JPH024514Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a thickness-shear transducer for an ultrasonic delay line.

The vibrator used as the input/output transducer of the conventional ultrasonic delay line uses the basic vibration mode of thickness shear, and as shown in Fig. An electrode 2 was formed, and the direction of arrow A in the length direction of the diaphragm along the electrode 2 was the polarization direction, and the direction of arrow B in the thickness direction of the diaphragm was the electric field direction. For this reason, unnecessary vibrations are likely to occur in the vicinity of resonance and anti-resonance, and since the entire vibrator vibrates, the vibrations are suppressed by the solder or conductive adhesive when attaching the lead wire to the electrode 2. However, there was a problem in that it was greatly affected by the lead wire attachment.

In view of the above points, it is an object of the present invention to obtain a thickness shear vibrator for an ultrasonic delay line, which can prevent the generation of unnecessary vibrations and eliminate the influence of lead wire attachment.

That is, the present invention is a thickness-shear transducer for an ultrasonic delay line that is attached to one end surface of a delay medium and used as an input/output transducer for the ultrasonic delay line, and in which at least a part of the piezoelectric vibrator This piezoelectric vibrator is polarized along the thickness direction, and two or more excitation electrodes are provided on at least one of both surfaces of the piezoelectric vibrator to obtain the energy of third-order thickness shear vibration. Since the thickness shear vibration is used, there is less unnecessary vibration and the influence of lead wire attachment is reduced.

An embodiment of the present invention will be described below based on the drawings. FIG. 2 is a front view of a thickness-shear transducer for an ultrasonic delay line according to an embodiment of the present invention. In FIG. 2, 3 is a piezoelectric vibrator, and at both ends of the piezoelectric vibrator 3, excitation electrodes 4a,
4b is provided. The direction of arrow A is the polarization direction along the thickness direction of the vibrator, and the direction of arrow D is the electric field direction along the length direction of the vibrator. Note that the excitation electrodes 4a, 4b
may be provided only on one surface of the piezoelectric vibrator 3.
Further, the polarization may be applied only to the vibrator portion where the excitation electrodes 4a and 4b are not provided.

FIG. 3 is a front view of a thickness-shear transducer for an ultrasonic delay line in another embodiment. In this way, another excitation electrode 4c may be provided in the center between the excitation electrodes 4a and 4b at both ends. Note that arrows E and F indicate the direction of the electric field. Also in this case, the excitation electrodes 4a, 4b,
4c may be provided only on one surface of the piezoelectric vibrator 3.

FIG. 4 is a front view of a main part of an ultrasonic delay line using the tertiary thickness-shear vibration mode energy trap type thickness-shear vibrator shown in FIG. 2 as an input/output transducer. Reference numeral 5 denotes a delay medium such as glass, and two thickness-shear oscillators shown in FIG. 2 are attached to this delay medium 5 with an adhesive 6. 7 is a lead wire attached to the excitation electrodes 4a, 4b, one for input/output and the other for grounding. By using the thickness shear oscillator of the tertiary thickness shear vibration mode energy trapping type as described above, the parts where the excitation electrodes 4a and 4b are not provided vibrate to obtain the energy of the tertiary thickness shear vibration, and the excitation electrode 4a , 4b are provided, and the attachment of the lead wires 7 to the excitation electrodes 4a, 4b has no effect on vibration. Moreover, there is no need to provide a separate ground electrode for the delay medium 5 as in the conventional case, and the input/output lead wire 7 and the ground lead wire 7 can be installed on the same surface, so the installation method for the lead wire 7 is simple. become.

FIG. 5 is a front view of a main part of an ultrasonic delay line using the tertiary thickness-shear vibration mode energy trap type thickness-shear vibrator shown in FIG. 3 as an input/output transducer. According to such a configuration,
This is very advantageous because one piezoelectric vibrator 3 can be used as an input/output transducer.

As described above, according to the thickness-shear transducer for ultrasonic delay lines of the present invention, third-order thickness-shear vibration can be utilized, so unnecessary vibrations are reduced and it can be used at relatively high frequencies. Further, there is no need to separately form a ground electrode on the delay medium as in the prior art, and lead wires can be easily attached. Also, the influence of lead wire attachment is extremely small.

[Brief explanation of the drawing]

Fig. 1 is a front view of a conventional thickness-shear transducer for ultrasonic delay line, Fig. 2 is a front view of a thickness-shear transducer in one embodiment of the present invention, and Fig. 3 is a front view of a thickness-shear transducer in another embodiment. 4 is a front view of the main part of the ultrasonic delay line using the thickness-shear transducer shown in Fig. 2, and Fig. 5 is a front view of the main part of the ultrasonic delay line using the thickness-shear transducer shown in Fig. 3. It is a front view of the main part of a line. 3... Piezoelectric vibrator, 4a to 4c... Excitation electrode,
5...Delay medium, 6...Adhesive, 7...Lead wire.

Claims (1)

[Claims for Utility Model Registration] 1. A thickness-shear transducer for an ultrasonic delay line that is attached to one end surface of a delay medium and used as an input/output transducer for the ultrasonic delay line,
At least a part of the piezoelectric vibrator is polarized along the thickness direction, and two or more excitation electrodes are provided on at least one of both surfaces of the piezoelectric vibrator to obtain the energy of third-order thickness shear vibration. Thick-shear transducer for ultrasonic delay line configured as follows. 2. The thickness shear vibrator for an ultrasonic delay line according to claim 1, wherein the excitation electrodes are provided at two or more locations on one surface of the piezoelectric vibrator. 3 There are two excitation electrodes on each side of the piezoelectric vibrator.
A thickness shear transducer for an ultrasonic delay line according to claim 1 of the patented utility model, wherein the thickness shear transducer is provided at more than one location. 4. The excitation electrode is provided at both ends of one surface of the piezoelectric vibrator.
Thickness shear transducer for ultrasonic delay line as described in . 5. The thickness shear vibrator for an ultrasonic delay line according to claim 1, wherein the excitation electrodes are provided at both ends of both sides of the piezoelectric vibrator. 6. The thickness shear vibrator for an ultrasonic delay line according to claim 1, wherein the excitation electrodes are provided on both ends of the piezoelectric vibrator over both sides.