JPS5991946A - Ultrasonic probe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus for diagnosing tissues in the body using ultrasonic waves, and in particular an array-type ultrasonic diagnostic apparatus that aims to improve the scanning line density in the ultrasonic scanning direction. relating to ultrasonic probes.

(b) Conventional technology and problems In ultrasound diagnostic equipment, a probe containing a probe that transmits and receives ultrasound waves is placed in close contact with the body surface to transmit a predetermined ultrasound wave into the body, and the reflection of this ultrasound wave is detected. A predetermined tomographic image is formed by obtaining the following information. The probes used in such ultrasonic diagnostic equipment are generally mechanical scan type, which performs fan-shaped scanning by swinging or rotating the probe, and electronic probes, which have multiple probes arranged. There is a play type that performs scanning.

The array type ultrasonic probe is constructed as shown in FIG. FIG. 1 is a side sectional view of a conventional ultrasound probe.

A vibrator formed by fixing electrodes 3 and 4 to sandwich a piezoelectric element 2 is fixed to a backing layer 1 made of a member that absorbs ultrasonic waves. Electrode 4 is C1
C1 to Cn are independently driven as vibrators by connecting the electrode 3 to ground and inputting or outputting a signal to each of C1 to Cn of the electrode 4.

Therefore, in ultrasonic scanning, the scanning lines are first focused on 21 points by driving C1 to C4, and then C7 to C4 are focused.
! The scanning line is focused on 28 points by driving the .

In order to reduce the focusing pitch of such scanning lines, that is, to increase the scanning line density, the scanning line density can be improved by reducing the division width of the electrodes 4. However, reducing the division width has a limit in terms of machining accuracy. Therefore, a method called half-pitch scanning was used. When C1 to C6 are driven after driving C3 to C4 described above, the scanning line is 2 points between the 28 points shown by the dotted line and the Ps point.
Focused on one point. Therefore, in this way, arrow A
By moving the focal point P11PttPs in the direction, the scanning density can be improved to some extent. However, in this case, the number of vibrators to be driven at the same time must be changed each time, such as four or five, resulting in the problem that the quality of the beam changes or that drive control becomes complicated.

(C) Object of the Invention The object of the present invention is to provide a device in which the above-mentioned problems are eliminated by dividing the electrodes provided oppositely on both sides of a piezoelectric element and relatively shifting their positions.

(d) Structure of the Invention The object of the present invention is to provide such an ultrasonic probe in which the electrodes of the transducer are divided into equal pitches of a predetermined width, and the opposed electrodes are arranged relative to the dividing direction. This is achieved by an ultrasonic probe characterized in that it is formed to have a predetermined positional deviation.

(,) Examples of the invention The present invention will be explained in detail below with reference to FIG.

FIG. 2 shows an embodiment of the ultrasonic probe according to the present invention (
(a) is a perspective view, and (b) is a side sectional view.

Rectangular electrodes 3 a1 to an are provided on the front side of the piezoelectric element 2, and rectangular electrodes 4 b8 to bn-1 are provided on the back side of the piezoelectric element 2 at equal pitches. is fixed so as to be shifted in position relative to the arrow X direction compared to a and an.

With this configuration, ultrasonic scanning can be performed as shown in (b).First, when driven by al-a4 and b1-b4, the scanning line is focused on point P+.

Next, when driven by al~a, -b, and so on, the scanning line is focused on pt. Similarly, a, ~a6,
-b, and the scanning line is focused on the point Ps. Thereafter, scanning in the direction of arrow A can be performed by sequentially shifting the a-side electrode 3 and the b-side electrode 4 one position at a time. In this case, since there are always four vibrators driven simultaneously, the beam quality does not change as described above, and the scanning density is also the same as that of the half-pitch scanning method.

FIG. 3 is an explanatory diagram showing an embodiment in which the scanning density is further improved. Piezoelectric element 2 on backing layer 1
With two layers, -1 and 2-2, the piezoelectric element 2-1 is driven by electrodes a and ~att, in which the electrode 3 is divided at equal pitches, and b1 to bn-1, in which the electrode 4 is divided at equal pitch. , the piezoelectric element 2-2 has b1~=4-bn-1 of the electrode 4 and d1~dn- where the electrode 5 is divided at equal pitches.
The dividing pitches of the electrodes 3, 4, and 5 are shifted by 1/3 pitch from each other so that a vibrator driven by the electrodes 3, 4, and 5 is formed.

Scanning is first driven by C1 to C4 and ~b4 to converge the scanning line to 21 points, driven by b1 to b4 and 61 to 6 to converge the scanning line to 23 points, and b2 ~bI
Driven by l, d, ~d4, the scanning line focuses on point Ps, and then driven by a, ~a, ~b, the scanning line converges at 24 points. sequentially electrode 3
．． 4. By shifting each of the 5's by 1 position, the arrow A
It is possible to scan in the direction. With this configuration, scanning by two sets of piezoelectric elements 2-1.
ts can be made small and the scanning line density can be made high.

Furthermore, by increasing the number of stacked piezoelectric elements 2 to three or four sets,
The scanning line density can be increased, and in this case, the mutual positional deviation of the divided electrodes is -1-, where the number of stacked electrodes is n.
By doing so, an equally spaced scanning line pitch PIIH3n+1 can be obtained.

(f) Detailed Description of the Invention As described in the present invention, one or more sets of piezoelectric elements 2 are used, the electrodes are divided at equal pitches, and the positions of the divided electrodes are shifted relative to each other. . This is K
In addition, the number of simultaneously driven transducers for scanning ultrasonic waves can always be a predetermined number, and the scanning line density can be improved. Compared to the conventional method, changes in beam quality can be prevented, drive control can be simplified, and the practical effects are great.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a conventional ultrasound probe, FIG. 2 is a perspective view of an embodiment of the ultrasound probe according to the present invention, and FIG. 2(b) is a side sectional view through FIG. Figure 3 shows an explanatory view showing another embodiment of the ultrasonic probe according to the present invention. In the figure, 1 is a backing layer, 2.2-1°2-2
〇7- Aki 1 shows the piezoelectric element and 3 and 4.5 the electrodes.

Claims (3)

[Claims] (1) Transmission and reception of ultrasonic waves is performed by a vibrator formed by comprising electrodes through which signals are input and output and a piezoelectric element, and the electrodes are fixed to face each other so as to sandwich the piezoelectric element. In the ultrasonic probe, the transducer is formed such that the electrode is divided into equal pitches of a predetermined width, and the opposing electrode has a predetermined positional shift relative to the dividing direction. An ultrasonic probe characterized by: (2) The ultrasonic probe according to claim (1), characterized in that a plurality of the electrodes and the piezoelectric elements are laminated so as to be assembled. (3) The ultrasonic probe according to claim (1), characterized in that the predetermined positional deviation is formed to be an integral multiple of -1- with respect to the number n of laminated layers of the piezoelectric element. Tentacle 0