JP2003230194A - Ultrasonic probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance operability by reducing the width of the piezoelectric plate of an ultrasonic probe in the short axis direction thereof, and to improve the azimuth revolving power of short distance and the penetration of long distance. <P>SOLUTION: The take-out opening of a ground electrode 2 formed on the ultrasonic wave radiating face side of the piezoelectric plate 1 of an ultrasonic probe is provided at an exposed part 7 of the end side face in the scanning direction and connected externally through a common ground line 11. Since the short axis effective opening width is equalized to the width of the piezoelectric plate 1 in the short axis direction, the width in the short axis direction can be shortened and the operability is enhanced. Since the short axis effective opening width of ultrasonic wave being radiated from the piezoelectric plate 1 is increased, a good ultrasonic tomographic image having reduced reflection noise is obtained even in case of scanning through a limited gap. When the ground electrode of a piezoelectric oscillator is divided in the short axis direction and switched selectively by means of a switch, an optimal beam can be formed depending on the measuring region by varying the short axis effective opening width. Consequently, the azimuth revolving power of short distance is enhanced and the penetration of long distance can be improved. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe, and more particularly, to an ultrasonic diagnostic apparatus which emits ultrasonic waves into the body of a subject and displays a tomographic image inside the body based on reflected ultrasonic waves. The ultrasonic probe used.

[0002]

2. Description of the Related Art A conventional ultrasonic probe is disclosed in Japanese Patent Application Laid-Open No. 9-
There is one disclosed in Japanese Patent No. 84194. FIG. 10 shows a schematic perspective view of a conventional ultrasonic probe. The ultrasonic probe is composed of a piezoelectric plate 50, a first matching plate 51, a second matching plate 52, an acoustic lens 53, and a backing 54. Piezoelectric plate
Electrodes are formed on two opposite surfaces of the 50. In the ground electrode 55 on the acoustic lens side, a wrap-in electrode is formed through the side surface at the end in the short axis direction of the piezoelectric plate 50 to a part of the backing surface of the piezoelectric plate 50. The ground electrode 55, which is placed on the backing side of the piezoelectric plate 50, is electrically connected to the copper foil 56. The signal electrode 57 is electrically connected to a printed circuit board 58 on which a wiring pattern is formed. Each electrode is led out from the end face of the piezoelectric plate 50 in the short axis direction. Further, the piezoelectric plate 50 and the plurality of matching plates are cut in parallel with the minor axis direction. As a result, the channel dividing groove 59 is formed, and a plurality of piezoelectric vibrators 60 are arranged in the scanning direction.

[0003]

In the above-mentioned conventional ultrasonic probe, the ground electrode 55 of the piezoelectric plate 50 on the acoustic lens side is used.
Is rotated to the backing side of the piezoelectric plate 50. Therefore, the short-axis effective opening width in which the piezoelectric vibrator 60 vibrates is the width obtained by subtracting the width of the wrapping electrode on the backing side and the groove 61 for preventing the short circuit between the signal electrode 57 and the ground electrode 55 from the piezoelectric plate width. . Therefore, the short axis width of the ultrasonic probe becomes larger than the short axis effective opening width, and there is a problem that the operability when contacting the subject deteriorates.

When the short-axis effective aperture width is large, the beam width becomes large and the azimuth resolution is deteriorated. Since the distance sound field region is shortened, there is a problem that the beam spreads in the far distance region and the lateral resolution and the contrast deteriorate.

The present invention solves the above conventional problems,
An object is to provide an ultrasonic probe having a short minor axis width and excellent operability. Further, it is an object of the present invention to provide an ultrasonic probe which can form an optimum beam according to a measurement region, has excellent lateral resolution at a short distance, and has excellent penetration even at a long distance.

[0006]

In order to solve the above problems, according to the present invention, an ultrasonic probe is provided with a lead-out terminal of an electrode formed on the ultrasonic wave emitting surface side of a piezoelectric plate in one of the scanning directions. The structure is provided on the side surfaces at both ends.

With this structure, the width of the piezoelectric plate and the width of the effective opening of the minor axis are the same, the width of the minor axis of the piezoelectric plate can be shortened, and the operability is improved.

Further, the ultrasonic probe is divided by arranging a plurality of notches along the short axis direction of the common ground electrode provided on the surface of the piezoelectric vibrator in the scanning direction so as to divide each common ground electrode in the scanning direction. Remove from one or both ends,
Each common ground electrode is selectively switched by a switch.

With this configuration, the short-axis effective aperture width is changed to form an optimum beam according to the measurement area, the lateral resolution at a short distance is enhanced, and the penetration is improved even at a long distance portion. be able to.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is
A plurality of piezoelectric vibrators arranged in the ultrasonic scanning direction,
A conductive first acoustic matching layer provided on the surface of the piezoelectric vibrator, a second acoustic matching layer laminated on the first acoustic matching layer, the first acoustic matching layer and the ground of the piezoelectric vibrator. The cut groove for dividing the electrode into a plurality of parts in the minor axis direction and each common ground electrode commonly connected by the first acoustic matching layer are externally connected to the outside by the first acoustic matching layer at one or both ends in the scanning direction. An ultrasonic probe comprising connecting means for connecting and switch means for variably controlling the acoustic aperture of the short axis by selectively switching the common ground electrode, and the piezoelectric plate width and the effective length of the short axis are the same. In addition, it has an effect of selectively switching each common ground electrode to change the short-axis effective opening length.

According to a second aspect of the present invention, a plurality of piezoelectric vibrators arranged in the ultrasonic scanning direction, and a conductive first acoustic matching layer provided on the surface of the piezoelectric vibrator are provided. A second acoustic matching layer laminated on the first acoustic matching layer, a metal thin film layer provided between the first acoustic matching layer and the second acoustic matching layer, the metal thin film layer and the first acoustic matching layer, 1 acoustic matching layer and a notch that divides the ground electrode of the piezoelectric vibrator into a plurality of portions in the minor axis direction, and each common ground electrode commonly connected by the first acoustic matching layer and the metal thin film layer to the scanning direction. A connecting means for connecting to the outside at the metal thin film layer at one or both ends or the first acoustic matching layer, and a switch means for selectively switching the common ground electrode to variably control the acoustic opening of the short axis. Is an ultrasonic probe that is effective for piezoelectric plate width and short axis With the same mouth length, each common ground electrode is switched selectively, has the effect of changing the minor axis effective aperture length.

FIG. 1 shows an embodiment of the present invention.
9 to FIG. 9 will be described.

(First Embodiment) In the first embodiment of the present invention, individual ground electrodes of a plurality of piezoelectric vibrators arranged in the scanning direction are arranged on the ground electrode surface of the piezoelectric vibrator. It is an ultrasonic probe in which the ground electrodes commonly connected by the conductive layer provided and commonly connected are taken out from one end or both ends in the scanning direction.

FIG. 1 is a schematic perspective view of an ultrasonic probe according to the first embodiment of the present invention. In FIG. 1, the piezoelectric plate 1
Is a piezoelectric element that transmits and receives ultrasonic waves, using a piezoelectric ceramic such as PZT system, a polymer such as PVDF, or a single crystal. Ground electrode 2 and signal electrode 3
Is an electrode formed by sputtering or plating gold or silver,
Alternatively, it is an electrode formed by baking silver on both opposite surfaces of the piezoelectric element.

The backing 4 is made of ferrite rubber, epoxy or urethane rubber mixed with microballoons, and is a backing material for holding the piezoelectric plate 1 and absorbing unnecessary ultrasonic waves. The conductive acoustic matching layer 5 is made of a conductive material such as epoxy resin and graphite to which an inorganic material is added, and is an acoustic matching layer provided on the subject side of the piezoelectric plate 1 for efficiently propagating ultrasonic waves. is there. The ground electrode 2 on the subject side of the piezoelectric plate 1 and the conductive acoustic matching layer 5 are electrically connected by a conductive adhesive. The acoustic matching layer 6 is made of a material such as an epoxy resin or a plastic material, and is an acoustic matching layer provided on the subject side of the conductive acoustic matching layer 5 in order to propagate ultrasonic waves efficiently. Further, in order to form the exposed portion 7 of the conductive acoustic matching layer at the end of the conductive acoustic matching layer 5 in the scanning direction, the acoustic matching layer 6 is longer than the conductive acoustic matching layer 5 in the scanning direction. Is short.

The channel dividing groove 8 is a dividing groove that divides the piezoelectric plate 1 to form a plurality of electrically independent piezoelectric vibrators 9. The ground electrode 2, the piezoelectric plate 1 and the signal electrode 3 are formed.
And part of the backing 4 is cut. The dividing groove 8 is mainly filled with a material such as silicone rubber, urethane rubber, or epoxy resin. The signal line 10 is a signal line extracted from the signal electrodes 2 of the plurality of piezoelectric vibrators 9. The common ground electrode wire 11 is made of Cu, Au, Cr, Ag, S
A metal foil of n, Ni, or the like, which is electrically connected to the exposed portion 7 formed at the end of the conductive acoustic matching layer 5 in the scanning direction with a conductive adhesive, , Has a role of a common ground electrode electrically connected to the ground electrode 2 on the subject side of each piezoelectric vibrator 9, and is taken out from the same side as the signal line 10.

Although not shown, the acoustic lens provided on the subject side of the acoustic matching layer 6 is made of a material such as silicone rubber, urethane rubber, or plastic, and is used for focusing ultrasonic waves. The side has a convex curved surface shape, and the opposite flat surface is bonded to the acoustic matching layer 6 with a silicone adhesive or an epoxy resin.

In the ultrasonic probe of the first embodiment shown in FIG. 1, the piezoelectric vibrators 9 are divided at equal intervals, and the channel dividing groove 8 forming a channel has silicone rubber or urethane rubber. Or filling with epoxy resin. The smaller the acoustic impedance of the material to be filled, the higher the independence of the divided piezoelectric vibrators and the wider the directional angle.
Since the mechanical strength is lowered, it is better to use an appropriate value. Silicon rubber or urethane rubber having an acoustic impedance of 1.0 to 2.5 Mrayl is particularly desirable as a material for filling the dividing grooves.

The operation of the ultrasonic probe configured as described above will be described. A plurality of electric signals transmitted from the transmission unit of the ultrasonic diagnostic apparatus main body (not shown) with arbitrarily delayed time timing are applied to the plurality of piezoelectric elements 9 via the cable and the signal line 10. The piezoelectric element 9 to which the electric signal is applied generates ultrasonic waves, and the ultrasonic waves are radiated into the patient's body via the conductive acoustic matching layer 5 and the acoustic matching layer 6 and the acoustic lens. The ultrasonic wave is converged or deflected in a target direction among the scanning directions and propagates in accordance with the delay of the time timing from the transmitter.

Ultrasound waves are reflected according to the difference in acoustic impedance at the boundary of each internal organ of the patient. The reflected ultrasonic wave is again received by the piezoelectric vibrator 9, converted into an electric signal, and then transmitted to the receiving unit of the ultrasonic diagnostic apparatus main body via the cable. By performing signal processing on this received signal and displaying a reflection image on the display unit of the ultrasonic diagnostic apparatus main body, a tomographic image in the patient can be confirmed. These operations are the same as those of the conventional ultrasonic probe, but as the ultrasonic transmission / reception system of the ultrasonic probe of the first embodiment, any other system can be used. .

Although the common ground electrode wire 11 is taken out from one end in the scanning direction in FIG. 1, the common ground electrode wire 11 may be taken out from both ends. Although the common ground electrode line 11 is taken out from the exposed portion of the end of the conductive acoustic matching layer 5 in the scanning direction to the same side as the signal line 10,
It may be taken out from the opposite side of the signal line 10 or the side surface in the scanning direction. As the common ground electrode wire 11, a flexible printed board having a wiring pattern formed of a polymer material may be used instead of the metal foil.

Further, in the first embodiment, the case where the conductive acoustic matching layer 5 has one layer has been described, but the conductive acoustic matching plate 5 may have two or more layers. Although a conductive adhesive is used for bonding the ground electrode 2 and the conductive acoustic matching layer 5, an insulating epoxy resin adhesive may be used. In this case, in order to make the adhesive layer thin enough, the adhesive pressure is 3
Add more than Kg / cm2. The ground electrode 2 and the conductive acoustic matching layer 5 are partially brought into contact with each other so that the ground electrode 2 is commonly connected.

In the structure shown in FIG. 1, the piezoelectric plate and the backing are partially cut to form the channel dividing groove, but the piezoelectric plate is cut from the backing surface to a part of the conductive matching layer to form the channel. You may form a dividing groove.

As described above, in the first embodiment of the present invention, the ultrasonic probe is connected in common to the ground electrodes of the plurality of piezoelectric vibrators by the conductive acoustic matching layer, and the ultrasonic probe is connected in the scanning direction. Since the structure is taken out from one or both ends, the short axis width of the piezoelectric plate width can be shortened without shortening the short axis effective opening width, and the width of the patient contact portion can be narrowed, so that it is possible to perform intercostal scanning. Even from a very narrow gap, it is possible to obtain a good ultrasonic tomographic image with little reflected noise signal from the ribs.

Further, the effective aperture length can be increased with the same piezoelectric element width as in the conventional case. If the short-axis effective aperture length is large, the short-distance sound field area becomes long, making it possible to diagnose deep areas.In addition, the transmission / reception sensitivity can be improved, and the beam near the focal point can be easily focused. Although improved, it is preferable to use the short-axis effective opening width and the curvature of the acoustic lens according to the diagnosis site to be examined.

(Second Embodiment) In the second embodiment of the present invention, one or both ends of the conductive acoustic matching layer electrically connected to the ground electrode of the piezoelectric plate in the scanning direction. , A conductive side plate is electrically connected to the exposed portion provided on the backing surface of the conductive acoustic matching layer with a conductive adhesive, and a common ground electrode of a plurality of piezoelectric vibrators arranged in the scanning direction is formed in the scanning direction. Is an ultrasonic probe that is taken out from the end of the. The second embodiment differs from the first embodiment in that a conductive side plate is used to take out the ground electrode from the conductive acoustic matching layer, and the backing side of the conductive acoustic matching layer is exposed. The point is that the common ground electrode is taken out from the section.

FIG. 2 is a schematic cross-sectional view in the scanning direction of an ultrasonic probe according to the second embodiment of the present invention. In FIG.
The ground electrode 2, the signal electrode 3, the backing 4, the channel dividing groove 8, the piezoelectric vibrator 9, and the signal line 10 are the same as those in the first embodiment.

The conductive acoustic matching layer 12 is longer than the length of the piezoelectric plate in the scanning direction and is exposed on the backing surface at the end in the scanning direction.
14 are provided. The conductive side plate 15 is a conductive material whose main component is an epoxy material or graphite to which an inorganic substance is added, and an exposed portion 14 provided on the backing surface at the end of the conductive acoustic matching layer 12 in the scanning direction. It is electrically connected by a conductive adhesive. The acoustic matching layer 13 is an acoustic matching layer provided on the subject side of the conductive acoustic matching layer 12 in order to propagate ultrasonic waves efficiently, and is made of a material such as epoxy resin or plastic material.

The acoustic lens 16 is made of a material such as silicone rubber, urethane rubber, or plastic and is used for converging ultrasonic waves. The object side has a convex curved surface shape and the opposite flat surface has an acoustic matching layer. It is bonded to 13 with a silicone adhesive or epoxy resin.

The operation of the ultrasonic probe constructed as described above is the same as that of the first embodiment, and therefore its explanation is omitted. In FIG. 2, the conductive side plates 15 are formed at both ends in the scanning direction, but they may be formed at only one end. In addition, FIG. 2 shows the case where the conductive acoustic matching layer 12 is one layer, but the channel dividing groove 8 uses the two layers of the conductive acoustic matching layer 12 to connect the ground electrode 2 of the piezoelectric vibrator 9 to each other. The first conductive acoustic matching layer to be connected may be divided and the second conductive matching plate may be used as a common ground electrode.

As described above, in the second embodiment of the present invention, the ultrasonic probe is provided with the conductive side plate and the conductive acoustic matching layer at the exposed portion of the end portion in the scanning direction of the conductive acoustic matching layer. Since it is configured to be electrically connected, the width of the piezoelectric plate can be shortened without shortening the effective axis width of the short axis, the width of the patient contact portion can be narrowed, and the narrow gap like intercostal scanning can be performed. Also, it becomes possible to obtain a good ultrasonic tomographic image with little reflected noise signal from the ribs.

Further, it is possible to increase the minor axis effective opening length with the same piezoelectric plate width as the conventional one. By installing the side plate having high hardness at the end portion in the scanning direction, it is possible to improve impact resistance against an impact from the acoustic lens surface.

Furthermore, even if the conductive side plate comes into contact with the signal electrode at the end in the scanning direction or conducts with the conductive adhesive, the piezoelectric vibrator at the end does not contribute to the creation of the in-vivo image. Since it is a child and is electrically independent from other piezoelectric vibrators by the channel dividing groove, it is not short-circuited and the ultrasonic probe can be easily manufactured.

(Third Embodiment) In a third embodiment of the present invention, a metal foil is provided on the side surface of the backing in the scanning direction, and the side surfaces of the metal foil and the conductive acoustic matching layer in the scanning direction are made conductive. It is an ultrasonic probe that is electrically connected by a conductive adhesive and takes out the common ground electrode of the piezoelectric vibrator from the end portion in the scanning direction. The third embodiment differs from the first embodiment and the second embodiment in that the conductive acoustic matching layer is not provided with an exposed portion, and the common ground electrode can be easily taken out, and It facilitates production.

FIG. 3 is a schematic sectional view in the scanning direction of an ultrasonic probe according to the third embodiment of the present invention. In FIG.
Piezoelectric plate 1, ground electrode 2, signal electrode 3, backing 4, channel dividing groove 8, piezoelectric vibrator 9, signal line 10
Is the same as in the first embodiment. The acoustic lens 16
This is the same as the second embodiment.

The conductive acoustic matching layer 17 has the same length as the length of the piezoelectric plate 1 in the scanning direction, is a conductive material such as epoxy resin or graphite to which an inorganic material is added, and propagates ultrasonic waves efficiently. Therefore, the acoustic matching layer is provided on the subject side of the piezoelectric plate 1, and the ground electrode 2 and the conductive acoustic matching layer 17 on the subject side of the piezoelectric plate 1 are electrically connected by a conductive adhesive. . The acoustic matching layer 18 is made of a material such as an epoxy resin or a plastic material, and is an acoustic matching layer provided on the subject side of the conductive acoustic matching layer 17 in order to propagate ultrasonic waves efficiently. The ground wire 19 is a metal foil provided on the side surface of the backing 4 in the scanning direction, and is grounded from the side surface of the conductive acoustic matching layer 17 in the scanning direction with a conductive adhesive 20.
It is connected to 19 and the common ground electrode is taken out.

The operation of the ultrasonic probe constructed as described above is the same as that of the first embodiment, and therefore its explanation is omitted. In FIG. 3, the ground line 19 is formed at both ends in the scanning direction, but it may be formed at only one end. Further, FIG. 3 shows the case where the conductive acoustic matching layer 17 is one layer, but the channel dividing groove 8 is connected to the ground electrode of the piezoelectric vibrator 9 by using two conductive acoustic matching layers. The first conductive acoustic matching layer is divided, the second conductive acoustic matching layer is used as a common ground electrode, and the side surface in the scanning direction of the second conductive acoustic matching layer and the ground line are connected by a conductive adhesive. However, the common ground electrode may be taken out.

As described above, in the third embodiment of the present invention, the ultrasonic probe has a structure in which the common ground electrode is taken out from the side surface of the conductive acoustic matching layer in the scanning direction.
The lengths of the conductive acoustic matching layer and the acoustic matching layer in the scanning direction can be made equal to the length of the piezoelectric plate, which facilitates manufacturing.

Further, since the width of the piezoelectric plate can be shortened without shortening the short-axis effective opening width, the width of the patient contact portion can be narrowed and scanning is performed from a narrow gap like intercostal scanning. Even in this case, it is possible to obtain a good ultrasonic tomographic image with less reflected noise signal from the ribs. It is also possible to increase the short-axis effective opening length with the same short-axis width of the piezoelectric plate as the conventional one.

(Fourth Embodiment) In the fourth embodiment of the present invention, electrode bodies are provided at both ends in the scanning direction of a plurality of piezoelectric vibrators arranged in the scanning direction. Is an ultrasonic probe in which a ground electrode is connected in common by a conductive acoustic matching layer provided on the side of the subject on a plurality of piezoelectric vibrator surfaces including. Fourth
The embodiment is different from the first to third embodiments in that an electrode body for taking out the ground electrode is provided.

FIG. 4 is a schematic sectional view in the scanning direction of an ultrasonic probe showing a fourth embodiment of the present invention. Piezoelectric plate 1,
The backing 4, the channel dividing groove 8, the piezoelectric vibrator 9, and the signal line 10 are the same as those in the first embodiment. Acoustic lens
16 is the same as that of the second embodiment. The conductive acoustic matching layer 17 and the acoustic matching layer 18 are the same as those in the third embodiment.

A ground electrode 22 and a signal electrode 23 are formed on two opposing surfaces of the piezoelectric plate 1. Ground electrode
22 and the signal electrode 23 are electrodes formed by sputtering or plating gold or silver, or electrodes formed by baking silver or the like. The ground electrode 22 and the signal electrode 23 are electrically separated from each other. The ground wire 19 is formed of conductive metal, silicone rubber, urethane rubber, which is formed at the ends of the conductive acoustic matching layer 17 and the piezoelectric plate 1 in the scanning direction.
The electrodes 33, which are made of epoxy or the like, are electrically connected to the ground electrodes 22 of the individual piezoelectric vibrators 9, which are individually separated.

The operation of the ultrasonic probe constructed as described above is the same as that of the first embodiment, and therefore its explanation is omitted. Although the ground line 19 is taken out from the same side as the signal line 10 in FIG. 4, it may be taken out from the opposite side of the signal line 10 or the side surface at the end in the scanning direction. Although the ground wire 19 is taken out from both ends in the minor axis direction, it may be provided on only one side.

As described above, in the fourth embodiment of the present invention, in the ultrasonic probe, the ground electrodes are commonly connected by the conductive acoustic matching layer, and the electrodes are provided at both ends in the scanning direction. Since the common ground electrode is taken out from the body, the width of the piezoelectric plate can be shortened and the width of the patient contact portion can be narrowed without shortening the short axis effective opening width. Even in the case of scanning, it is possible to obtain a good ultrasonic tomographic image with little reflection noise signal from the ribs. It is also possible to increase the short-axis effective opening length with the same short-axis width of the piezoelectric plate as the conventional one.

(Fifth Embodiment) In the fifth embodiment of the present invention, the ground shunt electrode is formed on a part of the signal electrode surface through the end side surface in the scanning direction, and each ground electrode is formed. Is an ultrasonic probe in which the common ground electrode is taken out from the ground electrodes that are commonly connected by the conductive acoustic matching layer and are wound around the backing surface. The fifth embodiment differs from the first to fourth embodiments in that a ground winding electrode is provided via the side surface of the end portion of the piezoelectric plate in the scanning direction.

FIG. 5 is a schematic cross-sectional view in the scanning direction of an ultrasonic probe according to the fifth embodiment of the present invention. In addition, FIG.
It is an electrode formation drawing of the piezoelectric plate of the ultrasonic probe of a 5th embodiment. In FIG. 5, the backing 4, the channel dividing groove 8 and the signal line 10 are the same as those in the first embodiment. The acoustic lens 16 is the same as that in the second embodiment. The conductive acoustic matching layer 17 and the acoustic matching layer 18 are the same as those in the third embodiment.

The piezoelectric plate 21 is provided with a ground electrode 22 and a signal electrode, which are wound from the side surface of the end portion in the scanning direction, on two opposing surfaces. Ground electrode 22 and signal electrode
Reference numeral 23 is an electrode formed by sputtering or plating gold or silver, or an electrode formed by baking silver or the like.
A groove 24 is formed in the piezoelectric plate 21 so that the ground electrode 22 and the signal electrode 23 are not short-circuited. Since no electrode is formed in the groove 24 and the piezoelectric plate 21 is exposed, the ground electrode 22 and the signal electrode 23 are electrically separated from each other.

The ground line 19 has the piezoelectric plate 21 at the end in the scanning direction via the conductive acoustic matching layer 17 electrically connected to the ground electrode 22 of each piezoelectric vibrator 9 which is individually separated.
Are connected by the winding electrode of the ground electrode 22, and are electrically connected to the ground wire 19 from the backing side of the piezoelectric plate 21.

The operation of the ultrasonic probe configured as described above is the same as that of the first embodiment, and therefore its explanation is omitted. Although the ground line 19 is taken out from the same side as the signal line 10 in FIG. 5, it may be taken out from the opposite side of the signal line 10 or the side surface at the end in the scanning direction. Although the ground wire 19 is taken out from both ends in the minor axis direction, it may be provided on only one side. In FIG. 5 and FIG. 6, the ground electrode 22 of the piezoelectric plate 21 is wound from both ends in the scanning direction to the opposite surface, but only one side may be provided. Further, in FIG. 5, the electrode on one surface of the piezoelectric plate 21 forms a wrap-around electrode, but the ground electrode and the signal electrode on the solid surface are formed on both surfaces, and the conductive surface is formed on the side surface at the end in the scanning direction. The signal electrode on the backing side and the common ground electrode on the acoustic lens surface are electrically connected with an adhesive, and the piezoelectric element at the end electrically separated from the signal electrode 23 of the piezoelectric vibrator 9 other than the end by the channel dividing groove. The signal electrode 23 of the vibrator and the ground line 19 may be electrically connected.

As described above, in the fifth embodiment of the present invention, the ultrasonic probe is turned to the part of the signal electrode by passing the ground electrode on the object side through the side surface of the end portion in the scanning direction. By inserting the ground wire, the ground wire can be taken out from the backing side of the piezoelectric plate without electrically connecting to the conductive acoustic matching layer with the conductive side plate or the metal foil.

Further, by using a single printed circuit board on which an array pattern of signal lines and ground lines is formed, it is possible to easily carry out the production and reduce the number of parts. Since the short axis width of the piezoelectric plate and the short axis effective opening width can be made the same, the width of the patient contact area can also be made narrow, and the reflection noise signal from the ribs is small even from a narrow gap such as intercostal scanning. It becomes possible to obtain a tomographic image of various ultrasonic waves. It is also possible to increase the effective aperture length with the same piezoelectric element width as in the past.

(Sixth Embodiment) In the sixth embodiment of the present invention, the conductive acoustic matching layer, the piezoelectric plate and a part of the backing are separated by a channel dividing groove, and the ground electrode of the piezoelectric plate is Electrically common connection through the conductive acoustic matching layer and the metal thin film layer, and the ground electrode is connected to the outside through the conductive side plate electrically connected at the scanning direction end of the conductive acoustic matching layer. It is an ultrasonic probe. The sixth embodiment is the first
The difference from the fifth embodiment is that the conductive acoustic matching layer is also separated by the channel dividing groove to enhance the independence of the channel.

FIG. 7 is a schematic sectional view parallel to the scanning direction of the ultrasonic probe according to the fifth embodiment of the present invention. In FIG. 7, the piezoelectric plate 1, the ground electrode 2, the signal electrode 3,
The backing 4 and the signal line 10 are the same as those in the first embodiment. Further, the conductive acoustic matching layer 12, the acoustic matching layer 13, the conductive side plate 15, and the acoustic lens 16 are the same as those in the second embodiment.

The channel dividing groove 25 is a conductive acoustic matching layer.
Reference numeral 12 is a cut groove formed by cutting a part of the piezoelectric plate 1 and the backing 4, and the groove is filled with epoxy resin, silicone rubber, or urethane rubber. The metal thin film layer 26 is C
It is a thin film of u, Ag, Au, Cr, Ni, Ti, and Sn and has a thickness of 20 μm or less, and is electrically connected to the subject side of the conductive acoustic matching layer 12 with a conductive adhesive or an insulating epoxy adhesive. There is. In the case of bonding with an insulating epoxy adhesive, a bonding pressure of 3 kg / cm ² or more is applied in order to make the bonding layer sufficiently thin. The conductive acoustic matching layer 12 and the metal thin film layer 26 can be partially brought into contact with each other to obtain a conductive state. The ground electrodes 2 of the plurality of piezoelectric vibrators 9 arranged in the scanning direction are
The conductive acoustic matching layer 12 and the metal thin film layer 26 are electrically connected. The conductive side plate 15 electrically connected to the end of the conductive acoustic matching layer 12 in the scanning direction and the metal thin film layer 26 serving as a common ground electrode are electrically connected to form a common ground of each piezoelectric vibrator 9. is doing.

The operation of the ultrasonic probe configured as described above is the same as that of the first embodiment, and therefore its explanation is omitted. Note that, in FIG. 7, the ground electrode 2 is taken out by using the conductive side plate 15 connected to the end of the conductive acoustic matching layer 12 on the backing side in the scanning direction. As in the embodiment, it may be taken out with a metal foil, or a piezoelectric plate on which a wrap-around electrode is formed via an end in the scanning direction may be used. The metal thin film layer 26 is an acoustic matching layer.
Gold or silver may be formed on the backing side surface of 13 by sputtering or plating.

As described above, in the sixth embodiment of the present invention, since the ultrasonic probe has the structure in which the piezoelectric plate and the conductive acoustic matching layer are separated, the independence of the piezoelectric vibrator is enhanced. Therefore, it is possible to transmit an ultrasonic wave having a wide directional characteristic, the piezoelectric plate width and the minor axis effective opening width can be made the same, and the operability is improved.

(Seventh Embodiment) In the seventh embodiment of the present invention, the conductive acoustic matching layer, the metal thin film layer, and the ground electrode of the piezoelectric vibrator are divided into a plurality of parts in the minor axis direction, and they are dealt with. With an ultrasonic probe that connects the ground electrodes in common and takes them out from the metal thin film layer or the conductive acoustic matching layer at the end, and selectively switches the common ground electrode with a switch to variably control the acoustic aperture of the short axis. is there. The seventh embodiment is the first to the first.
The difference from the sixth embodiment is that the divided ground electrodes are selectively switched by a switch.

FIG. 8 is a perspective view of an essential part of an ultrasonic probe according to the seventh embodiment of the present invention. In FIG. 8, the piezoelectric plate 1, the ground electrode 2, the signal electrode 3, the backing 4,
The channel dividing groove 8 and the piezoelectric vibrator 9 are the same as those in the first embodiment.

The conductive acoustic matching layer 27 is a conductive material such as an epoxy resin or graphite to which an inorganic material is added. Since the ultrasonic waves are efficiently propagated, the acoustic matching layer 27 provided on the object side of the piezoelectric plate 1 is matched. The ground electrode 2 on the subject side of the piezoelectric plate 1 and the conductive acoustic matching layer 27 are electrically connected by a conductive adhesive. The acoustic matching layer 28 is a material such as an epoxy resin or a plastic material, and is an acoustic matching layer provided on the subject side of the conductive acoustic matching layer 27 in order to propagate ultrasonic waves efficiently. An exposed portion 29 is formed on the subject side at the end of the conductive acoustic matching layer 27 in the scanning direction. Also,
The acoustic matching layer 28 is shorter than the conductive acoustic matching layer 27 in the scanning direction in order to form the exposed portion 29. The common ground dividing groove 30 divides the common ground of the conductive acoustic matching layer 27 electrically connected to the ground electrodes 2 of the plurality of piezoelectric vibrators 9 in the short axis direction, and thereby divides the plurality of electrically independent common grounds. Electrodes are formed, and are electrically independent from the adjacent common ground electrode, and are grooves obtained by cutting the conductive acoustic matching layer 27 and the acoustic matching layer 28. The inside of the common ground dividing groove 30 is filled with epoxy resin, silicone rubber, urethane rubber, or the like. Further, the common ground division groove 30 is cut from the acoustic matching layer 28 to a part of the piezoelectric plate 1 and is divided into a plurality of pieces in the short axis direction to form a plurality of common ground electrodes electrically independent from each other. ing.
The common ground line 19 is a flexible printed circuit board or a copper foil, is electrically connected to the exposed portion 29 of the conductive acoustic matching layer 27 with a conductive adhesive, and is taken out from the side surface of the end portion in the scanning direction. The switch means 32 is a common ground line extracted from a plurality of common ground electrodes arranged in the short axis direction.
It is connected to 19 and can be selectively switched to control the short axis effective opening width of the ultrasonic wave reception and transmission of the piezoelectric plate.

The operation of the ultrasonic probe configured as above will be described with reference to FIGS. 8 and 9. FIG. 9 is a cross-sectional view in the short axis direction of the ultrasonic probe according to the seventh embodiment of the present invention. A plurality of electric signals transmitted by arbitrarily delaying the time timing from the transmission unit of the ultrasonic diagnostic apparatus main body (not shown) are applied to the plurality of piezoelectric vibrators 9 via the cable and the signal line 10. . The piezoelectric vibrator 9 to which an electric signal is applied generates an ultrasonic wave, and is delayed in the patient's body through the conductive acoustic matching layer 5, the acoustic matching layer 6, and the acoustic lens 16 due to the delay of the time timing from the transmitter. , The ultrasonic waves are propagated by converging or deflecting them with respect to the scanning direction. At this time, the common ground dividing groove 30 makes it possible to control the common axis electrodes independent of each other by the switch means 32 to control the effective short axis width. By controlling the short-axis effective aperture length, for example, at short distances,
The resolution can be improved by narrowing the short axis opening length.
Then, the ultrasonic waves reflected from the difference in the acoustic impedance of the internal organ boundaries of the patient are received by the piezoelectric vibrator 9 again while changing the focus by selectively switching the common ground line 19 as in the above. After being converted into an electric signal, the signal is transmitted to the receiving unit of the ultrasonic diagnostic apparatus main body via the cable. By performing signal processing on this received signal and displaying a reflection image on the display unit of the ultrasonic diagnostic apparatus main body, a tomographic image in the patient can be confirmed.

In FIG. 8, the same structure as that of the first embodiment is used as the method of taking out the common ground.
In addition to the above configuration, the configurations described in the second, third, fourth, fifth and sixth embodiments can be used. Further, in FIG. 8, the acoustic matching layer, the conductive acoustic matching layer, and the ground electrode of the piezoelectric plate are cut to divide the common ground electrode. However, in order to increase the strength against impact, the second matching plate is provided. You may make it a structure which is not cut. Although a convex curved surface is formed on the subject side of the acoustic lens in FIG. 8, the acoustic lens may have a uniform thickness. Further, instead of controlling the left-right symmetric common ground electrode as shown in FIGS. 8 and 9, the left-right symmetry may be connected or individually switched.

As described above, in the seventh embodiment of the present invention, in the ultrasonic probe, the common ground electrode is divided in the short axis direction, and the plurality of common ground electrodes are selectively connected by the switch means. With this configuration, the effective aperture width of the short axis can be controlled, and at a short distance, an ultrasonic probe having excellent lateral resolution in the short axis direction and excellent operability can be provided. it can.

[0063]

As described above, according to the present invention, the ultrasonic probe is arranged such that the ground electrode on the side of the object to be inspected in the ultrasonic scanning direction among the electrodes of the two opposite surfaces of the polarized piezoelectric plate. Since it is configured to extract from one or both end faces, the width of the piezoelectric vibrator is reduced, operability is improved, and the short-axis effective opening width of the ultrasonic waves emitted from the piezoelectric plate can be increased to allow intercostal scanning. Even in the case of scanning from a narrow gap as described above, it is possible to obtain an effect that a good ultrasonic tomographic image with few reflection noise signals from ribs can be displayed.

Further, since the ultrasonic probe is divided by making a plurality of cuts in the short axis direction of the common ground electrode of the piezoelectric vibrator and each common ground electrode is selectively switched by the switch, By changing the axial effective aperture width, an optimum beam is formed according to the measurement area, the lateral resolution at a short distance is enhanced, and the penetration can be improved at a long distance portion.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of an ultrasonic probe showing a first embodiment of the present invention,

FIG. 2 is a schematic sectional view in a scanning direction of an ultrasonic probe showing a second embodiment of the present invention,

FIG. 3 is a schematic cross-sectional view in the scanning direction of an ultrasonic probe showing a third embodiment of the present invention,

FIG. 4 is a schematic cross-sectional view in a scanning direction of an ultrasonic probe showing a fourth embodiment of the present invention,

FIG. 5 is a schematic cross-sectional view in a scanning direction of an ultrasonic probe showing a fifth embodiment of the present invention,

FIG. 6 is an electrode configuration diagram of a piezoelectric plate of an ultrasonic probe showing a fifth embodiment of the present invention,

FIG. 7 is a schematic cross-sectional view parallel to the scanning direction of the ultrasonic probe according to the sixth embodiment of the present invention,

FIG. 8 is a perspective view of an essential part of an ultrasonic probe showing a seventh embodiment of the present invention,

FIG. 9 is a cross-sectional view in the minor axis direction of an ultrasonic probe showing a seventh embodiment of the present invention,

FIG. 10 is a schematic perspective view of a conventional ultrasonic probe.

[Explanation of symbols]

1,21,50 piezoelectric plate 2,22,55 Ground electrode 3,23,57 Signal electrode 4,54 backing 5,12,17,27 Conductive acoustic matching layer 6,13,18,28 Acoustic matching layer 7,14,29 Exposed part 8,25,59 channel dividing groove 9,60 Piezoelectric vibrator 10 signal line 11,19 Common ground line 15 Conductive side plate 16,53 Acoustic lens 20 Conductive adhesive 24,61 groove 26 Metal thin film layer 30 Common ground division groove 32 switch means 33 Electrode body 51 First alignment plate 52 Second matching plate 56 copper foil 58 printed circuit board

Continued front page    (72) Inventor Wataru Tokunaga             3-1, Tsunashima-Higashi 4-chome, Kohoku-ku, Yokohama-shi, Kanagawa             Matsushita Communication Industry Co., Ltd. F term (reference) 2G047 AC13 CA01 EA02 EA05 GB02                       GB16 GB21 GB23 GB25 GB30                       GF20                 4C301 EE02 EE06 GB04 GB19 GB20                       GB22 GB24 GB27 HH13                 5D019 AA21 BB25 BB28

Claims (2)

[Claims] 1. A plurality of piezoelectric vibrators arranged in a scanning direction of ultrasonic waves, a conductive first acoustic matching layer provided on the surface of the piezoelectric vibrator, and laminated on the first acoustic matching layer. A second acoustic matching layer, a cut groove that divides the first acoustic matching layer and the ground electrode of the piezoelectric vibrator into a plurality of pieces in the minor axis direction, and each common connection by the first acoustic matching layer. Connection means for connecting the common ground electrode to the outside through the first acoustic matching layers at one or both ends in the scanning direction, and switch means for selectively switching the common ground electrode to variably control the acoustic opening of the short axis. An ultrasonic probe comprising: 2. A plurality of piezoelectric vibrators arranged in the ultrasonic scanning direction, a conductive first acoustic matching layer provided on the surface of the piezoelectric vibrator, and a laminate on the first acoustic matching layer. Second acoustic matching layer, a metal thin film layer provided between the first acoustic matching layer and the second acoustic matching layer, the metal thin film layer, the first acoustic matching layer, and the piezoelectric vibrator A plurality of slits for dividing the ground electrode in the short axis direction and the common ground electrodes commonly connected by the first acoustic matching layer to the metal thin film layer at one or both ends in the scanning direction or the first or second metal thin film layer. 1. An ultrasonic probe, comprising: a connection unit that is connected to the outside through one acoustic matching layer; and a switch unit that selectively switches the common ground electrode to variably control a short-axis acoustic aperture.