JPH0199536A - Ultrasonic probe - Google Patents

Abstract

PURPOSE:To obtain an ultrasonic tomographic image of high resolution for a wide range and distance, simplified in operation with a driving circuit having a simplified structure by a method wherein, a group of acoustic lens converging ultrasonic waves emitted from an opening corresponding to a plurality electrodes of electroacoustic converting element, on a central axis of an ultrasonic radiation, on positions different from each other by each element, is provided. CONSTITUTION:An electroacoustic convertion element 1 has a structure in which, a common electrode 3 is provided in front of a sheet of piezoelectric plate 2, while ring-shaped electrodes 5, 6, 7 positioned in sequence concentrically on the outer periphery of the back surface of the plates 2 together with a central circular electrode 4. On the front surface of the electroacoustic conversion element 1, an acoustic lens group 14-17 is formed unitarily on the side opposite to each electrodes 5, 6, 7. A driving voltage is applied on electrodes 3-6 through leadwires 8-12, ultrasonic waves are emitted from openings corresponding to each electrodes 4-7 caused by the excitation of the piezoelectric plate 2. These ultrasonic waves can be converged on the points different from each other on an ultrasonic radiation central axis 18 by the function of acoustic lenses 14-17. Accordingly, by applying the same phase voltage (without delay), a high resolution ultrasonic tomographic image ranging widely converging near to far distances of a body to be detected can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ultrasonic probe used in an ultrasonic diagnostic apparatus.

Conventional technology Conventionally, in order to improve the resolution of ultrasonic tomographic images, this type of ultrasonic probe has been configured for short distance and long distance use. Use them accordingly. For short distance use, the ultrasonic aperture area (electrode area) is formed small, and the focal point of the acoustic lens is set at short distance. For long-distance use, the ultrasonic aperture area (electrode area) is formed large, and the focus of the acoustic lens is set at a long distance. However, using multiple types of ultrasound probes as in the conventional example described above is inconvenient for diagnostic work.

To solve this problem, conventionally, there has been provided an ultrasonic probe that can be used for both short-range and long-range applications. This conventional example will be explained below with reference to FIG.

In FIG. 2, 51 is a disk-shaped electroacoustic element, 52,
Reference numerals 53 and 54 denote electroacoustic transducer elements that are sequentially provided concentrically around the outer periphery of the disc-shaped electroacoustic transducer element 51, and these electroacoustic transducer elements 51, 52, 53, and 54 are arranged on the front surface of the casing (not shown). It is located on the side. Each electroacoustic transducer 5
1.52.53.54 is a piezoelectric plate 55.56.57°58
Electrodes 59, 60, 61, 62, 63 and 6 on the front and back of
4.65 and 66 are provided. 67, 68.69.
70.71°72, 73.74 are each electrode 59.60.6
1. Lead wires, 75.76, 77 that connect 62.63.64.65°66 to the ultrasound diagnostic equipment main body (not shown)
, 78 is a back load material provided on the back surface of each electroacoustic transducer 51, 52, 53, 54, and 79 is an acoustic matching layer provided on the front surface of the electroacoustic transducer 51, 52, 53, 54.

Next, the operation of the above conventional example will be explained.

A drive voltage is applied to the electrodes 59-66 from the lead wires 67-74 to excite the piezoelectric plates 55-58, thereby emitting ultrasonic waves from each electroacoustic transducer element 51-54 to the subject.

At this time, by gradually increasing the application time of the driving voltage signal from the electroacoustic transducer 51 at the center to the electroacoustic transducers 52, 63, and 54 at the outer periphery, ultrasonic waves can be transmitted to arbitrary positions on the ultrasonic emission center axis. A convergence point can be obtained.

Problems to be Solved by the Invention However, in the conventional configuration as described above, the plurality of ring-shaped electroacoustic transducers 52, 53, 54 are uniformly arranged with respect to the disc-shaped electroacoustic transducer 51. It is difficult to do so and requires a lot of effort to manufacture. Further, a plurality of circuits for arbitrarily delaying signals are required in the drive circuit section of the ultrasonic diagnostic apparatus main body, which not only complicates the configuration but also makes operation troublesome.

The present invention solves the problems of the prior art as described above, and can be easily manufactured, the configuration of the driving circuit of the ultrasonic diagnostic apparatus main body can be simplified, and furthermore, the operation can be simplified. It is an object of the present invention to provide an ultrasonic probe that can improve the resolution of ultrasonic tomographic images.

Means for Solving the Problems In order to achieve the above object, the present invention comprises a piezoelectric plate, a common electrode provided on one side of the piezoelectric plate, and a plurality of electrodes arranged on the other side of the piezoelectric plate. an electroacoustic transducer;
The electroacoustic transducer is equipped with an acoustic lens group that converges ultrasonic waves from openings corresponding to the plurality of electrodes of the electroacoustic transducer element to different positions for each electrode on the ultrasonic radiation central axis.

action The effects of the above technical means are as follows.

That is, by applying a voltage to the electrodes of the electroacoustic transducer and exciting the piezoelectric plate, ultrasonic waves are emitted from the openings of each of the plurality of electrodes to the subject, and these ultrasonic waves are directed toward the center axis of ultrasound emission. Each electrode can be focused at a different position. Since the electroacoustic transducer is constructed by providing electrodes on a single piezoelectric plate, it is easy to manufacture.
Furthermore, by applying voltages of the same phase (without delay) to each electrode, it is possible to obtain ultrasonic convergence points over a wide range of distances as described above.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of essential parts of an ultrasonic probe according to an embodiment of the present invention.

In FIG. 1, an electroacoustic transducer 1 is provided on the front side of a housing (not shown), and this electroacoustic transducer 1 has a common electrode 3 provided on the front surface of a piezoelectric plate 2, and On the back side of the plate 2, there is a central disk-shaped electrode 3 and ring-shaped electrodes 5 arranged concentrically around its outer circumference. 6. 7 is provided. Multiple electrodes5. 6. 7 are arranged concentrically around the effective ultrasound radiation central axis 18. 8°9, 10.11.12 are each electrode 3. 4.
5. 6. 7 is a lead wire connecting to the ultrasound diagnostic device body (not shown), 13 is a back load material provided on the back of the electroacoustic transducer 1, and 14, 15, 16, 17 is a lead wire on the front of the electroacoustic transducer 1. Each electrode4. 5. 6.
In this embodiment, these acoustic lens groups are integrally formed. The curvature is set to gradually increase from the central acoustic lens 14 to the outer acoustic lens 17. Therefore, acoustic lenses 14.15. 16.17 each electrode 4,5.
6. The ultrasonic waves emitted from the opening corresponding to 7 are converged onto the ultrasonic radiation central axis 18, and the ultrasonic waves are gradually converged to a far distance as the acoustic lens 14 located at the center reaches the acoustic lens 17 located outside. can be done.

Next, the operation of the above embodiment will be explained.

Applying a driving voltage to the electrodes 3 to 6 from the lead wires 8 to 12,
By exciting the piezoelectric plate 2, ultrasonic waves are emitted from the openings corresponding to the respective electrodes 4-7. These ultrasonic waves can be focused at different points on the ultrasonic radiation central axis 18 by the acoustic lenses 14 to 17. Therefore, by applying voltages of the same phase (without delay), it is possible to obtain a high-resolution ultrasonic tomographic image over a wide range from short distances to long distances in the subject.

Effects of the Invention As described above, according to the present invention, a common electrode is provided on one side of the piezoelectric plate and a plurality of electrodes are provided on the other side to constitute an electroacoustic variable element, and this electroacoustic conversion Since the ultrasonic waves are focused from the apertures corresponding to the multiple electrodes of the element to different positions for each electrode on the ultrasonic radiation central axis using a group of acoustic lenses, the same phase (no delay) is transmitted to each electrode. By applying a voltage of The configuration of the drive circuit can also be simplified. Further, since the electroacoustic transducer is constructed by providing electrodes on a single piezoelectric plate as described above, it can be easily manufactured.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the main parts of an ultrasonic probe according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the main parts of a conventional ultrasonic probe. 1... Electroacoustic conversion element, 2... Piezoelectric plate, 3...
Common electrode, 4 to 7... Electrode, 8 to 12... Lead wire, 13... Back load material, 14 to 17... Acoustic lens, 18... Ultrasonic radiation central axis. Name of agent: Patent attorney Satoshi Nakao, and one other person No. 1 □ Bt Kata Katsuragi Junior High School <#I 1g ”. Figure 2

Claims (3)

[Claims] (1) An electroacoustic transducer consisting of a piezoelectric plate, a common electrode provided on one side of the piezoelectric plate, and a plurality of electrodes arranged on the other side of the piezoelectric plate, and each of the plurality of electroacoustic transducers An ultrasonic probe comprising an acoustic lens group that focuses ultrasonic waves from openings corresponding to the electrodes onto different positions for each electrode on the ultrasonic emission central axis. (2) The ultrasonic probe according to claim 1, wherein the plurality of electrodes are arranged in a ring shape around an effective central axis of ultrasonic radiation. (3) The ultrasonic probe according to claim 1, wherein the plurality of electrodes are arranged in an array around an effective central axis of ultrasonic radiation.