JPS6027384B2 - Sonic exploration method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention particularly improves the azimuth resolution in so-called ``sonic wave exploration devices'' that probe the inside of objects using ultrasonic waves, such as ultrasonic diagnostic devices and ultrasonic flaw detectors. The purpose is to

Taking an ultrasound diagnostic device as an example and looking at the current situation, the frequency f used is $MHZ, so the wavelength input value is 0.5 skin, and during exploration, the transmitted pulse is placed on the 1st or 2nd side. Since it can be set, the distance resolution is about 0.5 to 1 skin. On the other hand, in order to distinguish between two skins at points 200 degrees apart, the azimuth resolution would need to be 0.57o in the beam, so to create this beam, ultrasonic vibration The child's diameter d is 7 sails.

As a result, the distance L forming the near sound field is ^=. From d = 7 skin on the 5 side, L = S = 98 column, and 98 from the vibrator.
Since the detection between the two is within the close sound field, it is impossible to resolve within the 7th diameter side.

In view of the current situation, the present invention pays attention to the combination of the transmitting beam and the receiving beam, and in particular selects only a part of the transmitting beam and the receiving beam so that they overlap, resulting in an apparently narrow detection range. The aim is to improve azimuth resolution by forming

FIG. 1 shows the wave transmitting/receiving procedure of the transducer in the present invention,
FIG. 2 shows a procedure for combining a transmitting beam and a receiving beam, and FIG. 3 is a block diagram of an embodiment. As shown in Figure 1, the transducer is divided into three parts: V, V2, and V3, which make up the transducer. When transmitting waves, V and V2 are driven simultaneously, and when receiving waves, V2 and V3 are driven together. Let's go.

In this way, the transmitting beam and the receiving beam are formed as shown by A and B, respectively, as shown in Fig. 2, and the shared portion W between the two becomes narrow, and this narrow range contributes to detection, making it difficult to see. In selection, detection is performed in a narrow beam, improving azimuth resolution. In Figure 3, 1 is the transmitter and 2 is the diode D.
・An anti-TR circuit in which D2 and D2 are connected in reverse, 3 is the resonator V,
, a probe consisting of V2 and V3, and 4 a TR circuit (4) which is a combination of a resistor R and diodes D3 and D4 connected in reverse.
5 is a cathode ray tube indicator that displays the detected signals on the A scope.) The anti-TR circuit and TR circuit are used for transmitting and receiving signals in seeders and fish finders. This is a circuit diagram that is normally used when the receiver is used in combination, and is used to prevent the receiving system from being affected by the output during large oscillations during wave transmission, and to perform the wave receiving function normally.

With the above configuration, when the transmitter 1 is driven, the transducers V and V2 of the probe 3 act as a transmitter to create the transmitting beam shown in Figure 2, and the transducers V2 and V3 receive the wave. As a result, the received beam becomes B in Fig. 2.
The narrow beam shown in is the detection range and becomes the input to the cathode ray tube indicator 5. Figure 4 shows that using the above means,
This is an example of a case where scanning is performed continuously during a certain detection over an arbitrary range in the horizontal direction. However, as shown in the figure, the combination of transducers for transmitting and receiving waves is, for example, for transmitting waves, three transducers N, N2, and N3 are combined, and for receiving waves, the combination is shifted and N3 is used. N4 and N5, and move the vibrator combinations one by one in the same manner to A).

In this way, since the transmitting beam and the receiving beam partially overlap,
As a result, the effective detection range is narrowed and the azimuthal resolution is improved.

[Brief explanation of the drawing]

FIG. 1 shows how the transducer transmits and receives waves according to the present invention. FIG. 2 is an explanatory diagram of forming a narrow detection beam according to the wave transmission/reception procedure shown in FIG. FIG. 3 is a block diagram of the embodiment. 1...Transmitter, 2...Anti-T
R circuit, 3...Probe, 4...TR circuit, 5...CRT indicator, D,, D2, D3, D4...
...diode, V,, V2, V3... vibrator. FIG. 4 is an example diagram of scanning. *1 Ball Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1 In a method of transmitting and receiving sound waves that conducts exploration by transmitting and receiving sound wave pulses, some of the plurality of transducers arranged on a plane are combined, and arranged and received so that the exploration range is included in the near sound field.
A means for connecting and transmitting waves and a transducer located at one end of the group of transducers used for wave transmission, and on the opposite side from the one for wave transmission,
A sound wave exploration method characterized by forming a means for receiving waves by arranging and connecting them so that the exploration range is included in a nearby sound field.