WO1996024053A1

WO1996024053A1 - Acoustic probing apparatus

Info

Publication number: WO1996024053A1
Application number: PCT/JP1995/000144
Authority: WO
Inventors: Yoshihiro Michiguchi; Masahiro Koike; Yoshinori Musha; Yoshiaki Nagashima
Original assignee: Hitachi, Ltd.
Priority date: 1995-02-03
Filing date: 1995-02-03
Publication date: 1996-08-08
Also published as: JP3279572B2

Abstract

An acoustic probing apparatus with a delay controller of reduced size, in which the distortion of waveforms is reduced. The probing apparatus comprises a transmitter for transmitting waves from a plurality of transmission elements with mutually different delay times, a plurality of reception elements for receiving the reflected waves and converting them to electric signals, a plurality of analog shift registers corresponding to the reception elements to receive the signals, means for changing a shift speed of data inside each charge transfer device on the basis of a shift speed instruction signal, an adder for adding the output from each charge transfer device, and a display for visualizing the reflected waves on the basis of the output from the adder. The main application of the present invention is an ultrasonic flaw detector.

Description

Specification

Exploration equipment using waves

The present invention relates to an exploration device using a reflection result of a wave. Background art

Conventionally, as an inspection method for exploring the inside of a material or the inside of a human body using ultrasonic waves as a wave, there has been a method using an array in which ultrasonic transmitting / receiving elements (piezoelectric elements) are arranged. Principles and configurations are described on pages 122 to 138 and pages 144 to 152 of the “Electronic Machinery Manufacturers Association” Medical Ultrasound Equipment Handbook.

In other words, at the time of transmission, the timing of transmission to each element is controlled, and at the time of reception, the reception signal of each element is given an appropriate delay, and the reception signals from many elements are given. to add.

Thereby, the direction of transmission and reception from the probe and the focal position can be controlled.

As can be seen from this conventional example, a tapped delay line has been used as a signal delay element.

In order to control the amount of delay, it is necessary to have a switch that determines the position of the signal to be input to a large number of taps.To control the amount of delay accurately, a large number of switches are required. Equipment is large and complicated.

In addition, the delay line itself has a large volume, and if a delay line is used for a large number of transmission / reception elements such as an array in which transmission / reception elements are arranged in a two-dimensional plane, this part becomes large and practicality is impaired.

An example in which a CCD (Charge Coupled Device) is used to reduce the number of switches is disclosed in Japanese Patent Application Laid-Open No. Sho 53-115591. As is well known, a CCD has a configuration in which a plurality of charge storage elements are arranged, and charges are sequentially transferred from an end by a clock signal supplied to the CCD.

In this well-known example, the waveform is first captured in CCD, and after a set time, called with the same clock as the capture.

In other words, CCD is used to store waveforms, and the read start time of the stored waveform is changed to provide an equivalent delay effect.

In this method, it is necessary to stop the CCD clock while storing and holding the waveform, and there is a problem in that waveform distortion occurs due to leakage of each charge storage element during this time.

In addition, none of the conventional examples considers a method for controlling whether or not each ultrasonic transmitting / receiving element is used.

For this reason, only a predetermined pattern of the ultrasonic beam can be used, and there is a problem that a highly adaptive ultrasonic transmitting and receiving apparatus that controls the beam characteristics according to the object to be inspected cannot be obtained. Disclosure of the invention

An object of the present invention is to reduce the size of a delay control portion of an exploration apparatus using a wave and to reduce waveform distortion.

The above object is to provide a transmitter that transmits a wave with a different delay time for each transmitter from a plurality of transmitters, a plurality of receivers that receive a reflected wave of the wave and convert the reflected wave into an electric signal, A plurality of analog shift registers corresponding to the respective receivers to which respective signals from the respective receivers are input, and means for changing a shift speed of data in each of the charge transfer elements based on a shift speed command signal And an adder for adding outputs from the charge transfer elements, and a display for visualizing the reflected wave based on the outputs from the adders. Is achieved by the exploration equipment.

When wave energy is transmitted from a plurality of transmitters with different delay times, the main axis of the wave energy can be directed in a desired direction by a combination of delay time elements given to each wave energy.

In the direction of the main axis, the wave energy is reflected by the object to be searched and returned as a plurality of reflected waves to each receiver with a time delay corresponding to the reflection distance of each reflected wave. is converted into a signal, in which each electrical signal _t each charge transfer device, which is input as data of the charge in each charge transfer devices corresponding to each receiving terminal, the charge transfer device on the basis of the data into the shift Bok speed command signal The shift speed is shifted to the output side, the shift speed is changed on the way based on the shift speed command signal, and the shift operation is controlled so that the shift operation does not stop until reaching the output. The transfer element removes the time delay element of each reflected wave, matches the time axis, and outputs.

The output signal from each charge transfer element is added by a calculator, and an effect of being visually displayed on a display is obtained.

By this action, the shift operation in each charge transfer element does not stagnate until the time axis of the charge data of the waveform is output and aligned in each charge transfer element. There is no distortion due to leakage of charge data in the waveform while storing and holding charge data, and the use of charge transfer elements provides a smaller exploration device than one that uses many delay lines, taps and switches The effect that it can be obtained is obtained. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram showing the basic configuration of an ultrasonic flaw detector according to a first embodiment of the present invention, FIG. 2 is a block diagram showing the detailed configuration of the control device 2 in FIG. 1, and FIG. Fig. 4 is a block diagram showing the detailed configuration of the transmission / reception circuit 3. FIG. 5 is an explanatory diagram of the delay amount for each ultrasonic reflection path in the embodiment of the present invention, FIG. 5 is an explanatory diagram of the operation of the CCD employed in the embodiment of the present invention, and FIG. 6 is a clock control circuit of FIG. 10 is a block diagram showing a detailed configuration of FIG. 10, FIG. 7 is an explanatory diagram of a delay amount for each ultrasonic reflection path in the second embodiment of the present invention, and FIG. 8 is each block diagram in the third embodiment of the present invention. FIG. 9 is a block diagram showing a detailed configuration of three transmission / reception circuits of FIG. 1 according to a fourth embodiment of the present invention, and FIG. 10 is a fifth embodiment of the present invention. Fig. 11 is an overall block diagram of the device according to the example. Fig. 11 is a flowchart of the control data setting process of the microcomputer 201 shown in Fig. 2. Fig. 12 is an inspection of the microcomputer 201 shown in Fig. 2. It is a process flow figure in a process. BEST MODE FOR CARRYING OUT THE INVENTION

The first embodiment of the present invention is an example of a so-called one-dimensional array probe in which ultrasonic transmitting and receiving elements are arranged in a straight line. FIG. 1 shows a schematic configuration thereof.

In FIG. 1, 1 is an ultrasonic image display device, and 2 is a transmission / reception control device.

3 i (i = 1,..., M) is a transmission / reception circuit provided for each ultrasonic transmission / reception element.

FIG. 2 shows a detailed configuration of the control device 2, and FIG. 3 shows a detailed configuration of the transmission / reception circuit 3 (subscripts are omitted in the following description unless otherwise specified).

In FIG. 2, reference numeral 201 denotes a microcomputer, reference numeral 202 denotes a data memory, and reference numeral 203 denotes a selector.

Reference numeral 204 denotes a trigger generator which receives a signal from the display device 1 via the terminal 27 1.

Reference numeral 205 denotes a clock generator, and reference numeral 206 denotes an adder.

In FIG. 3, 35 i is a transmitting / receiving element, and the piezoelectric element Is emitted and detected.

302 is a gate circuit, 303 is a counter circuit, 304 is a pulse generator, and 305 is a transmission / reception switch.

At the time of transmission, the electric pulse signal generated in 304 passes through the transmission / reception switch 305, reaches the transmission / reception element 35i, and is emitted as an ultrasonic pulse.

At the time of reception, the reflected ultrasonic wave that has reached 35 i becomes an electric signal, passes through 30 5 and reaches the amplifier 30 6.

Reference numeral 307 denotes a charge transfer element (eg, CCD, Chagc Coupled Device, charge-coupled element), which is a clock control circuit 310 controlled by two counters 308 and 309. change.

The delayed signal is led to the control device 2 through the switch circuit 3 1 1.

Reference numeral 312 denotes a memory element for storing count data of the counters 303 and 309, and data for determining whether the gate 302 and the switch circuit 311 are turned on and off. I do.

Reference numeral 313 denotes a gate circuit for setting whether or not to transfer data to the memory element 312.

Hereinafter, the 307 charge transfer elements will be described as CCD.

Here, the mutual connection state of the display device 1, the control device 2, and the transmission / reception circuit 3 is described, but only the signal line is described, and the power supply line and the like are omitted.

From the display device 1, control information to be described later is sent to the control device 2 (terminal 271 in FIG. 2), and the reflected signal is sent from 1 to 1 for display (terminal 272 in FIG. 2). As the display device 1, a known device can be used.

The control information sent from the display device 1 to the control device 2 includes the range of the focal position of the ultrasonic wave to be set and the set interval, the spatial position of each transmitting / receiving element 35 i, The sound velocity of the seed medium, etc., will be described in detail later. There are two types of connection between the control device 2 and the transmission / reception circuit 3.

One type is connected from the control device 2 for each transmission / reception circuit, and the other type is a connection common to the entire transmission / reception circuit.

In the former case, the signal is transferred from the selector 203 to each transmission / reception circuit via the terminals 281 to 28M, and the signal is transmitted from the transmission / reception circuit via the terminals 291 to 29M. It is connected to the container 206.

The latter common connection is a signal line which is transferred from the control device 2 to the transmission / reception circuit, and four terminals 273 to 276 are used.

2 7 3 is the terminal of the data line such as the count value of the counter, 2 7 4 is the terminal of the transfer line for the timing of starting the reception operation, 2 7 5 is the terminal of the trigger line, and 2 7 6 is the terminal. Terminal for the transfer line.

Through the terminals 273 to 276, the four signal lines are connected to each of the M transmission / reception circuits from 31 to 3M.

The configuration and the connection state have been described above with reference to FIGS. Next, the operation of the present invention will be described in detail.

The explanation is divided into transmission time and reception time, and the explanatory diagram of the delay amount in Fig. 4 is used in addition to Figs.

As shown in FIG. 4, let us consider a case where ultrasonic transmitting / receiving elements from 35 1 to 35 M are arranged on the X axis.

The positions from 35 1 to 35 M are XI to XM.

Take the y axis perpendicular to the x axis.

At the time of transmission, consider focusing the ultrasonic beam on the coordinates F (X F, Y F).

For focusing, the radiated wavefront from each ultrasonic transmission element needs to coincide at the focal position F (XF, YF). The distance between each ultrasonic transmitting / receiving element and the focal point F can be obtained by Expression (1).

L i = f (XF-X i) ² + YF ² Equation (1) If the distance from each ultrasonic transmitting / receiving element to the focal point F is the largest (35 M in the example of FIG. 4), the focal point If the ultrasonic wave generated from the circle C 1 centered on F reaches F at the same time, it focuses on F.

In this example, since the radius of the circular arc C1 is LM, it is necessary to delay the transmission timing for 35i by the ultrasonic propagation time of a distance of ΔLi from 35M.

ΔL i is obtained by equation (2).

Δ L i = L M-L i Equation (2) This delay time Δ T i is

ΔT i = ΔL i / V Equation (3) (V is the propagation speed of the ultrasonic wave).

The signal serving as a reference for the delay amount ΔT i is a signal from the trigger generator 204.

For this reason, in the present embodiment, the delay amount of the ultrasonic transmitting / receiving element 35M is 0, and the other ultrasonic transmitting / receiving elements are set to have the delay represented by the equation (3) as compared with 35M.

On the other hand, considering the reverse propagation, the ultrasonic waves generated from F are detected by each ultrasonic receiving element at the same time even at the time of reception, so a delay of Δ Τ i is necessary for 35 i as in transmission. And

The arc C2 in FIG. 4 is based on the element from which the ultrasonic wave from the focal point F is detected earliest during reception, which will be described later. So far, the necessary delay amount of each transmitting / receiving element has been described. The actual operation will be described below.

As an example, when observing an ultrasonic beam focused on F (XF, YF) think of.

The clock generator 205 generates a clock signal of D for one cycle. In the _t data memory 202, data on the amount of delay at the time of transmission is stored as the number of clock pulses.

That is, the equation (4), which is the number of counts obtained by dividing the required delay amount ΔΠ (i = l,…, M) from each ultrasonic transmitting / receiving element 35 1 to 35 M by D,

K i = ΔT i ZD Equation (4) is stored.

Further, the data of the delay amount at the time of reception is also stored in 202, and the specific value will be described in detail in the control of the receiving section described later.

Further, in 202, in addition to the number of counts corresponding to the transmission delay amount and the reception delay amount, data indicating whether the corresponding ultrasonic transmitting / receiving element is used for transmission or not is also stored. .

The stored data is transferred to the memory element 312 provided for each transmitting / receiving circuit.

This transfer is under the control of the microcomputer 201.

The microcomputer 201 controls the selector 203 and outputs it to a specific one of the output lines from 203.

If 203 selects terminal 28i, gate circuit 313 can be turned on through 28i and terminal 38i.

As a result, data can be transferred to the memory element 312.

The microcomputer 201 sends the data of the solid data memory 202 to a signal line common to the transmitting / receiving circuits via the terminal 273, and the gate 3 of the transmitting / receiving circuits Data is sent to the memory element 3 1 2 only when 13 is conductive.

As described above, the data of 3 1 2 is a count corresponding to the amount of delay during transmission. The control data includes the number K i, the number of counts obtained from the delay amount at the time of reception described later, and whether the i-th ultrasonic transmission / reception element is used for transmission or not.

If the i-th transmitting / receiving element is used for transmission, the gate 302 is turned on, and if it is used for reception, the switch circuit 311 is turned on.

For this reason, the i-th ultrasonic transmission / reception element can be used for either transmission only or reception only, and can be controlled to be used for both transmission and reception. In the transmission delay control, the delay K i stored in the memory element 3 12 is loaded into the counter 303 and is sequentially reduced from K i by the clock signal via the terminal 276. .

When the coefficient value becomes 0, it is output to the pulse generator 304, and a pulse signal is generated at 304 at this timing.

This pulse signal is guided to the ultrasonic transmission / reception element 35i through the well-known transmission / reception tandem device 305, and is emitted as an ultrasonic signal.

The timing of this radiation is delayed by ΔT i from the radiation time of the reference transmitting / receiving element (35 M in the example in Fig. 4).

The other ultrasonic transmitting / receiving elements are also delayed for each element, so that the ultrasonic waves are focused at the position of the focal point F.

Next, the delay control at the time of reception will be described.

The reflected waveform detected by the ultrasonic transmitting / receiving element 35 i passes through the transmission / reception switch 305, is amplified by the amplifier 306, and reaches a charge transfer element, for example, a CCD 307. In the delay control during transmission, a pulse was finally generated after the delay in the counter 303.

On the other hand, at the time of reception, the detected waveform itself must be delayed without being distorted, and the delay method at the time of transmission cannot be used as it is. For this reason, a delay circuit composed of the CCD 307, two counters 308, 309, and a clock control circuit 310 has been devised.

The CCD 307 has a structure in which N elements from 1 to N are arranged as shown in FIG.

As is well known, a CCD requires a clock signal, and the clock sequentially transfers the signal input from the extreme end (1 in FIG. 5) to the opposite side (N in FIG. 5). ) Side.

Assuming that one cycle of this clock is D, which is the same as that of the transmitting side, it takes ND time to pass through CCD.

Here, the first n clocks from the CCD operation start time are one cycle D clocks, and the (N−n−1) data from (n + 1) to (N−1) is p D (p> l). A clock with a certain cycle, and the last one is operated with the D clock. <By using a clock controlled in this way, the time T i that passes through the CCD is −

T i = n D + p (N-n-1) D. + D equation (5)

= DN p-D (n + l) (p-l) Equation (6) (where p> 1).

The difference between the CCD transit time when all the CCDs are operated with a clock having a period D and the transit time Ti when the above clock control is performed is:

T i −N D = D (N−n−l) (p−1) Equation (7).

Here, if the clock frequency, that is, the clock period D, the CCD length N, and the change ratio (division ratio) of the clock period, are set, the reception delay amount is changed by changing n. It can be controlled by the formula (7).

Taking the ultrasonic transmission / reception element as a reference even when the reflected wave detection time is slow, (35 M in Fig. 4), the required delay of 35 i is calculated from equation (7).

Δ Ti = Ti-ND Equation (8).

Therefore, if N, D, and p are set, in order to obtain the required amount of delay Δ Τ C, the length η of C C D using a clock with period D is

n = N−l−A Ti / D (p−1) Equation (9)

The value of n is transferred to the counter 309 via the memory element 312.

Constant data (N-1) is always supplied to the counter 308. A clock having a period D is supplied to the two counters 308 and 309 via the terminal 276. The receiving operation start timing signal provided via the terminal 274 causes the transfer data to start counting from the transfer data. When the count of the counter 309 is reduced to 0 from the transfer data n, a timing signal is sent to the clock control circuit 310.

Similarly, in the counter 308, when the data (N-1) is decremented to 0, a timing signal is sent to 310.

FIG. 6 shows the configuration of the clock control circuit 310.

In FIG. 6, 3101 is a memory element, 3102 is a selector, 3103 is a frequency dividing circuit, and 3104 is a gate.

The frequency divider 3103 receives a clock having a period D from the terminal 276, and multiplies the period D by p.

For example, when p = 2, a flip-flop element can be used, and other known frequency dividers can be used.

The memory element 3101 is set by the output of the counter 309 and reset by the output of the counter 308. The selector 3102 selects either the clock with the period D or the clock with pD in the state of the memory 3101.

When the memory 3101 is in the reset state, the selector 3102 outputs a clock signal having a period D, and when the memory 3101 is in the set state, it outputs a frequency-divided pD clock.

In this way, of the N CCDs, n can be transferred with a clock with period D, the next (N_n-1) with pD, and the last one with D. The desired delay amount Δ 量 i can be obtained.

Here, the relationship between the gate circuit 3104 in FIG. 6, the reception operation start timing signal at the terminal 274, and the trigger signal at the terminal 275 will be described.

The gate 3104 performs a gate operation to determine whether or not to add the clock signal from the selector 3102 to the CCD of the switch 3107.

In this operation, the gate is turned off by the trigger signal from the switch 275, and the gate is turned on by the reception start timing signal from the switch 274.

In other words, the clock signal is sent from the clock control circuit 310 to the CCD 307 after the reception start timing signal from the terminal 274 is input to the CCD 307.

The reception operation start timing signal is output from the microcomputer 2-1 in FIG.

This output timing will be described.

In FIG. 4, the ultrasonic transmission / reception element (35 M in FIG. 4) having the largest distance from the focal point F was selected as a reference for delay.

During transmission, the delay from the trigger was set to 0 at 35 M, and appropriate delays were given to the other transmitting and receiving elements.

At the time of reception, a start timing for acquiring reflection data to the CCD is required. Yes, and its value is given by equation (10).

A S = (L + L s-a) / V formula (10)

ΔS is the time from the trigger, and Ls is the distance from the focal point F to the nearest ultrasonic transmitting / receiving element.

A is a value that determines from how close to the focal point the reflected waveform is sampled.

When the focal position and the position of each ultrasonic transmitting / receiving element are determined, LM and Ls are determined.

The propagation velocity V of the ultrasonic wave is known, and if a is set in advance, equation (10) can be calculated.

Up to this point, the delay amount control for transmission and reception has been described in detail.

Upon reception, the delayed reflected signal is output from the CCD 307.

At this time, if the switch circuit 311 is conductive, the delayed reflected signal is guided to the adder 20-6 through the terminal 39i.

The adder 206 functions to add the delayed reflected wave of the switch circuit of each receiving circuit that is conductive.

As a result, the output of the adder 206 becomes a reflected wave from the focal point F, that is, a reflected signal in which the observation position is set to F.

If the position of the focal point F (XF, YF) is changed, for example, if YF is fixed and XF is changed, the focal point will be scanned at a constant depth. It is possible to display a reflection image. Also, if both XF and YF are changed, an ultrasonic reflection image in the X-axis and y-axis cross sections can be obtained.

Since these are all observation results with the focus, that is, with the ultrasound beam focused, it is possible to obtain images with extremely high resolution. The operation described above is regarded as the processing flow of the microcomputer 201. j ₄

Figures 11 and 12 summarize the results.

The operation of the microcomputer 201 is roughly divided into receiving control information, calculating transmission / reception control data of each element, storing the data in the data memory, and inspecting while reading the control data of the element from the data memory. .

The former is prior to the transmission and reception of ultrasonic waves, and is shown in FIG. The latter is an operation of performing inspection while repeating transmission and reception, and the flow is shown in FIG.

First, the flow of FIG. 11 will be described.

The control information sent from the display device to the microcomputer 201 is basically a parameter necessary for the calculation from the equations (1) to (10).

Specifically, the setting range of the focal position F (XF, YF), the setting interval, the position of the ultrasonic transmitting / receiving element and information on which element is used for transmission and reception, the ultrasonic wave propagation speed V, the clock interval D , The number of CCD elements N, and the value a, which determines how close the reflected wave should be sampled from the focal point.

This operation corresponds to 401 in FIG.

In this embodiment, the coefficient for multiplying one clock cycle in equations (5) to (9) is determined in advance by hardware. When the control information is transferred from the display device 1 to the microcomputer 20。, the length n of the CCD using the clock of the period D is calculated for each transmitting / receiving element.

First, at 402 in FIG. 11, the first focus position to be calculated is set, and the time △ S from the trigger in equation (10) is calculated and stored in the data memory 202 (see FIG. 1 1 4 3).

Next, a transmitting / receiving element to be calculated in 404 is set.

4 Determine whether the element set in 4 is used for transmission or not, and _{1 &}

In this case, the number of counts K i is calculated from equations (1) and (4) and stored in temporary memory (406).

If the element is not used for transmission, the calculation at 406 is skipped,

Step 407 is processing for determining whether the element is used for reception.

When used for reception, after calculating ΔT i by using Equations (1) to (3) in 408, n is calculated by Equation (9) and temporarily stored in memory.

If it is determined in 407 that the element is not used for reception, the calculation processing in 408 is omitted.

In 409, the on / off signal indicating whether the element is used for transmission and reception and the values of Ki and n temporarily stored in the memory are transferred to the data memory.

Whether all the elements to be calculated have been completed is determined by 410, and if not completed, the process proceeds to the next element (4 1 1) and the processing from 405 is repeated.

If the calculation of all the elements has been completed in 10, it is determined whether the entire focus setting range has been completed (4 1 2), and if not completed, the next focal position is set ( 4 1 3), continue processing from 4 0 3.

If all set focus positions have been completed, writing to the data memory is completed.

The above is the data setting process prior to the inspection, and then the inspection operation with the focus shifted.

The contents of this inspection operation will be described with reference to the flow of FIG.

When the inspection starts, an initial focus position is set (45 1), and control data of each element corresponding to the position is transmitted from the data memory to each transmitting / receiving circuit (45 2).

More specifically, in the i-th transmission / reception circuit, i is selected by the selector 203, the gate 31 3 in the transmission / reception circuit is made conductive by the output, and data is transmitted through the terminal 273. . jg

Next, the focal position set on the display device 1 is output (4553), but the focus setting order and the like are known in advance, and if there is data on the display device 1, there is no need to transfer the data. That is clear.

At this stage, a transmission trigger signal is sent via the terminal 275 (4554), and the time ΔS already calculated is waited for (4556).

During this ΔS, each transmitting / receiving circuit performs a transmitting operation according to the given delay amount. The details have already been described.

After ΔS elapses from the oscillation trigger, a reception operation start signal is transmitted to each transmission / reception circuit via the terminal 274 (457), and the reception operation is started.

An oscillation trigger and a reception operation start signal are sent to the display device 1 via the terminal 271, as necessary.

As a result of the above operation, a reflected signal delayed by the set delay is output from the terminal 29 i, added at 206, and sent to the display device 1 via the terminal 27 2. ―

This operation is performed at all the preset focal positions (458, 549), and the inspection is completed.

As above, the first embodiment of the present invention has been described in detail.

In this embodiment, the amount of transmission / reception delay divided by the use / non-use of transmission / reception was determined based on the data stored in the memory 2 2.

Of course, ultrasonic transmission / reception elements that are not used for transmission do not require transmission delay data, and elements that are not used for reception do not require reception data. Transmission / reception delay data and transmission / reception element usage data can be calculated in advance and stored in memory, transferred from the display device 1, or controlled by a microcomputer 201 while calculating. A modified embodiment is given.

In addition, the actual control of the delay amount during reception by changing the clock cycle of the CCD ₁ ?

It is also possible to apply the method of the embodiment to the transmitting side.

At this time, it goes without saying that the transmission standard is the one that has passed through CCD the earliest.

Further, among the components of the present invention, the portion excluding the 35 i ultrasonic transmission / reception element of the transmission / reception circuit of 3 and the control device of 2 can all be manufactured by integrated circuits.

All the transmitting and receiving circuits have the same configuration.

For this reason, the part of the transmission / reception circuit 3 excluding 35 i is formed by an integrated circuit for each ultrasonic transmission / reception element, and is electrically connected to 35 i.

The configuration in which the control device 2 is also made of an integrated circuit and the transmission / reception circuit 3 and the control device 2 have an integrated structure can be given as a modification of this embodiment.

Next, a second embodiment of the present invention will be described.

In the first embodiment, one-dimensional ultrasonic transmitting / receiving elements are arranged in a line.

This embodiment is characterized in that the one-dimensional ultrasonic transmission / reception elements are arranged with a curvature, but the configurations shown in FIGS. 1 to 3 and FIG. The data transferred from the microcomputer 1 to the memory 312 in Fig. 3 is different.

As shown in Fig. 7, M ultrasonic transmission / reception elements from 351 to 35M are installed at arbitrary positions with one-dimensional curvature, and the intervals between them are different.

The position of each ultrasonic transmitting / receiving element is (X i, Y i) (where i = 1, 2,..., M).

As in the first embodiment, consider a case where an ultrasonic beam is focused on a focal point F (XF, YF).

The distance between the focal point F and the transmission / reception element 35 i is represented by Expression (11).

L i = (XF-X i) ² + (YF-Y i) ² Equation (1 1) g

Let the transmitting / receiving element farthest from the focal point F be 35 j, and let the distance from F be L j.

Since L j is the radius of the circle C 1 in FIG. 7, it is necessary for the transmitting / receiving element 35 i to delay transmission timing by an ultrasonic propagation time of ΔL i from 35 M.

This delay time Δ T i is

Δ T i = (L j −L i) / V Equation (1 2) (where V is the propagation speed of the ultrasonic wave), and the number of counts corresponding to the delay amount at this time is the same as Equation (4) .

In other words, the method and configuration of the first embodiment for determining the delay amount of each transmitting / receiving element based on the ultrasonic transmitting / receiving element farthest from the focal point F can be used as it is.

It is easily conceivable that a similar argument can be made on the receiving side.

The distance L s (the radius of the circle C 2) between the transmitting / receiving element and F which is close to F in FIG. 7 is determined, and the reception operation start timing according to equation (10) is determined from this.

Further, the CCD length n for switching the period of the cycle corresponding to the reception delay amount ΔT i is also obtained from the equation (9).

As described above, in the second embodiment, by changing the data given to the memory 312 of the first embodiment, it is possible to focus the ultrasonic transmitting / receiving elements arranged in an arbitrary dimension.

The third embodiment is a two-dimensional extension of the one-dimensional arrangement of the ultrasonic transmission / reception elements according to the second embodiment.

As shown in Fig. 8, the focal point F (XF, YF, ZF) and the ultrasonic transmitting / receiving element 35i (i = 1, 2,…, M) are arranged in the space consisting of the X, y, and z axes. ing. The position of the transmitting / receiving element is (Xi, Yi, Zi).

As in the previous embodiment, the distance between the focal point F and each ultrasonic transmitting / receiving element is expressed by the following equation.

L i = (XF—X i) ² + (YF−Y i) ² + (ZF—Z i) '. A spherical surface C 3 having a radius L j is formed.

If a straight line connecting the transmitting / receiving element 35 i from the focal point F is extended, it hits the spherical surface C 3, and this position is designated as Q i in FIG.

The distance between 35 1 and 0 1 is the delay amount △ L i described above. From this, the delay amount Δ Τ i and the count value K i force are obtained from equations (3) and (4), respectively. Also, at the time of reception, it is possible to determine the receiving operation start timing according to equation (10) with the transmitting / receiving element close to the focal point F and determine the CCD length n for switching the clock by equation (9). .

In this way, the transmission / reception delay amount can be controlled even with the ultrasonic transmission / reception elements arranged in a two-dimensional state, whereby the observation position of the ultrasonic beam can be three-dimensionally changed.

With this S-change control, the inspection target can be inspected with high resolution using the focused ultrasonic beam.

As a modification of this embodiment, there is a method in which data of all the transmitting / receiving elements is not transferred by a microcomputer of 201, but is divided into a specific group and a microcomputer is provided for each.

This is used when the number of ultrasonic transmitting / receiving elements provided in a two-dimensional manner increases and data transfer cannot be performed in time.

In this case as well, the display device 1 or one of the microcomputers may be used as the center, and the focus F and the delay amount for that position may be calculated. ₂ .

-There is also a method in which the data is stored in the memory of the group, read out by the microcomputer of each group, and transferred.

The fourth embodiment is an example in which each transmission / reception circuit 3 i is changed.

As shown in FIG. 9, the present embodiment is characterized in that, in 3 i, amplifier 30 6 is changed to gain control type amplifier 3 26, and further, gain control data is given to memory 3 12. .

As is well known, ultrasonic transmitting / receiving elements have directional characteristics. For this reason, the transmission and reception sensitivities may differ depending on the transmitting and receiving directions of the element.

In this embodiment, the difference in sensitivity is corrected by controlling the amplification on the receiving side.

The amplification degree can be determined based on the characteristics of each ultrasonic transmitting / receiving element and the relative position between the element and the focal point, and is transferred to the memory 312.

As a modification of this embodiment, a method of controlling the regenerative output of the 304 pulse generator or a combination of controlling the pulse output and the amplification degree is also conceivable.

According to this embodiment, it is possible to remove the influence of the directivity of the transmission / reception element and correct the difference in the detection sensitivity depending on the focal position.

The fifth embodiment is an embodiment applied to visualization of the inside of a human body, an industrial structure, or the like.

The display device 1, the control device 2, and the transmission / reception circuit 3 shown in FIG. 10 have the same configurations as those of the previous embodiments.

The control device 2 and the transmission / reception circuit 3 are configured as IC circuits, and are small.

The ultrasonic transmission / reception surface of the transmission / reception circuit in (3) is placed near the surface to be inspected, such as a human body or a structure, in (4), and ultrasonic waves are introduced into the interior of (4) through an ultrasonic coupling (5) such as water / glycerin. Transmits and receives reflected waves. The transmission and reception control method is described in detail in the first to fourth embodiments.When the ultrasonic wave is focused inside the inspection object 4 and the focal position is changed to display the intensity distribution of the reflected wave, the human body Accurate identification of internal organs and lesions.

Defects inside structures can also be detected.

According to the present invention, the characteristics of the ultrasonic beam can be controlled extremely flexibly.

That is, in addition to the method of imaging by changing the focal position as described above, the present invention can be applied to oblique flaw detection in which an ultrasonic beam is obliquely applied to a structure.

In addition, by properly switching the ultrasonic transmission / reception elements used for oblique flaw detection, it is possible to observe a certain inspection point from various directions, and to understand the situation inside the structure in detail.

The sixth embodiment is an example in which the present invention is applied to imaging of an object in water or an opaque liquid.

The configuration is not shown in the drawing because it is the same as the previous embodiment.

Transmitter / receiver circuit 3 is placed in a liquid, and the object is visualized by transmitting ultrasonic waves and detecting reflected waves.

For the control of transmission and reception, the method described in the above embodiments is used.

This embodiment is effective in visualizing, for example, underwater with extremely poor visibility or in liquid metal.

The present invention has been described in detail with reference to the embodiments.

The present invention is characterized in that a clock supplied to CCD is controlled because a charge transfer element such as CCD is used for delaying a received signal.

In addition, each ultrasonic transmission / reception element can be controlled to be used for both transmission and reception, used only for transmission, used only for reception, and not used.

These control data are stored in the memory for each transmitting / receiving circuit: With these controls, flexible data such as the beam focal position and beam direction The beam characteristics can be changed in various ways, and a compact beam characteristic variable type ultrasonic transceiver can be provided, which has a great engineering effect.

The common feature of the embodiments of the present invention is that a charge transfer element such as a CCD is used for delaying a received signal, so that a clock supplied to the CCD is controlled. Can be controlled to be used for both transmission and reception, used only for transmission, used only for reception, and not used. These control data are stored in memory for each transmission and reception circuit.

By these controls, the beam characteristics such as the beam focal position and the beam direction can be flexibly changed, and the size can be reduced, so that a small ultrasonic transmitter / receiver with variable beam characteristics can be provided. Great engineering effect.

Claims

The scope of the claims

1. A transmitter that transmits a wave from a plurality of transmitters with different delay times for each transmitter, a plurality of receivers that receive a reflected wave of the wave and convert the reflected wave into an electric signal, and each of the receivers A plurality of charge transfer elements corresponding to the respective receivers to which respective signals from the respective elements are input; and means for changing a shift speed of data in the respective charge transfer elements based on a shift speed command signal. An exploration apparatus using a wave, comprising: an adder that adds outputs from the charge transfer elements; and a display that visualizes the reflected wave based on the output from the adder.

2. In the transmission / reception device that changes the transmission timing given to a plurality of ultrasonic transmission / reception elements and the transmission / reception characteristics of the ultrasonic wave by controlling the delay amount of the reflected wave, the transmission / reception provided for each ultrasonic transmission / reception element A charge transfer element, a clock control device that switches a clock signal to be applied to the charge transfer element, a numerical data obtained from a transmission / reception delay amount, and each ultrasonic transmission / reception element are used for transmission or reception in a reception signal processing unit. A storage element for storing control data of whether or not the counter element determines a switching timing of a clock to be applied to the charge transfer element from numerical data obtained from the delay amount, and is turned on based on the control data. A gate or switching element to be turned off, numerical data obtained from the delay amount, setting of the control data, and transfer operation to the storage element. And a display for visualizing the reflected wave based on the output from the adder, and a plurality of ports having different periods. By controlling the signal transfer delay amount of the charge transfer element with the clock signal, the transmission timing or reception delay amount of each selected ultrasonic transmission / reception element is determined, and the ultrasonic reception waveform is obtained. An exploration device that uses the characteristic ultrasonic waves as waves.

3. The ultrasonic transmitting and receiving apparatus according to claim 2, further comprising: a computing unit that determines an operation start time of the charge transfer element after transmitting the ultrasonic wave and generates an operation start signal. An exploration apparatus using ultrasonic waves as waves, wherein the generation timing of the operation start signal is set based on the position of the ultrasonic transmission / reception element, the characteristics of the ultrasonic beam to be controlled, and the speed of the ultrasonic waves.

4. The ultrasonic transmitting and receiving apparatus according to claim 2 or 3, wherein for each ultrasonic transmitting and receiving element, a controller for a transmission signal amplitude, or a variable amplifier capable of controlling the degree of amplification of a reception signal, and a transmission amplitude or And a storage element for storing amplification degree setting data. Based on the characteristics of the ultrasonic beam, the transmission amplitude and the reception amplification degree are obtained, and the transmission amplitude or the amplification degree is determined by the stored data stored in the storage element. An exploration device using ultrasonic waves as waves, which is controlled.

5. The ultrasonic transmission / reception apparatus according to claim 2, 3, or 4, wherein a plurality of ultrasonic transmission / reception elements are arranged along a one-dimensional or multidimensional curved surface. An exploration device using waves as waves.

6. In the ultrasonic transmitting and receiving apparatus according to any one of claims 2 to 5, the timing of transmission and the amount of delay of reception are determined by the position of each transmitting / receiving element and the ultrasonic propagation medium. An exploration device using ultrasonic waves as waves, comprising a calculating device for obtaining the ultrasonic wave propagation speed and the ultrasonic transmission / reception characteristics.

7. The ultrasonic transmission / reception device according to any one of claims 2 to 6, further comprising a transmission / reception signal processing unit and a control unit manufactured by an integrated circuit, wherein the transmission / reception processing unit, the ultrasonic transmission / reception element, An exploration device using ultrasonic waves as waves, which is electrically connected to and integrated with a control device integrated into an integrated circuit.