JPH03159499A - Ultrasonic vibrator - Google Patents

Abstract

PURPOSE:To extend a bandwidth by forming grooves concentric circularly at least on one face of one of the circular vibrator, dividing the vibrator into the several regions and vibrating with the proper frequencies of devided vibrators decided by each dimension. CONSTITUTION:A circular ultrasonic vibrator 10 with radius d forming the electrodes on both sides is formed with the grooves Q forming three concentric circles of radii a, b, c respectively on one side, and is divided in four concentric regions A, B, C, D. In the case, as the upper electrodes P are also separated in four pieces, the crossing wires 11 mutually connecting each electrode are set. In this vibrator 10, when the electric signal having wideband components are put in between the lead wires 12 from both electrodes P, the vibrators of each regions A, B, C, D vibrate with each proper resonant frequencies as they have different radii a, b, c, d. The radii a, b, c are decided to a radius d so that these resonant frequencies are arranged in equal intervals. By this means, this functions as a wideband transmit/receive wave equipment as the overall output characteristics.

Description

[Detailed description of the invention] [Industry] Second visit! lIF]

The present invention relates to an ultrasonic transducer used in underwater detection devices and the like, and particularly to an ultrasonic transducer having a wide frequency range {]}.

[Conventional technology]

An ultrasonic transducer that transmits ultrasonic waves and converts the echo waves into electrical signals is generally a disk-shaped piezoelectric element as shown in Figure 8, with electrodes on both sides for applying signals. is formed. If its radius is a, this oscillator has a natural resonant frequency r, which is half proportional to the radius a. (1k/
a), therefore, even if an electric signal that develops a wide frequency component is applied to this vibrator, the vibrator will emit a resonant frequency f. as shown in FIG. Narrow circumference l2 with beak
Only the iE number band is emitted. Naturally, in terms of wave reception, it is only sensed near this resonance frequency r0. However, in a fish finder, for example, in order to increase resolution, the transmitted ultrasonic waves need to have broadband frequency components. Furthermore, even when transmitting at a single frequency determined by the resonant frequency, if a PM variable is applied to the transmitted signal, the transmitted signal deviates from the resonant frequency r0, so it only responds to a single frequency failure. Conventional vibrators cannot be used. Therefore, in order to solve this problem, we
In the multi-frequency ultrasonic transducer according to No. 394, as shown in FIG. They are arranged in concentric circles. According to this multi-frequency ultrasonic transducer, each transducer has a different radius and therefore has a different unique resonance frequency. By applying the voltage, each of the transducers 51 to 53 emits ultrasonic waves having a unique resonance frequency, and functions as a broadband ultrasonic transducer. It also has broadband reception characteristics.

[Problem to be solved by the invention]

However, since the vibrator is generally made of a solid and brittle piezoelectric ceramic, it is difficult to form a ring-shaped vibrator as in the multi-frequency ultrasonic receiver described in 2. However, it is necessary to provide a driving circuit and a receiving circuit for driving each vibrator, making the configuration of the device complex. The present invention has been made to eliminate the above-mentioned problems, and an object of the present invention is to provide an ultrasonic transducer with a simple configuration.

[Means to solve the problem]

The present invention is an ultrasonic transducer that transmits ultrasonic waves and converts the echo waves into electrical signals, and in which one transducer is divided into a plurality of regions. It is characterized by forming i]'4 on at least one surface.

[Effect]

For example, if you install multiple concentric circles 714 to divide a disk-shaped vibrator into multiple regions, each region divided by the grooves (each with a different radius) is installed. Therefore, they resonate at a unique frequency determined by this radius and emit ultrasonic waves at different frequencies, so they function as broadband ultrasonic transducers.

【Example】

FIG. 1 is a plan view showing an example of an ultrasonic transducer according to the present invention, and FIG. 2 shows a side sectional view along the Y-Y' direction in the figure. For a disk-shaped ultrasonic transducer 10 with a radius d and electrodes P formed on both sides, grooves Q forming three concentric circles with radii a, b, and C are formed on one side to form four concentric circles. It is divided into regions A, B1C, and D. In that case, the electrode P on the upper surface in the figure is also divided into four regions, so there is a crossing line l1 for connecting each electrode to each other.
will be applied. The width and depth of the groove Q are determined depending on the size and material of the vibrator. Note that when forming the electrode P after shaping the iMQ, the crossover wire 11 is not necessary. When an electric signal having a broadband component is applied between the lead wires 12 from both electric stocks Q to the vibrator having such a configuration, the vibrator in each region A, B, C, and D becomes as follows. Since they have different radii a11), c, and d, they have their own unique resonance frequencies ra (1 k/a) and fb (=k/b
), fc (=k/c), and fd (1k/d) will resonate. As shown in Figure 3, these resonant frequencies are
The radii a, b, and C are determined relative to the radius d so that they are arranged at equal intervals. As shown in Figure 3, each area A, B
, C, and D each have a unique resonance frequency ra,
Since ultrasonic waves are emitted by resonating at ``b, rc, and d'', the overall output characteristic is as shown by the envelope shown by the broken line in Fig. 3. It has radiation characteristics and functions as a wideband transducer. Furthermore, several rings of vibrators divided into each region can be handled by one wideband driving circuit and receiving circuit. In Fig. 2, ultrasonic waves are radiated from both the upper and lower parts, but normally the lower face is fixed and temporarily attached so that it is radiated only from one side, for example, the upper face.
At this time, a fixing plate is provided on the upper surface provided with the groove Q, and ultrasonic waves having respective unique resonance frequencies are radiated from the lower surface. In addition, corresponding to the position of the groove Q, 714 can also be provided on the lower surface. FIGS. 4 and 5 are a plan view and a side sectional view showing another example of real blood according to the present invention, in which MQs are provided at equal intervals. In addition, since the vibrator itself is hard and brittle, if providing the grooves as described above may cause cracks, a wavy iMQ may be provided as shown in the side cross-sectional view of Fig. 6. . FIG. 7 shows yet another embodiment, in which one spiral groove Q'' is provided. In this case, the radius of the vibrator changes continuously, so it also has a broadband frequency characteristic. can be expected.

【Effect of the invention】

As explained above, the present invention forms waste on at least one side of a single vibrator, divides the vibrator into a plurality of regions, and each divided vibrator is divided into two regions. It resonates at a unique frequency determined by the size of the oscillator, making it possible to provide a broadband ultra-M wave oscillator.

[Brief explanation of the drawing]

1 and 2 are a plan view and a side sectional view showing an example of the ultrasonic transducer of the present invention, and FIG. 3 is a diagram showing the frequency vs. FIGS. 4 and 5 are a plan view and a side sectional view showing another embodiment, and FIG. 6 is a diagram showing a modified example of the groove to be formed.
111 sectional view, FIG. 7 is a plan view showing another embodiment in which spiral grooves are formed, FIG. 8 is a perspective view showing the conventional vibrator, and FIG. 9 is the vibration shown in FIG. 8. FIG. 10 is a plan view showing an example of a multi-frequency ultrasonic transducer made up of a plurality of transducers. 10... Vibrator, 1 1... Crossing wire, l2 - Leading wire, P - Electrode, Q Q', Q" - Groove. Patent applicant Furuno Electric Co., Ltd.

Claims (2)

[Claims] (1) An ultrasonic transducer that transmits ultrasonic waves and converts the echo waves into electrical signals, in which at least one of the transducers is divided into a plurality of regions. An ultrasonic transducer characterized by having grooves formed on its surface. (2) The ultrasonic transducer according to claim 1, wherein the groove is formed concentrically with respect to the disc-shaped transducer.