JP3367841B2 - Ultrasonic sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic sensor having an acoustic lens which is applied to an ultrasonic imaging device (sodium see-through device) for imaging a liquid such as a turbid liquid or liquid sodium. Regarding

[0002]

2. Description of the Related Art An example of a conventional multi-ultrasonic sensor used in such an imaging apparatus will be described with reference to FIG. In the figure, (a) is its sectional view, (b) is its EE arrow view, 62 is a protective plate of a multi-ultrasonic sensor composed of a smooth flat plate (metal foil, etc.), 3 is a protective plate A plurality of ultrasonic transducers supported by the plate 62, 4 is a reinforcing girder, 5 is a reinforcing plate, and the ultrasonic transducers 3 and 4 are
Is reinforced at multiple points to give strength. 6 is a coaxial cable from each ultrasonic transducer, 9 is its ground wire, and 7 is a multicore connector for connecting these coaxial cable 6 and ground wire 9. These are housed in the case 8 and the lower surface is protected by a protection plate 62 as shown in FIG.
It constitutes a multi-ultrasonic sensor.

In the multi-ultrasonic sensor constructed and manufactured as described above, one ultrasonic sensor can be constructed by the ultrasonic transducer 3 and the protective plate 62. Will be determined by the directivity of this individual ultrasonic sensor.

The above-mentioned conventional multi-ultrasonic sensor has a small number of lines for expanding the directivity, and as shown in FIG. 11, the directivity 11 of natural expansion from the width 10 of the vibrator diameter of the ultrasonic vibrator 3. Therefore, the external ultrasonic waves 12 within this range can be received, but the external ultrasonic waves 13 wider than this range cannot be received.

As another conventional example, there is a case where an ultrasonic lens is used for the ultrasonic sensor, and this lens is shown in FIG.
As shown in 2, a hemispherical acoustic lens 31 is attached, and the ultrasonic wave generated by the ultrasonic transducer 3 is bent and expanded on the spherical surface as shown by 32. Although the ultrasonic beam spreads with this hemispherical acoustic lens, the thickness of the lens is required, but it cannot be applied to a small one such as a multi-ultrasonic sensor.

FIG. 13 shows an example of a conventional multi-ultrasonic sensor using the hemispherical acoustic lens described above. An example of using a hemispherical acoustic lens for transmission is shown in FIG. b) is an FF arrow line view. In FIG. 13, 3
Reference numeral 1 is a conventional hemispherical acoustic lens, and reference numeral 72 is a protective plate of a receiving oscillator 3 of a multi-ultrasonic sensor composed of a smooth flat plate (metal foil or the like). Reference numeral 34 is an ultrasonic transducer for output that propagates ultrasonic waves to the acoustic lens 31. Reference numeral 70 denotes a transmitting transducer, which is composed of the acoustic lens 31 and the ultrasonic transducer 34. Reference numerals 4 and 5 denote a reinforcing girder and a reinforcing plate of the multi-ultrasonic sensor, which give strength to the multi-ultrasonic sensor. 6 is a coaxial cable, 9 is a wire on the ground side, 7 is a multi-core connector, and 8 is a case of a multi-ultrasonic sensor.

In the multi-ultrasonic sensor configured, manufactured and arranged as described above, ultrasonic waves are emitted by the transmitting transducer 70 installed at the center, and reflected waves from the target to be visualized are transmitted by the transmitting transducer. Ultrasonic transducer 3 for reception arranged around 70
You can enter in.

The diffusion acoustic lens 31 used in the conventional transmitting transducer 70 has a spherical shape, and the ultrasonic beam emitted from the ultrasonic transducer 34 as shown in FIG. , 112, and the beam near the center of the ultrasonic transducer indicated by 113, the ultrasonic waves are concentrated near the center of the acoustic lens 31 and the density of the ultrasonic waves is high.

When this is represented by the ultrasonic intensity of the ultrasonic beam emitted outside the acoustic lens 31, the ultrasonic intensity indicated by reference numeral 122 in FIG. 15 is obtained, and the ultrasonic wave directly below the center of the acoustic lens 31 is the strongest ultrasonic wave. It is an acoustic lens.

[0010]

However, the above-mentioned FIG.
In the conventional technique shown in FIG. 11, although the external ultrasonic signal 12 within the directivity 11 of the ultrasonic transducer 3 alone can be received among the ultrasonic signals coming in as shown in FIG. Since the external ultrasonic signal 13 outside the directivity 11 of the child cannot be received, there is a problem that the multi-ultrasonic sensor cannot obtain a sufficient aperture width necessary for imaging.

Further, in the conventional technique shown in FIG. 13, the acoustic lens 31 for diffusion used in the transmitting transducer 70 has a spherical shape.
As shown in FIG. 4, the ultrasonic beam output from the ultrasonic transducer 34 comes to the center. That is, the beam at the middle position of the ultrasonic transducer 112 and the beam near the center of the ultrasonic transducer 113 are collected near the center of the acoustic lens 31. When these ultrasonic beams are expressed by the ultrasonic intensity of the ultrasonic beam emitted outside the acoustic lens 31, it becomes as shown in FIG. 15, and the position directly below the center of the acoustic lens 31 becomes the strongest.

The ultrasonic wave is most strongly radiated to the target directly below the transmitting transducer 70 composed of the acoustic lens 31. Therefore, the reflection from the target is also strongly reflected at the position directly below the transmitting transducer 70. There is a small amount of diffusion around 70. Therefore, it was not possible to spread the ultrasonic beam and widen the aperture width required for imaging.

[0013]

The present invention provides the following means (1) to (5) in order to solve such problems.

(1) In an ultrasonic sensor having an ultrasonic transducer and a protective plate on the lower surface thereof, a plurality of concentric grooves are added to the ultrasonic receiving surface of the protective plate, and each of the grooves is An ultrasonic sensor having a random inclined surface.

(2) In the above (1), the ultrasonic sensor comprises a plurality of ultrasonic sensors, and the protective plate is provided with a plurality of concentric grooves corresponding to the respective ultrasonic sensors to visualize ultrasonic waves. An ultrasonic sensor characterized by being used in a device.

(3) An ultrasonic transducer for outputting an ultrasonic wave and an ultrasonic wave transmitting transducer composed of an ultrasonic acoustic lens arranged on the output side thereof, and a plurality of ultrasonic transducers for receiving ultrasonic waves. In the ultrasonic sensor, the acoustic lens has a conical shape in which a bottom surface of the acoustic lens is arranged on the output side of the ultrasonic transducer for output.

(4) The ultrasonic wave according to the above (3), characterized in that a plurality of ultrasonic transducers for receiving the ultrasonic wave have protective plates on their lower surfaces and are used in an ultrasonic imaging apparatus. Sensor.

(5) In the above (4), concentric circular grooves are added to the ultrasonic wave receiving surface corresponding to each ultrasonic transducer of the protective plate, and each groove has a random inclined surface. An ultrasonic sensor for use in a sonic imager.

In the ultrasonic sensor of the present invention by the above means, in the above (1), the protective plate is made of, for example, metal foil or plastics, and the lower surface thereof has concentric circular grooves having a random inclined surface. Since the external ultrasonic signals coming in from these multiple grooves are received, the directivity differs depending on the random inclination of each of the multiple grooves. Ultrasonic waves having a directivity out of the range can also be received by the groove having an inclination matching the external directivity among the grooves having the random inclination. Therefore, a wide range of ultrasonic waves can be received.

In (2), a plurality of ultrasonic vibrators are provided, and a plurality of concentric circular grooves are provided on the protective plate corresponding to these, so as to visualize the inside of a liquid such as cloudy liquid or liquid sodium. Since it can be used for the ultrasonic imaging device, the incoming ultrasonic waves can be received in a wide range, and a sufficient aperture width for imaging as a multi-ultrasound sensor can be obtained. The image obtained by the digitizer is significantly improved.

In (3), the conical acoustic lens used for the transmitting transducer has a state of ultrasonic beam as shown in FIG. 8 due to refraction due to the difference in sound velocity depending on the material of the acoustic lens and the type of liquid. Become. In the figure, 101 is a typical ultrasonic wave generated from the end of the ultrasonic vibrator, 102 is a typical ultrasonic wave generated from the middle position of the ultrasonic vibrator, and 103 is a typical ultrasonic wave generated from the vicinity of the center. Shows ultrasound.

Here, the sound velocity of the acoustic lens is C₁, Liquid
Speed of sound is C₂And θ₁Is the incident angle, θ ₂Is the refraction angle
For example, θ₂= Sin^-1[(C₂/ C₁) ・ Sin θ₁]]
The ultrasonic waves are emitted at an angle.

The conical acoustic lens can make the refraction angle θ ₂ in the above equation smaller than that of the spherical lens, and can further spread the ultrasonic beam. Also,
The conical lens can reduce the ultrasonic waves emitted just below the lens (see FIG. 9). As a result, it is possible to radiate ultrasonic waves to the periphery of the transmission transducer over a wide range, and it is possible to widen the aperture width required for imaging.

In (4), protective plates are provided on the lower surfaces of the plurality of receiving ultrasonic transducers of the ultrasonic sensor of (3), and in (5), the ultrasonic sensor of (3) is provided. Since the concentric grooves having random inclined surfaces are added to the lower surface of the protective plate, it is possible to obtain a sufficient opening width in the ultrasonic imaging apparatus using the ultrasonic sensor and further enhance the effect.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. 1A and 1B show an ultrasonic sensor according to a first embodiment of the present invention, FIG. 1A is a sectional view thereof, and FIG.

In the figure, reference numerals 3 to 9 are the same members as those of the conventional one shown in FIG. 10, and these will be explained again, but 1 is a groove having a random inclination and depth which is a feature of the present invention. Is an acoustic lens that is concentrically processed,
It receives a wide range of incoming ultrasonic waves. Two
Is a metal foil or the like (or plastic or the like) which is a protective plate of the multi-ultrasonic sensor, and a plurality of acoustic lenses 1 are processed on the lower surface thereof as shown in FIG.

FIG. 2 shows the structure of the acoustic lens described above, (a) is a side view thereof, and (b) is a BB arrow view thereof. As shown in this figure, a plurality of grooves 14 each having a random inclination and a depth are concentrically processed on the lower surface of the protective plate 2 to form an acoustic lens.

FIG. 3 is an enlarged view of the portion C in FIG. 2 (a), which is an enlarged sectional view of the groove of the acoustic lens 1 described above. As shown in the drawing, grooves 14 having a random inclination are formed on the surface of the acoustic lens 1, each of which has a different valley portion 15 and a different mountain portion 16, and the slope 1
7 has a plurality of different grooves.

Returning to FIG. 1, a plurality of ultrasonic transducers 3 are arranged to receive ultrasonic waves. Reference numerals 4 and 5 denote a reinforcing girder and a reinforcing plate of the multi-ultrasonic sensor, which give strength to the multi-ultrasonic sensor. Reference numerals 6 and 9 are a coaxial cable and a wire on the ground side thereof, and 7 is a multi-core connector for connecting them. All of these are housed in the case 8 to form a multi-ultrasonic sensor.

In the multi-ultrasonic sensor configured as described above, one ultrasonic transducer 3, a protective plate 2, and one acoustic lens 1 concentrically processed on the protective plate 2. One ultrasonic sensor can be configured, and the directivity of the ultrasonic beam of the multi-ultrasonic sensor is determined by the directivity of this individual ultrasonic sensor.

FIG. 4 is an explanatory view of the directivity of such one ultrasonic transducer 3 and the acoustic lens 1. The beam divergence 25 of each ultrasonic sensor constructed as described above is shown in the figure. Thus, the beam divergence of the ultrasonic transducer 3 alone becomes larger than the beam divergence 11. Therefore, the ultrasonic waves 13 coming between the spreads 11 and 25 can be received in a wide range.

FIG. 5 is a diagram showing the directional characteristics of the acoustic lens.
Is the directional characteristic of the ultrasonic transducer 3 alone, and 22 is the directional characteristic to which the concentric acoustic lens according to the first embodiment of the present invention is added. As shown, the ultrasonic sensor according to the first embodiment of the present invention has a directivity 22 in which a concentric acoustic lens is added, rather than the directivity 21 of the ultrasonic transducer 3 alone.
As described above, the reception range can be widened, and the opening width required for an ultrasonic imaging apparatus for imaging a liquid such as turbid liquid or liquid sodium can be sufficiently obtained.

As described above, the multi-ultrasonic sensor including the ultrasonic transducer 3, the protective plate 2, and the acoustic lens 1 according to the first embodiment of the above-described embodiment is used for ultrasonic imaging of cloudy liquid or liquid sodium. Although it is applied to an apparatus (sodium see-through apparatus), the present invention is not limited to this, and can be widely applied to imaging of an object in an opaque liquid and an ultrasonic diagnostic apparatus (echo).

6A and 6B show the structure of an ultrasonic sensor according to the second embodiment of the present invention. FIG. 6A is a sectional view and FIG. 6B is a view taken along the line DD in FIG. FIG. 7 shows the acoustic lens in FIG. 6, (a) is a plan view, and (b) is a side view. In these figures, 3 is supported by the protective plate 52 by a plurality of ultrasonic transducers. The protective plate 52 is composed of a smooth flat plate (metal foil, plastic, etc.). 4 is a reinforcing girder, 5 is a reinforcing plate, and 6 is a coaxial cable.
Is a ground wire, 7 is a multi-core connector for connecting the coaxial cable 6 and the ground wire 9, and 8 is a case for housing the whole. The configurations shown by 3 to 9 have the same functions as the conventional ones.

Reference numeral 51 is a conical acoustic lens,
60 transmitting transducers are configured with 24 transmitting ultrasonic transducers and emit ultrasonic waves. The shape of this acoustic lens can change the direction of the emitted ultrasonic beam even if the ridge of the acoustic lens 51 having a conical shape has a bulge and becomes a curve, and the same effect can be obtained.

In the multi-ultrasonic sensor of the second embodiment configured and manufactured as described above, ultrasonic waves are emitted by the transmitting transducer 60 installed at the center and reflected by the target to be imaged. Ultrasonic waves can be input to the ultrasonic transducers 3 for reception, which are installed in large numbers around the transmitting transducer 60.

As described above, in the second embodiment,
A conical acoustic lens 51 is provided as the transmitting transducer 60 of the multi-ultrasonic sensor so that the ultrasonic beam from the transmitting ultrasonic transducer 24 does not collect immediately below the center of the acoustic lens 51. It can be diffused and emitted to the peripheral position of 60. As a result, the ultrasonic beam can be effectively diffused to the periphery.

FIG. 9 is a distribution diagram of the ultrasonic wave intensity in the second embodiment of the present invention. The dotted line 122 shows the conventional distribution, and the solid line 121 shows the distribution of the second embodiment of the present invention. It can be seen that it is low in the part and strong in the peripheral part.

[0039]

As described above in detail, according to the present invention, the protective plate of the ultrasonic sensor is provided with a plurality of concentric grooves having random inclined surfaces. In this configuration,
Multiple ultrasonic transducers are provided, and a plurality of concentric circular grooves are also provided on the protective plate corresponding to these transducers to be used as an ultrasonic imaging device. Also, the ultrasonic transducer on the output side has a conical shape. A configuration using an acoustic lens, further, in this configuration, a protective plate is provided on the lower surface of the receiving ultrasonic transducer, or a plurality of concentric circles having random inclined surfaces on the lower protective plate of each receiving ultrasonic transducer. Since it is characterized by the structure in which the groove is provided, the following effects are obtained.

(1) It is possible to realize an ultrasonic sensor which can receive incoming ultrasonic waves over a wider range than conventional ultrasonic sensors.

(2) The multi-ultrasonic sensor can sufficiently obtain the aperture width required for imaging, and the ultrasonic imaging is significantly improved.

(3) By forming the acoustic lens of the transmitting transducer of the multi-ultrasonic sensor into a conical shape, the ultrasonic beam is not collected immediately below the central position of the acoustic lens, but diffused and emitted to peripheral positions. be able to. As a result, the aperture width necessary for imaging with the multi-ultrasonic sensor is sufficiently obtained, and the ultrasonic image image is significantly improved.

[Brief description of drawings]

FIG. 1 shows an entire structure of an ultrasonic sensor according to a first embodiment of the present invention, (a) is a sectional view thereof, and (b) is (a).
FIG. 6 is a view on arrow AA in FIG.

FIG. 2 is a detailed structural diagram of an acoustic lens of the ultrasonic sensor according to the first embodiment of the present invention, in which (a) is a side view thereof,
(B) is a BB arrow line view in (a).

FIG. 3 is an enlarged detailed sectional view of a C portion in FIG. 2 (a).

FIG. 4 is an explanatory diagram of acoustic lens directivity of the ultrasonic sensor according to the first embodiment of the present invention.

FIG. 5 is a directional characteristic diagram of an acoustic lens of the ultrasonic sensor according to the first embodiment of the present invention.

6A and 6B show an overall structure of an ultrasonic sensor according to a second embodiment of the present invention, in which FIG. 6A is a sectional view thereof, and FIG.
FIG.

7A and 7B show an acoustic lens in the ultrasonic sensor shown in FIG. 6, where FIG. 7A is a plan view and FIG. 7B is a side view.

FIG. 8 is a view for explaining the action of the acoustic lens of the ultrasonic sensor according to the second embodiment of the present invention.

FIG. 9 is a distribution diagram of ultrasonic wave intensities of the ultrasonic sensor according to the second embodiment of the present invention.

FIG. 10 shows the overall structure of a conventional ultrasonic sensor,
(A) is the sectional view, (b) is a EE arrow view in (a).

FIG. 11 is an explanatory diagram of an ultrasonic sensor directivity that does not use a conventional acoustic lens.

FIG. 12 is an explanatory diagram of a conventional ultrasonic sensor with a spherical ultrasonic lens.

13A and 13B show a structure of a conventional multi-ultrasonic sensor using an acoustic lens for transmission, FIG. 13A is a sectional view, and FIG. 13B is a view taken along the line FF in FIG. 13A.

FIG. 14 is an explanatory diagram of a beam of a conventional acoustic lens for transmission.

FIG. 15 is a distribution chart of ultrasonic intensity when a conventional acoustic lens is used.

[Explanation of symbols]

1,51 Acoustic Lens 2,52 Protective Plate 3,24 Ultrasonic Transducer 4 Reinforcing Girder 5 Reinforcing Plate 6 Coaxial Cable 7 Connector 8 Case 9 Ground Wire 11 Directivity of Ultrasonic Transducer Single Unit 12, 13 External Ultrasonic Wave 14 Groove 15 Valley 16 Crest 17 Slope 22 Directional characteristics when an acoustic lens is added 25 Ultrasonic beam divergence when a concentric acoustic lens is added 60 Transducer for transmission

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Claims (5)

(57) [Claims] 1. An ultrasonic sensor comprising an ultrasonic transducer and a protective plate on the lower surface thereof, wherein a plurality of concentric grooves are added to the ultrasonic receiving surface of the protective plate, and the grooves are each random. An ultrasonic sensor having a flat inclined surface. 2. The ultrasonic sensor comprises a plurality of ultrasonic sensors, and the protective plate is provided with a plurality of concentric circular grooves corresponding to the ultrasonic sensors, respectively, and is used in an ultrasonic imaging apparatus. The ultrasonic sensor according to claim 1. 3. An ultrasonic transducer for outputting an ultrasonic wave and an ultrasonic wave transmitting transducer comprising an ultrasonic acoustic lens arranged on the output side thereof, and a plurality of ultrasonic transducers for receiving ultrasonic waves. In the ultrasonic sensor, the acoustic lens has a conical shape in which a bottom surface of the acoustic lens is arranged on the output side of the output ultrasonic transducer. 4. The ultrasonic sensor according to claim 3, wherein each of the plurality of ultrasonic transducers for receiving the ultrasonic waves has a protective plate on a lower surface thereof and is used in an ultrasonic imaging apparatus. 5. An ultrasonic wave receiving surface corresponding to each ultrasonic transducer of the protective plate is provided with concentric grooves, each groove having a random inclined surface, which is used in an ultrasonic imaging apparatus. The ultrasonic sensor according to claim 4, wherein: