.
Here, since the coil wire end portions 17a, 17b are drawn out to a portion having a sufficient working space, workability is greatly improved in this respect as well, and the manufacturing cost can be further reduced. Further, the upper surface electrode 1b of the piezoelectric element 1 is connected to the housing 2 through the protrusion 11 of the housing 2 on the assembly side.
The electrical connection to the ultrasonic probe is now completed. In this way, the matching coil (in this example, the coil wire 17
A small ultrasonic probe in which a matching coil consisting of is embedded is stable and easy to assemble.

In the ultrasonic wave incident probe thus obtained, the matching coil composed of the coil element wire 17 is connected in parallel to the piezoelectric element 1, and this ultrasonic wave probe is, for example, It is suitable as an ultrasonic probe with an ultrasonic probe in a body cavity that is endoscopically inserted into the body cavity. The following is a supplementary description of an ultrasonic diagnostic apparatus that projects an ultrasonic pulse on a living body and receives an echo thereof to obtain an ultrasonic image, including the function of the matching coil. The ultrasonic probe is connected to the apparatus main body side via the coaxial cable 5, and the electrodes 1a and 1b of the piezoelectric element 1 are connected.
When an electric pulse is applied between them, ultrasonic waves are generated, and when the reflected wave in the living body returns to the piezoelectric element, a voltage is generated between the electrodes. An ultrasonic tomographic image is obtained by comparing the magnitude of this echo signal with the positional relationship and imaging. here,
Generally, the piezoelectric element also has a property as a dielectric, and a capacitor is formed between the positive electrode and the negative electrode, and the capacitor component is called a damping capacitance. When the drive pulse generator on the main body side and the piezoelectric element are connected by a coaxial cable to guide the piezoelectric element between the piezoelectric element electrodes, the combined capacitance of the stray capacitance of the coaxial cable and the braking capacitance is , Exist in parallel with the elements that contribute to the vibration of the piezoelectric element. However, when an electric pulse is applied in such a state, most of the pulse current is shunted into this electrostatic capacitance, and the degree of contribution to the original vibration energy is reduced, and ultrasonic waves with sufficient power are generated. Where it cannot be obtained, in this ultrasonic probe, a coil having an inductance constant selected to a value that causes parallel resonance with the capacitance near the resonance frequency of the piezoelectric element 1 used is used as the matching coil as described above. As described above, since it can be stably incorporated and can be inserted in parallel with the piezoelectric element 1, an ultrasonic wave with sufficient power can be obtained. That is, if parallel resonance occurs, the parallel impedance between the capacitance and the inserted coil will be a sufficiently large value,
As a result, the braking capacity and the stray capacity of the cable are canceled. Therefore, a high-performance ultrasonic diagnostic image is secured, and an ultrasonic probe that realizes this can be stably and efficiently assembled easily. Moreover, it is desirable to arrange such a matching coil in the vicinity of the piezoelectric element. Especially, in the body cavity ultrasonic probe in which the ultrasound probe is inserted into the body cavity endoscopically, the physical size is not limited. Strictly, it is not allowed to increase the size by adding a coil, but in this respect, the ultrasonic probe can meet the demand.

Next, FIGS. 2 to 4 show another embodiment of the present invention.
(Second embodiment) is shown. The same parts as those in the embodiment (first embodiment) are designated by the same reference numerals. Also in this embodiment,
A coil holding member having a thread cut and a piezoelectric element holding member having a thread fitted to the screw of the coil holding member are used. The coil holding member has the following configuration. Figure
3 shows an example of a flexible printed circuit board having a pattern for forming a coil used in this embodiment. In the illustrated example, the printed circuit board 31
Are the bonding electrodes 32a to 32e, 33a arranged at both ends at regular intervals.
.About.33e are provided, and the pattern 34 is wired so as to connect the bonding electrodes at both ends by shifting one by one. Furthermore,
The uppermost pattern 35 is also connected to the upper electrode 37 arranged on the protruding portion to the upper side, is routed to the back surface of the substrate through the through hole, and is guided to the lower positive electrode 38. On the other hand, the lowermost pattern 36 is also connected to the negative electrode 39.

The flexible printed circuit board 31 thus constructed is rolled into a cylindrical shape as shown in FIG. 4, the edges are adhered with an adhesive, and the corresponding bonding electrodes 32a, 33a at both edges are set to 32e, 33e. The coils are formed by soldering each of the groups. Further, the portion of the upper electrode 37 is bent inward in the radial direction of the cylinder as illustrated. As a result, similar to the above-described embodiment, when the coil holding member to be described later is screwed in, the coil formed of the pattern 34 and the piezoelectric element electrode constitute an electrode portion for pressure contact conduction in the process of screwing and inserting. The flexibility of the flexible printed circuit board can be used for the pressure contact. Further, in this case, a coil having an arbitrary inductance value can be obtained by arbitrarily selecting the pitch of the pattern 34, the radius of the cylinder, and the like.

FIG. 2 shows an ultrasonic probe in which the coil formed by the above method is mounted as a matching coil. In the present embodiment as well, the screw 16 is similarly cut on the coil holding member 40 formed of the damping material, but the coil holding member 40 has a cylindrical shape with a depth from the upper surface to the lower surface of the holding member. The coil holding groove 41 is formed. A recess for the bent upper electrode 37 is formed on the upper surface of the holding member facing the annular coil holding groove 41, and a cable connection hole 42 is formed on the side surface near the lower surface of the holding member. There is. In addition, the coil holding member 40 of the present embodiment has a lower portion of the housing as shown in the drawing.
2 so that it slightly protrudes from the lower end surface of the insulating member 12,
The cable connection hole 42 can be provided in this portion.

As for the holding of the coil by the coil holding member 40, the coil having the coil formed by the above-mentioned method is used.
The cylindrical printed board 31 of 4 is inserted into the coil holding groove 41 from above, the upper electrode 37 is aligned, and the positive electrode 38 and the negative electrode 39 are aligned with respect to the cable connection hole 42, This can be done by fixing with an adhesive. In this embodiment, the coil is held in this way.

Coil holding member obtained as described above
40 can be assembled in the same procedure as in the case of the above-mentioned embodiment, and the coil holding member 40 is screwed into the similarly screwed piezoelectric element holding member side to insert the piezoelectric element electrode and the coil holding member. Electrical connection is made by pressing the electrode portion on the member 40 side. That is, here, as shown in FIG. 2, the piezoelectric element 1 having the same structure as that of the first embodiment described above,
An assembly of the housing 2 and the insulating member 12 is used, and similarly, the coil holding member 40 is screwed into this using a screwdriver, and the upper electrode 37 is pressed against the piezoelectric element lower surface electrode 1a. After fixing, the coaxial cable is passed through the cable connection hole 42.
The central conductor 6a of 5 is soldered to the positive electrode 38. The outer conductor 6b is soldered to the negative electrode 39,
The outer conductor 6b is also connected to the housing 2. These operations can also be performed in a space with the same margin.
1 The upper surface electrode 1b is electrically connected to the housing 2 through the protrusions 11 and the like, which is similar to the case of the first embodiment (these points are also the same in the third embodiment described later).

In this way, also in the case of this embodiment, the matching coil (pattern of the printed circuit board) is used as the backing material.
A small ultrasonic probe in which the coil (by connecting 34) is embedded can be stably and easily assembled.
Similar to the above-mentioned embodiment, the inductance constant as a matching coil is stable, the process is simple and inexpensive, and even a small ultrasonic probe with a built-in matching coil may be deformed during the coil mounting work. Not only can a stable coil having a stable shape be used, but wiring to the piezoelectric element electrode can be easily performed without requiring special skill.

In addition, a threaded coil retaining member 40
Coil forming printed circuit board 31 to be inserted into the coil holding groove 41 of
Since it is possible to easily prepare a coil having different inductance constants by changing the pitch of the pattern, and insert or fix a coil having an inductance value necessary for use in the coil holding groove 41, the coil wire Compared to the first embodiment in which the pitch is restricted by the fixing screw groove pitch, the compatibility is further improved, and a coil with a desired inductance constant is inserted into the coil holding groove 41 separately from the piezoelectric element holding member side. Since it can be handled while it is held, it is easy to handle. The present applicant has previously proposed a technique in which a flexible substrate is provided as an insulating layer, and a matching coil pattern and an electrode drawing pattern are formed on the substrate (Japanese Patent Application No. 2-126890). ) However, compared to this, this ultrasonic probe is much easier to manufacture,
The assembly workability is excellent, and it is possible to stabilize the characteristics at a lower cost.In the previously proposed one, the coil holding member is screwed and fixed to the piezoelectric element holding member, and at the same time, the coil and the piezoelectric It does not have the function of connecting to the device electrode. Further, in the above example, as shown in FIGS. 3 and 4, the pattern 34 was set obliquely, but when setting a parallel pattern and rolling the printed circuit board, the bonding electrodes (lands) at both ends are moved vertically. It is also possible to shift them one by one and form the coil by soldering or adhesion with a conductive adhesive.

5 to 7 show another embodiment of the present invention.
(Third embodiment) FIG. 3 shows the same parts as those in FIG. The main part will be described below. This embodiment is also a modification of the second embodiment using the printed circuit board, and as shown in FIG. 6, a flexible printed circuit board 51 with a coiled pattern pre-etched is used.
To use. In this case, by arbitrarily selecting the pitch and the like of the coiled pattern 52, it is possible to easily obtain a coil having an arbitrary inductance.

As shown in the figure, on a disk-shaped printed circuit board 51, an extending portion 53 is formed and an electrode 54 is provided at the tip thereof, while a protruding portion 55 is formed and a positive electrode 56 and a negative electrode 57 are formed. Set up. The outermost peripheral pattern 58 of the coil-shaped pattern 52 is connected to the electrode 54, is turned to the back side of the substrate in the drawing through a through hole, and is guided to the positive electrode 56. On the other hand, the pattern 59 at the center is turned to the back side of the substrate in the drawing through the through hole and is guided to the negative electrode 57. As shown in FIG. 7, the flexible printed circuit board 51 configured as described above is bent and fixed with an adhesive to a cylindrical holding member 60 formed of a damping material as shown in the figure. At that time, the electrode
The portion 54 is further bent and positioned on the surface (upper end surface) opposite to the coil fixing surface (lower end surface) to which the disc-shaped printed circuit board portion of the holding member 60 is bonded. The portion 57 is fixed to the cylindrical side surface of the holding member 60. In this embodiment, the bent electrode 54 constitutes an electrode portion by pressure contact, and a recess for the upper electrode is formed on the upper surface of the cylindrical holding member 60 (see FIG. 5).

FIG. 5 shows an ultrasonic probe in which the coil formed by the above method is mounted as a matching coil. In this case as well, the coil holding member 61 formed of the damping material is provided with the screw 16 on the outer circumference, while the coil holding space having a bottomed cylindrical shape as shown in the present embodiment is provided inside the coil holding member 61.
62 are formed. Further, the coil holding member 61 has its lower part slightly projected, and a cable connection hole is formed on the side surface near the lower surface thereof.
63 is open. In this example, with respect to such a coil holding member 61, the coil-attached holding member 60 formed by the method described above is inserted into the coil holding space 62 from above, and the positive electrode 56 and the negative electrode are inserted into the cable connection hole 63. The coils are held by aligning the positions so that 57 are aligned and fixing them with an adhesive. The assembly is basically the same as the above-mentioned case, and the above-mentioned coil is attached to the insulating member 12 in which the female screw 13 is cut in the assembly of the piezoelectric element 1, the housing 2, and the insulating member 12 having the same configuration as the first embodiment. Holding member
61 may be screwed and fixed, and the electrode 54 (upper electrode) is pressed against the piezoelectric element lower surface electrode 1a. Then, after fixing, the center conductor 6a of the coaxial cable 5 is soldered to the positive electrode and the outer conductor 6b is soldered to the negative electrode 57 through the cable connection hole 63, and the outer conductor 6b may be connected to the housing 2 as well.

In this way, in the case of the present embodiment as well, similarly, a backing material (in this example, a cylindrical holding member 60 of a damping material and a coil holding member 61 which is also made of the damping material and fixed inside). ) To matching coil
A small ultrasonic probe in which (a coil having a coil pattern) is embedded can be stably and easily assembled. Further, it has the same advantages as those of the second embodiment.

[0028]

According to the ultrasonic probe of the present invention, when a matching coil is built in, a stable matching coil having a shape that does not deform during coil mounting work is used. Therefore, connection to the piezoelectric element electrode can be easily realized without requiring special skill.

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of an ultrasonic probe according to the present invention.

FIG. 2 is a cross-sectional view showing the configuration of another embodiment of the ultrasonic probe according to the present invention.

FIG. 3 is a plan view of a coil-forming printed board applicable to the embodiment in a developed state.

FIG. 4 is a perspective view showing a state where the printed circuit board is formed into a cylindrical shape.

FIG. 5 is a cross-sectional view showing the configuration of still another embodiment of the ultrasonic probe according to the present invention.

FIG. 6 is an external view of a printed circuit board having a coil pattern that can be applied to the embodiment.

FIG. 7 is a perspective view showing a state in which the printed circuit board is attached to a cylindrical holder.

FIG. 8 is a cross-sectional view showing a configuration of a conventional ultrasonic probe.

[Explanation of symbols]

 1 Piezoelectric element 1a, 1b Piezoelectric element electrode 2 Housing 5 Coaxial cable 11 Protrusion 12 Insulation member 13 Female screw 15,40,61 Coil holding member 16 Male screw 17 Coil element wire 18 Element groove 21 Electrode section 31,51 Printed circuit board 34 Pattern -37 37 Upper electrode 41 Coil holding groove 52 Coil pattern 54 Electrode 60 Cylindrical holding member 62 Coil holding space

[Procedure amendment]

[Submission date] July 10, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art A diagnostic method is widely used, in which ultrasonic waves are applied to the inside of a body and the state of the inside of the body is drawn from the echo signal to detect and diagnose a lesion, which is used in such an ultrasonic diagnostic apparatus. An ultrasonic probe is disclosed in Japanese Patent Laid-Open No. 1-129184. This uses a piezoelectric element as a means for generating ultrasonic waves and has a matching coil in the vicinity of the piezoelectric element.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004]

According to this, it is possible to realize an ultrasonic probe with a built-in matching coil,
Even in the case of an ultrasonic probe in an intracorporeal ultrasonic probe that is inserted endoscopically into the body cavity, the capacity of the coaxial cable and the damping capacity of the transducer are canceled without increasing the size by adding a coil. Therefore, the sensitivity can be improved, but there is still room for improvement when considering the following aspects.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

In the latter assembly part on the side of the coil-wound coil holding member 15, at this stage, a coil having a stable shape is formed on the coil holding member 15 on which the fixing screw for the former assembly is threaded. It will be. A coil holding member 15 in which a wire groove 18 for holding a coil wire is formed together with a screw groove.
This coil body formed by including the above-mentioned electrode portion 21 by winding the coil wire 17 around the coil has a stable physical shape and is easy to handle. Therefore, the electrical characteristics exhibiting a desired inductance value necessary for matching are obtained. In the stable state, the arrangement of the matching coil in the vicinity of the piezoelectric element and the electrical connection to the matching coil are easily performed as follows.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

That is, the coil holding member 15 on which the coil wire 17 is wound is inserted inside the insulating member 12 on the assembly side,
It is screwed in using the thread groove that fits. Therefore, the matching coil can be easily arranged by this screwing. At the time of screwing, a screwdriver can be put into the driver groove 22 to facilitate the work in this example.
The electrode part 21 is screwed in until it comes into contact with the piezoelectric element lower surface electrode 1a, and tightened with a torque that provides a contact pressure necessary for electrical connection. You can then fix it as shown and screw 1
Since 3,16 is provided, in the process of screwing in,
An electrode part that is electrically connected to the coil provided on the coil holding member 15.
21 (in this example, the exposed coil wire itself) is the piezoelectric element 1
The coil and the piezoelectric element are pressed into contact with the lower surface electrode 1a, and the electrical connection between the coil and the piezoelectric element is also included in the work and simultaneously performed. Therefore, of course, the connection via the wire 7 as shown in FIG. 8 is unnecessary, and the work for the purpose of special electrical connection to the piezoelectric element lower surface electrode 1a is not necessary.
The number of steps can be reduced. Although the coil wire 17 is used as it is in the electrode portion 21 here, a dedicated electrode member having a spring property may be attached for reliable conduction.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

In the ultrasonic probe thus obtained, the matching coil composed of the coil wire 17 is connected in parallel to the piezoelectric element 1. This ultrasonic probe is, for example, an endoscope. It is suitable as an ultrasonic probe with an ultrasonic probe in a body cavity that is physically inserted into the body cavity. The following is a supplementary description of an ultrasonic diagnostic apparatus that projects an ultrasonic pulse on a living body and receives an echo thereof to obtain an ultrasonic image, including the function of the matching coil. The ultrasonic probe is connected to the apparatus main body side via a coaxial cable 5, and when an electric pulse is applied between the electrodes 1a and 1b of the piezoelectric element 1, an ultrasonic wave is generated and a reflected wave in the living body is generated by the piezoelectric element. When it returns to, a voltage is generated between the electrodes. An ultrasonic tomographic image is obtained by comparing the magnitude of this echo signal with the positional relationship and imaging. Where, in general,
The piezoelectric element also has a property as a dielectric, and a capacitor is formed between the positive electrode and the negative electrode, and the capacitor component is called a damping capacitance. When the drive pulse generator on the main body side and the piezoelectric element are connected by a coaxial cable for use in guiding between the element electrodes, the combined capacitance of the stray capacitance of the coaxial cable and the braking capacitance is the piezoelectric It will exist in parallel with the elements that contribute to the vibration of the element. However, when an electric pulse is applied in such a state, most of the pulse current is shunted into this electrostatic capacitance, and the degree of contribution to the original vibration energy is reduced, and ultrasonic waves with sufficient power are generated. Where it cannot be obtained, in this ultrasonic probe, a coil having an inductance constant selected to a value that causes parallel resonance with the capacitance near the resonance frequency of the piezoelectric element 1 used is used as the matching coil as described above. As described above, since it can be stably incorporated and can be inserted in parallel with the piezoelectric element 1, an ultrasonic wave with sufficient power can be obtained. That is, if parallel resonance occurs, the parallel impedance between the electrostatic capacitance and the inserted coil has a sufficiently large value, and as a result, an effect of canceling the braking capacitance and the stray capacitance of the cable is produced. Therefore, a high-performance ultrasonic diagnostic image is secured, and an ultrasonic probe that realizes this can be stably and efficiently assembled easily. Moreover, it is desirable to arrange such a matching coil in the vicinity of the piezoelectric element. Especially, in the body cavity ultrasonic probe in which the ultrasound probe is inserted into the body cavity endoscopically, the physical size is not limited. Strictly, it is not allowed to increase the size by adding a coil, but in this respect, the ultrasonic probe can meet the demand.

[Procedure Amendment 6]

[Document name to be corrected] Drawing

[Correction target item name] Figure 8

[Correction method] Change

[Correction content]

[Figure 8]

Claims (1)

[Claims] 1. An ultrasonic probe having a piezoelectric element and a matching coil in the vicinity of the piezoelectric element, the coil holding member having a threaded portion, and the threaded portion of the coil holding member. An ultrasonic probe, comprising: a piezoelectric element holding member provided with a threaded portion, and an electrode for electrically connecting the holding coil and the electrode of the piezoelectric element to the coil holding member.