JPH0570115B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ultrasonic device, and more particularly, to an ultrasonic device that detects proximity sense using ultrasonic waves.

(Prior art and its problems) If sensor output signals are used for robot control,
It is known that the scope of application of playback type robotic devices can be expanded. In other words, with playback type robot equipment, it was necessary for the workpiece to be placed at a predetermined position and in a predetermined posture. , posture, etc. can be detected with high accuracy, restrictions on the position, posture, etc. of the work object will be relaxed. A robot device that autonomously determines work procedures and work contents using output signals from such various sensors is also called an intelligent robot device. The key to realizing intelligent robot equipment is the practical application of various sensors. One such sensor is a proximity sensor. The proximity sensor is a sensor that detects the distance between the sensor and the object to be detected, and conventionally,
Various methods have been proposed. Examples include sensors using ultrasonic technology, sensors using coil-capacitor resonance circuits, and sensors using eddy current. However, in the latter two methods, since the detection target is required to be metal, there is a drawback that they do not have any detection function for plastics, wood, etc. In the former case, an ultrasonic transmitter and an ultrasonic receiver are combined, and beam-shaped ultrasonic waves with directivity emitted from the transmitter are reflected by the detection target, and this reflected wave is detected by the receiver. There are certain characteristics. However, usually only a single transmitter and a single receiver are combined, and the radiation direction of the beam-like ultrasound or
It is not possible to change the direction of reception or to scan. For this reason, the object to be detected can only be roughly captured, and it has been difficult to accurately detect the distance depending on the shape and dimensions of the object to be detected. On the other hand, it is well known that ultrasound technology is applied to medical diagnostic equipment. In such application fields,
The human body can be roughly regarded as the same as water, and takes advantage of the advantages of faster sound speed than in air and lower propagation loss than in air. In addition, in this device, the ultrasonic transmitter and receiver are configured with an element array arranged in a linear manner, and the ultrasonic transmission pulse to each element constituting the array and the ultrasonic wave reaching each element are transmitted. By individually changing the delay time of the voltage signal generated by the received sound wave pulse, the beam directions of the transmitted and received waves are changed to obtain tomographic images inside the human body. In this application field, research has been carried out to make the tomographic image clearer, but the results of this research are not necessarily directly applied to the proximity sensor of the present invention. For example, differences in the speed of sound within a medium for transmitting ultrasonic waves, differences in propagation loss within the medium, etc. are factors that inhibit application. Furthermore, if the sensor is to be mounted on a robot device, it is required that the external size of the sensor be small and that its signal processing circuit be miniaturized and simplified. As described above, with conventional proximity sensors, the distance information to the detection target is unreliable, making it difficult to apply ultrasonic technology to medical diagnostic equipment.

(Object of the Invention) An object of the present invention is to provide an ultrasonic device as a proximity sensor that eliminates the drawbacks of the prior art and facilitates application to robotic devices.

(Structure of the Invention) According to the present invention, N elements (N≧2) arranged in a one-dimensional or two-dimensional array and capable of generating ultrasonic waves, and each element constituting the array In an ultrasonic device having means for individually supplying burst-like ultrasonic transmission pulses, the outputs of two delay circuits are connected to each element via a circuit for adding the two outputs and an amplifier. and means for inputting a common pulse waveform to the delay circuit constitute means for supplying the burst-like ultrasonic transmission pulse,
When one of two delay circuits connected to each of the N elements via an adder circuit and an amplifier is a first delay circuit group and the other is a second delay circuit group, the first delay circuit The delay time in the N delay circuits constituting the group increases sequentially in the order of the appropriately ordered element numbers of the array, and the delay time in the N delay circuits constituting the second delay circuit group increases. An ultrasonic device is obtained in which the element numbers of the array are sequentially decreased in order.

(Example) Next, a detailed explanation will be given using drawings.

FIG. 1 is a diagram illustrating a conventional sensor using ultrasound technology. In the figure, 1 is an ultrasonic transmitter, 2 is an ultrasonic receiver, 3 is a directivity pattern indicating the directivity of the ultrasonic beam emitted from 1, and 4 is a directivity of the ultrasonic wave received by 2. Directivity patterns 5 and 6 are detection targets. Figure 2 shows the first
FIG. 3 is a diagram showing the operation of the sensor shown in the figure, and shows changes in waveforms over time. In the figure, 10 is an ultrasonic waveform emitted from 1, and 11 is a waveform received by 2. At time t ₀ , ultrasonic waves 12 having directional patterns 1 to 3 are emitted. 10 shows an example of an ultrasonic waveform consisting of two sinusoidal cycles. The emitted ultrasonic waves reach the detection target 5 existing in the area covered by the directional pattern 3, and are reflected on the surface of the 5. As a result of this reflection, a reflected ultrasonic wave is generated as if a sound source were present at 5, and the reflected wave travels toward receiver 2. Since 5 exists in the area covered by the directivity pattern of 4, a part of the reflected wave reaches 2, and in the received waveform illustrated in 11, a waveform 13 corresponding to 12 appears after time _t1. observed. The time difference between times t ₀ and t ₁ is equal to the time it takes for the ultrasound to reach 2 after it is emitted from 1 and reflected at 5, and if the speed of sound in the ultrasound propagation medium is constant. , correspond to spatial distances of 1, 5, and 2. For this reason,
If the time between t ₀ and t ₁ is measured, the distance to the detection target 5 can be estimated, and the configuration shown in FIG. 1 can be used as a proximity sensor. However, with the configuration shown in FIG. 1, the shape of the detection target 5 cannot be determined, and only the presence or absence of the detection target 5 can be known. Furthermore, detection target 5
The detection target 6, which actually exists at a closer distance than the above, cannot be detected because it does not exist in the area covered by the directional patterns 3 and 4. Since the transmitter 1 and the receiver 2 are usually mounted in a common housing (not shown), in the example shown in FIG.
If both 1 and 2 are moved in the direction of 5, there is a risk that the casing will collide with 6 before it reaches 5. For this reason, the conventional example shown in FIG. 1 can be said to be unsuitable as a proximity sensor for a robot device.

FIG. 3 is a diagram showing a prior art ultrasound device applied to a medical diagnostic device. In the figure, 20a, 20b, . . . are elements capable of generating ultrasonic waves, and a structure in which four elements are arranged in a one-dimensional array is shown. The element may be an inorganic, organic, or composite piezoelectric material, electrostrictive material,
Comprised of any magnetostrictive material or combination thereof. 21a, 21b, ... are the 20a,
20b, . . . 22 is an original oscillator that intermittently supplies burst-like ultrasonic transmission pulses to each element constituting the array;
Its output is a delay circuit 23 with different delay times.
a, 23b, . . . Each output of the delay circuit is input to the amplifier. Fourth
The figure is a diagram explaining the operation of FIG. 3, and shows waveform timings of the main components. In the figure, 122 is the output waveform of 22, 121a, 12
1b, . . . are output waveforms of 21a, 21b, . 23a, 23b shown in FIG.
..., the 122 pulse waveforms undergo different time delays, and the delayed pulses 21a, 2
1b,... are amplified to the desired voltage level necessary for excitation of 20a, 20b,..., and 121a,...
Pulses with waveforms shown in 121b, . . . are obtained.
Ultrasonic waves having wavefronts conceptually shown as 24a, 24b, . . . in FIG. 3 are emitted from the 20a, 20b, . radiated. That is, as shown in FIG. 4, the ultrasonic wave is emitted from the element 20a temporally earliest, and
The ultrasonic wave is emitted from the element d temporally latest. Because there is a difference in the emission time and the ultrasonic wave is in a burst shape as shown in FIG. It has the spatial distribution shown below. 24a, 24
Since b, . 24a,2
If the wavefronts 4b, . That is, it can be considered that the element arrays 20a, 20b, . . . emit ultrasonic beams in which ultrasonic energy is concentrated only in the direction 27. The direction of 27 is determined by the difference in emission time of the ultrasonic waves from 20a, 20b, . In other words, 121a, which is individually supplied to each element within an arbitrary intermittent period, for example, within the period indicated as τ ₀ in the figure, as illustrated in 122 in FIG.
By setting the times of the ultrasonic pulses indicated by 121b, . . . (denoted as θ ₀ , θ ₂ , θ ₂ , θ ₃ in FIG. 4) to a desired relationship, it is possible to The ultrasound beam can be emitted in any one direction in a vertical plane, for example in 27 directions. Then, following τ ₀ , another period (denoted as τ ₁ in Figure 4)
Within, the time differences corresponding to θ ₀ , θ ₁ , . . . are changed to θ ₀₁ , θ ₀₂ , . . . , respectively. Fourth
In the figure, θ ₀₁ , θ ₀₂ , . . . are shown to be smaller than θ ₀ , θ ₁ , .
In other words, by changing the time difference, the radiation direction of the ultrasonic transmission wave can be changed, and the area to be detected can be scanned with the ultrasonic beam. Next, according to the above operation, the emitted ultrasonic beam is reflected by the detection target 28 existing within the reach range of the beam, and a reflected wave having a circular wavefront 29 as if a point source exists is generated at 28. form a pattern. In addition, in Figure 3, 28
Although it is drawn as if it does not exist in the radial direction of 27, this is to avoid confusion in the drawing, and it is assumed that 28 actually exists in the direction of 27. The wavefront 29 sequentially reaches elements 30d, 30c, . . . having a sound pressure/electrical conversion function over time. The elements 30a, 30b, 30c, 30d
has a function opposite to that of 20a, 20b, . The electrical signals from 30a, 30b, . . . are input to delay circuits 33a, 33b, . Output. For the illustrated wavefront shape 29, three
Similar reflected ultrasound signals are detected at 0d, 30c, 30b, and 30a. The time difference in which the reflected ultrasound waves reach the element is 33d, 33c, 33b, 3
By appropriately setting the delay time of 3a, the output of the delay circuit 30d and 30 is compensated.
The detection signals at c, . . . are made to be at the same time. That is, by changing the delay times of 33a, 33b, ..., it is possible to electronically provide a focusing function to the reflected waves from the detection target existing within the reach area of the radiated ultrasonic waves. Become. According to the configuration of FIG. 3 explained above, 20a, 20
It is possible to detect a two-dimensional ultrasound image of the object to be detected that exists in front of 30a, 30b, . It becomes possible to easily detect the distance to the detection target based on the time, and it can be used as a proximity sensor mounted on a robot device.

However, there are serious drawbacks when applying the configuration of FIG. 3 to the proximity sensor. The drawbacks will be discussed below. Proximity sensors for robotic devices are required to be able to accurately detect objects within a distance of up to 50 cm. In normal industrial robot equipment, the propagation medium of the emitted ultrasonic waves is air, so the propagation speed of the ultrasonic waves is 340 m/sec, which is the sound speed in air.
is equal to If the distance to the detection target is 50cm,
The ultrasonic wave propagates a distance of 1 m round trip, and the time required for propagation over this distance is approximately 3 msec. That is, the periods τ ₀ and τ ₁ shown in Fig. 4 are set to 3 msec.
Must be set above. In order to cover an omnidirectional range of 90° by changing the radiation direction indicated by 27 in Figure 3 by 1°, it is necessary to emit the ultrasonic wave 90 times, and the detection target within the omnidirectional range is required. Approximately 270 msec is required to detect. If the reciprocal of the scanning period of the omnidirectional range is defined as the frame frequency, the frame frequency will be 3.7 Hz for the numerical example. It is clear that the 3.7 Hz frame frequency is too low for controlling robotic equipment. In other words, when moving a part of a robot device, such as an arm, based on ultrasonic images that appear at 3.7 times per second, it becomes difficult to move at high speed, which reduces productivity in industrial robot devices. However, there was a serious drawback in that it was difficult to apply this device to fields that required high-speed response.

The present invention has been made to avoid the above-mentioned drawbacks, and FIG. 5 shows an embodiment of the present invention.
FIG. 5A is a partial configuration example of an ultrasonic device according to the present invention, and FIG. 1B is a diagram showing timing. In the figure, elements 50a, 50b, 50c, and 50d are capable of generating ultrasonic waves, and a structure in which four elements are arranged in a one-dimensional array is illustrated. The main component of the element is a piezoelectric material, an electrostrictive material, a magnetostrictive material made of an inorganic material, an organic material, or a composite material, or a combination thereof. Also, 51a, 51b, 51c, 5
1d is 50a, 50b, 50c, 50d respectively
This is an intermittent burst-like ultrasonic transmission pulse waveform supplied to the The elements 50a, 50b, 50
c, 50d, through an adder circuit and an amplifier,
Two delay circuits are connected to each element, and within any given intermittent period 40, each element receives two delay pulses, 61a and 65a, 61b and 65.
b, 61c, 65c, 61d and 65d are supplied, and if we pay attention to the pulse trains 61a, 61b, 61c, 61d, these are set so that the delay time increases sequentially, while 65a, 65
The pulse trains b, 65c, and 65d are set so that their delay times decrease sequentially. Due to the pulse, the instantaneous wavefronts of the ultrasonic waves emitted from 50a, 50b, . . . at the same time are 62a, 62b, .
..., 66a, 66b, . Figure b
If you refer to the pulse supply timing in
61a, 61b, 61c, 61d, 65a, 65
The wavefronts corresponding to pulses b, 65c, 65d are 62a, 62b, 62c, 62, respectively.
d, 66a, 66b, 66c, and 66d. Wavefronts are synthesized in the ultrasonic propagation medium 63 existing in front of the element, so the wavefronts synthesized by 62a, 62b, ..., 66a, 66b, ... have the shape shown by 70, 71. , the resultant wavefronts 70, 71 travel in directions of radiation 72, 73, respectively. To be more specific, 62a, 62b, 62c, 62d
The wavefront synthesized by 71, 66a, 66
The liquid level synthesized by b, 66c, and 66d is 70
become. By supplying the ultrasonic transmission pulse to an array of elements capable of generating ultrasonic waves, it is possible to radiate the ultrasonic waves in different directions 72 and 73 in a plane perpendicular to the array within the period 40. I understand. That is, the pulse trains 61a, 61b, 61 are set such that the delay time increases sequentially.
The wavefront of the ultrasonic wave transmitted through the delay circuit group forming c and 61d is 73, while the pulse train 65a and 6 are set so that the delay time decreases sequentially.
The wavefront of the ultrasound transmitted through the delay circuit group forming 5b, 65c, and 65d is 72, and as a result, the ultrasound transmitted from the ultrasound elements 50a, 50b, 50c, and 50d has a wavefront of 72 and a wavefront of 73. It becomes a composite wave with . Therefore, within the period 40, by appropriately setting the phase difference between the ultrasonic transmission pulses 51a, 51b, .
2, 73)) (for example, 70,
71) can be realized. In addition, in the cycle 41 following 40, as shown in FIG. 5, 51a, 51
The time relationships between the two groups of burst-like pulse trains b, . . . are different. That is, 6 based on 61a
Delay time differences between 1b, 61c, and 61d θ ₁₀ , θ ₁₁ , θ ₁₂
The delay time difference θ ₂₀ , θ ₂₁ , within the corresponding 41 corresponding to
θ ₂₂ is each larger than the value within 40. In such a relationship, the slope of the composite wavefront corresponding to 70, 71 in FIG. 5a becomes closer to vertical, and at the same time, the angle formed by the two radiation directions becomes larger. That is, the time difference can be changed every cycle, and the direction of the radiation can be changed every cycle. Furthermore, in this embodiment, since the two ultrasonic waves are emitted at the same time or approximately at the same time within an arbitrary cycle, detection targets existing in the omnidirectional range of the 90° radiation as described above can be detected. The number of times the ultrasonic waves are emitted in order to detect all the waves is 45 times. In other words, the frame frequency mentioned above increases to 7.4Hz, which makes it difficult to control the robot equipment.
This has the effect of doubling the upper limit of the arm's operating speed. In the explanation of FIG. 5, a two-cycle rectangular wave pulse is used for a one-dimensional array having four elements, but the invention is not limited to this. That is, the number of elements may be any natural number, the array shape may be two-dimensional, and there are no restrictions on the number of pulse repetitions or the pulse shape. Furthermore, 50a, 50b, 50c,
The pulse height value to 50d does not need to be a constant value, and may have a different pulse height value for each element within the period, and the pulse height value may change for each period. Note that when the number of elements is odd, the sound pressure of the ultrasound emitted from the element located at the center of the one-dimensional array can be set to twice the sound pressure of the ultrasound emitted from the other elements. desirable. Furthermore, although the delay time difference within the same period in Figure 5b is set constant, the direction of radiation is asymmetric (Figure 5a).
Then, 72 and 73 are the directions of left-right symmetry),
Further, the delay time difference may be set to a desired relationship in order to make the composite wavefront concave in the radial direction and to concentrate the sound pressure near a specific distance from the array. In the case of such a concave shape, the direction of the radiation is fixed over a plurality of periods, and only the curvature or shape of the concave shape is changed for each period,
A method in which the specific distance is changed every cycle is preferable. Further, by arranging N pulse groups within the period 40 or 41, the ultrasonic waves can be emitted in N different directions within the period. In such a case, the above-mentioned frame frequency is increased to (3.7×N) Hz, thereby further improving the above-mentioned arm operation speed. Alternatively, the ultrasonic waves may be emitted repeatedly while maintaining a constant time relationship within a plurality of consecutive cycles. Although this operation has the drawback that the frame frequency is reduced, the reflected wave pattern from the detection target is the same within the period, so the S/N ratio can be improved by performing average value calculation on the ultrasonic receiving circuit side. This has the advantage of improving detection accuracy.

FIG. 6 is an embodiment of the present invention for realizing the timing of FIG. 5b. In the figure, the fifth
The same numbers as in the drawings indicate the same components. In the figure, 50a, 50b, . . . are shown as being separated, but they may have an integrated configuration as shown in FIG. In the figure, four such elements 50a, 50b, 50c, arranged in a one-dimensional array are shown.
Two delay circuits (82
a and 83a, 82b and 83b, 82c and 83c,
and 82d and 83d), the circuit that adds the two outputs (81a, 81b, 81c, and 81d) and the amplifier circuit (80a, 80b,
80c and 80d). A common pulse waveform from the original oscillator 84 is input to the eight delay circuit groups. 82
The delay circuits a, 82b, 82c, and 82d also serve as the first delay circuit group 83a, 83b, and 83d.
The delay circuits c and 83d constitute a second delay circuit group, respectively. The delay times in the four delay circuits constituting the first delay circuit group are 82a, 82b, 82c, 82 in the element arrangement direction of the array.
It increases sequentially in the order of d. In FIG. 6a, the delay time of the delay circuit is conceptually shown corresponding to the length on the drawing. Further, the delay time in the four delay circuits constituting the second delay circuit group is 83a, 83 in the element arrangement direction of the array.
b, 83c, and 83d are sequentially decreased in this order. Since the operation of such an arrangement can be easily understood by those skilled in the art, a detailed description will be avoided and 50a
We will only describe the waveforms. The burst pulse waveform exemplified at 184 generated at 84 is 82a
As a result, the waveform is delayed by the time τ ₁₀ and becomes the waveform 182a. Further, the waveform 184 is delayed by the time τ ₁₁ by 83a and becomes the waveform 183a. Next, 81
The waveforms of 182a and 183a are added by a,
Furthermore, it is amplified by 80a to a voltage level sufficient to excite 50a, and a burst-like ultrasonic transmission pulse waveform of 180a is obtained. The 180a is 5
0a, and ultrasonic waves are emitted from 50a. Although all waveforms in this embodiment are displayed as bipolar burst pulses having three levels of positive, zero, and negative, the present invention is not limited to this. For example, 1
84, 182a, 183a, and 180a may all be sinusoidal burst pulses. Also, 18
4, 182a, and 183a are logic circuit output waveforms having binary levels of zero and positive, which are represented by a TTL logic circuit, and may be converted into a desired waveform by 80a. In such a case, 84, 82a, 8
There is an advantage that 3a, 81a, etc. can be configured with TTL or CMOSIC shift registers, random access memories, etc. Note that if 82a, 83a, etc. are configured with well-known charge-coupled devices, it is possible to delay the output waveform in an analog manner by a predetermined delay time while maintaining the shape of the output waveform, regardless of the shape of the output waveform of 84. is also possible. 80a, 80b,... is 50
It has the function of amplifying and converting the waveform to the desired voltage level necessary for excitation of 8.
If the output signals of 1a, 81b, ... have a level and waveform sufficient for the excitation, 80a, 80b,
It is possible to omit .... This will be explained with reference to FIG. 5. The radiation direction of the ultrasonic wave depends on τ ₁₀ and τ ₁₁ in FIG. The direction of the radiation can be changed. In particular, in the configuration of FIG. 6, 82a and 83d, 82b and 83
If delay times c, 82c and 53b, and 82d and 83a are set to be equal to each other, the direction of radiation will always be symmetrical. The situation is shown in FIG. In this figure, the same numbers as in FIG. 6 indicate the same components. 72 and 73 in FIG. 5 are shown in FIG. 5A, and in FIG. 9
0.91 is shown. That is, the first group of delay circuits 82a, 50b, . . . shown in FIG.
The ultrasonic transmission pulses processed by 82b, 82c, and 82d also send the second delay circuit group 83a, 82 to the second region 94 on the right side of 92.
The ultrasonic waves are emitted by the ultrasonic transmission pulses processed by 3b, 83c, and 83d. In addition, in order to realize this situation, as mentioned above, 82a, 82b, ..., 83a, 83 in FIG.
As conceptually shown by the difference in the length of b, ... on the drawing, the delay times 82a, 82b, 82c, 82d
In the order of 83d, 83c, 83b, and at the same time.
It is necessary that the length increases in the order of 83a.

FIG. 8 is a diagram showing an example of the configuration of elements 50a, 50b, 50c, and 50d that can generate the ultrasonic waves shown in FIG. 5a. Figure a shows an example of a configuration in which electrodes 96 and 97 are provided on both sides of a piezoelectric body 95. The material of the 95 can be selected from a wide range of materials such as inorganic materials such as ZnO, PZT, PLZT, and AlN, organic materials such as PVDF, and hybrid materials that are a mixture of inorganic and organic materials. Further, the materials 96 and 97 can be selected from any material as long as it has high adhesion to the material 95 and can maintain good reliability even against the piezoelectric vibrations of the material 95. In this configuration example, the ultrasonic transmission pulse is supplied to 96 and 97, and 95 vibrates due to the well-known inverse piezoelectric effect and emits ultrasonic waves. Note that the structure consisting of the 95, 96, and 97 may be fixed on the silicon substrate with an adhesive, paste, or the like via an insulating means. FIG. 8b shows an example of a configuration using silicon integrated circuit technology. In the figure, 100 is a silicon substrate having a first conductivity type, 101, 102
100 is a diffusion layer having a different conductivity type, 103 is an insulating film, 104 and 106 are electrodes, and 105 is a thin piezoelectric film. The material of the material 105 can be considered to be the same as that of the material 95, but ZnO, AlN, etc., which can easily form a piezoelectric thin film by sputtering technology, are preferable. In this configuration, by supplying the ultrasonic transmission pulse to 104 and 106, 105 is vibrated, and 1
Ultrasonic waves can be emitted in a direction perpendicular to 00. Furthermore, in this configuration, if 104 is disconnected from an external circuit (not shown) and placed in a floating state, and 106 is connected to a DC voltage source as appropriate, ultrasonic waves arriving from a direction perpendicular to 100 can cause It is possible to induce charges in 105 according to the piezoelectric effect of . The induced charge modulates the channel current of the FET, which is appropriately biased so that 101 acts as a source and 102 acts as a drain.
This structure has the advantage of being able to be used as an ultrasonic detector. That is, this configuration is applicable not only to the ultrasonic oscillation element in the present invention, but also to the 3 in FIG.
Since it also functions as an element having a sound pressure/electrical conversion function as exemplified as 0a, 30b, . . . , there is an advantage that the ultrasonic device can be implemented as an IC.

FIG. 9 is a diagram showing another embodiment of the present invention. In the figure, 82a, 82b, . . . in FIG. 6a,
Portions 83a, 83b, . . . , 81a, 81b, . . . are shown in detail. This embodiment is characterized in that the delay circuit group and the addition circuit are constructed of charge-coupled devices. Since the basic structure and operating principles of charge-coupled devices are well known,
In the figure, only a plan view of a three-phase drive type surface channel type charge coupled device is shown. In the same figure, 1
30 is a line indicating the end of a channel stop region buried in the silicon substrate; 131 is a line indicating the end of an input diffusion layer region of a conductivity type opposite to that of the silicon substrate, which serves as a charge injection source to the device; 132a; ,1
32b, . . . are lines indicating the ends of output diffusion layer regions of the opposite conductivity type to the silicon substrate for detecting charges from the device. An input diffusion layer region 133 surrounded by 131 is provided with means for making an electrical connection, and is connected to an input terminal 134 having means for connection to the aforementioned 84. 132
A, 132b, . . . are surrounded by output portion diffusion layer regions 135a, 135b, .
6a, 136b, . . . are connected to each region. 137a, 137b, 137c, ... are transfer electrodes of the charge coupled device, and terminals 138a, 138b, to which three-phase transfer pulses for driving are supplied,
138c. Reference numeral 143 denotes an output gate electrode of the charge-coupled device, which has means for being connected to a terminal 142 connected to a DC voltage source. 140
a, 140b, 140c, 140d, 141a,
141b, 141c, 141d are 82a, 82b, 82c, 82d, 83 in FIG. 6a, respectively.
These are channel regions of the charge coupled device corresponding to a, 83b, 83c, and 83d. The channel areas are 133, 135a, 135b, 135c, 13
It is located between 5d and 140a, 140
b, 140c, 140d, 141a, 141b,
The numbers of transfer electrodes 141c and 141d are 6, 12, 18, 24, 24, 18, 12, and 6, respectively. Since the charge-coupled device is a three-phase drive type, the number of devices in each channel region is 2, 4, and 4, respectively.
6, 8, 8, 6, 4, 2. That is, in the embodiment of FIG. 9, 82a, 82b, 82c, 82d,
Each delay circuit 83a, 83b, 83c, 83d is 2, 4, 6, 8, 8, 6, 4, 2, respectively.
A case is shown in which the device is constructed of an analog delay circuit consisting of a charge-coupled device. In this configuration, when the pulse at 86 is a sine wave with a frequency of 40 KHz and the frequency of the transfer pulse is 100 KHz, in 82a, a 40 KHz sine wave delayed by 20 μsec is outputted to 136a. The number of elements is merely an example, and other numbers of elements may be used.
In the vicinity of the output diffusion layer region of the channel region,
A merging of the channel regions occurs and 140a and 14
1a is 135a, 140b and 141b are 135
b, 140c and 141c are 135c, 140
d and 141d are terminated by 135d. Since the merging of the channel regions means that the signal charges transferred through the respective channel regions are mixed, analog addition can be realized. That is, due to the said merging, 8
Addition circuits 1a, 81b, 81c, and 81d are configured. 136a, 136b, 136c, 136
Each output terminal of d is connected to the above-mentioned 80a and 80
It has means for connecting to the input terminals of the amplifier circuits b, 80c, and 80d. If this configuration is used, there is an advantage that the configuration shown in FIG. 3a can be realized entirely as a silicon integrated circuit. Furthermore, in this embodiment, by controlling the repetition frequency of the three-phase transfer pulses supplied to 138a, 138b, and 138c, the delay time in the channel region can be changed all at once, and the ultrasonic device can be driven It is clear that this will be very effective. In the explanation of this embodiment, the operation of the charge-coupled device was explained using a conceptual plan view.
The present invention is not limited to the merely illustrated example, but includes techniques related to well-known charge-coupled devices, such as various charge injection methods, charge detection methods, charge transfer driving methods, and various device structures including a buried channel type. It is clear from the description of this specification that these may be combined, and all of these are included in the present invention.

(Effects of the Invention) The present invention has been described above in detail using the drawings. Although the explanation is limited to transmission of ultrasonic waves, the conventional example shown in FIG. 3 can be applied to reception of reflected waves. Of course, in the present invention, since ultrasonic pulses are emitted in multiple radiation directions,
It is necessary to prepare a plurality of sets of the configuration for reception illustrated in FIG. According to the present invention, an object to be detected existing in the air can be detected at a high frame frequency, and the shape of the object and the distance to the object can be easily and accurately detected.

[Brief explanation of the drawing]

FIG. 1 is a conventional sensor using ultrasonic technology, and FIG. 2 is a diagram explaining the operation of FIG. 1. FIG. 3 is a conventional ultrasonic device, and FIG. 4 is a diagram explaining the operation of FIG. 3. FIG. 5 is a diagram showing an embodiment of the present invention. 6a and 6b, 7a and 7b, and 8a and 8b are diagrams explaining a part of FIG. 5a in more detail. FIG. 9 is a diagram showing another embodiment of the present invention. In the figure, 1... Ultrasonic transmitter, 2... Ultrasonic receiver, 3, 4... Directional pattern, 5, 6,
28...Detection target, 10...Ultrasonic waveform, 11...
... Received waveform, 20a, 20b, 20c, 20d,
50a, 50b, 50c, 50d... Elements capable of generating ultrasonic waves, 21a, 21b, 2
1c, 21d...Amplifier, 23a, 23b, 23
c, 23d, 33a, 33b, 33c, 33d,
82a, 82b, 82c, 82d, 83a, 83
b, 83c, 83d...Delay circuit, 22, 84...
...Original oscillator, 30a, 30b, 30c, 30d...
...Element having sound pressure/electrical conversion function, 24a, 2
4b, 24c, 24d, 29, 62a, 62b,
62c, 62d, 66a, 66b, 66c, 66
d...Wave surface, 26,70,71...Synthesized wave surface, 27,72,73,90,91...Direction of radiation, 34...Output terminal, 122, 121a, 12
1b, 121c, 121d, 51a, 51b, 5
1c, 51d, 184, 182a, 183a, 1
80a... Waveform, 40, 41... Period, 81a,
81b, 81c, 81d...addition circuit, 92...
Center line, 93, 94... area, 95... piezoelectric body,
105... thin film piezoelectric film, 96, 97, 104, 1
06... Electrode, 103... Insulating film, 100... Silicon substrate, 101, 102... Diffusion layer, 80
a, 80b, 80c, 80d...amplifier circuit, 13
0...End of channel stop area, 131,1
32a, 132b, 132c, 132d... end of diffusion layer region, 133, 135a, 135b, 1
35c, 135d...Diffusion layer region, 134...Input terminal, 136a, 136b, 136c, 136
d...Output terminal, 137a, 137b, 137c
...Transfer electrode, 138a, 138b, 138c,
142...terminal, 143...output gate electrode, 1
40a, 140b, 140c, 140d, 141
a, 141b, 141c, 141d...channel areas.

Claims (1)

[Claims] 1 Arranged in a one-dimensional or two-dimensional array,
N pieces that can generate ultrasonic waves (N≧2)
In an ultrasonic device having an element and means for individually supplying a burst-like ultrasonic transmission pulse to each element constituting the array, each element has the following steps:
The outputs of the two delay circuits are connected to each other via a circuit and an amplifier for adding the two outputs, and means for inputting a common pulse waveform to the delay circuits to generate the burst ultrasonic waves. The means for supplying the transmission pulse is configured, and one of two delay circuits connected to each of the N elements via an adder circuit and an amplifier is a first delay circuit group, and the other is a second delay circuit group. In this case, the delay times in the N delay circuits constituting the first delay circuit group increase sequentially in the order of appropriately ordered element numbers of the array, and the second delay circuit group is constituted. An ultrasonic device characterized in that delay times in N delay circuits decrease sequentially in order of element numbers of the array.