JPS61184091A - Transmitting and receiving device - Google Patents

Abstract

PURPOSE:To irradiate a search signal whose signal intensity is constant within a prescribed direction angle by exciting a wave front by a signal having an amplitude of a point of a prescribed curve corresponding to the eave front so as to form a transmission beam within the direction angle. CONSTITUTION: Electrodes divided into three by a main electrode 2, 2l in length and two sub electrodes 3, l in length is adhered closely to the upper side of a rectangular piezoelectric vibrator 1 and lne rectangular electrode 4 is adhered closely to the lower side. A signal where a prescribed carrier frequency is subject to amplitude modulation by a prescribed amplitude of pulse is fed to the primary winding of a transformer 5. One end of the secondarh winding 6 of the transformer 5 is connected to the electrode 2 and the other end is connected to the electrode 3, and the tap 7 is connected to the electrode 4. A signal curve fed to the electrodes 2-4 is expressed in SinA/A, where A=2piXtheta0, theta0 is a direction angle, ¦X¦<=l/lambda, and lambda is a wavelength of the carrier frequency. A signal with a reference amplitude (a) is fed to the electrode 4, a signal with an amplitude (b) is fed to the electrode 2 and a signal with amplitude (c) is fed to the electrode 3 respectively, the direction angle theta0=lambda/2l, and the signal intensity irradiated in the angle theta0 is constant as shown in figure (B).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) This invention relates to a transducer with improved directional characteristics. This transducer emits a detection signal so that the signal strength within a predetermined angle can be approximately constant,
Further, signals arriving from within a predetermined angle can be received with substantially constant sensitivity.

(Prior Art) The directivity characteristics of a conventional transducer are shown in Fig. 5, and it is not possible to emit a detection signal such that the signal strength within the directivity angle is constant, and it is difficult to emit a detection signal such that the signal intensity within the directivity angle is constant. It was not possible to receive the signal with a certain sensitivity. In conventional transducers, for example, a detection signal of the same amplitude is applied to the entire surface of the electrode of a vibrator.

(Problems to be Solved by the Invention) When a conventional transducer having a directional characteristic as shown in FIG. 5 is used in an underwater detection device, for example.

When a reflected signal from an object to be detected captured using this transducer is displayed on a display, the surroundings of the image are not clearly displayed and are displayed indistinctly. Another problem is that when the amplification degree of the receiver that amplifies the captured reflected signal is changed, the size of the image changes, making it impossible to accurately determine the size of the object to be detected.

(Means for solving the problem) One electrode of the vibrator is divided into multiple parts symmetrically with respect to the center of the vibrator, and at least a main electrode including the center of the vibrator and a sub-electrode are placed outside the main electrode. applying signals of different polarity to the main and auxiliary electrodes with respect to the signal level applied to the other electrodes of the vibrator, or to the level of the signal extracted from the other electrodes of the vibrator. On the other hand, the configuration is such that signals of mutually different polarities are extracted from the main electrode and the sub-electrode.

(Example) FIG. 1 shows an embodiment of the invention.

FIG. 2 shows the relationship between the signal applied to the electrodes of the vibrator shown in FIG. 1 or the signal taken out from the electrodes of the vibrator and the directivity characteristics of the vibrator.

FIG. 3 shows another embodiment of the invention.

In FIG. 1, the electrode that is brought into close contact with the upper side of the rectangular piezoelectric vibrator 1 is divided into three parts such that the main electrode 2 has a length of two lengths, and the sub-electrode 3 has a length of two lengths.

A single rectangular electrode 4 is tightly attached to the lower side of the vibrator 1. The primary side of the transformer 5 has a carrier frequency of, for example, 5.
A pulse signal amplitude modulated with a constant amplitude pulse of 0 KHz is supplied. One end of the secondary winding 6 of the transformer 5 is connected to the main electrode 2, the other end is connected to two sub-electrodes 3, and the intermediate terminal 7 thereof is connected to the lower electrode 4 of the vibrator 1.

FIG. 2(A) shows the signals applied to the electrodes 2.3.4 of the transducer 1, FIG. 2(B) shows the length of the pointing privilege of the transducer 1, and the input is the wavelength of the carrier frequency signal. , θ represents the azimuth angle. At points 21, 22, 23, and 24, a reference amplitude signal a is supplied from the open terminal 7 to the electrode 4, a signal with an amplitude of b is supplied to the main electrode 2, and a signal with an amplitude of C is supplied to the sub-electrode 3. is supplied to

As a result, it has been confirmed in experiments that the intensity of the signal emitted from the vibrator 1 becomes constant at a predetermined angle θ-, that is, a directivity characteristic as shown in FIG. 2(B) is obtained.

Next, the case of receiving an incoming signal will be explained.

When an incoming signal of the same amplitude is received by the main electrode 2 and the sub-electrode 3, a signal with the amplitude shown in FIG. 8, and based on the signal captured by the auxiliary electrode 3, a signal with an amplitude C in the figure is transmitted to the primary side 8 of the transformer 5, and based on the output signal of the electrode 4, a signal with an amplitude a in the figure is transmitted to the primary side 8 of the transformer 5. is transmitted to the temporary side of the transformer 5. As a result, the incoming signal captured by the receiving beam having the directional characteristics shown in FIG. 2(B) is output from the primary side of the transformer 5.

In FIG. 3, the electrode that is brought into close contact with the upper side of the circular piezoelectric vibrator 11 is divided into two parts in a circular shape such that the main electrode 12 has a diameter of 2 cm and the sub-electrode 13 has a width of 2 cm.

A single circular electrode 14 is tightly attached to the lower side of the vibrator 11. The primary side of the transformer 5 is supplied with a pulse signal whose carrier frequency is, for example, 50 KHz and which is amplitude-modulated with a constant amplitude pulse. One end of the secondary winding 6 of the transformer 5 is connected to the main electrode 12 , the other end is connected to the sub-electrode 13 , and the intermediate terminal thereof is connected to the lower electrode 14 of the vibrator 11 .

Figure 4 shows the signals applied to the electrodes 12, 13, and 14 of the vibrator 11. represents. A reference amplitude signal m is supplied from the intermediate terminal 7 of the transformer 5 to the electrode 14, a signal with an amplitude of P is supplied to the main electrode 12, and a signal with an amplitude of q is supplied to the sub-electrode 13.
is supplied to

As a result, as shown in FIG. 2(B), the predetermined angle θ. It has also been confirmed in experiments that a directional characteristic in which the intensity of the signal emitted from the vibrator 11 is constant can be obtained within the transducer 11.

Next, the case of receiving an incoming signal will be explained.

When incoming signals of the same amplitude are received by the main electrode 12 and the sub-electrode 13, a signal with an amplitude p shown in FIG. 4 is sent to the primary winding 8 of the transformer 5 based on the signal captured by the main electrode 12. Based on the signal captured by the sub-electrode 13, a signal with an amplitude q in the figure is transmitted to the primary side 8 of the transformer 5.
Based on the output signal of the electrode 14, a signal with an amplitude m is transmitted to the primary side. As a result, the incoming signal captured by the receiving beam having the directional characteristics shown in FIG. 2(B) is output from the primary side of the transformer 5.

In the above embodiment, signals were applied to each electrode via a transformer, and signals were extracted from each electrode, but the carrier frequency was It is also possible to supply each electrode with a 50 KHz probe pulse signal. It is also possible to extract the signals picked up by each electrode via different amplifiers of juxtaposed amplifiers.

(Effects of the Invention) As described above, the present invention emits a detection signal such that the signal strength within a predetermined directivity angle can be made constant with a simple configuration, and also detects signals arriving from within this directivity angle. It is possible to provide a transducer having directional characteristics that can receive with a certain sensitivity.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, with FIG. 1(A) being a plan view and FIG. 1(B) being a front view. FIG. 2 is a diagram showing the relationship between the signal applied to the electrode of the vibrator or the signal extracted from the electrode of the vibrator and the directivity characteristic of the transducer. Third
The figures show another embodiment of the invention, in which (A) is a plan view and (B) is a front view. FIG. 4 shows signals applied to the electrodes of the vibrator shown in FIG. Figure 5 shows
This is the directional characteristic of a conventional transducer.

Claims (1)

[Claims] (1) One electrode of the vibrator is divided into multiple parts symmetrically with respect to the center of the vibrator to form a main electrode that includes at least the center of the vibrator and a sub-electrode outside the main electrode. Applying signals of different polarities to the main electrode and the sub-electrode relative to the signal level applied to the other electrodes, or from the main electrode and the sub-electrode relative to the level of the signal extracted from the other electrode of the vibrator. A transducer characterized by extracting signals of mutually different polarities.