JPS6316240Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a piezoelectric vibrator used in an ultrasonic probe that emits ultrasonic waves.

Configuration of conventional example and its problems Figures 4 to 6 show conventional piezoelectric vibrators, where 1 is a circular piezoelectric element, and 2 and 3 are formed almost concentrically on both sides of piezoelectric element 1. The electrode 3 has an extension extending toward the electrode 2 side through the side surface of the piezoelectric element. That is, the electrode 2 is a circular electrode with a part cut out, and the extension part 5 of the electrode 3 is provided in this cutout part at a constant distance from the electrode 2. Reference numerals 6 and 7 are lead wires connected to the electrode 2 and the extension portion 5, respectively.

FIG. 6 shows an example of an ultrasonic probe using the piezoelectric vibrator shown in FIG. 4. The piezoelectric vibrator is bonded onto the load material 8 and housed in a case 9, and an adhesive 10 is filled between the piezoelectric vibrator and the load material 8 and the case 9 and fixed. Further, an acoustic matching layer 11 is bonded to the front surface of the piezoelectric vibrator in order to match the acoustic impedance with the subject. In such a configuration, since the folded extension part 5 of the electrode 3 is on the electrode 2 side and a part of the electrode 2 is cut out, when an electric signal is applied between the lead wires 6 and 7, the piezoelectric vibrator No voltage is applied to the portion sandwiched between the extension portion 5 of the electrode 3 and its opposing surface, and therefore no driving force is generated. For this reason, the ultrasonic waves emitted from the front surface of the piezoelectric vibrator become asymmetrical with respect to the central axis as shown in FIG.

Purpose of the Invention The object of the present invention is to improve the structure of the electrodes of a piezoelectric vibrator, and to provide a piezoelectric vibrator that has uniform and symmetrical directivity and can emit ultrasonic waves with small side lobes.

Structure of the device: substantially concentric circular electrodes are provided on both sides of a circular piezoelectric element, an insulating material is applied or adhered to the electrode on one side, and the electrode on the other side is extended onto the insulating material through the side surface of the piezoelectric element. .

DESCRIPTION OF EMBODIMENTS FIGS. 1 and 2 show an embodiment of the present invention, and FIG. 3 shows an embodiment used as an ultrasonic probe. Reference numeral 1 denotes a circular piezoelectric element, and substantially concentric circular electrodes 2 and 3 are provided on both surfaces of the piezoelectric element. The diameter of the electrode 2 is made somewhat smaller than the diameter of the piezoelectric element 1, and the diameter of the electrode 3 is made the same as or somewhat smaller than the diameter of the piezoelectric element 1. An electrically insulating material is applied and dried on one surface of the electrode 2, or an electrically insulating film 4 is adhered thereto. Further, a conductive material is applied to the side surface of the piezoelectric element 1 and a part of the electrically insulating material, and the electrode 3
It constitutes an extension part 5 of. As described above, in the present invention, the electrode 3 is extended onto the electrical insulating material 2 through the side surface of the piezoelectric element 1 using conductive paint,
The electrode 2 and the extension 5 of the electrode 3 are insulated from each other by an electrically insulating material 4. Reference numerals 6 and 7 are lead wires connected to the extensions 5 of the electrodes 2 and 3, respectively. What is shown in FIG. 3 is the case where an ultrasonic probe is constructed, and 8 is a load material, and this load material 8
A piezoelectric vibrator is pasted on top. 9 is the case,
10 is an adhesive, and 11 is an acoustic matching layer. In this configuration, the piezoelectric element 1, electrode 2, and electrode 3 are all circular and concentric, so the emitted ultrasonic waves A are symmetrical about the central axis.

Effects of the invention In the present invention, the electrodes 2 and 3 constitute a substantially concentric circle, and the extension part 5 of the electrode 3 is provided with an electrical insulating material, so that the electrode 2 is not cut out, so that the voltage can be applied over the entire surface. is applied, and the emitted ultrasonic waves are formed symmetrically about the central axis. Therefore, the direction of propagation of the ultrasonic waves is also in the direction of the central axis, and the side lobes are also extremely small.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the piezoelectric vibrator of the present invention, Fig. 2 is a sectional view of the same, Fig. 3 is a sectional view showing an example of application to an ultrasonic probe, and Fig. 4 is a perspective view of a conventional example. FIG. 5 is a sectional view of the conventional example, and FIG. 6 is a sectional view of the conventional example applied to an ultrasonic probe. DESCRIPTION OF SYMBOLS 1... Piezoelectric element, 2, 3... Electrode, 4... Electrical insulation material, 5... Extension part.

Claims (1)

[Scope of utility model registration request] First and second circular electrodes are provided on both principal surfaces of the circular piezoelectric element, and an electrically insulating material is formed on the first circular electrode, and the second circular electrode is connected to the piezoelectric element. A piezoelectric vibrator comprising an extension extending through a side surface of the element and onto the electrical insulating material.